New version of a relativity FAQ
Pmb
A new version of the FAQ "Does mass increase with speed?" was written and is
now online at
http://math.ucr.edu/home/baez/physics/Relativity/SR/mass.html
This is a well written article on this whole relativistic mass thing. The
author makes a great point
-------------------------------------------------------------------------------
A common argument against the use of relativistic mass is the fact that the
equation E=mc^2 says that a body's relativistic mass equals its total
energy, so why should we use two terms for what is essentially the same
quantity? We
should just stay with energy, and use the word "mass" to refer only to rest
mass. But this argument neglects the definitions of the words mass and
energy. Mass is a property of a body that we have an intuitive feel for;
its definition as a resistance to acceleration is very fundamental. Energy,
on the other hand, is defined in physics in rather ad hoc ways. Neither
concept is even remotely understood by modern physics.
-------------------------------------------------------------------------------
sniff sniff. I'm getting all misty at the quality of his writing :)
To the author - Well done sir!
Best wishes
Pete
Dono
> sniff sniff. I'm getting all misty at the quality of his writing :)
>
> To the author - Well done sir!
>
Well, you see, Pete if you wanted to do any useful physics, like
calculating the trajectory of a charged particle in a seprator, the
"relativistic mass" is of no use to you, but \gamma*m_0 , where m_0 is
the rest mass and \gamma=1/sqrt(1-(v/c)^2)) is instrumental.
Along the same line, try calculating the mass of a photon gas cloud.
I think that the "new" FAQ article is unfortunately very "retro" :-)
N:dlzc D:aol T:com (dlzc)
"Pmb" <peter....@somewhere.net> wrote in message
news:GaSdndZG-uirT8DV...@comcast.com...
How funny that we caution newbies not to let "intuition" and
"common sense" guide them through relativity, then we splice the
bullsh*t of a "mass" that is different to different axes of
acceleration in as having an "intuitive feel". And try and
justify it by glancingly referring to E=mc^2 (or even Newton's E
= 1/2mv^2), which is *not* where the "intuitive feel" of mass
comes from. 'Twas Mr. Koks' idea to resurrect this particular
slant.
> To the author - Well done sir!
I just publish the links, I don't have to agree with them.
Personally, I feel it to be a giant step backwards. It yields
yet another arcane formulation that will stand between the newbie
and understanding, with *none* of the "intuitive feel" sought.
But hey, I am just a mechanical engineer.
And I understand you (and Don) do not agree.
David A. Smith
Pmb
"Dono" <sa...@comcast.net> wrote in message
news:71c9ee81-5883-4cc3...@v1g2000pra.googlegroups.com...
On Jun 21, 8:21 pm, "Pmb" <peter.m.br...@somewhere.net> wrote:
> sniff sniff. I'm getting all misty at the quality of his writing :)
>
> To the author - Well done sir!
>
>Well, you see, Pete if you wanted to do any useful physics, like
>calculating the trajectory of a charged particle in a seprator, the
>"relativistic mass" is of no use to you, but \gamma*m_0 , where m_0 is
>the rest mass and \gamma=1/sqrt(1-(v/c)^2)) is instrumental.
And you think that's all there is to relativity? Wrong. The author changed
it with a much better understanding of the subject than you have
Pmb
"N:dlzc D:aol T:com (dlzc)" <dl...@cox.net> wrote in message
news:OUu7k.5173$_T7....@newsfe08.phx...
> I just publish the links, I don't have to agree with them. Personally, I
> feel it to be a giant step backwards.>
That's due to your incomplete understanding of the subject matter.
> And I understand you (and Don) do not agree.
Wrong. That's more of a lie than being in error too since its absolutely
wrong. Don and I agree very much. We have disagreed in the past on minor
things but we always came to a common agreement and understanding. On
everything as a matter of fact. Don certainly has a better understanding of
the subject that you do that's for sure. There are more erroneous assertions
that occur because of the other definition of mass than I care to list.
Intuition is important. That's why terms are defined as such
Pmb
"Dono" <sa...@comcast.net> wrote in message
news:71c9ee81-5883-4cc3...@v1g2000pra.googlegroups.com...
> sniff sniff. I'm getting all misty at the quality of his writing :)
>
> To the author - Well done sir!
>
Well, you see, Pete if you wanted to do any useful physics, like
calculating the trajectory of a charged particle in a seprator, the
"relativistic mass" is of no use to you, but \gamma*m_0 , where m_0 is
the rest mass and \gamma=1/sqrt(1-(v/c)^2)) is instrumental.
---------------------------------------------------------------------
Einstein would disagree if the question were asked in terms of GR. Read his
text "The Meaning of General Relativity" and see for yourself
>Along the same line, try calculating the mass of a photon gas cloud.
Its not what you think it is. If you calculate the total mass of the cloud
then its inertial mass is proportional to the proper mass. The proper mass
determined solely from the total energy as measured in the zero momentum
frame. However if the cloud is not of finite size and you're looking for the
mass density then I'll let you take a guess and see if you know what you're
talking about
>I think that the "new" FAQ article is unfortunately very "retro" :-)
You're certainly entitled to your opinion. Too bad you're not finding out
the reason for the change and basing your opinion only on the fact that it
was changed. Big mistake
Tell you what. Calculate the mass density of photon gas
Calculate the inertial mass, and the proper mass, of a uniform magnetic
field.
Calculate the inertial mass and proper mass of a rod under stress.
N:dlzc D:aol T:com (dlzc)
"Pmb" <peter....@somewhere.net> wrote in message
news:_YKdnShbTJ20DMPV...@comcast.com...
>
> "N:dlzc D:aol T:com (dlzc)" <dl...@cox.net> wrote in message
> news:OUu7k.5173$_T7....@newsfe08.phx...
>
>> I just publish the links, I don't have to agree
>> with them. Personally, I feel it to be a giant
>> step backwards.>
>
> That's due to your incomplete understanding
> of the subject matter.
No, that is due to my having to explain it. Mass that is
different for different directions of acceleration, is not the
scalar quantity the newbie (and Newton) had in mind.
>> And I understand you (and Don) do not
>> agree.
>
> Wrong. That's more of a lie ...
I left the sentence incomplete, and you assumed what I did not
intend. I stated my opinion, then in this sentence I observed
that you and Don did not agree (with me). Not each other.
Pull your claws back in.
David A. Smith
Pmb
>
> "Dono" <sa...@comcast.net> wrote in message
> news:71c9ee81-5883-4cc3...@v1g2000pra.googlegroups.com...
> On Jun 21, 8:21 pm, "Pmb" <peter.m.br...@somewhere.net> wrote:
>> sniff sniff. I'm getting all misty at the quality of his writing :)
>>
>> To the author - Well done sir!
>>
>
>
> Well, you see, Pete if you wanted to do any useful physics, like
> calculating the trajectory of a charged particle in a seprator, the
> "relativistic mass" is of no use to you, but \gamma*m_0 , where m_0 is
> the rest mass and \gamma=1/sqrt(1-(v/c)^2)) is instrumental.
> ---------------------------------------------------------------------
That's kind of a silly comment since \gamma=1/sqrt(1-(v/c)^2)) is
iinsufficient to determine the world line of a particle in general since the
mass is also required. And p = \gamma*m_0*v only holds under special
circumstances
Since you know all there is to know of this subject please give an example
of when p = \gamma*m_o*v does not hold.
Pete
ps - Please don't get the idea that I'm insulting you. I never had that
intention in mind. I'm criticizing you, which is very very different. I'm
addressing only your knowledge, and not your person
Pmb
> Dear Pmb:
>
> "Pmb" <peter....@somewhere.net> wrote in message
> news:_YKdnShbTJ20DMPV...@comcast.com...
>>
>> "N:dlzc D:aol T:com (dlzc)" <dl...@cox.net> wrote in message
>> news:OUu7k.5173$_T7....@newsfe08.phx...
>>
>>> I just publish the links, I don't have to agree
>>> with them. Personally, I feel it to be a giant
>>> step backwards.>
>>
>> That's due to your incomplete understanding
>> of the subject matter.
>
> No, that is due to my having to explain it. Mass that is different for
> different directions of acceleration, is not the scalar quantity the
> newbie (and Newton) had in mind.
Nonsesnse. I know of all of these arguements, seemingly much better than you
do as a matter of fact. That has nothing to do with why it was changed. And
your assertion that mass is different in different directions is based on an
invalid assumption about how mass is defined. Mass is *not* defined as m =
F/a. That is merely an equality which holds under special circumstances. Its
accredited to Euler who stated it under special circumstances (constant mass
motion). Newton defined mass as the m in p = mv and that's how its defined
in relatity too. Proper mass is defined similarly in that P = m_0 U where P
= 4-momentum, U = 4-velocity and m_0 = proper mass.
That mass was a scalar quantity in Newtonian mechanics is not found in its
definition. It is deduced from observation. Definitions need not be based on
observations but only to describe a theory. If the theory changes that
doesn't mean that the definitions need to change. The definition of
3-velocity never changed even though its transformation properties did.
>>> And I understand you (and Don) do not
>>> agree.
>>
>> Wrong. That's more of a lie ...
>
> I left the sentence incomplete, and you assumed what I did not intend. I
> stated my opinion, then in this sentence I observed that you and Don did
> not agree (with me). Not each other.
I noticed that you snipped off the important part. The whole thing read
"That's more of a lie than being in error too since its absolutely wrong."
Okay. Its not a lie. So you're merely understand. If you state something
like "I understand.." then that is *not* an opinion, its an assertion.
Please learn the difference. An opinion is something which is "a view,
judgment, or appraisal formed in the mind about a particular matter". So
what is your view?
Tell me something - On what did you base your "understanding" about whether
Don and I agreed or not? I'm sure the class would love to hear it!
> Pull your claws back in.
Oy! You're seeing claws where none exist. Trying to read my mind are you?
So
Pmb
>
> "N:dlzc D:aol T:com (dlzc)" <dl...@cox.net> wrote in message
> news:xuw7k.5176$_T7....@newsfe08.phx...
(Stuff)
Dave - As I said to Dono; Please don't get the idea that I'm trying
insulting you or put you down. I never had that intention in mind. I'm
criticizing you, which is very very different. I'm addressing only your
knowledge, and not your person. It seems that you assumed I was trying to
insult you or that you thought I was attacking or getting emotional due to
your response about the claws. That was never the case. If you want to know
how I feel then ask me, please don't assume it. Don't try to be a mind
reader. Okay?
When I say that you don't understand the subject then that is not an insult
but an evaluation of your knowledge based on the content of what you've
posted.
Pete
ps - If you'd like to read what Don and I talked about I'd be more than
happy to forward those e-mails to you if you get Don's permission. Don did
point something out to me which I'm thankful for. It was more of reminding
me of something I had forgotten at the moment. Don's a very smart man.
Please give him more credit than you have. If you disagree with what he
wrote then why don't you do something about it. I.e. e-mail him and relay
your concerns.
N:dlzc D:aol T:com (dlzc)
"Pmb" <peter....@somewhere.net> wrote in message
news:OpCdncE_UfeOBsPV...@comcast.com...
Have a nice Sunday.
I refuse to have an argument with you today.
David A. Smith
Pmb
No problem. I wasn't looking for one. I have a web page to create on the
derivation on time dilation regarding an accelerating frame so my time is
best spent there.
Have a nice Sunday yourself David.
Pete
Tom Roberts
> A new version of the FAQ "Does mass increase with speed?" was written and is
> now online at
> http://math.ucr.edu/home/baez/physics/Relativity/SR/mass.html
>
> This is a well written article on this whole relativistic mass thing. The
> author makes a great point
> -------------------------------------------------------------------------------
> A common argument against the use of relativistic mass is the fact that the
> equation E=mc^2 says that a body's relativistic mass equals its total
> energy, so why should we use two terms for what is essentially the same
> quantity? We
> should just stay with energy, and use the word "mass" to refer only to rest
> mass. But this argument neglects the definitions of the words mass and
> energy. Mass is a property of a body that we have an intuitive feel for;
> its definition as a resistance to acceleration is very fundamental. Energy,
> on the other hand, is defined in physics in rather ad hoc ways. Neither
> concept is even remotely understood by modern physics.
> -------------------------------------------------------------------------------
I think we're going to have to review changes to the FAQ more carefully.
This page now just mentions a few straw-man objections to "relativistic
mass", and does not discuss at all the actual reason why "mass" is best
considered to be an invariant. And worse: it is internally inconsistent
in just this area.
For instance, I would not say "[mass's] definition as a resistance to
acceleration is very fundamental", I would say its definition as "how
much 'stuff' is present" is more fundamental. "relativistic mass" does
not obey this, but the usual terminology does.
In the physics 101 I took many years ago, the example given
was to differentiate mass from weight, as the former should
not vary with position, but for a given object the latter
diminishes at the top of a mountain or in orbit. Having
"mass" vary with velocity is equally inappropriate, as is
having it vary with direction. "How much stuff is present"
is CLEARLY independent of such variations.
A more serious objection is that the author says "Mass is a property of
a body" (which I agree with), but "relativistic mass" IS NOT A PROPERTY
OF A BODY (it varies with the body's motion and its physical situation).
This article is internally self-inconsistent.
Another inconsistency: "resistance to acceleration" is dependent on the
direction of the applied force, but "relativistic mass" is not direction
dependent. The author has abandoned his own "very fundamental" definition.
Like PMB, tears come to my eyes from this page :-). But not
because of its relationship to my personal beliefs (which PMB
calls "quality of writing"), but rather because it is internally
inconsistent and therefore wrong. And it is wrong in subtle
ways that can easily confuse its target audience. That is
diametrically opposed to the purpose of a FAQ page.
The first paragraph ends "which concept is more useful?", but the
article only mentions elementary uses and never touches on the real
issue: the relationship between kinematics and dynamics.
The underlying question is: What is the best way to generalize
terminology and concepts from Newtonian physics to relativity? Note I
said "relativity", not "SR", and that is an important aspect of this.
There are two very different generalizations:
The one which has become standard:
Term Newton SR GR
------- ------------ ---------- ----------
velocity 3-vector 4-vector 4-vector
momentum m*v m*V m*V
mass invariant invariant invariant
force 3-vector 4-vector 4-vector
acceleration 3-vector 4-vector 4-vector
And the one that article advocate:
Term Newton SR GR [*]
------- ------------ ---------- ----------
velocity 3-vector 3-"vector" (none)
momentum m*v gamma*m*v (none)
mass invariant gamma*m (none)
force 3-vector 3-"vector" (none)
acceleration 3-vector "matrix mess" (none)
[*] These are not discussed at all, and I base them on the
fact that in GR any coordinates are equally valid.
Note, please, that these terms are those that appear in the DYNAMICS of
a physical theory, but their definitions are KINEMATICAL. The whole
point of kinematics is to make the dynamics simpler by making
fundamental symmetries be incorporated into the terminology and
notation. This second table completely abandons that. I challenge
advocates of this second table to write down the Lagrangian of classical
electrodynamics using those quantities, and compare to the standard
formulas. Then for extra credit try the Lagrangian of QED (this will be
exceedingly perverse, and I'll be surprised if it fits on one page).
Comparing these tables shows why the standard terminology has become
standard. "Relativistic mass" and the other entries in the second table
are of use ONLY pedagogically, and ONLY in teaching elementary SR. They
are essentially useless in advanced SR and in real physical theories
like QED and GR, beause those definitions do NOT reflect the underlying
kinematical symmetry (local Lorentz invariance); the standard meanings
do reflect it, which is at base why they are so much better. And I
challenge the pedagogical use of "relativistic mass" -- IMHO stressing
symmetries is an EXTREMELY important part of teaching physics.
Remember in Newtonian mechanics different 3-vectors
transform differently under boosts, but in SR all 4-vectors
transform identically. This gets amplified in the differences
between the two tables, and the "matrix mess" for acceleration
is truly perverse compared to the transformation of
4-acceleration. But that is minor compared to the complexity
of writing dynamical equations using the second table, and
the difficulty of generalizing them to GR....
At the turn of the last century J.W. Gibbs went on a crusade to
establish the 3-vector notation we all use today. My arguments are quite
similar to his: the notation should reflect the underlying symmetry.
Gibbs obviously won that dispute; I have no doubt about a similar
ultimate result of this terminological and notational dispute. For the
same reasons.
I think this page needs to be re-written again. It should discuss the
origins of the terms "mass" and "relativistic mass", and why the latter
has gone out of favor in research and advanced classrooms, and why the
current terminology is better -- it simplifies the DYNAMICS of any
relativistic theory by making the KINEMATICAL relationships obey the
underlying symmetry. As is, it takes a rather superficial and elementary
viewpoint.
Tom Roberts
Androcles
"Tom Roberts" <tjrobe...@sbcglobal.net> wrote in message
news:ABz7k.2385$LG4...@nlpi065.nbdc.sbc.com...
LIAR !
Dono
> "Dono" <sa...@comcast.net> wrote in message
>
> news:71c9ee81-5883-4cc3...@v1g2000pra.googlegroups.com...
> On Jun 21, 8:21 pm, "Pmb" <peter.m.br...@somewhere.net> wrote:
>
> > sniff sniff. I'm getting all misty at the quality of his writing :)
>
> > To the author - Well done sir!
>
> >Well, you see, Pete if you wanted to do any useful physics, like
> >calculating the trajectory of a charged particle in a seprator, the
> >"relativistic mass" is of no use to you, but \gamma*m_0 , where m_0 is
> >the rest mass and \gamma=1/sqrt(1-(v/c)^2)) is instrumental.
>
> And you think that's all there is to relativity?
I didn't say that.
> The author changed
> it with a much better understanding of the subject than you have
You don't know that. Clearly.
Dono
>
> Tell you what. Calculate the mass density of photon gas
>
> Calculate the inertial mass, and the proper mass, of a uniform magnetic
> field.
>
> Calculate the inertial mass and proper mass of a rod under stress.
I asked you first, let's see you do it :-)
harry
As the FAQ points out at the end, "relativistic mass" has an intuitive feel
and is NOT direction dependent. Of course force and acceleration are not
along the same line, but that's how nature works and relativistic mass even
gives an understanding of why this is the case.
> And try and justify it by glancingly referring to E=mc^2 (or even Newton's
> E = 1/2mv^2), which is *not* where the "intuitive feel" of mass comes
> from. 'Twas Mr. Koks' idea to resurrect this particular slant.
Actually, the FAQ misses the important point that since c is not constant in
the way it was assumed in SRT, E and m are not only physically different
entities, but they are in general not even proportional.
http://groups.google.com/group/sci.physics.research/msg/dcd13814f4019d50
>> To the author - Well done sir!
>
> I just publish the links, I don't have to agree with them.
Sure. If you find an error in the FAQ, just tell the author what the error
is. However, if you find no error, there can be no scientific disagreement
either. And if you can think of another advantage of invariant mass that
isn't mentioned, you can ask him to add that in order to make it more
balanced (but watch out for faulty arguments).
> Personally, I feel it to be a giant step backwards. It yields yet another
> arcane formulation that will stand between the newbie and understanding,
> with *none* of the "intuitive feel" sought. But hey, I am just a
> mechanical engineer.
Instead I agree with Feynman that it is very helpful.
Cheers,
Harald
harry
"Tom Roberts" <tjrobe...@sbcglobal.net> wrote in message
news:ABz7k.2385$LG4...@nlpi065.nbdc.sbc.com...
And how would you decide ""how much 'stuff' is present" ? Clearly when atoms
bind into molecules, LESS mass is present than before they bound but the
same amount of particles is present. I agree that it may be useful to put in
your argument but of course with the counter argument.
> In the physics 101 I took many years ago, the example given
> was to differentiate mass from weight, as the former should
> not vary with position, but for a given object the latter
> diminishes at the top of a mountain or in orbit. Having
> "mass" vary with velocity is equally inappropriate, as is
> having it vary with direction.
Why would it vary with direction? Did you mean "position" perhaps?
> "How much stuff is present"
> is CLEARLY independent of such variations.
See above - nobody uses a mass definition that doesn't change with energy.
> A more serious objection is that the author says "Mass is a property of a
> body" (which I agree with), but "relativistic mass" IS NOT A PROPERTY OF A
> BODY (it varies with the body's motion and its physical situation). This
> article is internally self-inconsistent.
Hmm, he more or less defines what he means with that between the brackets.
Would you say that (relativistic) length is a property of a body? If yes,
why? If no, why not, and why would this be self-inconsistent with its use?
> Another inconsistency: "resistance to acceleration" is dependent on the
> direction of the applied force, but "relativistic mass" is not direction
> dependent. The author has abandoned his own "very fundamental" definition.
Indeed: he should clarify somewhere that relativistic mass only is a measure
for resistance to acceleration when it remains constant, such as in a
cyclotron (which was the preferred definition of Feynman).
> Like PMB, tears come to my eyes from this page :-). But not
> because of its relationship to my personal beliefs (which PMB
> calls "quality of writing"), but rather because it is internally
> inconsistent and therefore wrong.
Just tell him about the errors; if you are convincing, I'm sure he'll
improve it. :-)
> And it is wrong in subtle
> ways that can easily confuse its target audience. That is
> diametrically opposed to the purpose of a FAQ page.
The old version was wrong in subtle AND not-so-subtle ways...
> The first paragraph ends "which concept is more useful?", but the article
> only mentions elementary uses and never touches on the real issue: the
> relationship between kinematics and dynamics.
Perhaps you want to add that?
> The underlying question is: What is the best way to generalize terminology
> and concepts from Newtonian physics to relativity? Note I said
> "relativity", not "SR", and that is an important aspect of this.
The fact that c is not a universal constant as in SRT makes the relationship
E=m*c^2 more meaningful.
> There are two very different generalizations:
>
> The one which has become standard:
>
> Term Newton SR GR
> ------- ------------ ---------- ----------
> velocity 3-vector 4-vector 4-vector
> momentum m*v m*V m*V
> mass invariant invariant invariant
> force 3-vector 4-vector 4-vector
> acceleration 3-vector 4-vector 4-vector
>
> And the one that article advocate:
>
> Term Newton SR GR [*]
> ------- ------------ ---------- ----------
> velocity 3-vector 3-"vector" (none)
> momentum m*v gamma*m*v (none)
> mass invariant gamma*m (none)
> force 3-vector 3-"vector" (none)
> acceleration 3-vector "matrix mess" (none)
>
> [*] These are not discussed at all, and I base them on the
> fact that in GR any coordinates are equally valid.
I would be surprised if that is right - almost certainly all equations can
be written in terms of gamma*m!
> Note, please, that these terms are those that appear in the DYNAMICS of a
> physical theory, but their definitions are KINEMATICAL. The whole point of
> kinematics is to make the dynamics simpler by making fundamental
> symmetries be incorporated into the terminology and notation.
Hmm... that reminds me of some articles by Harvey Brown, such as:
http://philsci-archive.pitt.edu/archive/00001385/01/9908048.pdf
> This second table completely abandons that.
It is your table. ;-)
> I challenge advocates of this second table to write down the Lagrangian of
> classical electrodynamics using those quantities, and compare to the
> standard formulas. Then for extra credit try the Lagrangian of QED (this
> will be exceedingly perverse, and I'll be surprised if it fits on one
> page).
>
> Comparing these tables shows why the standard terminology has become
> standard. "Relativistic mass" and the other entries in the second table
> are of use ONLY pedagogically, and ONLY in teaching elementary SR. They
> are essentially useless in advanced SR
?? Please give an example of a real-world problem where relativistic mass is
"essentially useless".
> and in real physical theories like QED and GR, beause those definitions do
> NOT reflect the underlying kinematical symmetry (local Lorentz
> invariance); the standard meanings do reflect it, which is at base why
> they are so much better. And I challenge the pedagogical use of
> "relativistic mass" -- IMHO stressing symmetries is an EXTREMELY important
> part of teaching physics.
The LT do stress symmetries, don't they?
> Remember in Newtonian mechanics different 3-vectors
> transform differently under boosts, but in SR all 4-vectors
> transform identically. This gets amplified in the differences
> between the two tables, and the "matrix mess" for acceleration
> is truly perverse compared to the transformation of
> 4-acceleration. But that is minor compared to the complexity
> of writing dynamical equations using the second table, and
> the difficulty of generalizing them to GR....
>
> At the turn of the last century J.W. Gibbs went on a crusade to establish
> the 3-vector notation we all use today. My arguments are quite similar to
> his: the notation should reflect the underlying symmetry. Gibbs obviously
> won that dispute; I have no doubt about a similar ultimate result of this
> terminological and notational dispute. For the same reasons.
>
> I think this page needs to be re-written again. It should discuss the
> origins of the terms "mass" and "relativistic mass", and why the latter
> has gone out of favor in research and advanced classrooms, and why the
> current terminology is better -- it simplifies the DYNAMICS of any
> relativistic theory by making the KINEMATICAL relationships obey the
> underlying symmetry. As is, it takes a rather superficial and elementary
> viewpoint.
As long as the old errors are not reintroduced (or new errors!), that's fine
of course. :-)
Cheers,
Harald
Tom Roberts
> As the FAQ points out at the end, "relativistic mass" has an intuitive feel
> and is NOT direction dependent
Yes. But that is inconsistent with the author's claim "its definition as
a resistance to acceleration is very fundamental", as resistance to
acceleration is NOT given by "relativistic mass" except in one specific
case: magnetic force on a charged particle (i.e. 3-force is always
perpendicular to 3-velocity).
And worse, it is also inconsistent with the author's statement that
"Mass is a property of a body" -- I agree with that particular
statement, but disagree with the entire approach and conclusion of the page.
> course force and acceleration are not
> along the same line, but that's how nature works and relativistic mass even
> gives an understanding of why this is the case
I see no such "understanding" at all, merely ad-hoc equations.
As I said before, this new version of this FAQ page misses the point
entirely, and does not present the mainstream viewpoint adequately at
all. In actual usage among physicists who use relativity daily, "mass"
is an invariant, and "relativistic mass" is an anachronism. And the
reason for this is completely absent in the webpage: kinematical terms
and notation should incorporate the underlying symmetry, so the
description of dynamics is simplified.
Tom Roberts
Tom Roberts
> "Tom Roberts" <tjrobe...@sbcglobal.net> wrote in message
> news:ABz7k.2385$LG4...@nlpi065.nbdc.sbc.com...
>> acceleration is very fundamental", I would say its definition as "how much
>> 'stuff' is present" is more fundamental. "relativistic mass" does not obey
>> this, but the usual terminology does.
>
> And how would you decide ""how much 'stuff' is present" ?
One measures it, of course.
My point here was basically for a single, given object (as my example
showed) -- it's mass should be an intrinsic property of the object, and
should not vary with its position, velocity, or direction, or which
observer is looking at it.
The basic notion that mass is an intrinsic property of
an object directly requires that mass be an invariant.
This disqualifies "relativistic mass" as being mass.
> Clearly when atoms
> bind into molecules, LESS mass is present than before they bound but the
> same amount of particles is present.
Sure. But then, those atoms are DIFFERENT from those molecules made up
of the atoms. And when the atoms combine into molecules, energy is
released, and we know in relativity that energy and mass are related.
Indeed, apply E=mc^2 to the released energy, and as long as both atoms
and molecules are at rest that gives the mass difference.
>> In the physics 101 I took many years ago, the example given
>> was to differentiate mass from weight, as the former should
>> not vary with position, but for a given object the latter
>> diminishes at the top of a mountain or in orbit. Having
>> "mass" vary with velocity is equally inappropriate, as is
>> having it vary with direction.
>
> Why would it vary with direction? Did you mean "position" perhaps?
The resistance of an object to acceleration depends on the direction of
the applied force relative to its velocity. The webpage mentions this,
but then essentially ignores it.
> nobody uses a mass definition that doesn't change with energy.
Your words are ambiguous. Yes, the mass of a closed system is directly
related to the energy contained within. But the mass of an object does
NOT depend on that object's velocity relative to an observer (and hence
its kinetic energy as measured by that observer) -- this _IS_ the
definition of "mass" used by physicists who use relativity daily,
regardless of what this FAQ page claims.
>> A more serious objection is that the author says "Mass is a property of a
>> body" (which I agree with), but "relativistic mass" IS NOT A PROPERTY OF A
>> BODY (it varies with the body's motion and its physical situation). This
>> article is internally self-inconsistent.
>
> Hmm, he more or less defines what he means with that between the brackets.
> Would you say that (relativistic) length is a property of a body?
Of course not! Proper length is a property of an object, not whatever
length that some arbitrary observer might assign to it.
>> Another inconsistency: "resistance to acceleration" is dependent on the
>> direction of the applied force, but "relativistic mass" is not direction
>> dependent. The author has abandoned his own "very fundamental" definition.
>
> Indeed: he should clarify somewhere that relativistic mass only is a measure
> for resistance to acceleration when it remains constant, such as in a
> cyclotron (which was the preferred definition of Feynman).
Indeed, "relativistic mass" is the resistance to acceleration only for
one specific case: the magnetic force on a charged particle. This does
NOT include the cyclotron, in which the RF accelerating field does not
obey that.
>> Term Newton SR GR [*]
>> ------- ------------ ---------- ----------
>> velocity 3-vector 3-"vector" (none)
>> momentum m*v gamma*m*v (none)
>> mass invariant gamma*m (none)
>> force 3-vector 3-"vector" (none)
>> acceleration 3-vector "matrix mess" (none)
>>
>> [*] These are not discussed at all, and I base them on the
>> fact that in GR any coordinates are equally valid.
>
> I would be surprised if that is right - almost certainly all equations can
> be written in terms of gamma*m!
Not true! There is no "gamma" for null coordinates (i.e. two light-like
coords and two spacelike coords). The 3-vectors ESSENTIAL to this usage
have no meaning except in inertial frames, and in GR there are no such
inertial frames.
> ?? Please give an example of a real-world problem where relativistic mass is
> "essentially useless".
As I challenged before: write down the Lagrangian for classical
electrodynamics in terms of "relativistic mass" and all those 3-vectors.
Then do it for QED. THESE are the sort of problems with which
theoretical physicists are concerned; indeed, these are SIMPLE and
WELL-KNOWN problems, the real point is to use the known symmetries of
the world to find NEW theories. "Relativistic mass" completely abandons
the underlying symmetry, and is indeed useless for that; the 4-vectors
used by mainstream theoretical physicists make the Lorentz symmetry
completely transparent (i.e. one can tell at a glance if one's guessed
Lagrangian is Lorentz invariant or not).
> The LT do stress symmetries, don't they?
Lorentz transforms do no such thing, at least as taught in most
elementary treatments. The Lorentz group, however, does.
Tom Roberts
harry
> harry wrote:
>> As the FAQ points out at the end, "relativistic mass" has an intuitive
>> feel and is NOT direction dependent
>
> Yes. But that is inconsistent with the author's claim "its definition as a
> resistance to acceleration is very fundamental", as resistance to
> acceleration is NOT given by "relativistic mass" except in one specific
> case: magnetic force on a charged particle (i.e. 3-force is always
> perpendicular to 3-velocity).
David repeated a collossal error of the old FAQ that now has been corrected.
About the inconsistency, I partially agree; see my reply to your message.
> And worse, it is also inconsistent with the author's statement that "Mass
> is a property of a body" -- I agree with that particular statement, but
> disagree with the entire approach and conclusion of the page.
I'm afraid the page oscillates too much around neutral, let's hope the
oscillation will fade. At least the big errors were removed.
>> course force and acceleration are not along the same line, but that's
>> how nature works and relativistic mass even gives an understanding of why
>> this is the case
>
> I see no such "understanding" at all, merely ad-hoc equations.
Those who never used the concept don't have the understanding that goes with
it...
> As I said before, this new version of this FAQ page misses the point
> entirely, and does not present the mainstream viewpoint adequately at all.
IMHO, opinions that are a matter of taste should not even be expressed in a
science FAQ; moreover, it is debatable what "mainstream" is here (according
to the recent stats I saw, it's rather equal). However, it does appear to be
lacking explanation of the advantages of using invariant mass and I do agree
that it needs to be more balanced.
> In actual usage among physicists who use relativity daily, "mass" is an
> invariant, and "relativistic mass" is an anachronism.
That's what you say; I disagree. :-)
> And the reason for this is completely absent in the webpage: kinematical
> terms and notation should incorporate the underlying symmetry, so the
> description of dynamics is simplified.
That "should" is intolerant and based on taste, which is just what a science
FAQ should avoid!
Cheers,
Harald
N:dlzc D:aol T:com (dlzc)
"harry" <harald.vanlin...@epfl.ch> wrote in message
news:1214217...@sicinfo3.epfl.ch...
>
> "Tom Roberts" <tjrobe...@sbcglobal.net> wrote in message
> news:N6K7k.6297$cW3....@nlpi064.nbdc.sbc.com...
...
>>> course force and acceleration are not along the
>>> same line, but that's how nature works and
>>> relativistic mass even gives an understanding of
>>> why this is the case
>>
>> I see no such "understanding" at all, merely
>> ad-hoc equations.
>
> Those who never used the concept don't have the
> understanding that goes with it...
Gentlemen, recall this is a FAQ. It is not a wiki entry. It is
not a textbook section. It is not a product advertisement page.
We are answering the questions of someone that does not know, or
has forgotten.
I suspect in these cases, that a single webpage cannot present
all that is necessary to impart the necessary "understanding".
David A. Smith
N:dlzc D:aol T:com (dlzc)
"harry" <harald.vanlin...@epfl.ch> wrote in message
news:1214209...@sicinfo3.epfl.ch...
It does not! I have no feel whatsoever for it. So far I "know"
three people that prefer it. I "know" dozens that do not.
> and is NOT direction dependent.
Clearly untrue, as a global claim.
> Of course force and acceleration are not along the same line,
> but that's how nature
> works and relativistic mass even gives an
> understanding of why this is the case.
Not true. The "understanding" required to properly use
relativistic mass, carries with it the "understanding of why this
is the case". Familiarity breeds more than contempt...
...
>> Personally, I feel it to be a giant step
>> backwards. It yields yet another arcane
>> formulation that will stand between the
>> newbie and understanding, with *none* of
>> the "intuitive feel" sought. But hey, I am
>> just a mechanical engineer.
>
> Instead I agree with Feynman that it is very
> helpful.
Which is why I have attempted not to get into such an argument.
"Let each man lay his dead according to his own fashion." I
cannot explain r.m. to the newbie, so I don't. I leave the
equations to carry the direction dependency, where the newbie
expects it. Rather than hand them something that is redefined
from Newton, hoping that they understand.
All else is straining at gnats.
David A. Smith
Pmb
I already did. You failed to be more precise so I gave you both responses.
The (invariant) mass of a gas of photons equals the total energy, as
measured in the zero momentum frame, over c^2. If you're talking about the
mass density then you need to say that. You only said the mass.
Pmb
You're wasting your time with tom.
Pmb
would have complicated the issue more.
>>> To the author - Well done sir!
>>
>> I just publish the links, I don't have to agree with them.
>
> Sure. If you find an error in the FAQ, just tell the author what the error
> is. However, if you find no error, there can be no scientific disagreement
> either. And if you can think of another advantage of invariant mass that
> isn't mentioned, you can ask him to add that in order to make it more
> balanced (but watch out for faulty arguments).
>
>> Personally, I feel it to be a giant step backwards. It yields yet
>> another arcane formulation that will stand between the newbie and
>> understanding, with *none* of the "intuitive feel" sought. But hey, I am
>> just a mechanical engineer.
>
> Instead I agree with Feynman that it is very helpful.
Me too. :)
But its far more than that. There is no other way to logically define mass.
Pete
Pmb
>
> "Tom Roberts" <tjrobe...@sbcglobal.net> wrote in message
> news:N6K7k.6297$cW3....@nlpi064.nbdc.sbc.com...
>> harry wrote:
>>> As the FAQ points out at the end, "relativistic mass" has an intuitive
>>> feel and is NOT direction dependent
>>
>> Yes. But that is inconsistent with the author's claim "its definition as
>> a resistance to acceleration is very fundamental", as resistance to
>> acceleration is NOT given by "relativistic mass" except in one specific
>> case: magnetic force on a charged particle (i.e. 3-force is always
>> perpendicular to 3-velocity).
>
> David repeated a collossal error of the old FAQ that now has been
> corrected. About the inconsistency, I partially agree; see my reply to
> your message.
Unfortunately nobody is perfect. I too objected to the exact reading. Newton
never defined mass as m = F/a and it seems that people have erroneously
become convinced that this is how mass is, or should be, defined.
>
>> And worse, it is also inconsistent with the author's statement that "Mass
>> is a property of a body" -- I agree with that particular statement, but
>> disagree with the entire approach and conclusion of the page.
>
> I'm afraid the page oscillates too much around neutral, let's hope the
> oscillation will fade. At least the big errors were removed.
That's because there's too much anti-relativistic mass sentiment out there.
too much pressure. But the change was made because it represents the logical
thing to do. It must be kept in mind that what is written there much less
than what the author understands about the subject.
>
>>> course force and acceleration are not along the same line, but that's
>>> how nature works and relativistic mass even gives an understanding of
>>> why this is the case
>>
>> I see no such "understanding" at all, merely ad-hoc equations.
>
> Those who never used the concept don't have the understanding that goes
> with it...
Very true. :)
>> As I said before, this new version of this FAQ page misses the point
>> entirely, and does not present the mainstream viewpoint adequately at
>> all.
>
> IMHO, opinions that are a matter of taste should not even be expressed in
> a science FAQ; moreover, it is debatable what "mainstream" is here
> (according to the recent stats I saw, it's rather equal). However, it does
> appear to be lacking explanation of the advantages of using invariant mass
> and I do agree that it needs to be more balanced.
The mainstream view is flawed. That's the problem
>
>> In actual usage among physicists who use relativity daily, "mass" is an
>> invariant, and "relativistic mass" is an anachronism.
>
> That's what you say; I disagree. :-)
tom is used to a certain way of doing things and is blind to everything
else. E.g. the term "mass density" can never be used to refer to "rest mass
density" and have a general meaning since it is impossible to do so.. But
tom doesn't work in an area where that would come up. Also, many physicists
don't work with anything but particles. And we know that particles aren't
all that exists. When it comes to the theoretical treatement of things like
extended bodies in general situations then "rest mass" looses its meaning.
But then again tom doesn't concern himself with such things.
Pete
Pmb
Well said David
Dono
>
> I already did. You failed to be more precise so I gave you both responses.
> The (invariant) mass of a gas of photons equals the total energy, as
> measured in the zero momentum frame, over c^2.
Correct. Now, let me show you a more elegant way of computing it
without using any mass at all:
http://www.savefile.com/files/1625448
I also asked you to compute the trajectory of a charged particle
moving in a electro-magnetic field (E>0, B>0).
Pmb
People make the mistake that "inertial mass" is a resisance in acceleration.
Inertial mass is the property of matter which gives it momentum
>
>> and is NOT direction dependent.
>
> Clearly untrue, as a global claim.
Relativistic mass is a quantity described by one number. No more. If you're
thinking that relativistic mass is the m in F = ma then that is clearly
wrong. Relativistic mass is the m in p = mv. That's the definition by the
way.Unfortunately teh author didn't provide the definition.
> Not true. The "understanding" required to properly use relativistic mass,
> carries with it the "understanding of why this is the case". Familiarity
> breeds more than contempt...
I agree. Rel-mass, m, is related to force as F = d(mv)/dt. This implies the
relationship between force and acceleration that is given at the bottom of
the FAQ.
> Which is why I have attempted not to get into such an argument. "Let each
> man lay his dead according to his own fashion." I cannot explain r.m. to
> the newbie, so I don't. I leave the equations to carry the direction
> dependency, where the newbie expects it. Rather than hand them something
> that is redefined from Newton, hoping that they understand.
Relativistic mass is *not* redefined from Newton. It is exactly as defined
by Newton. One merely has to look in the definitions of the Principia to see
that. I can get that quote if anyone would like to read it?
Pete
Juan R.
> tom is used to a certain way of doing things and is blind to everything
> else.
I had detected something of that in my discussions with him. And he is
not the first time others also call him to learn something new :-)
Yours is an important remark. I will add something about 'blinded' people
(usually old academicians) in a new version of
http://www.canonicalscience.org/en/miscellaneouszone/guidelines.html
--
Center for CANONICAL |SCIENCE)
http://canonicalscience.org
Juan R.
> Pmb wrote on Mon, 23 Jun 2008 09:38:11 -0400:
>
>> tom is used to a certain way of doing things and is blind to everything
>> else.
>
> I had detected something of that in my discussions with him. And he is
> not the first time others also call him to learn something new :-)
typo: And *it* is not the first time others also call him to learn
Pmb
>> The author changed
>> it with a much better understanding of the subject than you have
>
> You don't know that. Clearly.
First off, I didn't mean that as an insult. If you took it that way that I
apologize. I stated that because you provided the same old argument that has
been provided for the last 20 years and that is an argument which is simply
wrong. There is a very good reason that the FAQ was changed. Unfortunately
the reasons are too complex/extensive to discuss in that FAQ. The author
wanted to keep it simple and within SR only. However I can tell you the
details if you're interested?
As far as your question
>Along the same line, try calculating the mass of a photon gas cloud.
Its answered in a previous post and is trivial. But as far as the more
complex question "What is the mass density of a gas cloud" I await your
response.
Pete
Pmb
> On Jun 21, 8:21 pm, "Pmb" <peter.m.br...@somewhere.net> wrote:
>>
>>
>
>
> calculating the trajectory of a charged particle in a seprator, the
> "relativistic mass" is of no use to you, but \gamma*m_0 , where m_0 is
> the rest mass and \gamma=1/sqrt(1-(v/c)^2)) is instrumental.
>
> Einstein would disagree if the question were asked in terms of GR. Read
> his text "The Meaning of General Relativity" and see for yourself
>
>>Along the same line, try calculating the mass of a photon gas cloud.
>
> then its inertial mass is proportional to the proper mass. The proper mass
> determined solely from the total energy as measured in the zero momentum
> frame. However if the cloud is not of finite size and you're looking for
> the mass density then I'll let you take a guess and see if you know what
> you're talking about
Dono - I answered your question yesterday in this post. See above. Why did
you ignore it and why didn't you respond to my questions? If you don't want
to discuss the subject then I understand and as such I won't ask you more
questions.
Pete
Pmb
I already did, i.e.
-----------
The proper mass determined solely from the total energy as measured in the
zero momentum frame.
----------
If E_0 is the total energy of the photon cloud as measured in the zero
momentum frame then the invariant mass m_0 is given by E_0 = m_0*c^2. The
inertial mass (aka relativistic mass) m is given by m = gamma*m_0
Your turn. :)
Pete
Juan R.
> People make the mistake that "inertial mass" is a resisance in
> acceleration.
Why would be a mistake?
> Inertial mass is the property of matter which gives it
> momentum
What gives momentum for photons and other massless particles?
> Relativistic mass is a quantity described by one number. No more. If
> you're thinking that relativistic mass is the m in F = ma then that is
> clearly wrong.
Why would be he wrong? One can rewrite the relativistic equation of
motion as
ma = f
where, of course, f is not Newtonian-Coulomb force in the general case.
Dono
>
> > Well, you see, Pete if you wanted to do any useful physics, like
> > calculating the trajectory of a charged particle in a seprator, the
> > "relativistic mass" is of no use to you, but \gamma*m_0 , where m_0 is
> > the rest mass and \gamma=1/sqrt(1-(v/c)^2)) is instrumental.
> > ---------------------------------------------------------------------
>
So, I keep asking you to use relativistic mass in order to calculate
the trajectory of a charged particle in a (E,B) field and you keep
giving the runaround. Is this because you are unable to do it?
Dono
>
> Dono - I answered your question yesterday in this post. See above. Why did
> you ignore it and why didn't you respond to my questions? If you don't want
> to discuss the subject then I understand and as such I won't ask you more
> questions.
>
> Pete
We are past this , Pete
You have been asked about 4 times to calculate the trajectory of a
charged partcle in an electromagnetic field (E>0, B>0) by using
relativistic mass. Stop trying to give the runaround :-)
Pmb
> On Jun 23, 6:24 am, "Pmb" <peter.m.br...@somewhere.net> wrote:
>
>>
>> I already did. You failed to be more precise so I gave you both
>> responses.
>> The (invariant) mass of a gas of photons equals the total energy, as
>> measured in the zero momentum frame, over c^2.
>
> Correct. Now, let me show you a more elegant way of computing it
> without using any mass at all:
Calculate the mass without using the mass? That question doesn't even have a
meaning!
> http://www.savefile.com/files/1625448
>
> I also asked you to compute the trajectory of a charged particle
> moving in a electro-magnetic field (E>0, B>0).
The trajectory is dependant on the field. Without stating the field the
trajectory can't be given. Plus, I'm not someone who is here to do problems
for you. I had asked you a question and you asked me to answer yours first.
That has now been done. I await your response.
Pete
Pmb
"Juan R. González-Álvarez" <juanR...@canonicalscience.com> wrote in
message news:pan.2008.06...@canonicalscience.com...
> Pmb wrote on Mon, 23 Jun 2008 09:38:11 -0400:
>
>> tom is used to a certain way of doing things and is blind to everything
>> else.
>
> I had detected something of that in my discussions with him. And he is
> not the first time others also call him to learn something new :-)
>
> Yours is an important remark. I will add something about 'blinded' people
> (usually old academicians) in a new version of
>
> http://www.canonicalscience.org/en/miscellaneouszone/guidelines.html
>
Let's not turn this into a tom-bashing thread. While I don't mind pointing
out his many errors and shortcomings in science, such as this one, I'm not
interest in flaming him. I don't wish to become like tom.
0
Pete
Dono
> "Dono" <sa...@comcast.net> wrote in message
>
> news:9d68ad9c-ed9e-4f2f...@v26g2000prm.googlegroups.com...
>
> > On Jun 23, 6:24 am, "Pmb" <peter.m.br...@somewhere.net> wrote:
>
> >> I already did. You failed to be more precise so I gave you both
> >> responses.
> >> The (invariant) mass of a gas of photons equals the total energy, as
> >> measured in the zero momentum frame, over c^2.
>
> > Correct. Now, let me show you a more elegant way of computing it
> > without using any mass at all:
>
> Calculate the mass without using the mass? That question doesn't even have a
> meaning!
>
The photon is a massless particle , Pete. You didn't know that?
> >http://www.savefile.com/files/1625448
>
> > I also asked you to compute the trajectory of a charged particle
> > moving in a electro-magnetic field (E>0, B>0).
>
> The trajectory is dependant on the field. Without stating the field the
> trajectory can't be given.
Let's make it easy for you. Make E=0 , B aligned with the z axis and
the initial velocity of the particle of mass m and charge q aligned
with the x-axis.
> Plus, I'm not someone who is here to do problems
> for you.
Well, it's a challenge. I bet you cannot do it by using relativistic
mass. Let's see you solve this simple problem.
Pmb
> On Jun 23, 6:24 am, "Pmb" <peter.m.br...@somewhere.net> wrote:
>
>>
>> I already did. You failed to be more precise so I gave you both
>> responses.
>> The (invariant) mass of a gas of photons equals the total energy, as
>> measured in the zero momentum frame, over c^2.
>
> Correct. Now, let me show you a more elegant way of computing it
> without using any mass at all:
>
> http://www.savefile.com/files/1625448
I just read that link.That's as old as the hills. I did that *years* ago and
its been on my website ever since.Its amount the first thing someone learns
when they're learning SR!!
What you've calculated there is the invariant mass of a system of photons.
Since that calculation can be done in any frame of reference whatsoever I
choose the rest frame. In that frame the invariant mass is simply the
energy/c^2. Just as I have already explained to you.
My web page that describes this is at
http://www.geocities.com/physics_world/sr/invariant_mass.htm
See Eq. (6)
Look at the bottom of that page to see the problems that arise with that
definition in more complicated situations.
Pet
Pmb
"Juan R. González-Álvarez" <juanR...@canonicalscience.com> wrote in
message news:pan.2008.06...@canonicalscience.com...
>
>> People make the mistake that "inertial mass" is a resisance in
>> acceleration.
>
> Why would be a mistake?
Because its based on the relation F = ma. This is not how Newton defined
mass and it is not a general expression for force. When the mass is constant
in time then its a valid equation. When its written as F = ma its known as
Euler's equation for force. Momentum is defined as p = mv and force is
defined as f = dp/dt. In relativity one can no longer assume that dm/dt = 0
and therefore one can't write F = ma.
>> Inertial mass is the property of matter which gives it
>> momentum
>
> What gives momentum for photons and other massless particles?
A photon has momentum p = mv where m = inertial (aka relativistic) mass. v =
speed of light. Therefore p = mc.
>
>> Relativistic mass is a quantity described by one number. No more. If
>> you're thinking that relativistic mass is the m in F = ma then that is
>> clearly wrong.
>
> Why would be he wrong?
F cannot be expressed as F = ma. See
http://www.geocities.com/physics_world/sr/long_trans_mass.htm
>One can rewrite the relativistic equation of motion as
>
> ma = f
That expression is incorrect if m = inertial mass, a = 3-acceleration and f
= 3-force. If by f you mean 4-force then the general expression is f = dp/dT
where p = 4-momentum and T = proper time.
Pete
Pmb
Its because you refused to answer my question
Pmb
You refused to answer my question. Why on earth would I answer yours if you
refuse to answer mine? The only reason I can think of is that you don't know
the answer. And your question is incomplete. You didn't specify the field
Pmb
> On Jun 23, 7:10 am, "Pmb" <peter.m.br...@somewhere.net> wrote:
>> "Dono" <sa...@comcast.net> wrote in message
>>
>> news:9d68ad9c-ed9e-4f2f...@v26g2000prm.googlegroups.com...
>>
>> > On Jun 23, 6:24 am, "Pmb" <peter.m.br...@somewhere.net> wrote:
>>
>> >> I already did. You failed to be more precise so I gave you both
>> >> responses.
>> >> The (invariant) mass of a gas of photons equals the total energy, as
>> >> measured in the zero momentum frame, over c^2.
>>
>> > Correct. Now, let me show you a more elegant way of computing it
>> > without using any mass at all:
>>
>> Calculate the mass without using the mass? That question doesn't even
>> have a
>> meaning!
>>
>
> The photon is a massless particle , Pete. You didn't know that?
>
>
>> >http://www.savefile.com/files/1625448
>>
>> > I also asked you to compute the trajectory of a charged particle
>> > moving in a electro-magnetic field (E>0, B>0).
>>
>> The trajectory is dependant on the field. Without stating the field the
>> trajectory can't be given.
>
> Let's make it easy for you. Make E=0 , B aligned with the z axis and
> the initial velocity of the particle of mass m and charge q aligned
> with the x-axis.
Trivial. Childs play. Its even on a web page that I constructed. Its there
waiting for you to answer my question.
>> Plus, I'm not someone who is here to do problems
>> for you.
>
> Well, it's a challenge. I bet you cannot do it by using relativistic
> mass.
That's silly. You're attempting to prove something which is not meaning
full. F = dp/dt = q[E + vxB] is the equation of motion where p = mv =
gamma*m_0*v. Like so many people in the past you are once again repeating
their flawed arguement that one can write the equation of motion as F =
d(gamma*m)/dt = q[E + vxB] where m = proper mass and as such the
"relativistic mass" never appears in the equation. The problem with that
kind of arguement is that the relativistic mass *is* there. You simply
didn't give it a symbol. Its M = gamma*m
This is one of those problems in which the relativistic mass is proportional
to the proper mass. That isn't always the case and its for that reason the
new FAQ was created.
>Let's see you solve this simple problem.
I will not answer another question until you answer mine. I had already
explained that to you. Continued refusal by you at this point will be
ignored and taken as an indication that you simply can't answer the problem
Dono
>
> >> > Well, you see, Pete if you wanted to do any useful physics, like
> >> > calculating the trajectory of a charged particle in a seprator, the
> >> > "relativistic mass" is of no use to you, but \gamma*m_0 , where m_0 is
> >> > the rest mass and \gamma=1/sqrt(1-(v/c)^2)) is instrumental.
> >> > ---------------------------------------------------------------------
>
> > So, I keep asking you to use relativistic mass in order to calculate
> > the trajectory of a charged particle in a (E,B) field and you keep
> > giving the runaround. Is this because you are unable to do it?
>
Pete,
There is a reason for asking you to solve the problem. Tom already
tried to show you how the "relativistic mass" doesn't work very well
in the context of more modern fields, like QED. His argument flew over
your bald spot :-)
I am challenging you to solve a simple electrodynamics problem using
the concept of relativistic mass.
This is not a quid pro quo in solving problems, this is an effective
way of showing that your antiquated concepts are insufficient when it
comes to solving modern problems.
If you cannot do it, why don't you admit it and be done with it? Why
give all this runaround?
Dono
OK
1. So , what is m? (Hint : rest mass)
2. You provided the BEGINNING of the solution, you need to calculate
the full differential equation.
So, calculate d(gamma*m)/dt and set up the full differential
equation.
3. Now, in order to have the trajectory, you need to SOLVE the
equation. Do you think you can do that?
> >Let's see you solve this simple problem.
>
> I will not answer another question until you answer mine. I had already
> explained that to you. Continued refusal by you at this point will be
> ignored and taken as an indication that you simply can't answer the problem
You haven't solved anythingyet, you just STARTED solving the problem.
Try solving it for real, ok?
Dono
<juanREM...@canonicalscience.com> wrote:
> Pmb wrote on Mon, 23 Jun 2008 09:45:08 -0400:
>
> > People make the mistake that "inertial mass" is a resisance in
> > acceleration.
>
> Why would be a mistake?
>
> > Inertial mass is the property of matter which gives it
> > momentum
>
> What gives momentum for photons and other massless particles?
>
Still PRETENDING to know physics, Juanshito?
> > Relativistic mass is a quantity described by one number. No more. If
> > you're thinking that relativistic mass is the m in F = ma then that is
> > clearly wrong.
>
> Why would be he wrong? One can rewrite the relativistic equation of
> motion as
>
> ma = f
>
> where, of course, f is not Newtonian-Coulomb force in the general case.
>
Bzzt, no. The above is quite hillarious. Especilally since it exposes
you as a PRETENDER, Juanshito.
Pete did a good job in exposing your crass ignorance, so I will not
belabour the point. I bet that such gross errors found their way in
your rejected paper.
harry
>>
>> "Tom Roberts" <tjrobe...@sbcglobal.net> wrote in message
>> news:N6K7k.6297$cW3....@nlpi064.nbdc.sbc.com...
> ...
>>>> course force and acceleration are not along the
>>>> same line, but that's how nature works and
>>>> why this is the case
>>>
>>> ad-hoc equations.
>>
>> Those who never used the concept don't have the
>> understanding that goes with it...
>
> Gentlemen, recall this is a FAQ. It is not a wiki entry. It is not a
> textbook section. It is not a product advertisement page. We are
> answering the questions of someone that does not know, or has forgotten.
>
> I suspect in these cases, that a single webpage cannot present all that is
> necessary to impart the necessary "understanding".
Yes indeed - it can only summarize some of the main points. And in that
respect, it appears to be now a bit lacking in mentioning the perceived
benefits of the use of invariant mass. Almost certainly the author will be
willing to elaborate a little more on that.
Regards,
Harald
dlzc
On Jun 23, 7:02 am, "Juan R." González-Álvarez
<juanREM...@canonicalscience.com> wrote:
> Pmb wrote on Mon, 23 Jun 2008 09:45:08 -0400:
>
> > People make the mistake that "inertial mass"
> > is a resisance in acceleration.
>
> Why would be a mistake?
It is not a "mistake", but certainly a "hasty generalization".
It should be experimentally separately testable that:
inertial mass =?= rest mass =?= gravitational mass
... and it has been, but ...
> > Inertial mass is the property of matter
> > which gives it momentum
>
> What gives momentum for photons and other
> massless particles?
The $64 question, to which there are only a few people that agree.
> > Relativistic mass is a quantity
> > described by one number. No more. If
> > you're thinking that relativistic mass
> > is the m in F = ma then that is
> > clearly wrong.
>
> Why would be he wrong? One can rewrite
> the relativistic equation of motion as
>
> ma = f
>
> where, of course, f is not Newtonian-
> Coulomb force in the general case.
He wants to say that
dp/dt = m*dv/dt + v*dm/dt
... is correct, that mass has a velocity dependent component (and it
does for relativistic mass), but it doesn't for most of the equations
people run into.
And we will go around and around for another couple of weeks, and no
one will be satisfied.
David A. Smith
dlzc
On Jun 23, 6:45 am, "Pmb" <peter.m.br...@somewhere.net> wrote:
> "N:dlzcD:aol T:com (dlzc)" <dl...@cox.net> wrote in messagenews:5qN7k.3760$to3....@newsfe15.phx...
...
> > Which is why I have attempted not to get
> > into such an argument. "Let each man lay
> > his dead according to his own fashion."
> > I cannot explain r.m. to the newbie, so
> > I don't. I leave the equations to carry
> > the direction dependency, where the
> > newbie expects it. Rather than hand
> > them something that is redefined from
> > Newton, hoping that they understand.
>
> Relativistic mass is *not* redefined from
> Newton.
Who derived F = ma from p = mv (or vice versa)? Newton.
> It is exactly as defined by Newton.
No.
> One merely has to look in the definitions
> of the Principia to see that. I can get
> that quote if anyone would like to read it?
He wrote more than that. Our pre-college physics programs teach more
than that.
That you like the flavor of R.M. is not at question. That I dislike
it is also not at question.
David A. Smith
harry
"N:dlzc D:aol T:com (dlzc)" <dl...@cox.net> wrote in message
news:5qN7k.3760$to3....@newsfe15.phx...
>>
>> "N:dlzc D:aol T:com (dlzc)" <dl...@cox.net> wrote in message
>> news:OUu7k.5173$_T7....@newsfe08.phx...
>>> Dear Pmb:
>>>
>>>> Hi folks
>>>>
>>>> A new version of the FAQ "Does mass increase with
>>>> speed?" was written and is now online at
>>>>
>>>> http://math.ucr.edu/home/baez/physics/Relativity/SR/mass.html
>>>>
>>>> This is a well written article on this whole relativistic
>>>> mass thing. The author makes a great point
>>>> -------------------------------------------------------------------------------
>>>> A common argument against the use of relativistic
>>>> mass is the fact that the equation E=mc^2 says
>>>> that a body's relativistic mass equals its total
>>>> energy, so why should we use two terms for
>>>> what is essentially the same quantity? We should
>>>> just stay with energy, and use the word "mass" to
>>>> refer only to rest mass. But this argument
>>>> neglects the definitions of the words mass and
>>>> energy. Mass is a property of a body that we
>>>> have an intuitive feel for; its definition as a
>>>> resistance to acceleration is very fundamental.
>>>> Energy, on the other hand, is defined in physics
>>>> in rather ad hoc ways. Neither concept is even
>>>> remotely understood by modern physics.
>>>> -------------------------------------------------------------------------------
>>>> his writing :)
>>>
>>> "intuition" and "common sense" guide them
>>> through relativity, then we splice the bullsh*t of a "mass" that is
>>> different to different axes of
>>> acceleration in as having an "intuitive feel".
>>
>> As the FAQ points out at the end,
>> "relativistic mass" has an intuitive feel
>
> It does not! I have no feel whatsoever for it. So far I "know" three
> people that prefer it. I "know" dozens that do not.
>
>
> Clearly untrue, as a global claim.
?! It is exactly as direction dependent as invariant mass as gamma isn't
direction dependent either.
>> Of course force and acceleration are not along the same line, but that's
>> how nature
>> works and relativistic mass even gives an
>> understanding of why this is the case.
>
> Not true. The "understanding" required to properly use relativistic mass,
> carries with it the "understanding of why this is the case". Familiarity
> breeds more than contempt...
I can only inform you that it was true for me.
> ...
>>> Personally, I feel it to be a giant step
>>> backwards. It yields yet another arcane
>>> formulation that will stand between the
>>> newbie and understanding, with *none* of
>>> the "intuitive feel" sought. But hey, I am
>>> just a mechanical engineer.
>>
>> Instead I agree with Feynman that it is very
>> helpful.
>
> Which is why I have attempted not to get into such an argument. "Let each
> man lay his dead according to his own fashion." I cannot explain r.m. to
> the newbie, so I don't. I leave the equations to carry the direction
> dependency, where the newbie expects it. Rather than hand them something
> that is redefined from Newton, hoping that they understand.
I'm afraid that that just doesn't work: each is a redefinition from Newton
and makes an according claim. Well said better not to get into such
arguments. :-)
> All else is straining at gnats.
I didn't know that expression!
Regards,
Harald
Pmb
"dlzc" <dl...@cox.net> wrote in message
news:7b18ab6d-4996-4a98...@h1g2000prh.googlegroups.com...
Dear Pmb:
On Jun 23, 6:45 am, "Pmb" <peter.m.br...@somewhere.net> wrote:
> "N:dlzcD:aol T:com (dlzc)" <dl...@cox.net> wrote in
> messagenews:5qN7k.3760$to3....@newsfe15.phx...
...
> > Which is why I have attempted not to get
> > into such an argument. "Let each man lay
> > his dead according to his own fashion."
> > I cannot explain r.m. to the newbie, so
> > I don't. I leave the equations to carry
> > the direction dependency, where the
> > newbie expects it. Rather than hand
> > them something that is redefined from
> > Newton, hoping that they understand.
>
> Relativistic mass is *not* redefined from
> Newton.
>Who derived F = ma from p = mv (or vice versa)? Newton.
No. Euler
> It is exactly as defined by Newton.
No.
>> One merely has to look in the definitions
>> of the Principia to see that. I can get
>> that quote if anyone would like to read it?
>He wrote more than that. Our pre-college physics programs teach more
than that.
You were referring to Newton, not pre-college physics programs. I was
referring to how Newton used these terms in his Princia. In the principia he
defined mass as the product of density and volume and "quantity of motion"
(what we call momentum) as the product of mass and velocity. He then related
momentum to force in a way similar to F = dp/dt. This is precisely how it is
done in relativity. For this reason nothing has been redefined.
Pete
Pmb
Dear Juan R." González-Álvarez:
------------
Not I. I will not repeat myself in this thread regarding those old
agreements from this point. I'm only interested in things that has not been
mentioned yet. They are imbedded in the questions I asked Dono who, not
surprisingly, refuses to answer them. lol!
Pete
dlzc
On Jun 23, 6:28 am, "Pmb" <peter.m.br...@somewhere.net> wrote:
> "harry" <harald.vanlintelButNotT...@epfl.ch> wrote in message
...
> >> Personally, I feel it to be a giant step
> >> backwards. It yields yet another arcane
> >> formulation that will stand between the
> >> newbie and understanding, with *none* of
> >> the "intuitive feel" sought. But hey, I
> >> am just a mechanical engineer.
>
> > Instead I agree with Feynman that it is
> > very helpful.
>
> Me too. :)
>
> But its far more than that. There is no
> other way to logically define mass.
That is untrue. This exactly countermands what high school students
are taught, where the lion's share of our cranks come from. To them,
rest mass == inertial mass, and that is "logically defined". And has
"intuitive feel".
"Intuition" and "common sense" grow on what you feed them. Must we
"put the lie" to everything that people learn in high school? Because
to do so only increases the numbers of people that must crank.
David A. Smith
Pmb
Dear Pmb:
On Jun 23, 6:28 am, "Pmb" <peter.m.br...@somewhere.net> wrote:
> "harry" <harald.vanlintelButNotT...@epfl.ch> wrote in message
...
> >> Personally, I feel it to be a giant step
> >> backwards. It yields yet another arcane
> >> formulation that will stand between the
> >> newbie and understanding, with *none* of
> >> the "intuitive feel" sought. But hey, I
> >> am just a mechanical engineer.
>
> > Instead I agree with Feynman that it is
> > very helpful.
>
> Me too. :)
>
> But its far more than that. There is no
> other way to logically define mass.
>That is untrue.
It is quite true.
> This exactly countermands what high school students
>are taught, where the lion's share of our cranks come from. To them,
>rest mass == inertial mass, and that is "logically defined". And has
>"intuitive feel".
That comes from assuming that the momentum can always be expressed as p =
gamma*m*v where p = rest mass. It cannot. That expression is only true under
certain circumstances and is not true in general.
>"Intuition" and "common sense" grow on what you feed them. Must we
>"put the lie" to everything that people learn in high school? Because
>to do so only increases the numbers of people that must crank.
There are no lies in what I'm saying.
Pete
Juan R.
>> Yours is an important remark. I will add something about 'blinded'
>> people (usually old academicians) in a new version of
>>
>> http://www.canonicalscience.org/en/miscellaneouszone/guidelines.html
>>
>>
> Let's not turn this into a tom-bashing thread. While I don't mind
> pointing out his many errors and shortcomings in science, such as this
> one, I'm not interest in flaming him. I don't wish to become like tom. 0
> Pete
Above link is a guide to help people to react when finding people as him
on the USENET.
And your remark that some people "is used to a certain way of doing
things and is blind to everything else" is an important remark i will add
to the guidelines.
Pmb
Note: I'd be more specific but I plan on waiting a few days to see if Dono
will accept my challenge and answer my questions. So far he's thrown up a
smoke screen by demanding I answer freshman sr questions. It wasn't enough
for him that I answered one. He seems to be using this as a reason to not
answer my questions. Thursday I'll post examples of what I'm saying. If
someone wants to see them earlier then please e-mail me and I'll send them
to you, as well as the answers to dono's trivial freshman questions. lol!
Pete
Dirk Van de moortel
Pete, whatever you have in mind, you totally sound like you just
came here again with this thread with the sole purpose of starting
a good old flame war - like in the old days.
I thought you had changed, and you said you had changed, with
your religion and all, but it looks like you haven't changed a bit.
This sentence is one one of most disgusting things you have ever
written:
"While I don't mind pointing out his many errors and
shortcomings in science, such as this one, I'm not interest
in flaming him. I don't wish to become like tom."
It deserves a prominent entry on my list:
"I'm not interested in flaming":
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/FlameInterest.html
Dirk Vdm
Juan R.
> "Juan R. González-Álvarez" <juanR...@canonicalscience.com> wrote in
> message news:pan.2008.06...@canonicalscience.com...
>> Pmb wrote on Mon, 23 Jun 2008 09:45:08 -0400:
>>
>>> People make the mistake that "inertial mass" is a resisance in
>>> acceleration.
>>
>> Why would be a mistake?
>
> Because its based on the relation F = ma. This is not how Newton defined
> mass and it is not a general expression for force.
The expression (f = ma) is general enough, but of course in the general
case f is not just Newton force F.
Also according to this
http://en.wikipedia.org/wiki/Inertia#Inertial_mass
Inertial masses are measured by applying a known force to an unknown
mass, measuring the acceleration, and applying (m = f/a).
> When its written as F = ma
> its known as Euler's equation for force. Momentum is defined as p = mv
> and force is defined as f = dp/dt. In relativity one can no longer
> assume that dm/dt = 0 and therefore one can't write F = ma.
Well but i wrote (f = ma) *and* said that my f is not Newtonian, i.e. my
f is not dp/dt.
>>> Inertial mass is the property of matter which gives it momentum
>>
>> What gives momentum for photons and other massless particles?
>
> A photon has momentum p = mv where m = inertial (aka relativistic) mass.
> v = speed of light. Therefore p = mc.
Ah! you call inertial mass to the relativistic mass. I follow usual
inertial mass to be the rest mass.
>
>>> Relativistic mass is a quantity described by one number. No more. If
>>> you're thinking that relativistic mass is the m in F = ma then that is
>>> clearly wrong.
>>
>> Why would be he wrong?
>
> F cannot be expressed as F = ma. See
> http://www.geocities.com/physics_world/sr/long_trans_mass.htm
>
>>One can rewrite the relativistic equation of motion as
>>
>> ma = f
>
> That expression is incorrect if m = inertial mass, a = 3-acceleration
> and f = 3-force. If by f you mean 4-force then the general expression is
> f = dp/dT where p = 4-momentum and T = proper time.
We are using different notations.
If you have a *relativistic* equation of motion (F = dp/dt) you can
rewrite it as
f = ma
always with (F /= f) in the general case. Note this f is not your f of
above and my m is rest mass.
The expression (f = ma) may be more or less adequate but it is, of
course, not incorrect because it may be equivalent to (F = dp/dt).
The expression F = dp/dt is better theoretically (i use as definition of
force) but for some practical problems (f = ma) may be (or not) more
useful.
See test after eqs. (10) and (12) on
http://arxiv.org/pdf/0803.1326v1
Pmb
"Dirk Van de moortel" <dirkvand...@ThankS-NO-SperM.hotmail.com> wrote
in message news:5jQ7k.122969$9x.2...@newsfe05.ams2...
> .. totally sound ..
To who?
Pmb
"Juan R. González-Álvarez" <juanR...@canonicalscience.com> wrote in
message news:pan.2008.06...@canonicalscience.com...
> Pmb wrote on Mon, 23 Jun 2008 10:26:47 -0400:
>
>> "Juan R. González-Álvarez" <juanR...@canonicalscience.com> wrote in
>> message news:pan.2008.06...@canonicalscience.com...
>>> Pmb wrote on Mon, 23 Jun 2008 09:45:08 -0400:
>>>
>>>> People make the mistake that "inertial mass" is a resisance in
>>>> acceleration.
>>>
>>> Why would be a mistake?
>>
>> Because its based on the relation F = ma. This is not how Newton defined
>> mass and it is not a general expression for force.
>
> The expression (f = ma) is general enough,
That is incorrect.
Dirk Van de moortel
and by the way, do take some time to properly acquaint
yourself with the modus operandi of the disgusting shit you
are talking to here in this thread:
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Guidelines.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/IFollowGuidelines.html
I don't think his are religiously inspired like yours, but he
"Follows Guidelines" as well.
Dirk Vdm
Pmb
I see your back into the flame mode huh? Sorry Dirk but just because I'm not
going to flame people it doesn't mean that I'm not going to point out there
flaws.
Since you are flaming again - plonk!
Dirk Van de moortel
> "Dirk Van de moortel" <dirkvand...@ThankS-NO-SperM.hotmail.com> wrote
> in message news:6HQ7k.122971$9x.3...@newsfe05.ams2...
>> Pmb <peter....@somewhere.net> wrote in message
>> nZWdnRltzYUrSMLV...@comcast.com
>>> "Dirk Van de moortel" <dirkvand...@ThankS-NO-SperM.hotmail.com>
>>> wrote
>>> in message news:5jQ7k.122969$9x.2...@newsfe05.ams2...
>>>> Pmb <peter....@somewhere.net> wrote in message
>>>> d82dnQhDcOjnMsLV...@comcast.com
>>>
>>>> .. totally sound ..
>>>
>>> To who?
>>
>> and by the way, do take some time to properly acquaint
>> yourself with the modus operandi of the disgusting shit you
>> are talking to here in this thread:
>> http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Guidelines.html
>>
>> http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/IFollowGuidelines.html
>>
>> I don't think his are religiously inspired like yours, but he
>> "Follows Guidelines" as well.
>>
>> Dirk Vdm
>
> I see your back into the flame mode huh?
Take some time, Pete.
And take care.
Dirk Vdm
Ken S. Tucker
> Hi folks
>
> A new version of the FAQ "Does mass increase with speed?" was written and is
> now online at
>
> http://math.ucr.edu/home/baez/physics/Relativity/SR/mass.html
>
> This is a well written article on this whole relativistic mass thing. The
> author makes a great point
> -------------------------------------------------------------------------------
> A common argument against the use of relativistic mass is the fact that the
> equation E=mc^2 says that a body's relativistic mass equals its total
> energy, so why should we use two terms for what is essentially the same
> quantity? We
> should just stay with energy, and use the word "mass" to refer only to rest
> mass. But this argument neglects the definitions of the words mass and
> energy. Mass is a property of a body that we have an intuitive feel for;
> its definition as a resistance to acceleration is very fundamental. Energy,
> on the other hand, is defined in physics in rather ad hoc ways. Neither
> concept is even remotely understood by modern physics.
> -------------------------------------------------------------------------------
> sniff sniff. I'm getting all misty at the quality of his writing :)
>
>
> Best wishes
>
> Pete
Hi Pete
Here's one paragraph that sums it all up,
http://physics.trak4.com/MST_Mass-Definition.pdf
There is no Internationally accepted definition
of mass, so we made one.
Regards
Ken S. Tucker
Juan R.
> http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/
Guidelines.html
I like the last part
(\blockquote
Tom you are doing a fine job at educating people about elementary
questions on relativity. Keep it up! But avoid to reply to advanced
research questions, specially in those topics you NEVER studied or did
any contribution.
)
Very good advice indeed!
Juan R.
Yes, and then one can rewrite that like
f = ma
where as i already several times before f is not F = dp/dt.
It seems that he mis-interpreted my f as being its F.
Dono
> demanding I answer freshman sr questions.
>
....questions that you are obviously unable to answer :-)
Juan R.
(snip)
Ok, you deleted my post, further explanation, and references. What
follows is not addressed to you but rest of readers.
Using relativistic mass M
F = dp/dt
and p = Mv
Then
F = v(dM/dt) + Ma
(F - v(dM/dt)) = f = Ma
I prefer to work with rest mass m, then
F = dp/dt
and p = m gamma v
Then
F = mv(dgamma/dt) + m gamma a
((F - v(dM/dt)) / gamma) = f = ma
Expressions relating F to p are very useful for theoretical analysis and
also for certain kind of observations (e.g. scattering between initial
and final states with well defined momenta).
Expressions relating f to a are very useful for analysis of data of
spatial trajectories and is used for measurements of rest mass m.
Above can be also repeated in proper time formulation p = mu or even for
EM and GR corrections.
As stated (F = dp/dt) is theoretically preferred.
In any case, one can always define some f like
f = ma = m {{r, H}, H}
where {,} is the Poisson bracket, r the position of the particle and H
the Hamiltonian. See equation (12) on
http://arxiv.org/pdf/0803.1326v1
and applications of (12) to AB effect
Pmb
"Juan R. González-Álvarez" <juanR...@canonicalscience.com> wrote in
message news:pan.2008.06...@canonicalscience.com...
>
>> http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/
> Guidelines.html
>
> I like the last part
>
> (\blockquote
> Tom you are doing a fine job at educating people about elementary
> questions on relativity. Keep it up! But avoid to reply to advanced
> research questions, specially in those topics you NEVER studied or did
> any contribution.
> )
>
> Very good advice indeed!
Its hero worship like that which leads to people like dirk flaming when the
"hero"s errors/flaws are pointed out
Pmb
"Juan R. González-Álvarez" <juanR...@canonicalscience.com> wrote in
message news:pan.2008.06...@canonicalscience.com...
>
> (snip)
>
> Ok, you deleted my post, further explanation, and references.
I only quote that which I'm addressing. I don't "delete" (in your words). If
I omit something its because I'm not responding to it.
Pmb
"Ken S. Tucker" <dyna...@vianet.on.ca> wrote in message
news:b6a2a649-a6dc-414e...@l42g2000hsc.googlegroups.com...
:)
dlzc
On Jun 23, 8:43 am, "harry" <harald.vanlintelButNotT...@epfl.ch>
wrote:
> "N:dlzcD:aol T:com (dlzc)" <dl...@cox.net> wrote in messagenews:5qN7k.3760$to3....@newsfe15.phx...
...
> > All else is straining at gnats.
>
> I didn't know that expression!
I say this not to make you feel creepy, just so you know where it came
from:
"Ye blind guides, which strain at a gnat, and swallow a camel."—
Matthew 23:24
David A. Smith
Juan R.
> Pmb wrote on Mon, 23 Jun 2008 12:57:07 -0400:
>
> (snip)
>
> Ok, you deleted my post, further explanation, and references. What
> follows is not addressed to you but rest of readers.
>
> Using relativistic mass M
>
> F = dp/dt
>
> and p = Mv
>
> Then
>
> F = v(dM/dt) + Ma
>
> (F - v(dM/dt)) = f = Ma
>
> I prefer to work with rest mass m, then
>
> F = dp/dt
>
> and p = m gamma v
>
> Then
>
> F = mv(dgamma/dt) + m gamma a
>
> ((F - v(dM/dt)) / gamma) = f = ma
Better rewrite that like
((F - mv(dgamma/dt)) / gamma) = f = ma
>
> Expressions relating F to p
F = dp/dt
> are very useful for theoretical analysis and
> also for certain kind of observations (e.g. scattering between initial
> and final states with well defined momenta).
>
> Expressions relating f to a
f = ma
> are very useful for analysis of data of
> spatial trajectories and
f = ma
> is used for measurements of rest mass m.
>
> Above can be also repeated in proper time formulation p = mu or even for
> EM and GR corrections.
>
> As stated (F = dp/dt) is theoretically preferred.
>
> In any case, one can always define some f like
>
> f = ma = m {{r, H}, H}
>
> where {,} is the Poisson bracket, r the position of the particle and H
> the Hamiltonian. See equation (12) on
>
> http://arxiv.org/pdf/0803.1326v1
>
> and applications of (12) to AB effect
Above expressions also hold for quantum case, For example the definition
for quantum f follows from transforming classical brackets in quantum
brackets [,] and classical r and H into operators.
Ken S. Tucker
> "Ken S. Tucker" <dynam...@vianet.on.ca> wrote in messagenews:b6a2a649-a6dc-414e...@l42g2000hsc.googlegroups.com...
...
> >>http://math.ucr.edu/home/baez/physics/Relativity/SR/mass.html
...
> > Hi Pete
> > Here's one paragraph that sums it all up,
> >http://physics.trak4.com/MST_Mass-Definition.pdf
> > There is no Internationally accepted definition
> > of mass, so we made one.
>
> :)
I have to thank Pete for forcing me to find
an acceptable definition of mass, apart from
1000 Napolean penis's that are sitting in
Paris, apparently shivelling, that will do in
the interm until the genius's agree in 2011,
where - it is hoped - the Paris Kilogram will
be replaced by a universal definition.
My linked definition, while not a practical
lab standard yet, is based on the fundamental
value of the charge invariant and the definition
of time, like the meter is based on the invariant
"c" and time, so I use it as a theoretical standard.
BTW Pete, using the covariant 3 velocity
P_i=0 {i=1,2,3}, works really well.
Regards
Ken S. Tucker
Raghar
>
> You haven't solved anythingyet, you just STARTED solving the problem.
> Try solving it for real, ok?
Why don't you answer his question? He showed an effort.
Androcles
"harry" <harald.vanlin...@epfl.ch> wrote in message
news:1214209...@sicinfo3.epfl.ch...
|
| "N:dlzc D:aol T:com (dlzc)" <dl...@cox.net> wrote in message
| news:OUu7k.5173$_T7....@newsfe08.phx...
| > Dear Pmb:| > news:GaSdndZG-uirT8DV...@comcast.com...
| > sense" guide them through relativity, then we splice the bullsh*t of a
| > "mass" that is different to different axes of acceleration in as having
an
| > "intuitive feel".
|
| As the FAQ points out at the end, "relativistic mass" has an intuitive
feel
| and is NOT direction dependent. Of course force and acceleration are not
| along the same line, but that's how nature works and relativistic mass
even
| gives an understanding of why this is the case.
|
| > And try and justify it by glancingly referring to E=mc^2 (or even
Newton's
| > E = 1/2mv^2), which is *not* where the "intuitive feel" of mass comes
| > from. 'Twas Mr. Koks' idea to resurrect this particular slant.
|
| Actually, the FAQ misses the important point that since c is not constant
in
| the way it was assumed in SRT, E and m are not only physically different
| entities, but they are in general not even proportional.
| http://groups.google.com/group/sci.physics.research/msg/dcd13814f4019d50
|
| >> To the author - Well done sir!
| >
|
| Sure. If you find an error in the FAQ, just tell the author what the error
| is.
Ok.
The error is:
If the speed of light from A to B is c-v,
and the speed of light from B to A is c+v,
the "time" each way is NOT the same, DUMBFUCK!
1/2[tau(A)+tau(A')]= tau(B)
where
A = (0,0,0,t)
A' =(0,0,0,t+x'/(c-v) +x'/(c+v))
B = (x',0,0,t+x'/(c-v))
x' = x-vt
Ref: http://www.fourmilab.ch/etexts/einstein/specrel/www/figures/img22.gif
"Easy: he did NOT say that." - cretin harald.vanlin...@epfl.ch
According to moron van lintel, Einstein did not write the equation he wrote.
Tom Roberts
> it is debatable what "mainstream" is here (according
> to the recent stats I saw, it's rather equal).
I have no idea what "stats" you saw. The two fields of physics that
inherently use relativity every day are HEP and GR. I have hundreds of
connections in the first and many in the second; all of the physicists I
have asked [#] use the word "mass" to mean an invariant, and it is fair
to say that in the main they consider "relativistic mass" to be useless
and confusing at best, and agree that "anachronism" is a good description.
[#] Three times I have made an informal poll of everybody
in the room before a physics meeting. I am including at
least 100 physicists in this statement. One of these meetings
was a colloquium on LIGO at Fermilab, so it was dominated by
HEP, but the astrophysics group was certainly represented.
In each case several people expressed the opinion that my
poll was ridiculous as the answer is obvious. NOBODY in these
polls has suggested "relativistic mass" is useful or of more
than historical interest (of course peer pressure might keep
some silent, but most of the physicists I know are quite
outspoken on such things); several expressed the opinion that
"relativistic mass" should be taught but not used; a comparable
number said it should be stomped out until dead.
While "voting" and informal polls have no place in physics, remember
that science is a SOCIOLOGICAL endeavor, and the terminology is
determined by actual usage. In the research communities of HEP and
gravitation, "relativistic mass" is not used much if at all (just look
at the literature). Other research communities would be unaware of the
question, as they rarely if ever use relativity. Please note that all
references to the literature in this thread (and in the wider discussion
over the years) are about TEACHING physics, not DOING physics.
Tom Roberts
Tom Roberts
> tom is used to a certain way of doing things and is blind to everything
> else.
Your claims about me are very far from the mark.
I dislike "relativistic mass" because it is an unwelcome and confusing
pun on the word "mass". No more, no less. This is not "a certain way of
doing things", this is the way the mathematics works out, and the way
the words are actually used today in the fields I study (see my recent
post on this).
> E.g. the term "mass density" can never be used to refer to "rest mass
> density" and have a general meaning since it is impossible to do so..
I think you got this backwards, but it's not obvious what you meant to
say. No matter.
> But
> tom doesn't work in an area where that would come up.
I haven't a clue how you got that notion -- mass density is inherent in
most solutions of GR.
What, pray tell, would "relativistic mass density" mean in the context
of GR? Or how would "relativistic mass" apply in GR in any situation and
make things simpler or more descriptive or "better" in whatever sense
you mean?
And it's quite clear that you do not work in an area where my argument
comes up: why don't you meet my challenge and show us the Lagrangian of
classical electrodynamics using "relativistic mass"? And then the
Lagrangian of QED?
> Also, many physicists
> don't work with anything but particles. And we know that particles aren't
> all that exists.
Hmmm. How do "we know" that "particles aren't all that exists"? After
all, no continuous structure has EVER been observed.
> When it comes to the theoretical treatement of things like
> extended bodies in general situations then "rest mass" looses its meaning.
Yes, rest mass is not the whole story for such objects; but then neither
is "relativistic mass". Note also that there _ARE_ no such "extended
bodies" in the world we inhabit (as far as we know today), there are
just collections of many (many!) particles. You can APPROXIMATE many
situations as if they involved extended bodies, but it does you no good
to confuse the approximation with the theory or observations. You can
MODEL many situations using a continuous MODEL, but that doesn't mean
the world obeys your model. I repeat: no continuous structure has ever
been observed -- objects are built of atoms, and atoms are built of
particles down to the best resolutions we have achieved (~10^18 m).
> But then again tom doesn't concern himself with such things.
On the contrary, I consider them often. But I don't intermix and confuse
theory, observation, and approximation. And I prefer to avoid puns and
to use the terminology of the fields I study; that simply does not
include "relativistic mass". Nothing you do or say is going to change
this fact. <shrug>
Tom Roberts
Tom Roberts
> Gentlemen, recall this is a FAQ. It is not a wiki entry. It is
> not a textbook section. It is not a product advertisement page.
> We are answering the questions of someone that does not know, or
> has forgotten.
> I suspect in these cases, that a single webpage cannot present
> all that is necessary to impart the necessary "understanding".
Yes. But I think the FAQ pages should present the mainstream terminology
and understanding of physics, and not pander to a few loudmouth
wannabes. "Relativistic mass" simply is not part of mainstream physics
today, as a perusal of the relevant literature shows -- all references
to usages of "relativistic mass" around here have been to TEACHING
physics, not DOING physics.
I think the FAQ page should say this. It should also refer to historical
usages of "relativistic mass" and "mass varying with speed", and explain
why those phrases are no longer used, and why "mass" today refers to an
invariant.
If they want to influence the terminology, advocates of "relativistic
mass" should explain why it is better, in ways that count for DOING
physics, not just teaching it. To start, they should display the
Lagrangians for classical electrodynamics and QED using "relativistic
mass", and show why they are better than the conventional methods (which
use invariants). Absent that, they have no leg to stand on.
Tom Roberts
Dono
> A photon has momentum p = mv where m = inertial (aka relativistic) mass. v =
> speed of light. Therefore p = mc.
>
>
This is precious , Pete
Hold onto this idea, it may get you the Nobel Prize one day.
Dono
> >> What gives momentum for photons and other massless particles?
>
> > A photon has momentum p = mv where m = inertial (aka relativistic) mass.
> > v = speed of light. Therefore p = mc.
>
> Ah! you call inertial mass to the relativistic mass. I follow usual
> inertial mass to be the rest mass.
>
Juanshito,
You only follow Pete's idiocy by compounding it with your very own.
> We are using different notations.
>
> If you have a *relativistic* equation of motion (F = dp/dt) you can
> rewrite it as
>
> f = ma
>
Nice try, Juanshito
Dono
<juanREM...@canonicalscience.com> wrote:
> Pmb wrote on Mon, 23 Jun 2008 12:57:07 -0400:
>
> (snip)
>
> Ok, you deleted my post, further explanation, and references.
Juanshito,
Only you can delete your own posts, stop lying.
> Using relativistic mass M
>
> F = dp/dt
>
> and p = Mv
>
> Then
>
> F = v(dM/dt) + Ma
>
> (F - v(dM/dt)) = f = Ma
>
You realize that you are sinking deeper and deeper in a shithole,
don't you, Juanshito?
Tom Roberts
> People make the mistake that "inertial mass" is a resisance in acceleration.
That's not what the FAQ page said.
But OK, take that as defining mass m. In Newtonian mechanics one has:
p = m v (p and v are 3-vectors, m is a scalar)
In relativity one has:
P = m V (P and V are 4-vectors, m is a scalar)
The generalization from Newton to relativity is 3-vectors => 4-vectors,
not a redefinition of mass. Mass remains a scalar (i.e. an invariant).
> Relativistic mass is a quantity described by one number. No more.
This is simply not true. A given object has a different "relativistic
mass" in every different frame. This is counter-intuitive (to say the
least), and is in direct conflict with mass as an intrinsic property of
an object.
> Relativistic mass is the m in p = mv.
Yes. But using 3-vectors and "relativistic mass" in relativity is
ignoring completely the long history of learning how useful invariants
are in physics.
In mainstream physics today, mass is the m in P = m V (see above). The
generalization from Newton to relativity is 3-vectors => 4-vectors, not
a redefinition of mass. EVERY quantity in my formula is an invariant,
NONE of the quantities in PMB's formula are invariants. Guess which is
easier to apply in multiple frames.... Guess which notation is easier to
use to search for Lorentz-invariant theories....
> Rel-mass, m, is related to force as F = d(mv)/dt.
The corresponding mainstream relation is F = d(mV)/d\tau; here F and V
are 4-vectors and m is the (invariant) mass. Once again, the
generalization from Newton to relativity is 3-vectors => 4-vectors, not
a redefinition of mass.
I repeat the rationale: the mainstream 4-vector formulas
are valid for any coordinates, in both SR and GR. PMB's
3-vector formulas are valid only for inertial frames in SR
(they aren't even valid for rotating coordinates in SR).
Gibbs's crusade for 3-vectors a century ago was based on the same basic
argument: the notation should reflect the underlying symmetry. Back then
it was rotations, today [#] it is Lorentz invariance. A similar crusade
for 4-vectors was not needed because the older notation ("relativistic
mass" and 3-vectors) was not so solidly established, and people
remembered Gibbs's arguments. In both cases the notation reflecting the
symmetries has "won".
[#] in this discussion; the issue was settled >40 years
ago (long before my or PMB's time).
For the record: yes, "relativistic mass" is used in some textbooks
(mostly older ones, and exclusively elementary ones; no GR textbook I
have seen mentions it at all except possibly in an historical note). It
is used sometimes in TEACHING physics, but not in DOING physics.
Tom Roberts
Tom Roberts
> Because [F = ma] is not how Newton defined
> mass and it is not a general expression for force. When the mass is constant
> in time then its a valid equation. When its written as F = ma its known as
> Euler's equation for force.
Again you show how divorced from the mainstream you are. While this may
be technically and historically true, zillions of physicists and
textbooks call that equation "Newton's second law". While I don't defend
the historical inaccuracy of this, it is most definitely how these words
are used.
Tom Roberts
Tom Roberts
> [...] F = dp/dt = q[E + vxB] is the equation of motion where p = mv =
> gamma*m_0*v. Like so many people in the past you are once again repeating
> their flawed arguement that one can write the equation of motion as F =
> d(gamma*m)/dt = q[E + vxB] where m = proper mass and as such the
> "relativistic mass" never appears in the equation. The problem with that
> kind of arguement is that the relativistic mass *is* there. You simply
> didn't give it a symbol. [...]
A better way of writing that is:
F = dP/d\tau = Faraday(.,U)
or in components:
F_i = dP_i/d\tau = Faraday_ij U^i
Where F is the 4-force, P is the 4-momentum, Faraday is the EM field
tensor, and U is the 4-velocity. There's no "relativistic mass"
anywhere, with a symbol or without one -- EVERY symbol in those
equations is an invariant or the components of an invariant tensor (NONE
of your symbols are invariant).
This way is better because the underlying Lorentz symmetry is manifest.
In your equation is it present, but is hidden extremely well.
Exercise for the reader: prove that PMB's equation is
Lorentz invariant. Then do so for mine. Hint: these are the
same equation using different notation. I estimate
about a page of algebra vs 1 line.
After doing that exercise, think about how one would search for a
Lorentz-invariant Lagrangian of a new theory of physics. Which concepts
and notation would make that be easier? Note that this was precisely the
problem facing the architects of the standard model; they did not use
"relativistic mass"....
Tom Roberts
Tom Roberts
> "Juan R. González-Álvarez" <juanR...@canonicalscience.com> wrote in
> message news:pan.2008.06...@canonicalscience.com...
>
> That is incorrect.
I agree. In both Newtonian mechanics and relativity, the equation f=ma
(F=mA) must be accompanied with the caveat that m remains constant. The
equation f=dp/dt (F=dP/d\tau) needs no such caveat.
Tom Roberts
Pentcho Valev
sci.physics.relativity:
Bravo Roberts bravo Tom bravo Albert Einstein of our generation
(Hawking is no longer the Albert Einstein of our generation)! However
at the end of his life the original Albert Einstein (Divine Albert)
suddenly became honest and explained to Einstein zombie world the
aftermaths of the continuous (field) concept of light:
http://www.perimeterinstitute.ca/pdf/files/975547d7-2d00-433a-b7e3-4a09145525ca.pdf
John Stachel: "It is not so well known that there was "another
Einstein," who from 1916 on was skeptical about the continuum as a
foundational element in physics..." Albert Einstein: "I consider it
entirely possible that physics cannot be based upon the field concept,
that is on continuous structures. Then nothing will remain of my whole
castle in the air, including the theory of gravitation, but also
nothing of the rest of contemporary physics."
When are you going to become honest Roberts Roberts? At the end of
your life, like Divine Albert?
Pentcho Valev
pva...@yahoo.com
Pmb
"Dono" <sa...@comcast.net> wrote in message
news:c1a20cea-d370-4b53...@79g2000hsk.googlegroups.com...
On Jun 23, 7:26 am, "Pmb" <peter.m.br...@somewhere.net> wrote:
> A photon has momentum p = mv where m = inertial (aka relativistic) mass. v
> =
> speed of light. Therefore p = mc.
>
>
>
>This is precious , Pete
Hmmm. Seems that you are refraining from agreeing or disagreeing with this
but are merely being sarcastic about it, meaning that you (erronsously)
think something is wrong but you can't say what. Tell ya what. Let the rest
of the class know what your problem with it is and explain why this isn't
found in a modern SR texts. I'll then be happy to show you where its found,
even by Einstein if you'd like. LOL!!
>Hold onto this idea, it may get you the Nobel Prize one day.
Thank you for crediting me for this idea Donon. This is very nice of you.
LOL!!
Alas I was not the phyicist who came up with the idea. This can be found in
any and all special relativity textbooks which utilize the concept of
relativistic mass (e.g. Rindler, D'Inverno, Mould, French etc). This is a
good example of what I meant when I said that your posts demonstrate that
you don't know what you're talking about in the instances that you
mentioned.
Tell me Dono. Do you really believe that I'm going to respond in kind to
these kinds of trolls? Nope. Ain't gonna happen my friend. As you so rudely
indicated, I'm a "religious man" i.e. I'm a Christian and in trying to live
a Christian life I'm not about to start insulting people. However I will
point out there errors when I see them. In Tom's case I'll point out the
errors in his attitude.
I'm still waiting for you to answer at least one of my questions, or at
least give a reasonable explanation of why you refuse to respond to any of
them. I.e. why should I answer your questions, which I had already answered
one, and yet sit by while you refuse to answer mine? Hmmm? This I can't wait
to hear!!
Claiming that I can't solve that EM problem and am therefore "afraid" to
respond (or some nonsense) won't work, and doesn't intimidate me. Namely
because I don't care what you think about me. As far as others? I'm not to
interested in that for the most part. However I'm not worried in this
instance because I already solved that problem a long time ago and in this
newsgroup. I even readdressed it recently (March). Its on record here for
the world to see if they want to search in past posts so you can't deny it.
Ken Tucker knows this since he participated in that thread. The solution has
been on my website for years for all the world to see. Its been referenced
and discussed in this newsgroup several times in the past.
I'm sure we're all waiting to hear your response. If you are willing to
accept the challenge then answer this one
What is the active gravitational mass of a relativistic fluid.
Good luck Dono! :)
Pete
Dono
> "Dono" <sa...@comcast.net> wrote in message
>
> news:c1a20cea-d370-4b53...@79g2000hsk.googlegroups.com...
> On Jun 23, 7:26 am, "Pmb" <peter.m.br...@somewhere.net> wrote:
>
> > A photon has momentum p = mv where m = inertial (aka relativistic) mass. v
> > =
> > speed of light. Therefore p = mc.
>
> >This is precious , Pete
>
> Hmmm. Seems that you are refraining from agreeing or disagreeing with this
Bozo,
The photon is massless. Ever heard of p=h*f/c? No?
Look here, you may learn something:
http://en.wikipedia.org/wiki/Photon#Physical_properties
>
> I'm a "religious man" i.e. I'm a Christian and in trying to live
> a Christian life I'm not about to start insulting people.
You are an asshole, that much is clear.And a phony. A truly religious
man doesn't lie, you do.
>
> I.e. why should I answer your questions, which I had already answered
> one, and yet sit by while you refuse to answer mine?
Bozo,
The question that I put to you has direct bearing on the usage of
relativistic mass. Tom has already shown that relativistic mass is
virtually unusable in solving the simple problem I gave you. You are
unable to find the trajectory of a particle moving at a significan
fraction of c in a simple magnetic field. You have spent a whole day
trying to give the runaround but the bottom line is you CAN'T solve
the problem.
Pmb
On Jun 23, 4:37 pm, "Pmb" <peter.m.br...@somewhere.net> wrote:
> "Dono" <sa...@comcast.net> wrote in message
>
> news:c1a20cea-d370-4b53...@79g2000hsk.googlegroups.com...
> On Jun 23, 7:26 am, "Pmb" <peter.m.br...@somewhere.net> wrote:
>
> > A photon has momentum p = mv where m = inertial (aka relativistic) mass.
> > v
> > =
> > speed of light. Therefore p = mc.
>
> >This is precious , Pete
>
> Hmmm. Seems that you are refraining from agreeing or disagreeing with this
>Bozo,
More insults I see?
>The photon is massless.
It has zero proper mass and non-zero inertial (aka relativistic) mass. What
part of this are you having trouble with Dono?
Ever heard of p=h*f/c? No?
Of course. I heard
>Look here, you may learn something:
http://en.wikipedia.org/wiki/Photon#Physical_properties
>> I'm a "religious man" i.e. I'm a Christian and in trying to live
>> a Christian life I'm not about to start insulting people.
>You are an asshole, that much is clear.
I hope you don't kiss your mother with that mouth.
>And a phony. A truly religious man doesn't lie, you do.
I don't think that's true.If I was prisner of war and being tortured by the
enemy for secrets and it served my country, or saved American lives, then
I'd lie. And I don't think God would have a problem with that. In anycase I
never lied here. That you think so solely resides in your mind. Because you
disagree with something I said doesn't make it a lie.
> I.e. why should I answer your questions, which I had already answered
> one, and yet sit by while you refuse to answer mine?
>Bozo,
More insults huh? I wonder why Dirk ignores flames like this and then claims
that I posted "disgusting shit" when I said I didn't want to be like Tom
(and I don't). Ah well. I guess we'll never know.
>The question that I put to you has direct bearing on the usage of
>relativistic mass.
I never said I wouldn't answer it. I am merely waiting for you to answer the
question I asked you since I had answered a question that you asked me.
> Tom has already shown that relativistic mass is
> virtually unusable in solving the simple problem I gave you.
That's clearly wrong as any physcist can see.
> You are unable to find the trajectory of a particle moving at a significan
> fraction of c in a simple magnetic field. You have spent a whole day
> trying to give the runaround but the bottom line is you CAN'T solve
>the problem.
Clearly an attempt to delay demonstrating the fact that you can't answer any
of the questions I posed to you. Instead you resort to flaming.
Its silly to claim that I can't solve such an easy problem like that. I had
already told you that I did so and its on this newsgroup for the world to
see by anyone who wishes to look. Its the exact same problem in fact and
holds for any value or v < c. And you can't legitimately claim that I can't
solve it because the newsgroup has a record of the solution with a date and
time stamp. I've sent the URL to three people who post here along with the
URL containing the solution.
Nobody here is buying what you're trying to sell Dono.
Best wishes
Pete
Dono
> >The question that I put to you has direct bearing on the usage of
> >relativistic mass.
>
> I never said I wouldn't answer it.
...but you can't. Otherwise you wouldn't spend a whole day giving the
runaround. Who do you think you are fooling, Pete?
Pmb
> On Jun 23, 5:05 pm, "Pmb" <peter.m.br...@somewhere.net> wrote:
>
>> >The question that I put to you has direct bearing on the usage of
>> >relativistic mass.
>>
>> I never said I wouldn't answer it.
>
> runaround. Who do you think you are fooling, Pete?
This is clearly an avoidance tactic. You simply don't know the answer to the
question. Other posters here have my solution and can post the reference in
the forum when they want to.
When you're ready to start talking like an adult and stop repeating yourself
then I'll respond again. But not until you answer the question on the active
gravitational mass of a relativistic fluid
Pete
Dono
> "Dono" <sa...@comcast.net> wrote in message
>
> news:1ae3adc1-de66-41a6...@g16g2000pri.googlegroups.com...
>
> > On Jun 23, 5:05 pm, "Pmb" <peter.m.br...@somewhere.net> wrote:
>
> >> >The question that I put to you has direct bearing on the usage of
> >> >relativistic mass.
>
> >> I never said I wouldn't answer it.
>
> > ...but you can't Otherwise you wouldn't spend a whole day giving the
> > runaround. Who do you think you are fooling, Pete?
>
> This is clearly an avoidance tactic. You simply don't know the answer to the
> question. Other posters here have my solution and can post the reference in
> the forum when they want to.
Then you wouldn't have any problem posting the link to your solution,
wouldn't you?
Pmb
Nope. The moment (within seconds!) that you answer the question posed I will
post the URL to the solution. Then again I keep telling you this and you
keep refusing to answer. Hmmm,.
Sorry Dono but I have lost my patience with you. If your next post doesn't
contain at least a valid attempt to provide a solution, even an educated
guess, then you will go in my kill file. I will then post the solution when
someone really cares about it. Seems to me that you're the only one here who
doesn't think I can solve it. LOL!!!
Good luck or good bye
Pete
Dono
> "Dono" <sa...@comcast.net> wrote in message
>
> news:ba625936-46de-4fb5...@q24g2000prf.googlegroups.com...
>
>
>
> > On Jun 23, 5:38 pm, "Pmb" <peter.m.br...@somewhere.net> wrote:
> >> "Dono" <sa...@comcast.net> wrote in message
>
> >>news:1ae3adc1-de66-41a6...@g16g2000pri.googlegroups.com...
>
> >> > On Jun 23, 5:05 pm, "Pmb" <peter.m.br...@somewhere.net> wrote:
>
> >> >> >The question that I put to you has direct bearing on the usage of
> >> >> >relativistic mass.
>
> >> >> I never said I wouldn't answer it.
>
> >> > ...but you can't Otherwise you wouldn't spend a whole day giving the
> >> > runaround. Who do you think you are fooling, Pete?
>
> >> This is clearly an avoidance tactic. You simply don't know the answer to
> >> the
> >> question. Other posters here have my solution and can post the reference
> >> in
> >> the forum when they want to.
>
> > Then you wouldn't have any problem posting the link to your solution,
> > wouldn't you?
>
> Nope. The moment (within seconds!) that you answer the question posed I will
> post the URL to the solution. Then again I keep telling you this and you
> keep refusing to answer.
You have no solution. Stop lying, it is very unchristian :-)
>
> Sorry Dono but I have lost my patience with you. If your next post doesn't
> contain at least a valid attempt to provide a solution, even an educated
> guess, then you will go in my kill file.
BFD.
> I will then post the solution when
> someone really cares about it. Seems to me that you're the only one here who
> doesn't think I can solve it.
You don't even realise that the moment you cast the equation:
d(gamma*m*v)=q(E+v/c X B)
you lost your "beloved" relativistic mass. In the above equation, "m"
is the invariant mass.
Tom tried to teach you the invariant formulation but you are a real
mule, perfectly unable to learn.