Steve Carlip wrote in sci.physics.research on Aug 1, 1997:
Anthony F. Badalamenti wrote:
: In 1907 Einstein wrote the following in "On The Influence Of
: Gravitation On The Propagation Of Light":
: "From the proposition which has just been proved, that
: the velocity of light in the gravitational field is a
: function of the place..."
: Einstein is referring to the speed of light at this point, not its
: direction.
The problem here comes from the fact that "speed" is a coordinate-
dependent quantity, and is therefore somewhat ambiguous. To determine
speed---distance/time---you must first choose some standards of
distance and time, and different choices can give different answers.
This is already true in special relativity: if you measure the speed
of light in an accelerating reference frame, the answer will, in
general, differ from c. In special relativity, the speed of light is
constant when measured in any *inertial* frame. In general
relativity, the appropriate generalization is that the speed of light
is constant in any freely falling reference frame (in a region small
enough that tidal effects can be neglected). In this passage, Einstein
is not talking about a freely falling frame, but rather about a frame
at rest relative to a source of gravity. In such a frame, the speed
of light can differ from c, basically because of the effect of gravity
(spacetime curvature) on clocks and rulers.
Steve Carlip
car...@dirac.ucdavis.edu
______________________________________________________________________________
Zombies should first answer the following questions (hypnotists will
remain silent):
1. Does the speed of light "differ from c" in accordance with
Einstein's 1911 equation c'=c(1+V/c^2)?
2. Is the gravitational frequency shift factor (1+V/c^2) due to the
fact that the speed of light "differs from c"?
Pentcho Valev
John Baez wrote in sci.physics.research:
Squark wrote:
>In fact, it's hard for me to understand what "variable
>light-speed" means, as light-speed is a dimensionful constant, so
>in what sense does it vary?
Would you freak out if I told you the speed of sound varied? Don't
tell me you've never heard of a dimensionful constant varying! It
means that certain dimensionless constants vary in a way that can be
nicely explained by a theory in which this dimensionful constant
varies. Some people are trying to explain the possible variation in
the fine structure constant by a variable speed of light. Others are
trying to explain it by a variable electron charge. The difference is
not entirely something that can be settled by experiment - it's
partially a matter of which gives the more pleasing theory. It's like
this: you could say that you grew up since you were a kid, or you
could say that the rest of the world shrunk. Both can be made into
consistent theories, but most of us prefer the first way of looking at
it.
____________________________________________
That was written on March 24, 2003. Now John Baez is afraid of the
variable speed of light, the constant speed of light and any other
speed of light.
Pentcho Valev
Nobody is afraid. Take a deep breath and then go on a long vacation - you
need it!
Harald
Take a deep breath and then fuck off, you are not needed.
I'm assuming you mean "speed of light in vacuo" -- lightspeed is easily
proven variable by a simple prism. Of course, that prism isn't exactly
vacuous.
In any event, you are welcome to explain the creation of the tau lepton
by two electrons by using variable lightspeed theory. Bear in mind that
the two electrons, since they were accelerated using magnetic fields,
cannot possibly go faster than light (at least, as far as most non-SR
characterizations of the problems put it).
(Hint: m_t / m_e = 3477 or thereabouts.)
[rest snipped]
Followups.
--
#191, ewi...@earthlink.net
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Posted via a free Usenet account from http://www.teranews.com
"The Ghost In The Machine" <ew...@sirius.tg00suus7038.net> wrote in message
news:km13g4-...@sirius.tg00suus7038.net...
A lepton is a small particle such as an electron.
A hadron is a larger particle such as a proton.
> The Great Einstein Himself deduced an equation
> describing the change of light speed not by a whim of Allah or Zeus, but by
> the effect of the gravitational field.
The Great Houdini could escape from handcuffs and a straight jacket.
You can too if you can dislocate your shoulder and have special handcuffs.
The Great Einstein performed his magic tricks on paper.
You could too if you were a mathematician and knew how the trick is done.
However, magic tricks are not science, they are illusions, con jobs,
deception, sleight-of-hand, smoke and mirrors. The Great Einstein loved
mirrors as he puffed away on his pipe.
This is how he did it.
http://www.androcles01.pwp.blueyonder.co.uk/DominoEffect.GIF
The Great Newton and the Great Kepler deduced an equation describing
the change of planet angle not by a whim of Jehovah or Woden, but by
the effect of the gravitational field.
http://mathworld.wolfram.com/KeplersEquation.html
Solving that is beyond the capabilities of the Great Einstein, which is why
his nonsense concerning Mercury's advance of longitude of perhelion
is nonsense.
> And because both colliding electons
Elections only collide if they are voted on the same day. You'd be better
off voting for the lepton party.
All fine and dandy, but I'm not using that particular equation; it's not
relevant to this problem.
In any theory I can think of regarding variable lightspeed, one usually
ends up with the equation
KE = 1/2 m v^2.
As you've no doubt already noticed this is the exact same equation used
in Newtonian physics. While it is possible to add additional energy to
an electron ("ooh, magic!") in such theories, such would have to be
justified. Your above handwaving doesn't even come close.
If one combines KE with PE = mc^2, and has both electrons moving
at lightspeed, the total available energy is
TE = 3 * mc^2
(remember there are 2 electrons, smashing into one another).
The energy (or mass) of a tau is more like 3477 times that
of an electron at rest. Clearly, there's not enough energy
using this particular theory. Of course this is my strawman
theory; for all I know you've got magic gravity going in there.
Why does SR work? For starters, the energy available is
TE = 2 * gamma * mc^2
where m is the mass of the particle at rest, and
gamma = 1/sqrt(1-v^2/c^2). As v approaches 1, gamma can get
arbitrarily large -- and there's more than enough energy
if gamma = 1750, corresponding to a v of
about (1 - 1.633 * 10^-7) c.
It might be worth expanding this expression, using the
Binominal theorem.
gamma * mc^2 = mc^2 + 1/2 mv^2 + 3/8 mv^4/c^2 + 35/128 mv^6/c^4 + ...
Notice the second term. The third and subsequent terms usually vanish
(or are ignored) for v << c; for example, a horrific road collision
between two cars each going at 67 mph (30 m/s) might engender an error
of about 10^-14 by ignoring those terms. However, electrons can
obviously go a lot faster.
--
#191, ewi...@earthlink.net
/dev/signature: Not a text file
"The Ghost In The Machine" <ew...@sirius.tg00suus7038.net> wrote in message
news:8oh5g4-...@sirius.tg00suus7038.net...
So far Great Newton and Great Keppler concerns, I wish to provide a small
correction, namely, that Great Keppler had no idea about gravitation. He
only found equations describing the planetary orbits, without infinitesimal
calculus.
"Androcles" <Engi...@hogwarts.physics.co.uk> wrote in message
news:CHQXh.60754$aB1....@fe3.news.blueyonder.co.uk...
"Androcles" <Engi...@hogwarts.physics.co.uk> wrote in message
news:CHQXh.60754$aB1....@fe3.news.blueyonder.co.uk...
"kanuk" <sper...@shaw.ca> wrote in message
That's partly why the Great Newton developed calculus, but the Great
Kepler didn't need calculus to make empirical observations. The Great
Copernicus understood the Principle of Relativity, the Great Moron
Einstein denied it for light.
"Prominent theoretical physicists were therefore more inclined to reject the principle of relativity, in spite of the fact that no empirical data had been found which were contradictory to this principle." -- The Great |Idiot, 1920.
http://www.bartleby.com/173/7.html
http://www.androcles01.pwp.blueyonder.co.uk/PoR/PoR.htm
Fortunately the Great Sagnac proved the Great Loudmouth wrong whilst the Great Imbecile was pretending to be a physicist and mathematician in 1913.
http://www.androcles01.pwp.blueyonder.co.uk/Sagnac/Sagnac.htm
It's the squeaky wheel that gets greased, the other one runs on polytetrafluoroethylene bearings and gets you to your destination.
Consider:
A neutron has mass but no charge.
A proton has charge 1 and mass 1.
An electron has charge -1 as great as a proton.... but no mass.
"But of course it has mass", you say.
Does it? What's it made of?
The ancient Greeks argued that if you cut an apple in half
and then cut that in half again, eventually you'd arrive at a
piece of apple that you could not cut. They called that an atom.
Today we'd call it a molecule. Break into that to find atoms,
but there are much fewer types of atoms than molecules, just these:
http://www.webelements.com/
Break into an atom and the number of different parts is even less,
just three, neutrons, protons and electrons. Break those apart and
what are they made of? Quarks? Do they have mass?
Theory, that's all it amounts to, and nobody knows for sure.
The biggest idiots are those that pretend to know, Ghost is one
of them.
Why did you leave out the 'i' in election?
> "kanuk" <sper...@shaw.ca> wrote in message
> news:exXXh.131063$aG1.220@pd7urf3no...
> > Dear Androcles,
> > you have estimated very well my knowledge about elementary particles, as I
> > have some bleak ideas about what an electron and a proton are.
> >
> > So far Great Newton and Great Keppler concerns, I wish to provide a small
> > correction, namely, that Great Keppler had no idea about gravitation. He
> > only found equations describing the planetary orbits, without infinitesimal
> > calculus.
>
> That's partly why the Great Newton developed calculus,
But the Great Androfart didn't understand much of it, did he?
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/DiffConst.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Integral.html
http://users.telenet.be/vdmoortel/dirk/Physics/Fumbles/Limit.html
Dirk Vdm
Well, to tell the truth, I left out an "r", not "i". Maybe, that is one of
your errors, but no offence meant. We people are sometimes erring.
Oh I see, you left out an 'r' and it's my fault, I shod hae gesed hat ou eant.
I had a wife like you once.