What is the inertia of EM wave or field

[admformeto]

Mathew Orman

http://www.faster-than-light.us/

[papa...@gmail.com]

On 28 nov, 16:03, "admformeto" <admform...@onet.eu> wrote:
> Mathew Orman
>
> http://www.faster-than-light.us/

Another useless link and a strong candidate for the title of King of
Moronica

[micro...@hotmail.com]

The constant of the speed of light demonstrates its energy is not
kinetic. As all light waves would be of the same colour if their
energy were kinetic.

Mitchell Raemsch

[admformeto]

<micro...@hotmail.com> wrote in message
news:509f23fe-9da7-43d6...@z22g2000prd.googlegroups.com...

There is no kinetic energy in light or EM wave as the fields are mass-less.
The question is about inertia.

Mathew Orman

http://www.faster-than-light.us/

[John Larkin]

On Mon, 28 Nov 2011 21:38:57 +0100, "admformeto" <admfo...@onet.eu>
wrote:

Photons have momentum. Look it up.

John

[Bill Sloman]

On Nov 28, 8:53 pm, "microm2...@hotmail.com" <microm2...@hotmail.com>
wrote:

That argument doesn't work for ball-bearings compared with bowling
balls. Why should it work for photons?

--
Bill Sloman, Nijmegen

[Bill Sloman]

On Nov 28, 9:38 pm, "admformeto" <admform...@onet.eu> wrote:
> <microm2...@hotmail.com> wrote in message

>
> news:509f23fe-9da7-43d6...@z22g2000prd.googlegroups.com...
>
> > On Nov 28, 11:12 am, "papar...@gmail.com" <papar...@gmail.com> wrote:
> >> On 28 nov, 16:03, "admformeto" <admform...@onet.eu> wrote:
>
> >> > Mathew Orman
>
> >> >http://www.faster-than-light.us/
>
> >> Another useless link and a strong candidate for the title of King of
> >> Moronica
>
> > The constant of the speed of light demonstrates its energy is not
> > kinetic. As all light waves would be of the same colour if their
> > energy were kinetic.
>

> There is no kinetic energy in light or EM wave as the fields are mass-less.

There's energy associated with photons, and - as Einstein pointed out
- energy can be equated to mass. Photons may not have rest mass, but
if they were resting they wouldn't exist.

> The question is about inertia.

And photons have momentum and thus inertia. The question is ill-posed.

--
Bill Sloman, Nijmegen

[admformeto]

"John Larkin" <jjla...@highNOTlandTHIStechnologyPART.com> wrote in message
news:oh08d75p3e4gufh56...@4ax.com...

Yes, so they must also have inertia.

Mathew Orman

http://www.faster-than-light.us/

[admformeto]

"Bill Sloman" <bill....@ieee.org> wrote in message
news:05bffd74-5feb-4a80...@w1g2000vba.googlegroups.com...

Then how much inertia a photon has?

Mathew Orman

http://www.faster-than-light.us/

[mpm]

It's the "Dopeler Effect".
The ideas sound better the faster they come at you. :)

[PD]

On 11/28/2011 4:13 PM, admformeto wrote:
>

>>>
>>
>> Photons have momentum. Look it up.
>>
>> John
>>
>
> Yes, so they must also have inertia.

What do you think the relationship is between a photon's momentum and
its inertia?

[Tim Wescott]

On Mon, 28 Nov 2011 20:03:17 +0100, admformeto wrote:

> Mathew Orman
>
> http://www.faster-than-light.us/

Why are we feeding the troll?

--
My liberal friends think I'm a conservative kook.
My conservative friends think I'm a liberal kook.
Why am I not happy that they have found common ground?

Tim Wescott, Communications, Control, Circuits & Software
http://www.wescottdesign.com

[John Larkin]

On Mon, 28 Nov 2011 23:13:48 +0100, "admformeto" <admfo...@onet.eu>
wrote:

They have momentum but zero mass, and only exist at one speed. I don't
think it's meaningful to talk about their inertia.

John

[Chris Richardson]

On Mon, 28 Nov 2011 15:59:23 -0800, John Larkin wrote:

>
> They have momentum but zero mass, and only exist at one speed. I don't
> think it's meaningful to talk about their inertia.
>

No, but we can talk about the permitivity and permeability
of free space, which are properties that determine the EM
velocity in free space, and hence can conceptually be viewed
as an "inertia" (if we stretch things).

[ti...@physics.uq.edu.au]

On Mon, 28 Nov 2011, John Larkin wrote:

> On Mon, 28 Nov 2011 23:13:48 +0100, "admformeto" <admfo...@onet.eu>
> wrote:

>> "John Larkin" <jjla...@highNOTlandTHIStechnologyPART.com> wrote:
>>>
>>> Photons have momentum. Look it up.
>>

>> Yes, so they must also have inertia.
>
> They have momentum but zero mass, and only exist at one speed. I don't
> think it's meaningful to talk about their inertia.

Perfectly meaningful. What impulse (i.e., F*t) is needed to change the
velocity? Consider, for example, reflection changing the direction of the
velocity by 180 degrees. What is the impulse?

With this meaning of inertia, we have "inertia" = "momentum". (Not just
for light, but generally.)

Or we could talk about the "inertial mass", which is the total energy
expressed in units of mass. (Again, not just for light, but generally.)

Both of these meanings are used.

So it's meaningful to talk about inertia of light, but perhaps only if one
first defines what one means by "inertia".

[admformeto]

<ti...@physics.uq.edu.au> wrote in message
news:alpine.LNX.2.00.1...@kolmogorov.physics.uq.edu.au...

Now, the question is how large is inertia of a photon?
Is it wavelength dependent?

Mathew Orman

http://www.faster-than-light.us/

[ti...@physics.uq.edu.au]

On Tue, 29 Nov 2011, admformeto wrote:
> <ti...@physics.uq.edu.au> wrote:
>> On Mon, 28 Nov 2011, John Larkin wrote:
>>> On Mon, 28 Nov 2011 23:13:48 +0100, "admformeto" <admfo...@onet.eu>
>>> wrote:
>>>> "John Larkin" <jjla...@highNOTlandTHIStechnologyPART.com> wrote:
>>>>>
>>>>> Photons have momentum. Look it up.
>>>>
>>>> Yes, so they must also have inertia.
>>>
>>> They have momentum but zero mass, and only exist at one speed. I don't
>>> think it's meaningful to talk about their inertia.
>>
>> Perfectly meaningful. What impulse (i.e., F*t) is needed to change the
>> velocity? Consider, for example, reflection changing the direction of the
>> velocity by 180 degrees. What is the impulse?
>>
>> With this meaning of inertia, we have "inertia" = "momentum". (Not just for
>> light, but generally.)
>>
>> Or we could talk about the "inertial mass", which is the total energy
>> expressed in units of mass. (Again, not just for light, but generally.)
>>
>> Both of these meanings are used.
>>
>> So it's meaningful to talk about inertia of light, but perhaps only if one
>> first defines what one means by "inertia".
>
> Now, the question is how large is inertia of a photon?
> Is it wavelength dependent?

Classically, the inertia of light only depends on the energy, p=E/c for a
plane wave in free space, a nice 19th century result (Maxwell 1873, Umov
1874, Bartoli 1876, followed by Heaviside, Poynting, etc.), which is in
all the good classical EM books (see, e.g., Jackson, Stratton, Landau &
Lifshitz).

Quantumly, the number of photons per unit energy depends on the
wavelength, so we see that the inertia per photon depends on the
wavelength. The result is, of course, the very well-known p = hbar * k.
Which is in all the good quantum books.

[micro...@hotmail.com]

On Nov 28, 12:38 pm, "admformeto" <admform...@onet.eu> wrote:
> <microm2...@hotmail.com> wrote in message

Inertia is perpetual motion. There is no absolute rest.
It can be linear or circular.

Mitch Raemsch; the prize

>
> Mathew Orman
>
> http://www.faster-than-light.us/

[admformeto]

<ti...@physics.uq.edu.au> wrote in message
news:alpine.LNX.2.00.1...@kolmogorov.physics.uq.edu.au...

Thank you.
I guess it is assumed to be a scalar value and not related to direction of
propagation.

Mathew Orman

http://www.faster-than-light.us/

[John Fields]

On Mon, 28 Nov 2011 15:59:23 -0800, John Larkin

<jjla...@highNOTlandTHIStechnologyPART.com> wrote:

>On Mon, 28 Nov 2011 23:13:48 +0100, "admformeto" <admfo...@onet.eu>
>wrote:

>>"John Larkin" <jjla...@highNOTlandTHIStechnologyPART.com> wrote in message
>>news:oh08d75p3e4gufh56...@4ax.com...

>>> Photons have momentum. Look it up.
>>>
>>> John
>>>
>>
>>Yes, so they must also have inertia.
>
>They have momentum but zero mass,

---
Only at rest, so your argument is specious.
---

>and only exist at one speed.

---
Not true, otherwise Cherenkov radiation couldn't exist.
---

>I don't think it's meaningful to talk about their inertia.

---
Think about the different colors that photons can carry, and their
resultant inertia, and you might get a clue about why Einstein won the
Nobel prize for photoelectricity and why you're, well, on the trailing
edge of things.

--
JF

[Mark]

> >>Yes, so they must also have inertia.
>
> >They have momentum but zero mass,
>

>

I have had one of these on my window sill since i was a kid..

http://en.wikipedia.org/wiki/Radiometer

Mark

[John Larkin]

On Mon, 28 Nov 2011 19:27:55 -0600, John Fields
<jfi...@austininstruments.com> wrote:

>On Mon, 28 Nov 2011 15:59:23 -0800, John Larkin
><jjla...@highNOTlandTHIStechnologyPART.com> wrote:
>
>>On Mon, 28 Nov 2011 23:13:48 +0100, "admformeto" <admfo...@onet.eu>
>>wrote:
>
>>>"John Larkin" <jjla...@highNOTlandTHIStechnologyPART.com> wrote in message
>>>news:oh08d75p3e4gufh56...@4ax.com...
>
>>>> Photons have momentum. Look it up.
>>>>
>>>> John
>>>>
>>>
>>>Yes, so they must also have inertia.
>>
>>They have momentum but zero mass,
>
>---
>Only at rest, so your argument is specious.

Photons at rest? How do you manage that?

>---
>
>>and only exist at one speed.
>
>---
>Not true, otherwise Cherenkov radiation couldn't exist.
>---
>
>>I don't think it's meaningful to talk about their inertia.
>
>---
>Think about the different colors that photons can carry, and their
>resultant inertia, and you might get a clue about why Einstein won the
>Nobel prize for photoelectricity and why you're, well, on the trailing
>edge of things.

OK, what is the inertia of, say, a 500 nm photon? And what are the
engineering units of same?


John

[John Larkin]

On Mon, 28 Nov 2011 18:30:56 -0800 (PST), Mark <mako...@yahoo.com>
wrote:

But they spin backwards!

John

[alie...@gmail.com]

On Nov 28, 11:03 am, "admformeto" <admform...@onet.eu> wrote:
> Mathew Orman

EM waves don't have linear inertia but they do have "rotational
inertia" AKA angular momentum.

> http://www.faster-than-light.us/

Launching in only negative three days!


Mark L. Fergerson

[George Herold]

On Nov 28, 9:35 pm, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> On Mon, 28 Nov 2011 18:30:56 -0800 (PST), Mark <makol...@yahoo.com>

> wrote:
>
>
>
> >> >>Yes, so they must also have inertia.
>
> >> >They have momentum but zero mass,
>
> >I have had one of these on my window sill since i was a kid..
>
> >http://en.wikipedia.org/wiki/Radiometer
>
> >Mark
>
> But they spin backwards!
>
> John

"Let's not get started on radiometer's".. (fanning the flames.)

There's all this theory about holes in the vanes... but no real data!

Perhaps someone could write an NSF grant?

George H.

[Tim Williams]

"John Larkin" <jjla...@highNOTlandTHIStechnologyPART.com> wrote in

message news:grg8d7hi5a7bcj70l...@4ax.com...

> OK, what is the inertia of, say, a 500 nm photon? And what are the
> engineering units of same?

Well, if one wanted to be perfectly obtuse...
https://www.google.com/search?q=planck%27s+constant+%2F+%28500+nanometers+*+speed+of+light%29
4.42 x 10^-36 kg

Quantum spin is in units of hbar, which is J.s = kg.m^2 / s, angular
momentum. Inertia is kg.m^2, so a quantity of 1/s (exactly, angular
frequency) is required. This would ordinarily be the rotation frequency
of the object, but a photon isn't exactly a spherical chicken, with a
well-defined shape and [angular] velocity. It's questionable whether one
could use the frequency itself here (i.e., c / lambda = 600THz); a freely
propagating photon tends to be a linearly oscillating phenomenon, but it
also does a fine job oscillating in place if confined to a resonator, so
it might not be too horrible.
https://www.google.com/search?q=planck%27s+constant+*+500+nm+%2F+speed+of+light
1.1 x 10^-48 kg.m^2

Moments of inertia of geometric shapes have the form I = a * MR^2, where
/a/ depends on the mass distribution. If we use the wavelength as the
radius and this inertia, we get a = 1, which shouldn't be surprising as:

I = a * MR^2
and
I = k * lambda / c
M = k / (lambda * c)
R = lambda

k * lambda a * k * lambda^2
------------ = ------------------
c lambda * c

a = 1, basically what we started with.

At best, this implies that all the photon's angular momentum is carried on
the periphery (a thin ring or hoop spinning on axis).

Tim

--
Deep Friar: a very philosophical monk.
Website: http://webpages.charter.net/dawill/tmoranwms

[John Larkin]

On Mon, 28 Nov 2011 22:14:31 -0600, "Tim Williams"
<tmor...@charter.net> wrote:

>"John Larkin" <jjla...@highNOTlandTHIStechnologyPART.com> wrote in
>message news:grg8d7hi5a7bcj70l...@4ax.com...
>> OK, what is the inertia of, say, a 500 nm photon? And what are the
>> engineering units of same?
>
>Well, if one wanted to be perfectly obtuse...
>https://www.google.com/search?q=planck%27s+constant+%2F+%28500+nanometers+*+speed+of+light%29
>4.42 x 10^-36 kg

"Inertia" is usually considered to be synonymous with mass. But mass
is an official SI unit, and inertia is not. Photons are accepted to
have zero mass.

John

[Sam Wormley]

How are permittivity and permeability related to the non-inertia
of a massless photon?
http://en.wikipedia.org/wiki/Permeability_(electromagnetism)
http://en.wikipedia.org/wiki/Vacuum_permittivity

[Sam Wormley]

On 11/28/11 6:39 PM, admformeto wrote:
> Now, the question is how large is inertia of a photon?
> Is it wavelength dependent?
>
> Mathew Orman

Photons have no inertial mass.

Photon momentum
p = hν/c = h/λ

Photon Energy
E = hν

[Y.Porat]

-------------------
The relationship is
mass of photons !!!

MASS - THE ONLY MASS THAT EXIST !!
THE PHOTON HAS MASS !!
not relativistic ans nor schmelativistic mass!

NO MASS - THE ONLY MASS -
NO REAL PHYSICS !!!

NOT INERTIA AND NOT SCHMINERTIA
INERTIA IS A RESULT OF MASS !!

got it incurable walking blockhead DAMAGE CROOK ??
a damage to advance oF science !!

Y.Porat
-------------------------

[Chris Richardson]

On Mon, 28 Nov 2011 22:48:59 -0600, Sam Wormley wrote:

>
> How are permittivity and permeability related to the non-inertia
> of a massless photon?
>

The OP does not ask about photons, but about EM waves.

Since the permittivity and permeability of free space
determine the velocity of EM waves, we may want to look
upon these parameters as a kind of inertia. As I said,
it is a bit of a stretch, so don't treat this too seriously.
My purpose was to stimulate some thought on the matter
from the classical viewpoint.

[Y.Porat]

On Nov 29, 9:18 am, Chris Richardson <r...@localhost.localdomain>
wrote:

------------------
some news for you

Em waves IS COMPOSED OF PHOTONS !!
indeed a huge number of them
but still photons !!
and if you dont understand the basics
ie
th e photons
you have no chance to understand thoroughly
youre EM waves !!

ATB
Y.Porat
------------------------

[John Devereux]

Tim Wescott <t...@seemywebsite.com> writes:

> On Mon, 28 Nov 2011 20:03:17 +0100, admformeto wrote:
>
>> Mathew Orman
>>

>> http://www.ftlscams-r.us/

>
> Why are we feeding the troll?

He is still patiently planting links to his web site in the google
archives. Where he will shortly make available for sale his
faster-than-light cables to any gullible fool that will buy them.

(He even admits the MkI models he was selling before did not work, but
*this* time...)

--

John Devereux

[Bill Sloman]

On Nov 29, 12:59 am, John Larkin
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> On Mon, 28 Nov 2011 23:13:48 +0100, "admformeto" <admform...@onet.eu>
> wrote:
>
>
>
>
>
>
>
>
>
>
>
> >"John Larkin" <jjlar...@highNOTlandTHIStechnologyPART.com> wrote in message
> >news:oh08d75p3e4gufh56...@4ax.com...
> >> On Mon, 28 Nov 2011 21:38:57 +0100, "admformeto" <admform...@onet.eu>
> >> wrote:
>
> >>><microm2...@hotmail.com> wrote in message

> >>>news:509f23fe-9da7-43d6...@z22g2000prd.googlegroups.com...
> >>>> On Nov 28, 11:12 am, "papar...@gmail.com" <papar...@gmail.com> wrote:
> >>>>> On 28 nov, 16:03, "admformeto" <admform...@onet.eu> wrote:
>
> >>>>> > Mathew Orman
>
> >>>>> >http://www.faster-than-light.us/
>
> >>>>> Another useless link and a strong candidate for the title of King of
> >>>>> Moronica
>
> >>>> The constant of the speed of light demonstrates its energy is not
> >>>> kinetic. As all light waves would be of the same colour if their
> >>>> energy were kinetic.
>
> >>>> Mitchell Raemsch
>
> >>>There is no kinetic energy in light or EM wave as the fields are
> >>>mass-less.
> >>>The question is about inertia.
>
> >>>Mathew Orman
>
> >>>http://www.faster-than-light.us/
>
> >> Photons have momentum. Look it up.
>

> >Yes, so they must also have inertia.
>
> They have momentum but zero mass, and only exist at one speed. I don't
> think it's meaningful to talk about their inertia.

Their mass isn't zero - e=mc^2 - though their rest mass is zero. And
the speed of propagation of electromagnetic radiation varies with the
medium through which the radiation is propagating, so there is some -
transient - momentum transfer (think light pressure and solar sails),
which makes their inertia a meaningful concept.

--
Bill Sloman, Nijmegen

[Bill Sloman]

On Nov 29, 5:43 am, John Larkin

<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
> On Mon, 28 Nov 2011 22:14:31 -0600, "Tim Williams"
>

> <tmoran...@charter.net> wrote:
> >"John Larkin" <jjlar...@highNOTlandTHIStechnologyPART.com> wrote in

> >messagenews:grg8d7hi5a7bcj70l...@4ax.com...

> >> OK, what is the inertia of, say, a 500 nm photon? And what are the
> >> engineering units of same?
>
> >Well, if one wanted to be perfectly obtuse...

> >https://www.google.com/search?q=planck%27s+constant+%2F+%28500+nanome...

> >4.42 x 10^-36 kg
>
> "Inertia" is usually considered to be synonymous with mass. But mass
> is an official SI unit, and inertia is not. Photons are accepted to
> have zero mass.

Zero *rest* mass. Remember that e=mc^2 works both ways.

--
Bill Sloman, Nijmegen

[Jamie]

John Devereux wrote:

> Tim Wescott <t...@seemywebsite.com> writes:
>
>
>>On Mon, 28 Nov 2011 20:03:17 +0100, admformeto wrote:
>>
>>
>>>Mathew Orman
>>>
>>>http://www.ftlscams-r.us/
>>
>>Why are we feeding the troll?
>
>
> He is still patiently planting links to his web site in the google
> archives. Where he will shortly make available for sale his
> faster-than-light cables to any gullible fool that will buy them.

Damn, I wish I knew that earlier !

> (He even admits the MkI models he was selling before did not work, but
> *this* time...)
>

Jamie

[Jamie]

You were successful in one respect, you've stimulated a lot of
people but have not come away with any better results than
our country receiving stimulus packages.

Jamie

[PD]

On 11/29/2011 1:14 AM, Y.Porat wrote:
> On Nov 29, 12:38 am, PD<thedraperfam...@gmail.com> wrote:
>> On 11/28/2011 4:13 PM, admformeto wrote:
>>
>>
>>
>>>> Photons have momentum. Look it up.
>>
>>>> John
>>
>>> Yes, so they must also have inertia.
>>
>> What do you think the relationship is between a photon's momentum and
>> its inertia?
>
> -------------------
> The relationship is
> mass of photons !!!
>

What is the QUANTITATIVE relationship between the amount of a photon's
momentum and it's inertia. That is, give me a method by which, from a
value for the photon's momentum, I can calculate its inertia, or vice versa.

Do you know what "relationship" means in physics?

[PD]

On 11/28/2011 7:18 PM, admformeto wrote:
>
>
> <ti...@physics.uq.edu.au> wrote in message
> news:alpine.LNX.2.00.1...@kolmogorov.physics.uq.edu.au...

>>

>> Classically, the inertia of light only depends on the energy, p=E/c
>> for a plane wave in free space, a nice 19th century result (Maxwell
>> 1873, Umov 1874, Bartoli 1876, followed by Heaviside, Poynting, etc.),
>> which is in all the good classical EM books (see, e.g., Jackson,
>> Stratton, Landau & Lifshitz).
>>
>> Quantumly, the number of photons per unit energy depends on the
>> wavelength, so we see that the inertia per photon depends on the
>> wavelength. The result is, of course, the very well-known p = hbar *
>> k. Which is in all the good quantum books.
>
> Thank you.
> I guess it is assumed to be a scalar value and not related to direction
> of propagation.
>

Not so. Classically, the Poynting vector is a vector, and quantumly the
variable k is a vector.

[Phil Hobbs]

On 11/28/2011 05:13 PM, admformeto wrote:
>
>
> "John Larkin" <jjla...@highNOTlandTHIStechnologyPART.com> wrote in
> message news:oh08d75p3e4gufh56...@4ax.com...
>> On Mon, 28 Nov 2011 21:38:57 +0100, "admformeto" <admfo...@onet.eu>
>> wrote:
>>
>>>
>>>
>>> <micro...@hotmail.com> wrote in message

>>> news:509f23fe-9da7-43d6...@z22g2000prd.googlegroups.com...
>>>
>>>> On Nov 28, 11:12 am, "papar...@gmail.com" <papar...@gmail.com> wrote:
>>>>> On 28 nov, 16:03, "admformeto" <admform...@onet.eu> wrote:
>>>>>
>>>>> > Mathew Orman
>>>>>
>>>>> >http://www.faster-than-light.us/
>>>>>
>>>>> Another useless link and a strong candidate for the title of King of
>>>>> Moronica
>>>>
>>>> The constant of the speed of light demonstrates its energy is not
>>>> kinetic. As all light waves would be of the same colour if their
>>>> energy were kinetic.
>>>>
>>>> Mitchell Raemsch
>>>
>>> There is no kinetic energy in light or EM wave as the fields are
>>> mass-less.
>>> The question is about inertia.
>>>
>>> Mathew Orman
>>>
>>> http://www.faster-than-light.us/
>>>
>>

>> Photons have momentum. Look it up.
>>
>> John
>>
>
> Yes, so they must also have inertia.
>

> Mathew Orman
>
> http://www.faster-than-light.us/
>
>

What isn't meaningful is talking about photons as though they had a
separate existence, whereas they're just elementary excitations of the
EM field in a given set of boundary conditions.

EM fields have momentum and inertia--in fact the field's momentum
density is proportional to the refractive index, so if you shine a
flashlight on a glass surface, the reflected light pushes on the glass,
but the transmitted light _pulls_ on the glass. This effect was first
measured in the 1950s by R. V. Jones (one of my technical heroes) using
light bulbs and an optical lever. This is quite different from the
optical tweezers effect because it works even with plane waves, but it
isn't very big.

What makes photon drives such a losing proposition is that the
energy-to-momentum ratio of the electromagnetic field is so very big, so
it costs a ridiculous amount of power to get a tiny thrust.

(For EM fields, E=pc, whereas for matter at nonrelativistic speed, E =
p**2/(2M). The difference is a factor of 2c/v, which for a rocket with
an exhaust velocity of 4 km/s amounts to a factor of 150,000 penalty for
the electromagnetic drive versus a rocket.

As Jones says, the radiation pressure of sunlight is about equal to the
weight of one atomic layer's worth of the Earth's crust. _Not_ a big effect.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics

160 North State Road #203
Briarcliff Manor NY 10510
845-480-2058

hobbs at electrooptical dot net
http://electrooptical.net

[Phil Hobbs]

A body moving at relativistic speed effectively has a higher mass than
one at rest. (There are big-endian and little-endian schools of thought
on whether or not to call that a velocity dependent mass m =
m_0*gamma, where m_0 is the rest mass and gamma is 1/sqrt(1-v**2/c**2).)

[PD]

On 11/29/2011 12:58 PM, Phil Hobbs wrote:

>
> What isn't meaningful is talking about photons as though they had a
> separate existence, whereas they're just elementary excitations of the
> EM field in a given set of boundary conditions.
>
> EM fields have momentum and inertia--in fact the field's momentum
> density is proportional to the refractive index, so if you shine a
> flashlight on a glass surface, the reflected light pushes on the glass,
> but the transmitted light _pulls_ on the glass. This effect was first
> measured in the 1950s by R. V. Jones (one of my technical heroes) using
> light bulbs and an optical lever. This is quite different from the
> optical tweezers effect because it works even with plane waves, but it
> isn't very big.
>
> What makes photon drives such a losing proposition is that the
> energy-to-momentum ratio of the electromagnetic field is so very big, so
> it costs a ridiculous amount of power to get a tiny thrust.
>
> (For EM fields, E=pc, whereas for matter at nonrelativistic speed, E =
> p**2/(2M). The difference is a factor of 2c/v, which for a rocket with
> an exhaust velocity of 4 km/s amounts to a factor of 150,000 penalty for
> the electromagnetic drive versus a rocket.
>
> As Jones says, the radiation pressure of sunlight is about equal to the
> weight of one atomic layer's worth of the Earth's crust. _Not_ a big
> effect.
>
> Cheers
>
> Phil Hobbs
>

Excellent post, thank you.

[Timo Nieminen]

On Nov 30, 4:58 am, Phil Hobbs

<pcdhSpamMeSensel...@electrooptical.net> wrote:
>
> but the transmitted light _pulls_ on the glass.  This effect was first
> measured in the 1950s by R. V. Jones (one of my technical heroes) using
> light bulbs and an optical lever.  This is quite different from the
> optical tweezers effect because it works even with plane waves, but it
> isn't very big.

Jones's work was excellent; he was clearly one of the top physicists
of the era. Perhaps he gets less attention than he deserves, since he
was an applied physicist. As the example at hand shows, even applied
physicists can do fundamental stuff. Jones's papers on this topic make
for some excellent (technical) science reading:

Jones, R. V., 1951, Nature (London) 167, 439.
Jones, R. V., and J. C. S. Richards, 1954, Proc. R. Soc. London, Ser.
A 221, 480.
Jones, R. V., and B. Leslie, 1978, Proc. R. Soc. London, Ser. A 360,
347.
Jones, R. V., 1978, Proc. R. Soc. London, Ser. A 360, 365.

> What makes photon drives such a losing proposition is that the
> energy-to-momentum ratio of the electromagnetic field is so very big, so
> it costs a ridiculous amount of power to get a tiny thrust.

Acoustics (with the lower wave speed) is much friendlier this way. But
even worse than EM waves for space flight!

[Phil Hobbs]

;)

After some years of looking (mostly using the automatic 'want' list on
ABEBooks), I finally got a copy of Jones's "Instruments and
Experiences", which reprints his papers and adds about an equal length
of discussions that are very valuable for instrument builders. Highly
recommended if you can find a copy.

"The Wizard War", which is about his WWII experience as the Chief of
Scientific Intelligence, and his work in countering the German
radionavigation beams, is also amazing. (In the UK it's called "Most
Secret War".)

[Rock Brentwood]

On Nov 28, 1:12 pm, "papar...@gmail.com" <papar...@gmail.com> wrote:
> On 28 nov, 16:03, "admformeto" <admform...@onet.eu> wrote:
>
> > Mathew Orman
>
> >http://www.faster-than-light.us/
>
> Another useless link and a strong candidate for the title of King of
> Moronica

Haven't there been protests in the streets over there yet against the
undemocratic nature of the royalty? You'd expect the Arab Spring/
Occupy movement (which is really all just two outcroppings of one
movement) would have spread over there and would be leading to a Brain
Spring to complement the Arab Spring.

[Y.Porat]

--------------------
P photon is =hf /lambda
ie

hf/lambda= E /lambda = P

P times lambda/c^2 =mass of phootn
if i ddinr flop the algebra
but here goes the catch
that i am always talk about

E hf
is not the formula of a real singe photon!!
it is a huge number of single photon
ans you dont know hoe many single phtons are there
now
IF YOU WILL REMEMBER MY HISTORIC SUGGESTION
ie
to insert instesd in my formula
E minimum =hf times n etc etc
if we insert for n
THE SCALAR PAERT OF PLANCK TIME
YOU WILL GET HOW MANY SINGLE PHOTONS ARE THERE
AND YOU WILL FIND THE MASS
OF A REAL SINGLE PHOTON
JUST FO R GETTING AN IDEA

according to my above suggestion is
the mass of the real single photon
is about
exp -90 KILOGRAMS
and now you understand why you parrot
that the mas of the photon is zero !!

excuse my floppy typing
i am now watching a basketball game
(:-)

Y.Porat
-----------------------





P times lambda = E

[PD]

On 12/1/2011 2:05 PM, Y.Porat wrote:

>>
>> What is the QUANTITATIVE relationship between the amount of a photon's
>> momentum and it's inertia. That is, give me a method by which, from a
>> value for the photon's momentum, I can calculate its inertia, or vice versa.
>>
>> Do you know what "relationship" means in physics?
>
> --------------------
> P photon is =hf /lambda

Nope. Try again. You can look this up. It's easy. I know you can do it.

[George Herold]

On Nov 29, 3:04 pm, Phil Hobbs

It'd be great if someone would reprint it.

George H.

>
> "The Wizard War", which is about his WWII experience as the Chief of
> Scientific Intelligence, and his work in countering the German
> radionavigation beams, is also amazing.  (In the UK it's called "Most
> Secret War".)
>
> Cheers
>
> Phil Hobbs
>
> --
> Dr Philip C D Hobbs
> Principal Consultant
> ElectroOptical Innovations LLC
> Optics, Electro-optics, Photonics, Analog Electronics
>
> 160 North State Road #203
> Briarcliff Manor NY 10510
> 845-480-2058
>

> hobbs at electrooptical dot nethttp://electrooptical.net- Hide quoted text -
>
> - Show quoted text -

[George Herold]

On Nov 29, 1:58 pm, Phil Hobbs

<pcdhSpamMeSensel...@electrooptical.net> wrote:
> On 11/28/2011 05:13 PM, admformeto wrote:
>
>
>
>
>
>
>

> > "John Larkin" <jjlar...@highNOTlandTHIStechnologyPART.com> wrote in
> > messagenews:oh08d75p3e4gufh56...@4ax.com...
> >> On Mon, 28 Nov 2011 21:38:57 +0100, "admformeto" <admform...@onet.eu>
> >> wrote:
>
> >>> <microm2...@hotmail.com> wrote in message

That's pretty cool. As the light goes through the glass the light
slows down,
loss of momentum. For momentum conservation the glass has to make up
for the loss.
He must have used some high index piece of material. I assume this is
in his book.
(I must have missed it on the first reading.)

George H.

This effect was first
> measured in the 1950s by R. V. Jones (one of my technical heroes) using
> light bulbs and an optical lever.  This is quite different from the
> optical tweezers effect because it works even with plane waves, but it
> isn't very big.
>
> What makes photon drives such a losing proposition is that the
> energy-to-momentum ratio of the electromagnetic field is so very big, so
> it costs a ridiculous amount of power to get a tiny thrust.
>
> (For EM fields, E=pc, whereas for matter at nonrelativistic speed, E =
> p**2/(2M).  The difference is a factor of 2c/v, which for a rocket with
> an exhaust velocity of 4 km/s amounts to a factor of 150,000 penalty for
> the electromagnetic drive versus a rocket.
>
> As Jones says, the radiation pressure of sunlight is about equal to the
> weight of one atomic layer's worth of the Earth's crust. _Not_ a big effect.
>
> Cheers
>
> Phil Hobbs
>
> --
> Dr Philip C D Hobbs
> Principal Consultant
> ElectroOptical Innovations LLC
> Optics, Electro-optics, Photonics, Analog Electronics
>
> 160 North State Road #203
> Briarcliff Manor NY 10510
> 845-480-2058
>

[micro...@hotmail.com]

On Nov 28, 12:38 pm, "admformeto" <admform...@onet.eu> wrote:
> <microm2...@hotmail.com> wrote in message
>
> news:509f23fe-9da7-43d6...@z22g2000prd.googlegroups.com...
>
> > On Nov 28, 11:12 am, "papar...@gmail.com" <papar...@gmail.com> wrote:
> >> On 28 nov, 16:03, "admformeto" <admform...@onet.eu> wrote:
>
> >> > Mathew Orman
>
> >> >http://www.faster-than-light.us/
>
> >> Another useless link and a strong candidate for the title of King of
> >> Moronica
>
> > The constant of the speed of light demonstrates its energy is not
> > kinetic. As all light waves would be of the same colour if their
> > energy were kinetic.
>
> > Mitchell Raemsch
>
> There is no kinetic energy in light or EM wave as the fields are mass-less.
> The question is about inertia.
>
> Mathew Orman
>
> http://www.faster-than-light.us/

The Earth's Matter's rotation is an example of inertia of perpetual
motion. If there is no absolute rest then all inertia is perpetual
motion.

Mitch Raemsch

[Timo Nieminen]

On Dec 3, 10:16 am, George Herold <gher...@teachspin.com> wrote:
> On Nov 29, 1:58 pm, Phil Hobbs
>

> > EM fields have momentum and inertia--in fact the field's momentum
> > density is proportional to the refractive index, so if you shine a
> > flashlight on a glass surface, the reflected light pushes on the glass,
> > but the transmitted light _pulls_ on the glass.
>
> That's pretty cool.  As the light goes through the glass the light
> slows down,
> loss of momentum.   For momentum conservation the glass has to make up
> for the loss.

It gains momentum. The light isn't a massive object, with momentum
proportional to velocity; it's a wave, and we have momentum = power/
speed.

> He must have used some high index piece of material. I assume this is
> in his book.

Mirror immersed in liquid (with index > 1).