Excerpt from Strobel's Astronomy Notes.
http://www.astronomynotes.com/relativity/s3.htm


"Part of Einstein's genius was his ability to look at ordinary things
from a whole new perspective and logically follow through on the
consequence of the insights he gained from his new perspective.

He proposed an experiment involving two elevators:

one at rest on the ground on the Earth and another, far out in space
away from any planet, moon, or star, accelerating upward with an
acceleration equal to that of one Earth gravity (9.8 meters/second2).
(Modern readers can substitute ``rocket ship'' for Einstein's
elevator.)

If a ball is dropped in the elevator at rest on the Earth, it will
accelerate toward the floor with an acceleration of 9.8 meters/
second2.
A ball released in the upward accelerating elevator far out in space
will also accelerate toward the floor at 9.8 meters/second2.

The two elevator experiments get the same result!"

Einstein was wrong:

The two elevator experiments don't get the same result!

When photons emitted from the top of the elevator are measured
at the bottom, their wavelengths are blue-shifted when the elevator is
at rest on the Earth (cf. the Pound-Rebka experiment), wheras their
wavelengths are not shifted at all when the elevator is far out
in space away from any planet, moon, or star, but accelerating upward
with an acceleration equal to that of one Earth gravity.

Marcel Luttgens

Dear mluttgens:

wrote in message
oups.com...
....
The two elevator experiments don't get the same
result!

When photons emitted from the top of the elevator
are measured at the bottom, their wavelengths are
blue-shifted when the elevator is at rest on the
Earth (cf. the Pound-Rebka experiment), wheras
their wavelengths are not shifted at all when the
elevator is far out in space away from any planet,
moon, or star, but accelerating upward with an
acceleration equal to that of one Earth gravity.

Yes, they can get the same result, if the gravitating body is
much larger than the volume of the elevator.

Firstly, light received by a kinetically accelerating object
still has velocity, and so will still have (relativistic) Doppler
shift. So your claim that "wavelengths are not shifted at all"
is clearly false.

Secondly, observations of other processes, making assumptions
about things elsewhere, violates the reason that Galileo's
enclosed cabin, Einstein's railroad car, and the elevator car
were chosen. You are supposed to concerned with local physics.
The walls are supposed to be opaque. The only concern, what is
in the enclosed space, and what physics you can test there. Do
you think that light speed will be different between your
external stellar source and an internal one (remembering that all
light speed measurements are TWLS)?

David A. Smith

On 16 mar, 07:05, wrote:
Excerpt from Strobel's Astronomy Notes.http://www.astronomynotes.com/relativity/s3.htm

"Part of Einstein's genius was his ability to look at ordinary things
from a whole new perspective and logically follow through on the
consequence of the insights he gained from his new perspective.

He proposed an experiment involving two elevators:

one at rest on the ground on the Earth and another, far out in space
away from any planet, moon, or star, accelerating upward with an
acceleration equal to that of one Earth gravity (9.8 meters/second2).
(Modern readers can substitute ``rocket ship'' for Einstein's
elevator.)

If a ball is dropped in the elevator at rest on the Earth, it will
accelerate toward the floor with an acceleration of 9.8 meters/
second2.
A ball released in the upward accelerating elevator far out in space
will also accelerate toward the floor at 9.8 meters/second2.

The two elevator experiments get the same result!"

Einstein was wrong:

The two elevator experiments don't get the same result!

When photons emitted from the top of the elevator are measured
at the bottom, their wavelengths are blue-shifted when the elevator is
at rest on the Earth (cf. the Pound-Rebka experiment), wheras their
wavelengths are not shifted at all when the elevator is far out
in space away from any planet, moon, or star, but accelerating upward
with an acceleration equal to that of one Earth gravity.

Marcel Luttgens

I think you forgot to take into account the Doppler effect. In the
space inertial frame where the light is emitted at the top, the
receptor at the botton receives the light at a some higher velocity
than the emitter one, producing the same blue-shift than in Earth.

RVHG

wrote in message oups.com...
On 16 mar, 07:05, wrote:
Excerpt from Strobel's Astronomy Notes.http://www.astronomynotes.com/relativity/s3.htm

"Part of Einstein's genius was ...

.... he didn't have any.

http://www.androcles01.pwp.blueyonder.co.uk/SR.GIF

wrote in message oups.com...

Luttgens is back!
At last!

Excerpt from Strobel's Astronomy Notes.
http://www.astronomynotes.com/relativity/s3.htm


"Part of Einstein's genius was his ability to look at ordinary things
from a whole new perspective and logically follow through on the
consequence of the insights he gained from his new perspective.

He proposed an experiment involving two elevators:

one at rest on the ground on the Earth and another, far out in space
away from any planet, moon, or star, accelerating upward with an
acceleration equal to that of one Earth gravity (9.8 meters/second2).
(Modern readers can substitute ``rocket ship'' for Einstein's
elevator.)

If a ball is dropped in the elevator at rest on the Earth, it will
accelerate toward the floor with an acceleration of 9.8 meters/
second2.
A ball released in the upward accelerating elevator far out in space
will also accelerate toward the floor at 9.8 meters/second2.

The two elevator experiments get the same result!"

Einstein was wrong:

The two elevator experiments don't get the same result!

When photons emitted from the top of the elevator are measured
at the bottom, their wavelengths are blue-shifted when the elevator is
at rest on the Earth (cf. the Pound-Rebka experiment), wheras their
wavelengths are not shifted at all when the elevator is far out
in space away from any planet, moon, or star, but accelerating upward
with an acceleration equal to that of one Earth gravity.

Of course they are shifted. When the light was emitted at the ceiling,
the floor had a smaller velocity than when the light was received
because the craft is accelerating and therefor the floor changed its
velocity during the time of flight of the light.

Luttgens was wrong.
Always been and always will be.

Dirk Vdm

On Mar 16, 3:14 pm, "Dirk Van de moortel" dirkvandemoor...@ThankS-NO-
SperM.hotmail.com wrote:
wrote in ooglegroups.com...

Luttgens is back!
At last!





Excerpt from Strobel's Astronomy Notes.
http://www.astronomynotes.com/relativity/s3.htm

"Part of Einstein's genius was his ability to look at ordinary things
from a whole new perspective and logically follow through on the
consequence of the insights he gained from his new perspective.

He proposed an experiment involving two elevators:

one at rest on the ground on the Earth and another, far out in space
away from any planet, moon, or star, accelerating upward with an
acceleration equal to that of one Earth gravity (9.8 meters/second2).
(Modern readers can substitute ``rocket ship'' for Einstein's
elevator.)

If a ball is dropped in the elevator at rest on the Earth, it will
accelerate toward the floor with an acceleration of 9.8 meters/
second2.
A ball released in the upward accelerating elevator far out in space
will also accelerate toward the floor at 9.8 meters/second2.

The two elevator experiments get the same result!"

Einstein was wrong:

The two elevator experiments don't get the same result!

When photons emitted from the top of the elevator are measured
at the bottom, their wavelengths are blue-shifted when the elevator is
at rest on the Earth (cf. the Pound-Rebka experiment), wheras their
wavelengths are not shifted at all when the elevator is far out
in space away from any planet, moon, or star, but accelerating upward
with an acceleration equal to that of one Earth gravity.

Of course they are shifted. When the light was emitted at the ceiling,
the floor had a smaller velocity than when the light was received
because the craft is accelerating and therefor the floor changed its
velocity during the time of flight of the light.

Luttgens was wrong.
Always been and always will be.

Dirk Vdm

For the elevator at rest on Earth, the blue shift is ~ gh/c^2, where
g is ~ 9.8 m/s^2 and h is the distance top-bottom.

You are claiming that the wavelength are also shifted in the case
of the accelerated elevator, because when the light was emitted
at the ceiling, the floor had a smaller velocity than when the light
was received. Indeed, the craft is accelerating and therefore the
floor
changed its velocity during the time of flight of the light.

You are in fact implying that the velocity of light is *not*
independent
of the motion of its source or of the motion of the observer!

And what is the formula for your alledged shift?

Marcel Luttgens

On 16 Mar 2007 06:41:24 -0700, wrote:

On 16 mar, 07:05, wrote:
Excerpt from Strobel's Astronomy Notes.http://www.astronomynotes.com/relativity/s3.htm

"Part of Einstein's genius was his ability to look at ordinary things
from a whole new perspective and logically follow through on the
consequence of the insights he gained from his new perspective.

He proposed an experiment involving two elevators:

one at rest on the ground on the Earth and another, far out in space
away from any planet, moon, or star, accelerating upward with an
acceleration equal to that of one Earth gravity (9.8 meters/second2).
(Modern readers can substitute ``rocket ship'' for Einstein's
elevator.)

If a ball is dropped in the elevator at rest on the Earth, it will
accelerate toward the floor with an acceleration of 9.8 meters/
second2.
A ball released in the upward accelerating elevator far out in space
will also accelerate toward the floor at 9.8 meters/second2.

The two elevator experiments get the same result!"

Einstein was wrong:

The two elevator experiments don't get the same result!

When photons emitted from the top of the elevator are measured
at the bottom, their wavelengths are blue-shifted when the elevator is
at rest on the Earth (cf. the Pound-Rebka experiment), wheras their
wavelengths are not shifted at all when the elevator is far out
in space away from any planet, moon, or star, but accelerating upward
with an acceleration equal to that of one Earth gravity.

Marcel Luttgens

I think you forgot to take into account the Doppler effect. In the
space inertial frame where the light is emitted at the top, the
receptor at the botton receives the light at a some higher velocity
than the emitter one, producing the same blue-shift than in Earth.

RVHG

Yup, you can make the case. If the beam falls by h it takes time
T = h/c. In that time the accelerating floor acquires V = gT = gh/c.
Thus Doppler blue shift z = v/c = gh/c^2.
That's the same (approximate) expression for gravitational red shift z
for light on the way up.
But it's not the same, not by any means. The real rate of a clock is
reduced by gh/c^2 in a gravity well but no amount of mechanical
acceleration will reduce the rate of an atomic clock.
The frequency of the beam at top and bottom are the same (same
energy). Falling doesn't increase the energy of the light beam. In
falling it enters a heavier gravity environment where c is lower, so
the wave crests are squashed on the way down, making blue shift.
John Polasek

On Mar 16, 5:53 pm, John C. Polasek wrote:
On 16 Mar 2007 06:41:24 -0700, wrote:





On 16 mar, 07:05, wrote:
Excerpt from Strobel's Astronomy Notes.http://www.astronomynotes.com/relativity/s3.htm

"Part of Einstein's genius was his ability to look at ordinary things
from a whole new perspective and logically follow through on the
consequence of the insights he gained from his new perspective.

He proposed an experiment involving two elevators:

one at rest on the ground on the Earth and another, far out in space
away from any planet, moon, or star, accelerating upward with an
acceleration equal to that of one Earth gravity (9.8 meters/second2).
(Modern readers can substitute ``rocket ship'' for Einstein's
elevator.)

If a ball is dropped in the elevator at rest on the Earth, it will
accelerate toward the floor with an acceleration of 9.8 meters/
second2.
A ball released in the upward accelerating elevator far out in space
will also accelerate toward the floor at 9.8 meters/second2.

The two elevator experiments get the same result!"

Einstein was wrong:

The two elevator experiments don't get the same result!

When photons emitted from the top of the elevator are measured
at the bottom, their wavelengths are blue-shifted when the elevator is
at rest on the Earth (cf. the Pound-Rebka experiment), wheras their
wavelengths are not shifted at all when the elevator is far out
in space away from any planet, moon, or star, but accelerating upward
with an acceleration equal to that of one Earth gravity.

Marcel Luttgens

I think you forgot to take into account the Doppler effect. In the
space inertial frame where the light is emitted at the top, the
receptor at the botton receives the light at a some higher velocity
than the emitter one, producing the same blue-shift than in Earth.

RVHG

Yup, you can make the case. If the beam falls by h it takes time
T = h/c. In that time the accelerating floor acquires V = gT = gh/c.
Thus Doppler blue shift z = v/c = gh/c^2.

Are you sure that the beam will have travelled the distance h (I
presume that h is the height of the elevator) when it reaches the
accelerating floor?

Marcel Luttgens

That's the same (approximate) expression for gravitational red shift z
for light on the way up.
But it's not the same, not by any means. The real rate of a clock is
reduced by gh/c^2 in a gravity well but no amount of mechanical
acceleration will reduce the rate of an atomic clock.
The frequency of the beam at top and bottom are the same (same
energy). Falling doesn't increase the energy of the light beam. In
falling it enters a heavier gravity environment where c is lower, so
the wave crests are squashed on the way down, making blue shift.
John Polasek

wrote:
For the elevator at rest on Earth, the blue shift is ~ gh/c^2, where
g is ~ 9.8 m/s^2 and h is the distance top-bottom.

You are claiming that the wavelength are also shifted in the case
of the accelerated elevator, because when the light was emitted
at the ceiling, the floor had a smaller velocity than when the light
was received. Indeed, the craft is accelerating and therefore the
floor changed its velocity during the time of flight of the light.

Correct (velocities measured wrt some appropriate inertial frame).


You are in fact implying that the velocity of light is *not*
independent
of the motion of its source or of the motion of the observer!

Well, sort of. Remember that in SR the constancy of c holds only in
inertial frames, and the elevator is not inertial. In this case, an
INERTIAL observer outside the elevator would measure c for the speed of
the light inside the elevator, but an accelerated observer inside the
elevator would not. Indeed, it is this fact that permits one to compute
the blueshift.


And what is the formula for your alledged shift?

~ gh/c^2 of course (using the same approximation you used above).


Tom Roberts

wrote in message oups.com...
On Mar 16, 3:14 pm, "Dirk Van de moortel" dirkvandemoor...@ThankS-NO-
SperM.hotmail.com wrote:
wrote in ooglegroups.com...

Luttgens is back!
At last!





Excerpt from Strobel's Astronomy Notes.
http://www.astronomynotes.com/relativity/s3.htm

"Part of Einstein's genius was his ability to look at ordinary things
from a whole new perspective and logically follow through on the
consequence of the insights he gained from his new perspective.

He proposed an experiment involving two elevators:

one at rest on the ground on the Earth and another, far out in space
away from any planet, moon, or star, accelerating upward with an
acceleration equal to that of one Earth gravity (9.8 meters/second2).
(Modern readers can substitute ``rocket ship'' for Einstein's
elevator.)

If a ball is dropped in the elevator at rest on the Earth, it will
accelerate toward the floor with an acceleration of 9.8 meters/
second2.
A ball released in the upward accelerating elevator far out in space
will also accelerate toward the floor at 9.8 meters/second2.

The two elevator experiments get the same result!"

Einstein was wrong:

The two elevator experiments don't get the same result!

When photons emitted from the top of the elevator are measured
at the bottom, their wavelengths are blue-shifted when the elevator is
at rest on the Earth (cf. the Pound-Rebka experiment), wheras their
wavelengths are not shifted at all when the elevator is far out
in space away from any planet, moon, or star, but accelerating upward
with an acceleration equal to that of one Earth gravity.

Of course they are shifted. When the light was emitted at the ceiling,
the floor had a smaller velocity than when the light was received
because the craft is accelerating and therefor the floor changed its
velocity during the time of flight of the light.

Luttgens was wrong.
Always been and always will be.

Dirk Vdm

For the elevator at rest on Earth, the blue shift is ~ gh/c^2, where
g is ~ 9.8 m/s^2 and h is the distance top-bottom.

You are claiming that the wavelength are also shifted in the case
of the accelerated elevator, because when the light was emitted
at the ceiling, the floor had a smaller velocity than when the light
was received. Indeed, the craft is accelerating and therefore the
floor
changed its velocity during the time of flight of the light.

You are in fact implying that the velocity of light is *not*
independent
of the motion of its source or of the motion of the observer!

And what is the formula for your alledged shift?

Luttgens is an imbecile.
Always been and always will be.

Dirk Vdm