Maybe you guys can help me with this problem.

I read somewhere about a relativity experiment.

· Let's say you have two flashlights on the train. One facing front
the other facing the back. Each light is positioned such that inside
the train, if you were to turn on the lights at the same time. They
should hit the walls (both the front and back) at the same time.

· When light hits the wall of the train the door open.

For the observer on the train moving near light speed the lights are
turned on at the same time the doors open at the same time.

To the outside observer the back door will open first. Is this true?
Can someone please clarify?

Randy

"Randy" wrote in message
om...
Maybe you guys can help me with this problem.

I read somewhere about a relativity experiment.

It is a thought experiment.

· Let's say you have two flashlights on the train. One facing front
the other facing the back. Each light is positioned such that inside
the train, if you were to turn on the lights at the same time. They
should hit the walls (both the front and back) at the same time.

Why not just one light source in te middle of the train? (I think that you
modified it).

· When light hits the wall of the train the door open.

For the observer on the train moving near light speed the lights are
turned on at the same time the doors open at the same time.

That is usually right, but not necessarily so - see below.
Note that the light that comes back from the doors will arrive
simultaneously at the observer in the middle of the train (according to all
observers).

To the outside observer the back door will open first. Is this true?
Can someone please clarify?

That indeed follows from the Principle of Relativity, which has been shown
to be quite reliable for such situations.

- Assuming that the outside observer uses calibrated stopwatches along the
track, the calibration was for example done with radio signals, assuming
that the speed is isotropic c. As the back door moves towards the light, the
time to reach the back door is L/(c+v) while it is L/(c-v) to reach the
front door.

- If inside the train a similar, independent synchronization is done with
clocks, unavoidably the light pulses arrive at the same time, as a result of
that system calibration.

- If however the train has clocks that are synchronized by clocks along the
track while passing by, in the train the SAME timing result will be measured
as outside.

Harald

"Harry" wrote in message
...
|
| "Randy" wrote in message
| om...
| Maybe you guys can help me with this problem.
|
| I read somewhere about a relativity experiment.
|
| It is a thought experiment.
|
| · Let's say you have two flashlights on the train. One
facing front
| the other facing the back. Each light is positioned
such that inside
| the train, if you were to turn on the lights at the same
time. They
| should hit the walls (both the front and back) at the
same time.
|
| Why not just one light source in te middle of the train?
(I think that you
| modified it).
|
| · When light hits the wall of the train the door open.
|
| For the observer on the train moving near light speed
the lights are
| turned on at the same time the doors open at the same
time.
|
| That is usually right, but not necessarily so - see below.
| Note that the light that comes back from the doors will
arrive
| simultaneously at the observer in the middle of the train
(according to all
| observers).
|
| To the outside observer the back door will open first.
Is this true?
| Can someone please clarify?
|
| That indeed follows from the Principle of Relativity,
which has been shown
| to be quite reliable for such situations.
|
| - Assuming that the outside observer uses calibrated
stopwatches along the
| track, the calibration was for example done with radio
signals, assuming
| that the speed is isotropic c. As the back door moves
towards the light, the
| time to reach the back door is L/(c+v) while it is L/(c-v)
to reach the
| front door.

Nonsense.
The time to reach the back door is -L/(-c-v) and the time to
reach the front door is +L/(+c-v).
The sign of v has not changed, the directions are opposite
and the light speeds are opposite.

Am I just nit picking? NO.
This is a very important consideration that Einstein
overlooked, because
his equation only deals with one door, which he makes into a
mirror and reflects the light back to the middle of the
train.

He claims that
1/2 [(-L/(-c-v) + L/(c-v))] = L/(c-v),

but we must also have

1/2 [(-L/(-c-v) + L/(c-v))] = -L/(-c-v),

for the other door. So
L/(c-v) = -L/(-c-v).
You can if you wish (and did) rewrite it as

L/(c-v) = L/(c+v)

Divide through by L,

1/(c-v) = 1/(c+v)

(c+v)/(c-v) = 1

(c+v)=(c-v)

v = - v
2v = 0
v = 0, the train is not moving.



| - If inside the train a similar, independent
synchronization is done with
| clocks, unavoidably the light pulses arrive at the same
time, as a result of
| that system calibration.
|
| - If however the train has clocks that are synchronized by
clocks along the
| track while passing by, in the train the SAME timing
result will be measured
| as outside.
|

Waffle.
Androcles


| Harald
|
|

"Androcles" escribió en el mensaje
...

"Harry" wrote in message
...
|
| "Randy" wrote in message
| om...
| Maybe you guys can help me with this problem.
|
| I read somewhere about a relativity experiment.
|
| It is a thought experiment.
|
| · Let's say you have two flashlights on the train. One
facing front
| the other facing the back. Each light is positioned
such that inside
| the train, if you were to turn on the lights at the same
time. They
| should hit the walls (both the front and back) at the
same time.
|
| Why not just one light source in te middle of the train?
(I think that you
| modified it).
|
| · When light hits the wall of the train the door open.
|
| For the observer on the train moving near light speed
the lights are
| turned on at the same time the doors open at the same
time.
|
| That is usually right, but not necessarily so - see below.
| Note that the light that comes back from the doors will
arrive
| simultaneously at the observer in the middle of the train
(according to all
| observers).
|
| To the outside observer the back door will open first.
Is this true?
| Can someone please clarify?
|
| That indeed follows from the Principle of Relativity,
which has been shown
| to be quite reliable for such situations.
|
| - Assuming that the outside observer uses calibrated
stopwatches along the
| track, the calibration was for example done with radio
signals, assuming
| that the speed is isotropic c. As the back door moves
towards the light, the
| time to reach the back door is L/(c+v) while it is L/(c-v)
to reach the
| front door.

Nonsense.
The time to reach the back door is -L/(-c-v) and the time to
reach the front door is +L/(+c-v).
The sign of v has not changed, the directions are opposite
and the light speeds are opposite.

Am I just nit picking? NO.
This is a very important consideration that Einstein
overlooked, because
his equation only deals with one door, which he makes into a
mirror and reflects the light back to the middle of the
train.

He claims that
1/2 [(-L/(-c-v) + L/(c-v))] = L/(c-v),

but we must also have

1/2 [(-L/(-c-v) + L/(c-v))] = -L/(-c-v),

for the other door. So
L/(c-v) = -L/(-c-v).
You can if you wish (and did) rewrite it as

L/(c-v) = L/(c+v)

Divide through by L,

1/(c-v) = 1/(c+v)

(c+v)/(c-v) = 1

(c+v)=(c-v)

v = - v
2v = 0
v = 0, the train is not moving.

Oh, my!!! You are right!!! I have been blind all of these years.
Tonight I will burn all my books on relativity together, and I will initiate a
public collect to build you a statue of bronze in your honour. Varney was my
Physics idol, but now it is you, with such an elegant and simple refutation of
relativity. Superb, you are a genious.

Cesar
PS: Prfffffffffffffffffffff!!!!


| - If inside the train a similar, independent
synchronization is done with
| clocks, unavoidably the light pulses arrive at the same
time, as a result of
| that system calibration.
|
| - If however the train has clocks that are synchronized by
clocks along the
| track while passing by, in the train the SAME timing
result will be measured
| as outside.
|

Waffle.
Androcles


| Harald
|
|

"Randy" wrote in message om...
Maybe you guys can help me with this problem.

I read somewhere about a relativity experiment.


It is a thought experiment, based on Einstein's
two postulates.

· Let's say you have two flashlights on the train. One facing front
the other facing the back. Each light is positioned such that inside
the train, if you were to turn on the lights at the same time. They
should hit the walls (both the front and back) at the same time.

· When light hits the wall of the train the door open.

For the observer on the train moving near light speed the lights are
turned on at the same time the doors open at the same time.

To the outside observer the back door will open first. Is this true?
Can someone please clarify?

From the fact that you say the train is moving at near light
speed I assume this is not a homework question.

One of the original postulates is that light always
travels at a fixed speed (conditions apply) relative
to the observer.

Let us assume that both flashlights are near enough
at the same place. In fact they could be replaced
by a single light

The fact that the light hits both ends of the train at the
same time, as measured by the train observer, means
that the distance from the lights to the front of the train
must be the same as the distance to the rear of the train
since, to the train observer, the light travels at the same
speed in both directions. In other words the lights
must be situated at the centre of the train.

Now consider the situation from the point of view
of the outside (presumably stationary with respect to
the track) observer. He will observe the light to travel
out from the two flashlights at the same speed relative
to himself. He will also observe the train to be moving
forwards. The light going towards the back of the train
will therefore reach the end before the light going
forwards reaches the front.

Martin Hogbin

"Randy" wrote in message
om...
Maybe you guys can help me with this problem.

I read somewhere about a relativity experiment.

· Let's say you have two flashlights on the train. One facing front
the other facing the back. Each light is positioned such that inside
the train, if you were to turn on the lights at the same time. They
should hit the walls (both the front and back) at the same time.

· When light hits the wall of the train the door open.

For the observer on the train moving near light speed the lights are
turned on at the same time the doors open at the same time.

To the outside observer the back door will open first. Is this true?
Can someone please clarify?

Yes it is true. In SR what is simultaneous in one frame is not necessarily
simultaneous in another. Since the speed of light is the same during the
time it takes for the light beam to hit the rear door it would have moved a
bit thus hitting it sooner - for the moving observer.

Thanks
Bill

(Randy) wrote in message . com...
Maybe you guys can help me with this problem.

I read somewhere about a relativity experiment.

· Let's say you have two flashlights on the train. One facing front
the other facing the back. Each light is positioned such that inside
the train, if you were to turn on the lights at the same time. They
should hit the walls (both the front and back) at the same time.

· When light hits the wall of the train the door open.

For the observer on the train moving near light speed the lights are
turned on at the same time the doors open at the same time.

To the outside observer the back door will open first. Is this true?
Can someone please clarify?

Randy

Yes, because light travels at the same velocity for both
observers, according to SR.

However, the different perception of time by different
observers has been misunderstood, and no one has properly
explained how it works.

Einstein and Minkowski created an interpretation that has
sent the whole understanding of this reality in Physics
in a wrong direction that has endured for a century.

Alen

Yes, because light travels at the same velocity for both
observers, according to SR.

Ok, let's say we have the same train. This time we put clock A at the
front of the train and clock B at the back. Each clock will record
the moment light hits the wall opening the doors. What will the
clocks read when the experiment is executed? Will clock B actually
record being hit first? And if so, doesn't that mean clock B would
record a different speed of light inside the train? Or will the
clocks report being hit at the same time? If so, is Clock A moving
slower than clock B?

However, the different perception of time by different
observers has been misunderstood, and no one has properly
explained how it works.

So what is actually happening inside the train? Either in actual
reality the back door is being hit first or time is not just slowed
but skewed inside the train, right?

Einstein and Minkowski created an interpretation that has
sent the whole understanding of this reality in Physics
in a wrong direction that has endured for a century.

What was their interpretation?

Thanks in advance

"Randy" wrote in message
om...
| Yes, because light travels at the same velocity for both
| observers, according to SR.

Yeah... stupid, isn't it?


| Ok, let's say we have the same train. This time we put
clock A at the
| front of the train and clock B at the back. Each clock
will record
| the moment light hits the wall opening the doors. What
will the
| clocks read when the experiment is executed? Will clock B
actually
| record being hit first? And if so, doesn't that mean
clock B would
| record a different speed of light inside the train? Or
will the
| clocks report being hit at the same time? If so, is Clock
A moving
| slower than clock B?
|
| However, the different perception of time by different
| observers has been misunderstood, and no one has
properly
| explained how it works.

I've explained it lots of times, but few like the
explanation.
|
| So what is actually happening inside the train? Either in
actual
| reality the back door is being hit first or time is not
just slowed
| but skewed inside the train, right?
|
| Einstein and Minkowski created an interpretation that
has
| sent the whole understanding of this reality in Physics
| in a wrong direction that has endured for a century.

Yep.
|
| What was their interpretation?

A guess wrapped in quasi-mathematical nonsense.
Androcles

|
| Thanks in advance

"Randy" wrote in message om...

Einstein and Minkowski created an interpretation that has
sent the whole understanding of this reality in Physics
in a wrong direction that has endured for a century.

What was their interpretation?

Alen is one of the many crackpots we have on this group.
Have a look at some of the other replies.

Martin Hogbin