[Cap'n Refsmmat]

Bart, on 28 January 2012 - 06:51 PM, said:

Thanks. It means that the local time indications in the rocket will be exacly the same as on the Earth.

Thus it denies the existence of time dilation, and proves constancy of the time in the universe ?

No; an observer on the ground will see the rocket's clock as running slow.

You can see this effect on light clocks in this online demonstration:

http://www.refsmmat....tml#light-clock

In the first version (hit Play to start), photons bounce back and forth at a known rate. When you press Next, you switch to the reference frame of the high-velocity observer; to him, the photons must travel on the diagonal, so the light clock takes longer to tick.

An observer moving with the light clock will not notice this effect.

(Note: the demonstration will work best in recent versions of Firefox and Chrome.)

[Bart]

D H, on 28 January 2012 - 07:05 PM, said:

It means that the local time indications in the rocketwill be exacly the same as on the Earth.

Correct.


Thus it denies the existence of time dilation, and proves constancy of thetime in the universe ?


Incorrect.

Why incorrect? If I, being in a flying rocket, have on my clock an indication eg. 12.00 and at the same time, you on the Earth have also on your clock an indication 12.00, and after an hour I have an indication 13.00 and you also have an indication 13.00, etc. Thus, in my frame in a rocket and in your frame on the Earth, time passes at an identical rate. Does not it?

This post has been edited by Bart: 29 January 2012 - 11:04 AM

[swansont]

Bart, on 29 January 2012 - 10:54 AM, said:

Why incorrect? If I, being in aflying rocket have on my clock an indication,eg 12.00 and at the same time, you areon Earth have also on your clock an indication 12.00, and after an hour I havean indication 13.00 and you also have anindication 13.00, etc. Thus, in my framein a rocket and in your frame on the Earth, time passes at an identical rate,is not it?

Creating two frames where you have identical time dilation does not extrapolate to "constancy of the time in the universe". It's trivial to find two frames where the time won't agree.

[D H]

Bart, on 29 January 2012 - 10:54 AM, said:

Why incorrect? If I, being in a flying rocket, have on my clock an indication eg. 12.00 and at the same time, ...

Your conclusion does not follow from the premises. I cut your post off with the words "and at the same time" because that is the source of your error in understanding. One of the key consequences of relativity is that even simultaneity is relativity. There is no universal "at the same time".

You are wasting your time trying to disprove relativity mathematically. You aren't going to be able to that. The mathematics of special relativity is very sound. What you should be doing is trying to understand that mathematics.

Just because the mathematics of special relativity is very sound does not mean that it is right. After all, the mathematics of Newtonian mechanics is also very sound. Just because a theory is internally consistent does not mean it is correct. Scientific theories have an extra constraint: They have to describe reality. Experiment upon experiment have shown that it is relativity theory, not Newtonian mechanics, that describes what transpires at very high speeds.

[rigney]

swansont, on 29 January 2012 - 11:01 AM, said:

Creating two frames where you have identical time dilation does not extrapolate to "constancy of the time in the universe". It's trivial to find two frames where the time won't agree.

If relativity is correct, as to space and time being curved, wouldn't it be impossible to find two time frames that did agree?

This post has been edited by rigney: 29 January 2012 - 04:08 PM

[D H]

rigney, on 29 January 2012 - 04:06 PM, said:

If relativity is correct, as to space and time being curved, wouldn't it be impossible to find two time frames that did agree?

No. How did you arrive at that conclusion? Any two co-moving frames will agree on time.

[Cap'n Refsmmat]

Bart, on 29 January 2012 - 10:54 AM, said:

Why incorrect? If I, being in a flying rocket, have on my clock an indication eg. 12.00 and at the same time, you on the Earth have also on your clock an indication 12.00, and after an hour I have an indication 13.00 and you also have an indication 13.00, etc. Thus, in my frame in a rocket and in your frame on the Earth, time passes at an identical rate. Does not it?

After whose hour? The observer on Earth will claim that the rocket's clock is running slowly. An observer on the rocket will claim that it is running at exactly the right speed.

Watch the animation I posted.

[rigney]

D H, on 29 January 2012 - 04:34 PM, said:

No. How did you arrive at that conclusion? Any two co-moving frames will agree on time.

Unless two photons are superimposed, wouldn't they have different time frames?

[swansont]

rigney, on 29 January 2012 - 06:19 PM, said:

Unless two photons are superimposed, wouldn't they have different time frames?

Photons are not in an inertial frame. "Time frame" for a photon makes no sense.

[rigney]

swansont, on 29 January 2012 - 07:36 PM, said:

Photons are not in an inertial frame. "Time frame" for a photon makes no sense.

There is much in this link that I am totally ignorant of, which you might readily explain? But since this is my first look at it, I'll likely need more than a bit of time trying to figure it out.
http://www.circlon-t...nofphotons.html

This post has been edited by rigney: 30 January 2012 - 02:03 PM

[swansont]

rigney, on 30 January 2012 - 01:15 PM, said:

There is much in this link that I am totally ignorant of, which you might readily explain? But since this is my first look at it, I'll likely need more than a bit of time trying to figure it out.
http://www.circlon-t...nofphotons.html

The Absolute Motion Institute? Crackpot city. My suggestion is to learn actual relativity before trying to take on crap science.

[D H]

rigney, on 30 January 2012 - 01:15 PM, said:

There is much in this link that I am totally ignorant of, which you might readily explain? But since this is my first look at it, I'll likely need more than a bit of time trying to figure it out.
http://www.circlon-t...nofphotons.html

From that site:

Both of these postulates [the two postulates of special relativity] are vague, contradictory, and the elements within them are poorly defined. The results of many experiments performed since these postulates were first proposed in 1905 demand that their wording be altered and their elements to be more carefully defined in order to more accurately reflect reality.

Oh my. Where's the :rofl: emoticon when you need it? The postulates are very specific (= very testable) and are in concordance with one another. The results of experiments since 1905 are consistent with the results predicted by relativity. How much more wrong could that site be?

You have found one of a boatload of crackpot sites. I strongly suggest that you stop wasting your time and learn some real science instead.

[rigney]

D H, on 30 January 2012 - 03:33 PM, said:

From that site:

Both of these postulates [the two postulates of special relativity] are vague, contradictory, and the elements within them are poorly defined. The results of many experiments performed since these postulates were first proposed in 1905 demand that their wording be altered and their elements to be more carefully defined in order to more accurately reflect reality.

Oh my. Where's the :rofl: emoticon when you need it? The postulates are very specific (= very testable) and are in concordance with one another. The results of experiments since 1905 are consistent with the results predicted by relativity. How much more wrong could that site be?

You have found one of a boatload of crackpot sites. I strongly suggest that you stop wasting your time and learn some real science instead.

You're likely right. My total physics prowess came to an end when Einstein was demonstrating the up and down movement of an elevator and its effect on matter. Never really tried to associate it with time dilation.

[Bart]

D H, on 29 January 2012 - 02:16 PM, said:

Your conclusion does not follow from the premises. I cut your post off with the words "and at the same time" because that is the source of your error in understanding. One of the key consequences of relativity is that even simultaneity is relativity. There is no universal "at the same time".

You are wasting your time trying to disprove relativity mathematically. You aren't going to be able to that. The mathematics of special relativity is very sound. What you should be doing is trying to understand that mathematics.

Just because the mathematics of special relativity is very sound does not mean that it is right. After all, the mathematics of Newtonian mechanics is also very sound. Just because a theory is internally consistent does not mean it is correct. Scientific theories have an extra constraint: They have to describe reality. Experiment upon experiment have shown that it is relativity theory, not Newtonian mechanics, that describes what transpires at very high speeds.

Thank you DH, many thanks to All for interesting discussion and the search for truth in this intricate and perhaps still open topic.

"Man involved in science will never understand why he should believe in certain opinions simply because they are in a book. [...] Also he never deems its own results for the ultimate truth". A. Einstein

Reality does not always agree even with the most sound mathematics. If you put your one leg in boiling water (100 °C) and the other in a very cold ice (eg-50 ° C), then you should feel great, because the sound math shows that you are in the average temperature of 25 °C.

This post has been edited by Bart: 31 January 2012 - 06:10 PM

[derek w]

if you have a theory of an aether,then all particles would travel through or across it as a wave function.The particles that constitute mirrors in the michelson-morley and the particles that constitute the earth,would all be travelling through or across the aether,by the same principle that light would travel across the aether.In other words the light the experiment and the earth would all be travelling relative to each other across the aether.

This post has been edited by derek w: 31 January 2012 - 08:10 PM