Are laws of nature really the same in all reference frames?

DaleSpam

So I still don't know how you plan on doing the comparison. For the fourth or fifth time, what method are you using to do the comparison? Feel free to simply use one of my four or come up with your own, but be specific.

Mentz114

Bjarne, I find your post #154 difficult to follow. It is not logically argued and poses more questions than it gives answers.

Have you seen this ?

http://www-istp.gsfc.nasa.gov/stargaze/Smass.htm

It is about experiments carried out on a space station.

There is a universe of evidence that the laws of nature are the same everywhere. We know that atoms continue to emit and absorb the same pattern of spectral lines which have been recognised in millions of astronomical bodies. On a large scale, the GR cosmological models explain most of what we can measure about the universe.

What you are proposing is 'new' physics. If the laws of nature really are laws of nature, they must apply everywhere. If there is experimental evidence to support it, then they must be modified, like relativity altered Newtonian concepts.

Your position is impossible to argue unless you can produce this experimental evidence.

Bjarne

I cannot see this is neccesery
Either time is ticking different, or it is not.
According to relativity time is ticking different.
Many experiments and experiences confirm this.
So I still cannot see any point with the question.

DaleSpam

No, according to relativity, if you use methods B or C to do the comparison then time is the same, and only if you use methods A or D to do the comparison then is it different. There is no "hidden reality" under which you can simply say time is different or it is not. There are only experimental measurements, and relativity correctly predicts those.

Bjarne

What do you mean by "measure the rate of the reference"

DaleSpam

I mean to take the reference clock, place it locally next to the test clock (either the Earth clock or the ISS clock), and measure the duration of one "tick" of the reference clock using the local test clock.

Bjarne

B + C is local measurement
A + D is comparable measurement
I agree to all that, but it has not much with the question to do.
I do off course mean A+D

Do we know (for sure) whether distances are comparable different too, so as time and speed is (see A+D), - in different space-time.
I have read that mass-energy conservation will changes the Bohr radius, which also must apply to relativity?

DaleSpam

Finally, a straight answer to such a basic question. It is a shame that it took so many posts to get to that.

I see how to compare the time on two distant clocks using methods A or D. How would you propose to compare the different distances?

Please, let's not waste another dozen or more posts chasing this down. Just describe your experimental method of comparing two spatially separated distances as clearly and succinctly as possible.

Bjarne

I wrote comparable difference from the start.
It confused me you could misunderstand that so much.

Good question.
I believe it is impossible.
Maybe only mathematical possible.
Already we compare space with a stretching rubber band, - or use the expression "curvature"
What does that mean?
Can we get closer to an understandable nature of that?
What happens with the ruler in such “bended” space? ( what do we know or not know)
At least seen from a mathematical perspective, is space stretching like the rubber band?

DaleSpam

Comparable doesn't have a well-defined meaning in terms of experiment. I.e. there is no experiment called the "comparable" experiment. Writing "comparable" over and over and over was not helpful to the conversation and was one of the main sources of delay. I am not a mind reader to know that by the word "comparable" you meant something like A or D and not something like B or C.

Then there is no use discussing about whether or not lengths change at different locations.

The word "curvature" does not refer to space stretching like a rubber band. Curvature refers to deviations from (pseudo) Euclidean geometry.

Consider the difference between geometry on a sphere and geometry on a plane. On a plane, two straight lines which are parallel at one point remain parallel and never intersect. On a sphere, two neighboring lattitude lines are straight lines which are parallel at the equator and intersect at the poles. On a plane the sum of the interior angles of a triangle are 180°, but on a sphere the sum of the interior angles of a triangle are greater than 180°. This is the kind of thing that is meant by "curvature".

A rubber band which is stretched into a triangle shape on a flat table still has interior angles which sum to 180°, regardless of the stretching of the band.

Bjarne

Sorry, but it is still very difficult for me to understand how, - reality differences’ - at all is possible (in this case) when distances not is affected too.

Let’s return to the example, - the ISS and the Earth orbiting the exact same orbit around the Sun. – And both exactly 1 orbit.
Both places / both observers (A & B) will locally agree that it will take 1 year, - 31536000 second.
They will also agree about their orbit local speed is average exactly 30000 m/s

• I have claimed that distance cannot be the same.
• You have claimed that these 2 observers follows different path.

1. Do you mean these object follows 2 comparable different path?
2. Do you mean these path locally seems to be exactly the same ?
3. Or how would you describe the “different path”?

Because observer A (on the ISS) he will say it took exactly 31536000 ISS-second to complete one orbit, and the ISS-speed was exact averagely 30000m/s

Observer B on the Earth, orbiting the exact same orbit round the Sun will also say that that it took 31536000 earth-second to complete one orbit and the Earth-speed was exact averagely 30000m/s.

But according to the Shapiro delay experiments we know that the comparablespeed between the ISS and the Earth not is the same, - (even though it locally is the same) .
For exsample, - if it was possible for A and B to reflect a light beam on the Sun and get it back, it would take the exact same local time, and the exact same local speed.
But the comparable time and speed would not be the same.

Let us now say that the comparable speed difference is proven to be 50% .

Option 1.
The only way we mathematical can understand what happens here is that distances also must be 50% comparable different.
This is simple logic. Then both local and comparable different reality can both be true at the same time. - (Seen from both observer A+B+E).

Option 2.
is that we from Earth would see the ISS orbiting the Sun double as fast as the Earth (according to the exaggerated exsample) .
That would contradict that an external observer (E) would see both objects moving with the same (his) speed and using the same (his) time to complete one orbit.

If you disagree, to both these options, - can you please be more detailed according to;

• What you mean with that these 2 objects follows a “different path”?
• How is this at all possible without assuming that comparable distance differences also must be a fact.?

This REALLY confuse me. – Sorry that I not is so quick to understand this.

DaleSpam

If you cannot come up with an experiment for comparing distances then it doesn't make sense to claim that distances are not affected. You cannot know anything about the distances if you cannot experimentally compare them, so you cannot claim that they are affected and you also cannot claim that they are not affected.

No, this is option D from my post 151. They will measure 1 astronomical year to be a different number of seconds.

How does each measure that?

These claims do not contradict each other.

You like to put the word "comparable" in bold as though somehow putting it in bold magically helps give it some meaning. What is a "comparable different path"? I have never heard the term and as far as I know it has no meaning.

As far as how I would describe the different paths, I would use a 4D coordinate system. I would then write the different paths in terms of parameterized worldlines in the coordinate system. Probably the ecliptic coordinate system with the GPS time coordinate would be the easiest.

How do you experimentally compare speeds?

If you write "comparable time" then I know what you mean since we already discussed it. But we have not discusses "comparable distances" nor "comparable speeds", so don't bother to use those terms when you have not defined them. When you say "comparable speed" what experiment are you thinking about performing to compare the speed?

No, this is not correct. This is known as Shapiro delay.

This is true, the local speed of the light beam is c.

Again, please define the experiment for comparing speeds.

Again, what experiment are you using to compare distances?

How would we measure the speed of the ISS and how would the external observer measure both the Earth speed and the ISS speed?

Neither of the options is clear enough for me to either agree or disagree with them.

They follow different paths because the coordinates of their path are different in any coordinate system you might choose.

Again, you put an undefined term in bold as though that helps to convey meaning. It does not, it is simply irritating. What is a "comparable distance difference" and how would you measure it?

Please do not use the word "comparable" or any related word in our further discussions unless you have clearly defined the experiment you would perform to make the comparison.

Bjarne

Yes off course, this was a blunder..

Ok so this is then still an open question. This is what confused me.
The conclusion is then, - it seems more to discover, - but whether it is possible, is then a different question.

Thanks’ a lot for your patience, and detailed explanation.

DaleSpam

I wouldn't even call it an open question yet. I would call it an undefined term. Until you have defined all of the terms you don't even have a properly formed question.

You are welcome. I will be glad to continue the discussion if needed.

Bjarne

Since we know the comparable length of one second is relative stretching or shrinking in different spacetime, for exsample relative to one of ours seconds, we know 1 of 3 factors.

Hence the options are whether speed and /or distance does "the same", and whether that happens proportional.

Which is the most likely option.

• Is it that only speed follows the relative (proportional) stretch of time (and hence relative slowing or speeding)?
• Or is distance also involved in the same relative proportional change?

Of course there could be other combination, according to what these 2 other factors does or not does, - but I think these 2 are the most likely.

I know you twist these words, - but I also think you know what i mean.

DaleSpam

It is hard to claim that someone is twisting words which are undefined. I certainly do not know what you mean. In fact, I believe that you do not know what you mean either.

Note, this is not a personal criticism, this is a common problem when you are learning a new and difficult subject, the concepts are not clear and words often have subtly different meanings in the new context. It is just a simple fact that you need to be aware of and have patience with. People will be willing to help you, but you need to recognize that communication about this topic is inherently difficult. You need to ask people to define terms when you are confused and you need to be willing to define terms when asked.

GR is mathematically guaranteed to be a self-consistent framework. So, any time that you use an English description and come up with some inconsistency you immediately know that you are not correctly translating between the math and the English. That is typically due to using a poorly defined term or due to making a statement which is well defined and gramatically correct in English but is not mathematically correct.

Here, we have the first case. You use words like "comparable", "the same", "stretch", etc. but without a rigorous definition. Any inconsistencies you come up with are due to that, not due to the theory.

Bjarne

On the one hand I have heard that when people not get confused first time they hear about reality they haven’t understood it, so I am maybe legally excused (even though it is not first time).
On the other hand it must also be possible to explain it to grandmother according to Einstein.

I think I begin to understand a lot more, especially what we don't know.

Still I would be happy to hear some ideas / opinions (if any) about how the third factor, “distance” in space time, and whether these too possible can be a changing factor too (in the same way as time)
I mean how this factor most likely can be globally understood, - there must at last have been speculations about it, what is the opinion of the majority, - are there different theories, etc.. or is that what we don’t know a dead end. If possible explained in a “grandmother adaptable language” first at all, then later I believe it is easier to understand the math behind, if any.