Relativity, a theory of information?

[ghwellsjr]

In Special Relativity "event" has a very specific meaning but before we get to that, we need to cover some basic ground work. Could you please read section 1 of Einstein's 1905 paper introducing Special Relativity and note especially how many times he uses the word "define" or variations? See if you understand what he is saying.

 

[faen]

In Special Relativity "event" has a very specific meaning but before we get to that, we need to cover some basic ground work. Could you please read section 1 of Einstein's 1905 paper introducing Special Relativity and note especially how many times he uses the word "define" or variations? See if you understand what he is saying.

It's kinda long to read and I've already read the basics about special relativity before.. Could you please summarize what he means with define and variations if possible?

 

[ghwellsjr]

It's barely a page--I didn't mean the whole first part--just the first section called "Definition of Simultaneity". Can you at least read through it and tell me how many times he uses the word "define" or its variations?

 

[faen]

It's barely a page--I didn't mean the whole first part--just the first section called "Definition of Simultaneity". Can you at least read through it and tell me how many times he uses the word "define" or its variations?

Oh then it's no problem, I thought it was the whole kinematics part. It seems as if he defines simultaneity as when the clocks between two different frames measures the same time of light traveling back and forth. Which means that the frames are at equal speed.

It doesn't say anything there about how he defines unsimultaneous events. Does he believe that they are truly unsimultaneous, or just measured unsimultaneous? I get the impression that he doesn't conclude anything further than what can be measured.

I'm thinking about something like minkowsky space, that what is present for frame A, is something completely different from what is currently present at frame B. That is what I'm skeptic about.

A person wrote a book about how he believes that he has disproved presentism. What would your opinion be about something like that? Parts of his book is below in case you're interrested. I think the first page from the link would give an idea of his views.

http://books.google.hu/books?id=Azf...KpaDaCQ&sqi=2&redir_esc=y#v=onepage&q&f=false

 

[Dale]

I get the impression that he doesn't conclude anything further than what can be measured.

That is all that science can investigate. If there is something that cannot be measured then it is not amenable to investigation by the scientific method which relies on the outcome of experimental measurements to confirm or reject hypotheses.

The problem is not the science, but your desire for more than the science can provide. If you want more than what can be measured then you need to consult a preist or a philosopher, not a scientist.

 

[faen]

That is all that science can investigate. If there is something that cannot be measured then it is not amenable to investigation by the scientific method which relies on the outcome of experimental measurements to confirm or reject hypotheses.

The problem is not the science, but your desire for more than the science can provide. If you want more than what can be measured then you need to consult a preist or a philosopher, not a scientist.

I would disagree here. You can not measure every single molecule/atom, yet you assume that it is molecules/atoms constituting all of matter.

 

[ghwellsjr]

It's barely a page--I didn't mean the whole first part--just the first section called "Definition of Simultaneity". Can you at least read through it and tell me how many times he uses the word "define" or its variations?

Oh then it's no problem, I thought it was the whole kinematics part. It seems as if he defines simultaneity as when the clocks between two different frames measures the same time of light traveling back and forth. Which means that the frames are at equal speed.

It doesn't say anything there about how he defines unsimultaneous events. Does he believe that they are truly unsimultaneous, or just measured unsimultaneous? I get the impression that he doesn't conclude anything further than what can be measured.

I'm thinking about something like minkowsky space, that what is present for frame A, is something completely different from what is currently present at frame B. That is what I'm skeptic about.

A person wrote a book about how he believes that he has disproved presentism. What would your opinion be about something like that? Parts of his book is below in case you're interrested. I think the first page from the link would give an idea of his views.

http://books.google.hu/books?id=Azf...KpaDaCQ&sqi=2&redir_esc=y#v=onepage&q&f=false

Before you get into such things as minkowsky space or presentism, you need to thoroughly understand Special Relativity and by that time, maybe you won't care. At least I don't care about those things.

Now, you somehow got the idea that Einstein was talking about two different frames of reference in that first section of his paper and that they were traveling at some speed. He actually is defining the concept of what a frame is and he calls it the "stationary frame" so he's not concerned about any speeds (except the speed of light) at this point.

So let me take you through how Einstein is showing us how to create a Frame of Reference or a system of coordinates. He does this with a series of definitions. The first definition is with regard to the three spatial components where he says we use "rigid standards of measurement" or rulers at right angles to each other.

The next definition has to do with time where he says that we use the reading of a clock located next to the event we want to associate time with. And if we want to attach a time to two events that are located some distance from each other, we need two identical clocks and we need a definition of how to synchronize those two clocks.

To illustrate how this is done, he envisions a setup involving one clock at location A with a light source that can emit a flash and at location B, some distance away, measured with a rigid ruler is a mirror and a second clock. When the flash is emitted at location A, the time on clock A, t_A is noted. Then when the flash reaches the mirror, the time on clock B, t_B is noted. Finally, when the reflection of the flash returns to A, the time t'_A is noted.

He states that the round trip speed of light can be calculated by taking double the distance between the two clocks (2AB) and dividing it by the total time interval it took for the light to make the round trip (t'_A-t_A) and that experiments have shown this to always equal the universal constant, c.

But, we cannot know what time between t_A and t'_A the light arrived at location B unless we supply a definition. In other words, we don't know what portion of the total time the light took to get from A to B as compared to getting from B back to A. Without a definition, we have a subjective situation but with a definition, we make it objective. And Einstein's definition is to make those two time intervals equal. So after doing the experiment we see if t_B-t_A, the time interval for the first portion of the trip is equal to t'_A-t_B, the time interval for the second portion of the trip. If they are, then the two clocks are synchronized. If not, we change the time on clock B to make them equal and we repeat the test to see if we have performed the synchronization correctly and we repeat until we have.

Now that we know how to synchronize a clock located at a remote location from a master clock, we place clocks at numerous locations throughout our 3-dimensional grid of rulers and make sure they are all synchronized to the clock at the spatial origin of the co-ordinate system. So now if we want to know the co-ordinates of any event, we look at the readings on the 3-dimensional grid of rulers and the time on the synchronized clock at the location of the event.

Thus, an "event" in Special Relativity is the four co-ordinates (three spatial and one temporal) defined according to a specified Frame of Reference.

What I want you to notice is that Einstein's definition of a Frame of Reference makes objective what previously had been subjective.

So now if you want to know if two events are at the same location, you look at their respective three spatial co-ordinates. If they match, they are at the same location, even if they are at different times. In exactly the same way, if you want to know if two events are at the same time, you look at their time co-ordinates. If they match, they are simultaneous even if they are at different locations. If they don't match, then they are, as you say, unsimultaneous.

Remember, we are just talking about co-ordinates defined according to a given Frame of Reference that we have "constructed".

Of course, someone else can construct a different Frame of Reference with a different origin (for both the spatial and temporal co-ordinates), with the axes pointing in different directions, and moving with respect to our Frame of Reference and then we would expect the co-ordinates to be all different, wouldn't we? But we shouldn't find that disturbing, it's purely a result of a different Frame of Reference.

Does this all make sense to you?

 

[Dale]

You can not measure every single molecule/atom

Why not? Given some molecule/atom X why couldn't you measure it? Given some collection of molecules/atoms why couldn't you measure every single one?

The only limitations I can think of are economic, not scientific.

This is fundamentally different from what you are asking, which cannot be measured even in principle regardless of economic or technological resources contemplated.

 

[faen]

Before you get into such things as minkowsky space or presentism, you need to thoroughly understand Special Relativity and by that time, maybe you won't care. At least I don't care about those things.

Now, you somehow got the idea that Einstein was talking about two different frames of reference in that first section of his paper and that they were traveling at some speed. He actually is defining the concept of what a frame is and he calls it the "stationary frame" so he's not concerned about any speeds (except the speed of light) at this point.

So let me take you through how Einstein is showing us how to create a Frame of Reference or a system of coordinates. He does this with a series of definitions. The first definition is with regard to the three spatial components where he says we use "rigid standards of measurement" or rulers at right angles to each other.

The next definition has to do with time where he says that we use the reading of a clock located next to the event we want to associate time with. And if we want to attach a time to two events that are located some distance from each other, we need two identical clocks and we need a definition of how to synchronize those two clocks.

To illustrate how this is done, he envisions a setup involving one clock at location A with a light source that can emit a flash and at location B, some distance away, measured with a rigid ruler is a mirror and a second clock. When the flash is emitted at location A, the time on clock A, t_A is noted. Then when the flash reaches the mirror, the time on clock B, t_B is noted. Finally, when the reflection of the flash returns to A, the time t'_A is noted.

He states that the round trip speed of light can be calculated by taking double the distance between the two clocks (2AB) and dividing it by the total time interval it took for the light to make the round trip (t'_A-t_A) and that experiments have shown this to always equal the universal constant, c.

But, we cannot know what time between t_A and t'_A the light arrived at location B unless we supply a definition. In other words, we don't know what portion of the total time the light took to get from A to B as compared to getting from B back to A. Without a definition, we have a subjective situation but with a definition, we make it objective. And Einstein's definition is to make those two time intervals equal. So after doing the experiment we see if t_B-t_A, the time interval for the first portion of the trip is equal to t'_A-t_B, the time interval for the second portion of the trip. If they are, then the two clocks are synchronized. If not, we change the time on clock B to make them equal and we repeat the test to see if we have performed the synchronization correctly and we repeat until we have.

Now that we know how to synchronize a clock located at a remote location from a master clock, we place clocks at numerous locations throughout our 3-dimensional grid of rulers and make sure they are all synchronized to the clock at the spatial origin of the co-ordinate system. So now if we want to know the co-ordinates of any event, we look at the readings on the 3-dimensional grid of rulers and the time on the synchronized clock at the location of the event.

Thus, an "event" in Special Relativity is the four co-ordinates (three spatial and one temporal) defined according to a specified Frame of Reference.

What I want you to notice is that Einstein's definition of a Frame of Reference makes objective what previously had been subjective.

So now if you want to know if two events are at the same location, you look at their respective three spatial co-ordinates. If they match, they are at the same location, even if they are at different times. In exactly the same way, if you want to know if two events are at the same time, you look at their time co-ordinates. If they match, they are simultaneous even if they are at different locations. If they don't match, then they are, as you say, unsimultaneous.

Remember, we are just talking about co-ordinates defined according to a given Frame of Reference that we have "constructed".

Of course, someone else can construct a different Frame of Reference with a different origin (for both the spatial and temporal co-ordinates), with the axes pointing in different directions, and moving with respect to our Frame of Reference and then we would expect the co-ordinates to be all different, wouldn't we? But we shouldn't find that disturbing, it's purely a result of a different Frame of Reference.

Does this all make sense to you?

Yes I understand this. However, I am still seeking or interested in a deeper perspective as well. Or I'm still a presentist I'd say. Your explanation was still helpful in widening my perspective though since I didn't know of that way of defining simultaneity.

 

[faen]

Why not? Given some molecule/atom X why couldn't you measure it? Given some collection of molecules/atoms why couldn't you measure every single one?

The only limitations I can think of are economic, not scientific.

This is fundamentally different from what you are asking, which cannot be measured even in principle regardless of economic or technological resources contemplated.

Perhaps you could measure all the molecules, but you didn't. Taking into account that you still didn't measure all the molecules, you still believe that they constitute matter.

Do you believe that it is impossible that scientists will have a deeper understanding of the theory of relativity in the future?

Since you mentioned philosophy, I'd say that many philosophical theories can be scientific as well. For example that only one of the frames is "really" stationary, could be such a theory. It would then be based on the observation that time goes relatively slower in a frame. Fundamental reasons such as equal laws in all frames, causes them to still be uninformed about who is moving. Or perhaps there could be different layers of space moving relative to each other.. Those assumptions are fundamentally based on generalizing observations. It can't be tested which of any such assumption could be a correct one, or is it sufficient with the observations which they are already based on if such a theory is consistent? Nothing can be proven with 100% certainty anyway. Also, is string theory proven by experiments as well?

 

[ghwellsjr]

Yes I understand this. However, I am still seeking or interested in a deeper perspective as well. Or I'm still a presentist I'd say. Your explanation was still helpful in widening my perspective though since I didn't know of that way of defining simultaneity.

Well, I'm glad that helped because it is the basis of Special Relativity.

I mentioned earlier how another observer could create his own Frame of Reference with totally different co-ordinates and how that shouldn't be disturbing. Do you understand this and do you agree it's nothing to be disturbed about?

 

[Dale]

Since you mentioned philosophy, I'd say that many philosophical theories can be scientific as well.

If it can be experimentally tested then it is science, if it cannot then it is not science. That is the key defining characteristic of science. It seems like you have a misunderstanding of what constitutes science.

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

 

[faen]

Well, I'm glad that helped because it is the basis of Special Relativity.

I mentioned earlier how another observer could create his own Frame of Reference with totally different co-ordinates and how that shouldn't be disturbing. Do you understand this and do you agree it's nothing to be disturbed about?

Yes I realize this. However it is only measurements of the surface of something more mysterious.

 

[faen]

If it can be experimentally tested then it is science, if it cannot then it is not science. That is the key defining characteristic of science. It seems like you have a misunderstanding of what constitutes science.

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

I think I understand this concept better than whatever philosophers even came up with this idea. Anyway, this is the first link which came up when I googled if string theory is experimentally tested. http://io9.com/5714210/string-theory-fails-first-major-experimental-test

This means that string theory isn't physics anymore? Or perhaps you could explain to me why string theory is still science even if it can't be experimentally verified?

 

[Dale]

I think I understand this concept better than whatever philosophers even came up with this idea.

What are you referring to by "this idea" and "this concept"?

Anyway, this is the first link which came up when I googled if string theory is experimentally tested. http://io9.com/5714210/string-theory-fails-first-major-experimental-test

This means that string theory isn't physics anymore? Or perhaps you could explain to me why string theory is still science even if it can't be experimentally verified?

That link is a pop-sci link, not a scientific reference, so I am not sure about the report at all. However, I agree in general that string theory is not exempt from the experiment requirement. In order to be a scientific theory it must make experimentally testable predictions.

 

[ghwellsjr]

Well, I'm glad that helped because it is the basis of Special Relativity.

I mentioned earlier how another observer could create his own Frame of Reference with totally different co-ordinates and how that shouldn't be disturbing. Do you understand this and do you agree it's nothing to be disturbed about?

Yes I realize this. However it is only measurements of the surface of something more mysterious.

Something more mysterious? What is mysterious about Einstein's definition of a Frame of Reference?

 

[faen]

What are you referring to by "this idea" and "this concept"?

I didn't even read the article, but how about this; I think that a fundamental yet consistent assumption somewhat increases reliability, even without being tested. As opposed to a less fundamental assumption, e.g. that the universe was created in 7 days by something with human thinking characteristics/emotional patterns and appearance.

 

[faen]

Something more mysterious? What is mysterious about Einstein's definition of a Frame of Reference?

The thing is that a definition isn't objective it is subjective. Then by definition of definition it's objective "explanation" becomes "mysterious".

 

[ghwellsjr]

Something more mysterious? What is mysterious about Einstein's definition of a Frame of Reference?

The thing is that a definition isn't objective it is subjective. Then by definition of definition it's objective "explanation" becomes "mysterious".

Definitions are arbitrary. Every language has its own dictionary which is nothing more than the authoritative collection of definitions for that particular language. You can't use a definition from the dictionary of one language as the definition in another language. In Special Relativity, we accept the definitions provided by Einstein and although they are arbitrary, we accept them, otherwise, we cannot discuss the theory. Do you want to learn the theory or not?

 

[ZapperZ]

Locked, pending moderation.

Zz.