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The Red Shift without Expansion

 
 
layman
 
  0  
Reply Tue 7 Feb, 2017 07:35 pm
@Krumple,


OK, I watched this video. Pretty standard stuff, but there are still some subtle points that I may want to refer you back to in later posts.
0 Replies
 
layman
 
  0  
Reply Wed 8 Feb, 2017 02:02 am
@Krumple,
Krumps, if I get in my car and drive down the highway at 60 mph, then my subjective perception of the entire universe will be slightly different. Each and every one of the virtually limitless objects in the universe will now look slightly differently to me. My perception of their clocks will change. My perception of their measuring rods will change, etc.

Do you think that I have suddenly made a physical change to everything in the universe by virtue of deciding to drive down the road?

Or would you conclude that the only thing I have changed is my particular state of motion and, therefore, my personal, idiosyncratic, subjective perspective of the world?
Krumple
 
  1  
Reply Wed 8 Feb, 2017 02:23 am
@layman,
layman wrote:

Krumps, if I get in my car and drive down the highway at 60 mph, then my subjective perception of the entire universe will be slightly different. Each and every one of the virtually limitless objects in the universe will now look slightly differently to me. My perception of their clocks will change. My perception of their measuring rods will change, etc.

Do you think that I have suddenly changed everything in the universe by virtue of deciding to drive down the road?

Or would you conclude that the only thing I have changed is my particular state of motion and, therefore, my personal, idiosyncratic, subjective perspective of the world?


Its even more strange than the two conclusions you offer me.

Motion not only affects perspective it impacts time and space itself.

The beauty of it is knowing we are actually not caged by time. And yes time is an arbitrary unit of measure like meters, quarts and grams.

The consequences are strange. If time slows down for objects near C, is it the same for photons?

If yes then it's possible there is another paradox.

If time relative to the photon is slower than the observer of that photon, it means two things.

Photons are younger than they appear.
The speed of light itself might be a paradox in of itself.

If we were to match the two reference frames it would mean the photon doesn't actually cover the distance that it appears to cover by the observer.

It is as if the photon is skipping ahead of itself. Sort of like an image of an object proceeds its actual appearance.

Imagine you see an image of a car speeding then suddenly stop at a stop sign. Then following the image the "real" car copies what you already saw happen a few moments earlier.

So it isn't that a photon travels a great distance in a second (because that "second" was the observer reference frame, NOT the photon's second.

The photon's "second" is far longer than the observer's "second". Not a little bit longer. A lot longer!

So it only appears to travel as far as it does to the observer because of the difference in time.
layman
 
  0  
Reply Wed 8 Feb, 2017 03:04 am
@Krumple,
1. Do you have an answer to the question I just asked?
2. Do you have an answer to the question I asked earlier?

You make a lot of statements in this post, and you raise some interesting questions. I don't want to keep changing the topic with every post, though.

Per SR, as I understand it, at c time stops, distances shrink to nothing, and mass becomes infinite.

If you take this literally, then you could go back and forth across the universe (the distance would be zero) millions of times in no time at all (because time has stopped), even though your mass is infinite.

Of course those are just mathematical conclusions. It's hard to fathom the practical, physical meaning of such claims.
Krumple
 
  1  
Reply Wed 8 Feb, 2017 10:14 am
@layman,
layman wrote:

1. Do you have an answer to the question I just asked?
2. Do you have an answer to the question I asked earlier?

You make a lot of statements in this post, and you raise some interesting questions. I don't want to keep changing the topic with every post, though.

Per SR, as I understand it, at c time stops, distances shrink to nothing, and mass becomes infinite.

If you take this literally, then you could go back and forth across the universe (the distance would be zero) millions of times in no time at all (because time has stopped), even though your mass is infinite.

Of course those are just mathematical conclusions. It's hard to fathom the practical, physical meaning of such claims.


Time doesn't stop at C.

If time stops at C, nothing else can happen. You can't move at all without time. Its a necessary component to motion.

Also ONLY objects with mass to start with would have infinite mass at C. A photon has no mass but doesn't have infinite mass at C. Infact its actually impossible to get an object with mass to reach C. It would require infinite energy to achieve that last bit of acceleration to reach C. You can however; reach 99% of C with mass. They do it with electrons in colliders.

Krumple
 
  1  
Reply Wed 8 Feb, 2017 10:15 am
@layman,
layman wrote:

Krumps, if I get in my car and drive down the highway at 60 mph, then my subjective perception of the entire universe will be slightly different.

Do you think that I have suddenly made a physical change to everything in the universe by virtue of deciding to drive down the road?

Or would you conclude that the only thing I have changed is my particular state of motion and, therefore, my personal, idiosyncratic, subjective perspective of the world?


1. No.
2. No.
layman
 
  0  
Reply Wed 8 Feb, 2017 01:21 pm
@Krumple,
Krumple wrote:

layman wrote:

Krumps, if I get in my car and drive down the highway at 60 mph, then my subjective perception of the entire universe will be slightly different.

Do you think that I have suddenly made a physical change to everything in the universe by virtue of deciding to drive down the road?

Or would you conclude that the only thing I have changed is my particular state of motion and, therefore, my personal, idiosyncratic, subjective perspective of the world?


1. No.
2. No.


With respect to answer 2, I noticed that you made the vague claim that my little drive changed space and time somehow. For whom? The whole universe, or just for me?

Have I changed what time is? Have I changed what space is?

I will grant you that my motion has caused my watch to slow some, for example. But that would just be MY watch, and it wouldn't affect "time" for any other object in the universe. Is that all you're trying to say? That was included in what I said, by implication.

Quote:
Or would you conclude that the only thing I have changed is my particular state of motion...


0 Replies
 
layman
 
  0  
Reply Wed 8 Feb, 2017 01:34 pm
@Krumple,
Krumple wrote:

Time doesn't stop at C.

If time stops at C, nothing else can happen. You can't move at all without time. Its a necessary component to motion.


Well, I agree that it's not really clear what it would mean, as a physical matter, to say that "time stops." I already noted that when I said:

Quote:
Of course those are just mathematical conclusions. It's hard to fathom the practical, physical meaning of such claims.


But are you denying that, as a theoretical, mathematical matter, SR predicts that all clocks would cease to quit ticking at C? There would be no more accumulation of "time elapsed?"

Of course this raises other questions of interest. What do we mean by "time?" Is it different than just being "what clocks measure?"

If I die, I guess you could say that, for me, time stops. But of course the rest of the world just keeps on spinning. It would just be my subjective perception and sensation of time that stopped, not time itself.

Likewise, time might temporarily "stop," for me, if i was put into "suspended animation" for a year. But again, that would just be for me alone--it would affect time itself or any other object in the universe.
Krumple
 
  1  
Reply Wed 8 Feb, 2017 01:47 pm
@layman,
layman wrote:

Krumple wrote:

Time doesn't stop at C.

If time stops at C, nothing else can happen. You can't move at all without time. Its a necessary component to motion.


Well, I agree that it's not really clear what it would mean, as a physical matter, to say that "time stops." I already noted that when I said:

Quote:
Of course those are just mathematical conclusions. It's hard to fathom the practical, physical meaning of such claims.


But are you denying that, as a theoretical, mathematical matter, SR predicts that all clocks would cease to quit ticking at C? There would be no more accumulation of "time elapsed?"

Of course this raises other questions of interest. What do we mean by "time?" Is it different than just being "what clocks measure?"



A clock is no different than a tape measure or ruler. We have arbitrarily set the units of seconds, minutes, hours length.

Time ONLY changes for the "object's" reference frame to stay in sync.
layman
 
  0  
Reply Wed 8 Feb, 2017 01:54 pm
@Krumple,
Krumple wrote:


A clock is no different than a tape measure or ruler. We have arbitrarily set the units of seconds, minutes, hours length.

Time ONLY changes for the "object's" reference frame to stay in sync.


OK, I agree with this.

The IMPORTANT point here, as far as I'm concerned, is to always keep in mind that there is a difference between subjective perception and objective reality. This is a distinction that people can easily lose sight of when discussing topics like SR.

I later added the following to that post, which you may not have seen:

If I die, I guess you could say that, for me, time stops. But of course the rest of the world just keeps on spinning. It would just be my subjective perception and sensation of time that stopped, not time itself.

Likewise, time might temporarily "stop," for me, if i was put into "suspended animation" for a year. But again, that would just be for me alone--it would not affect time itself or any other object in the universe (well, except for the physical elements that my body is composed of, I mean).
Krumple
 
  1  
Reply Wed 8 Feb, 2017 03:14 pm
@layman,
layman wrote:

Krumple wrote:


A clock is no different than a tape measure or ruler. We have arbitrarily set the units of seconds, minutes, hours length.

Time ONLY changes for the "object's" reference frame to stay in sync.


OK, I agree with this.

The IMPORTANT point here, as far as I'm concerned, is to always keep in mind that there is a difference between subjective perception and objective reality. This is a distinction that people can easily lose sight of when discussing topics like SR.

I later added the following to that post, which you may not have seen:

If I die, I guess you could say that, for me, time stops. But of course the rest of the world just keeps on spinning. It would just be my subjective perception and sensation of time that stopped, not time itself.

Likewise, time might temporarily "stop," for me, if i was put into "suspended animation" for a year. But again, that would just be for me alone--it would not affect time itself or any other object in the universe (well, except for the physical elements that my body is composed of, I mean).


Here is another way to put it.

If C was not maximum velocity, time would not change in any reference frame at all.

Since the speed of light is maximum velocity time must adjust so that all objects including other sources of light do not exceed light speed. Most do not rephrase it like this because our perception of time is difficult to grasp when talking about two reference frames having different time frames.
layman
 
  0  
Reply Wed 8 Feb, 2017 03:25 pm
@Krumple,
Krumple wrote:

Here is another way to put it.

If C was not maximum velocity, time would not change in any reference frame at all.


This is wrong.

It does touch on some very important distinctions between SR and LR, however.

It is simply a demonstrated fact that clock rates vary with speed. No "theory" can alter that observation. That would happen whether or not c is a maximum velocity.

LR fully acknowledges, and incorporates into it's theory, changing clock rates.

And it's no wonder that it does. Einstein "stole" the lorentz transform, whole cloth, from Lorentz--who did NOT posit that the speed of light was "absolute."
0 Replies
 
layman
 
  0  
Reply Wed 8 Feb, 2017 03:44 pm
Quote:
In special relativity, a faster-than-light particle would have space-like four-momentum, in contrast to ordinary particles that have time-like four-momentum. Although in some theories the mass of tachyons is regarded as imaginary, in some modern formulations the mass is considered real, the formulas for the momentum and energy being redefined to this end.
0 Replies
 
layman
 
  0  
Reply Wed 8 Feb, 2017 04:48 pm
@Krumple,


This is basically just a re-formulation of the classic "twin paradox." Anyone with much familiarity with SR is well-aware of it.

It's also a very good illustration of the main difference between SR and LR, too.

In this clip, Carl Sagan himself uses the word "paradox," but he does so in a way that completely misstates the nature of the so-called "paradox."

Tell me, Krump, (or anyone who is interested), what is the "paradox" in the twin deal? Most people I've talked to get it wrong.

layman
 
  0  
Reply Wed 8 Feb, 2017 06:07 pm
@layman,
layman wrote:

Tell me, Krump, (or anyone who is interested), what is the "paradox" in the twin deal? Most people I've talked to get it wrong.


Hint: Here's a definition of the word "paradox:"

Quote:
a statement or proposition that, despite sound (or apparently sound) reasoning from acceptable premises, leads to a conclusion that seems senseless, logically unacceptable, or self-contradictory.


Here's another:

Quote:
a situation, person, or thing that combines contradictory features or qualities.
0 Replies
 
layman
 
  1  
Reply Wed 8 Feb, 2017 07:29 pm
@Krumple,
Krumple wrote:

Since the speed of light is maximum velocity time must adjust so that all objects including other sources of light do not exceed light speed. Most do not rephrase it like this because our perception of time is difficult to grasp when talking about two reference frames having different time frames.


Yeah, I think this is a good insight, with one exception. This does not result from the speed of light being the "maximum" velocity. It is a necessary consequence of the postulate that the speed of light is "constant" in all inertial frames of reference.

This is what I was getting at in my post regarding cars travelling between Chicago and New Orleans.

https://able2know.org/topic/363445-15#post-6352460
Krumple
 
  1  
Reply Wed 8 Feb, 2017 07:50 pm
@layman,
layman wrote:
Yeah, I think this is a good insight, with one exception. This does not result from the speed of light being the "maximum" velocity. It is a necessary consequence of the postulate that the speed of light is "constant" in all inertial frames of reference.


Yes that is a better way to state it but my point of maximum velocity is for any single reference frame it IS maximum.

layman wrote:

This is what I was getting at in my post regarding cars travelling between Chicago and New Orleans.

https://able2know.org/topic/363445-15#post-6352460


I'll have to go back and check it out.

0 Replies
 
Krumple
 
  1  
Reply Wed 8 Feb, 2017 08:04 pm
@layman,
I went back and read you Chicago to New Orleans explanation.

I have two initial arguments for the comparison.

The first is if measuring velocity was so arbitrary as saying the watch was bad or he took a different route there is still a distance to time ratio that must play out. But I understand your objection even though it would render all measurements flawed.

But you are not far off from my explanation of light not being bent by gravity, instead space is bent and light travels in a straight line following the bend in space. So from the light's (photon) perspective it always travels in straight lines but if space is bent in the presence of matter then the light appears to curve.

So light near a black hole is not bent in unable to escape, instead the space near the black hole is bent headed toward it. So light just follows the straight path of space which is curved.

layman
 
  1  
Reply Wed 8 Feb, 2017 08:09 pm
@Krumple,
Quote:
The first is if measuring velocity was so arbitrary as saying the watch was bad or he took a different route there is still a distance to time ratio that must play out. But I understand your objection even though it would render all measurements flawed.


Yeah, you're right. That example was greatly over-simplified in terms of detail. Obviously it's not that arbitrary.

It was just a simplified way of making the basic point, which was this:

Once you dogmatically dictate a supposedly "necessary" outcome, then you will have to adjust to "facts" to agree with the (pre-established) result.
0 Replies
 
layman
 
  1  
Reply Wed 8 Feb, 2017 08:16 pm
@Krumple,
Krumple wrote:

But you are not far off from my explanation of light not being bent by gravity, instead space is bent and light travels in a straight line following the bend in space. So from the light's (photon) perspective it always travels in straight lines but if space is bent in the presence of matter then the light appears to curve.


Well, that sounds like GR's explanation too. If you define a "straight line" as "the shortest distance between two points," then the nature of a "straight line" will depend on the nature of the "surface" you're working on.

Al had to abandon Euclidean plane geometry in favor of a "Reimannian" geometry where parallel lines WILL meet, etc. A "straight line" will be curved on the surface of a globe, like earth, for example.
 

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