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Light Speed, Are We Talking Relativity?

Light speed relativity

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#154 Amplituhedron

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Posted Yesterday, 08:50 AM

Yes, well... the past, present and future cannot just exist side by side, without believing the past and future are misnomers for just other present moments. While this could be true, I would never look too deep into it because sometimes physics can chase idea's like ghosts to over-simplify the dynamic structure around us.

 

If you consider Minkowski spacetime, every spacetime event is designated by four coordinates: three of space and one of time.

 

With respect to space, no one has any problem with the idea that “here” is an indexical — i.e., a point of view. “Here” is where I am. But I acknowledge that there are other “heres”, it is just that, from my point of view, I call them “theres.”

 

If Minkowski spacetime is real, as opposed to a mathematical model, then what is true for space, must be true for time as well. What I call “now” is when I happen to find myself. But, just as with space, I can acknowledge that there are other extant “nows” relative to me, only I call them “earlier” and “later.”

 

If we return to Einstein’s original relativistic train though experiment, it seems we have powerful evidence that the future must exist, relative to our own present. The rider on the train sees the lightning flash first at the front of the train, but sometime later, in his/her own future, sees the lightning flash at the back of the train. Meanwhile, the observer on the ground has seen both flashes simultaneously.

 

What are we to conclude? Although the rider on the train doesn’t it know it yet, he/she is guaranteed, sometime later, to see a lightning flash at the back of the train. The conclusion seems inescapable: The future is not open. It is just as fixed as the past.



#155 Dubbelosix

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Posted Yesterday, 08:52 AM

If you consider Minkowski spacetime, every spacetime event is designated by four coordinates: three of space and one of time.

 

With respect to space, no one has any problem with the idea that “here” is an indexical — i.e., a point of view. “Here” is where I am. But I acknowledge that there are other “heres”, it is just that, from my point of view, I call them “theres.”

 

If Minkowski spacetime is real, as opposed to a mathematical model, then what is true for space, must be true for time as well. What I call “now” is when I happen to find myself. But, just as with space, I can acknowledge that there are other extant “nows” relative to me, only I call them “earlier” and “later.”

 

If we return to Einstein’s original relativistic train though experiment, it seems we have powerful evidence that the future must exist, relative to our own present. The rider on the train sees the lightning flash first at the front of the train, but sometime later, in his/her own future, sees the lightning flash at the back of the train. Meanwhile, the observer on the ground has seen both flashes simultaneously.

 

What are we to conclude? Although the rider on the train doesn’t it know it yet, he/she is guaranteed, sometime later, to see a lightning flash at the back of the train. The conclusion seems inescapable: The future is not open. It is just as fixed as the past.

 

Events in spacetime can happen for different observers, this is known as simulteneity. No one disputes this, but what it means essentially at the core is that there is no preferred frame of reference, when it comes to moving observers.

 

Since everything is in motion, we need to redefine a two body problem into a three body problem in which you are at rest relative to the Earth.



#156 Mattzy

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Posted Yesterday, 11:45 PM

If you use a history of positions, you are employing a concept of time. 

Yes, a human concept. I'm not saying that I don't have a problem. I just can't give this concept a name and accept it as fact when I can't define it.

It's interesting that you talked of positive and negative numbers. That got me thinking because numbers are also uniquely human notation - as I suspect time is. 

Both are instrumental in the human mode of operation. They may be used at lower levels by other life forms - as 006 has said - which suggests genetic origin by random mutation - a useful tool.



#157 Mattzy

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Posted Today, 12:25 AM

Without time there could not be such a thing as musical pitch. 

Good point exchemist. But it goes to my problem of what is between the beats of a clock. It's the same question. What is between the pressure waves of sound?

It just occurred to me that there is absence. If we have a comparative reference frequency in our internal brain clock, then we can measure the absence of events.

So if the pressure wave at the ear is a recorded and memorised event, and we have a small number count between events, then we hear a high frequency. The highest frequency that we can hear tells us what our processing capacity is - or some other limitation - maybe mechanical.

This is not time, this is a ratio of event to absence. I reason here that life forms use regular frequencies and time has evolved in our minds.

What is between the beats? Answer: Nothing that we are concerned with for that task ie. hearing.

If there are a billion beats and nothing is detected then we have a billion beats recorded and a sense of a long time. But that sense is purely human. The universe has simply existed as matter and energy.

I think I can adjust to that acceptance as logical - until I'm convinced otherwise.



#158 Mattzy

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Posted Today, 12:40 AM

No time is not just a human conception, all animals run with chronological cycles. This gene is not specific to us alone.

This fits with the idea that time is a concept born of genetics and is at various levels of evolution depending on the species. I'll go along with that.



#159 Dubbelosix

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Posted Today, 12:45 AM

This fits with the idea that time is a concept born of genetics and is at various levels of evolution depending on the species. I'll go along with that.

 

In physics, it so much more than a human conception. Things with ''mass'' experience time. Without time, we have no concept of curvature as a manifested observable in three dimensional space. In physics, time is an inherent and intrinsic property of the quantization of space (Planck time). So no, I would not say genetics gave rise to time, it already existed before we had a concept of it.



#160 exchemist

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Posted Today, 03:34 AM

Good point exchemist. But it goes to my problem of what is between the beats of a clock. It's the same question. What is between the pressure waves of sound?

It just occurred to me that there is absence. If we have a comparative reference frequency in our internal brain clock, then we can measure the absence of events.

So if the pressure wave at the ear is a recorded and memorised event, and we have a small number count between events, then we hear a high frequency. The highest frequency that we can hear tells us what our processing capacity is - or some other limitation - maybe mechanical.

This is not time, this is a ratio of event to absence. I reason here that life forms use regular frequencies and time has evolved in our minds.

What is between the beats? Answer: Nothing that we are concerned with for that task ie. hearing.

If there are a billion beats and nothing is detected then we have a billion beats recorded and a sense of a long time. But that sense is purely human. The universe has simply existed as matter and energy.

I think I can adjust to that acceptance as logical - until I'm convinced otherwise.

But if you say it "has" existed, you are speaking of the past being something real. This again, like the succession of beats that make up a musical pitch, is something that requires that time is real.   



#161 Dubbelosix

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Posted Today, 04:20 AM

The only definition of time, we know for sure, the present moment by its truest definition. If anything breaks out of a present moment and is able to dilate time, then yes, time has real effects and it shouldn't be ignored. The past is something always behind and the future is like grasping to a present moment that just feels like it right round the corner. Succession, as Exchemist says, requires a notion of time. Two clocks synchronised then placed into gravitational fields, will always detect the one in the gravitational field ''as having slowed down.'' This requires a frame of reference to compare to another - which means change does happen and wherever a change exists, must in my opinion, involve a concept of how clocks tick. 


Edited by Dubbelosix, Today, 04:39 AM.


#162 Dubbelosix

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Posted Today, 04:44 AM

As Hestenes has rightly figured, energy is a frequency (but to it I add may not sufficient to explain time), in which energy is a ''diffused mass''
 
[math]E = \hbar \omega[/math]
 
Only matter can act as sufficient clocks, hence why mass is an energy (concentrated energy),
 
[math]E = mc^2[/math]
 
By binding the two we realize that mass is also a frequency, first observed by DeBroglie;
 
[math]\omega = \frac{mc^2}{\hbar}[/math]
 
Such that a mass has a periodic function
 
[math]\Psi(t) = e^{i \omega t}[/math]
 
It is this periodic function which can slow down - an atom can be replaced with the notion of a clock so long as we can detect a change in the system. It becomes fuzzy with particles like a photon because relativity states time no longer exists because the photon itself has no frame of reference, but to an observer on Earth, it certainly does take some time for a photon to leave the sun and reach Earth because stated quite simply, we have a frame of reference in which to apply that to.


#163 Dubbelosix

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Posted Today, 04:47 AM

And, for any matter, the periodic function may change, it can slow down, it can even stretch. This is the wonderful yet complicated world of relativity. It doesn't mean however an atom cannot decay, it just means that its periodic function can change indicating a longer life time (see experiments on Muons). There is a way however to make sure an atom may not decay and that requires a very subtle but accurate way in which we use other particles, like light for instance, to interact with the atom in such a way that it can theoretically remain infinitely stable! Do it the wrong way though and you can in fact speed up the process of its decay (the Zeno and anti-Zeno effect).



#164 sluggo

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Posted Today, 09:53 AM

exchemist#143;

 

It seems to me that once you get to this level, everything is "in the mind", so one might just as well redefine reality to be what is "in the mind", since otherwise we cannot function in the world at all.

 

[Perception is reality confined to the mind, but not all reality.

I have used the examples of ‘motion pictures’ and display screens to show the mental processing of sequential events as motion where there is no motion.

The Einstein train is another ‘trajectory' example. On the train an object drops vertically to the floor, while a platform observer describes its path as curved. How can one object have multiple paths? 

The reason is observer dependent. On the train the object has acquired the speed of the train. The observer on the platform has not.]

 

I think the notion that motion and change are illusions is a useless idea, leading to absurd results

 

.

 

[Lack of consideration of perception is one of the problems leading to protesters claiming the the results are illogical.]


Edited by sluggo, Today, 09:56 AM.


#165 Dubbelosix

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Posted Today, 01:09 PM

Time is not reserved for us, what part of the periodic function of matter did you not understand? Also, we are not special in terms of ''observers'' as it has been loosely applied in sci-pop books.





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