Direction of velocities in SR

[kamil]

Is time dilation a result of light consistency or is light consistency a

result of time dilation? Because I have accepted the second, and from it

came a paradox that is stuck in my mind. Firstly, it says that light moves at the same speed in every DIRECTION for every observer because the observers have different notions of time. And that the time dilation is directly due to speed(not velocity since direction doesnt matter).

So under these circumstances(If they are right) what would happen if i travelled north and chased a light beam heading north and at the same time saw a light beam heading south(towards me).

 

The first postulate of realitvity states that the light beams would move(in my perspective) at the same speed. And SR says that is because time has dilated for me. But if time dilation is the only factor that makes the light beam heading north go at 'c', then it clearly wouldn't make the light beam heading south heading 'c' contradicting the first postulate.

[xersan]

You have an uninfected (independent) brain. But you have difficulties to tell the others. Because they are infected by the fantastic conclusions of SR. I have trial about this case. And they sanctify the theory as a cult. They can not be rescued from the influance of localitive axioms.

 

Time contraction is possible in SR by taking (-) v (or c) for the opposite directions. The relations of SR (Lorentz's eq.) gives also "Time contraction" . But the blinker story in the science ( Murphy of science) is dominant.

[kamil]

You have an uninfected (independent) brain. But you have difficulties to tell the others. Because they are infected by the fantastic conclusions of SR. I have trial about this case. And they sanctify the theory as a cult. They can not be rescued from the influance of localitive axioms.

 

Time contraction is possible in SR by taking (-) v (or c) for the opposite directions. The relations of SR (Lorentz's eq.) gives also "Time contraction" . But the blinker story in the science ( Murphy of science) is dominant.

 

I didnt quite under stand what u ment by 'But the blinker story in the science ( Murphy of science) is dominant'. Anyway, can you answer my question or explain to me time dilation and the way it affects velocities in oppisite directions. By the way my brain is infected with the SR but if you admire Einstein than you should try to prove him wrong because he tried to prove Newton wrong, so if you want 2 continue Einsteins legacy than you should always be independent, other wise you'd be just as bad(or even worse) than a Newtonian.

[Qfwfq]

What's bad about a Newtonian?

 

Einstein didn't try to prove that Newton is wrong. Actually, he showed that Newton and Galileo weren't wrong.

[UncleAl]

Einstein didn't try to prove that Newton is wrong. Actually, he showed that Newton and Galileo weren't wrong.

 

Special Relativity unifies Newton (who assumed lighspeed was infinite, which is simpler and wrong) with Maxwell (who in turn unified electricity and magnetism using finite lightspeed) less gravitation. General Relativity adds gravitation. Both Newton and Galileo are wrong. The universe is Lorentzian.

 

Is time dilation a result of light consistency or is light consistency a result of time dilation?

Special relativity is Newton corrected for there being a finite lightspeed. SR is a self-consistent geometry. It postulates Lorentz Invariance. The three spatial and one temporal variables are components of the complete spacetime vector. As you hyperbolically rotate the geometry with velocity the vector stays constant as its components ooze and slosh amongst themselves.

[Qfwfq]

Special Relativity unifies Newton (who assumed lighspeed was infinite, which is simpler and wrong) with Maxwell (who in turn unified electricity and magnetism using finite lightspeed) less gravitation. General Relativity adds gravitation. Both Newton and Galileo are wrong.

Newton did not assume lighspeed was infinite, give a read to Philosophiae Naturalis Principia Matematica, which you have oft so Knowlegeably cited. Apparently without having read it.

 

Maxwell didn't use finite lightspeed, it popped out as a result. Mostly, it popped out in modulus, as a scalar, in a manner conflicting with Galilean relativity. Galileo was the first to state the principle of relativity, without calling it this. Newton argued for this principle based on his three axioms and even stated the principle of equivalence, as a corollary of them. He too did not give it this name.

 

Galileo and Newton weren't wrong. They did not state anything wrong, they simply lacked a fact or two. Point out something stated by them as a fact, not as a conjecture or speculation or simply a conclusion affected by lack of the fact of c being invariant, that is actually wrong.

 

Special relativity is Newton corrected for there being a finite lightspeed.

:rolleyes:

It is Newton corrected for the geometry of space time, with the property of the velocity c being invariant. A finite lightspeed wouldn't have so many implications, c isn't just the speed of light. If you don't understand this, don't presume to teach me what I learned in my physics courses.

[UncleAl]

Galileo and Newton weren't wrong. They did not state anything wrong, they simply lacked a fact or two.

An axiomatic system containing a demonstrated untrue postulate is falsified in all parts that depend upon the counterdemonstrated postulate.

 

Galilean transforms in Newton are, as Euclid is, wrong - though the proper word might be "incomplete." Euclid fell in the mid-1800s when Riemann and Bolyai-Lobechevsky demonstrated that self-consistent geometries result when an infinite or zero number of lines parallel to a given line, respectively, are postulated. Euclid's Fifth Postulate demands there be exactly one. All three classes of geometry together are in turn incomplete given

 

WP Thurston, "Three-dimensional manifolds, Kleinian groups and hyperbolic geometry," Bull. Amer. Math. Soc. 6 357-381 (1982)

 

If you have any doubt that Eucild was wrong, try surveying or navigating using Euclidean geometry. A mile square is not a square mile on the surface of the Earth. Its interior angles cannot all be 90 degrees and its opposite sides will not be parallel.

 

Newton knew lightspeed was large but finite. However, his physics postulates instantaneous action at a distance. That is c=infinity. It is a good approximation given common experience, and it is wrong. His logic is self-consistent. One of his founding postulates, as with Euclid's Parallel Postulate, does not obtain in the real world.

 

One thing Maxwell derived based on an aether-like medium was the particular form of the constitutive relations that in modern notation would have read:

 

D = epsilon_0 (E + G x :rolleyes:

 

where G is the velocity relative to the frame defined by the vacuum. (The corresponding relation for B and H would therefore read B = mu_0 (H - G x D)). This in fact is NOT what is currently known as Maxwell's theory - that has the constitutive relations

 

D = epsilon_0 E; B = mu_0 H.

 

that come from Lorentz.

 

The two theories

 

D = epsilon_0 (E + G x :naughty:; B = mu_0 (H - G x D)

versus

D = epsilon_0 E; B = mu_0 H

 

are NOT empirically equivalent. The former - the one that would be invariant under Galilean Relativity and true if Newtonian physics were true - is seriously out of kilter with the reality. Swimming pools would assume weird colorations given the dependence of D on B. The latter - invariant under Poincare Relativity and true if Special Relativity holds - is the one you actually see. Hence, no "aether frame". The reformulation was covariant without further manipulation.

 

Einstein reconciled Newton with Maxwell by explicitly inserting a finite value for lightspeed in Newton, making it the maximum speed at which information could convey, causing invisible terms in Newton (given c=infinity) to appear. As with Euclid vs. curved geometries, the theoretical framework remained valid while a founding postulate was corrected. Now, turn the handle again.

 

Special Relativity is immensely robust. SR appears to be bulletproof after 100 years of serious, voluminous challenges. General Relativity takes SR and further postulates that all bodies fall identically in vacuum - the Equivalence Principle - that inertial and gravitational masses are fundamentally indistinguishable. This originates spacetime curvature and gravitation. Poof! Just like that.

 

If you can supply two lumps that do not fall identically in vacuum - identical rates and parallel paths - General Relativity is falsified without ever having made a bad prediction vs. observation. Its founding postulate goes down and GR goes down with it. Within one part in ten trillion difference/average all chemical compositions, spinning bodies, magnets, superconductors, binding energies... and hyper-bound, hyper-spinning, hyper-magnetized, superconducting neutronium (binary pulsars) all fall by the book.

 

The last possible difference between two lumps is being tested as you read this. Final results are due in mid-September. If there is an Equivalence Principle anomaly finally detected it will be smaller than 10 parts-per-trillion given current data accumulation. That drops to 1 ppt in mid-August, this month - or, we see it. 0.1 ppt in mid-September. At that point we are seeing thermal jitter of the apparatus' atoms and can go no further.

[Qfwfq]

An axiomatic system containing a demonstrated untrue postulate is falsified in all parts that depend upon the counterdemonstrated postulate.

Newton gives three axioms in Principia. Which of these is demonstrated untrue?

 

Galilean transforms in Newton are, as Euclid is, wrong - though the proper word might be "incomplete."

Euclidean geometry is a branch of mathematics, how can you say that it's wrong? It's got nothing to do with surveying or navigating and even less to do with the surface of Earth. In SR, space-time is minkowskian but space is euclidean. The same aplies locally in GR.

 

Don't bring in irrelevant things just to confuse the matter. There's no need for you to tell me about Riemann and Bolyai-Lobechevsky.

 

Newton knew lightspeed was large but finite. However, his physics postulates instantaneous action at a distance. That is c=infinity.

Why then did you say that "Special relativity is Newton corrected for there being a finite lightspeed" as if Newton had postulated infinite lightspeed? The fact is that there's a difference between stating finite lightspeed and stating that there is a finite c and Minkowskian geometry. I cannot remember Newton's Principia postulating the action being instantaneous, where exactly do I find that? Tell me, and I'll check my copy at home.

 

I can't claim to have looked in detail at Maxwell's original 17 equations but I suspect the velocity G you mention, like the talk of the ether, came about because of the problem of the propagation velocity appearing as a scalar. I say this on grounds of what makes sense and what doesn't, from the point of view of scientific history.

 

Special Relativity is immensely robust. SR appears to be bulletproof after 100 years of serious, voluminous challenges. General Relativity takes SR and further postulates that all bodies fall identically in vacuum - the Equivalence Principle - that inertial and gravitational masses are fundamentally indistinguishable. This originates spacetime curvature and gravitation. Poof! Just like that.

The principle of equivalence was quite prior to GR. It started with Galileo and is Corollary VI after the three axioms in Principia, just after axiom V which is the principle of relativity. Quit teaching me SR and GR, I passed quite good courses in them by the time I graduated.

 

The so-called Galilean transformations weren't actually stated in the writings of either Galileo or Newton, they are simply what people naturally use when they don't know about c, or don't care since Lorentz transformations are tangent to them. In one or the other case, we translate Newton's axioms into either the 3-vector equation F = ma or the 4-vector one f_i = m û_i but the axioms are fine.

[EWright]

Yet another simple question turns into another heated debate; and the thread, as it relates to the initial post, decays into nothingess. What a short half life some inquiries have around here. For such a precise science, it's amazing that physicists have such trouble agreeing on so many things. It's no wonder they always revert back to simply believing Einstein.

[Qfwfq]

It's no wonder they always revert back to simply believing Einstein.

I find this a very odd conclusion to draw from the dabate, which had little to do with "just believing Einstein". It was more about understanding the history and the diffuse misconceptions that there are around.

[Tormod]

Yet another simple question turns into another heated debate; and the thread, as it relates to the initial post, decays into nothingess.

 

Huh? This is an excellent thread!