Time Dilation from First Principles

Choose your own first principle(s). This is one of my party pieces so it would be nice to see any links or favourite derivations first.

(Oct 23, 2018 11:48 PM)confused2 Wrote: Choose your own first principle(s). This is one of my party pieces...

Games, sports & hobbies?

Quote:...so it would be nice to see any links or favourite derivations first.

"Any links" in this case, since such doesn't qualify as "favorites" (I'm not reading any further than the openings, so that rules out even possible recreational value as favorite ########). Consequently, there may or may not be any radical alterations in ABCs from mainstream primitives (SRFFP, AWAT:SPFFP, L2:FPOSR&TD[PDF]) -- though on the surface the advertising suggests along that line given the facilitating of pre-conditional end goals.


New time dilation helps creation cosmology
https://creation.com/new-time-dilation-h...-cosmology

INTRO: A new solution of Einstein’s gravitational field equations I published in 20071 clarifies a new type of relativistic time dilation that I call achronicity, or ‘timelessness’. Here I explain achronicity and show how it helps creation cosmology, offering new ways to solve the starlight transit time problem.


Time Dilation Cosmological Models: Exegetical and Theological Considerations
https://answersingenesis.org/astronomy/s...derations/

ABSTRACT: In conjunction with efforts to resolve the light travel time problem, creationists have in recent decades proposed a variety of new cosmological models. Some of these models are contingent on the concept of time dilation, proposing that there was a relatively rapid passage of time—on the order of several billion years—in the distant reaches of the universe while only six days of time elapsed on earth during the Creation Week. This purportedly can account for how starlight from galaxies billions of light years from earth could have reached earth between the time of the creation of the cosmic bodies on Day Four and the creation of man on Day Six. The purpose of this paper is to evaluate such cosmological models from a biblical (exegetical and theological) perspective, seeking to determine if they are consistent with Scripture. The specific interpretive claims of these models will be examined, as well as their overarching implications concerning the principal focus of the Genesis creation narrative and the intent of the biblical author in light of his understanding of the text’s original readers. This paper concludes that these cosmological models are dependent on strained exegesis and that they introduce interpretations dependent on modern scientific ideas that would have been foreign to the original readers.

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Nice one CC. Not sure about the rest but the link to a lecture by the Sheffield Particle Physics and Particle Astrophysics Group is a really good derivation from first principles.
( http://www.hep.shef.ac.uk/edaw/PHY206/Si...06lec2.pdf )

1. All inertial frames are equivalent with respect to the laws of
physics.
2. The speed of light in a vacuum is the same to all observers.

Personally I feel 2. follows from 1. but I wouldn't argue the point if anyone wanted to disagree.

I like the derivation he gives - my only objection is the amount of algebra it generates - all high school stuff but you'd have to be a fairly determined high school student to plod through it. By the time you've substituted this into that the elegance is lost - IMHO an elegant derivation would keep one frame on one side of an equals sign and the other frame on the other side - maybe that's just me.

Any more, maybe not light clocky?

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(Oct 25, 2018 12:20 AM)confused2 Wrote: Nice one CC. Not sure about the rest but the link to a lecture by the Sheffield Particle Physics and Particle Astrophysics Group is a really good derivation from first principles.
( http://www.hep.shef.ac.uk/edaw/PHY206/Si...06lec2.pdf )

I may have misunderstood what you meant by "your own first principles", as I'd expect cranks to largely be indulging in re-conceptions (setting aside creative games / festive activities). Thus the creationist stuff.

=EDIT= A "party game" example below (of sorts), which is what the expression "one of my party pieces" logged on in my cluttered symbol grounding domain as possibly referring to (at the time).

Derive Time Dilation Yourself, Feel Like a Genius
https://sciencebasedlife.wordpress.com/2...-a-genius/

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I do see what CC referred to as the ambiguity of the OP - I (implicitly) meant a derivation from defined first principles - as usual - I knew what I meant.

Looking at abyss.uoregon.edu it seems to be a public posting place - not an academic site. Looking at http://abyss.uoregon.edu/~js/cosmo/lectures/lec06.html (lecture?-I don't think so) the writer seems to picked quite a lot of science words and concepts without really understanding them. He shows a light clock and claims "Therefore, the time between 'ticks' is longer for the moving clock, as seen from the rest frame.". He makes no attempt to calculate by how much one clock runs slower than the other - I'm guessing because he doesn't know how to. A 'derivation' would start from defined assumptions and produce a result along the lines of t= t'√(1-v²/c²).

"Likewise, a photon has no time. It uses all of its spacetime velocity in the spatial direction and has none leftover for time.There is no time for energy. Zero time has passed for a photon created at the beginning of the Universe."

When he writes "There is no time for energy." I feel he got a bit carried away with the science words.

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http://www.emc2-explained.info/ looks like another crackpot site.

Here he claims "E=mc² Solving the Equation"
http://www.emc2-explained.info/Emc2/Equa...9H7dIAnZB0

Nobody with any maths, physics or engineering in their education would refer to this as solving an equation. See https://en.wikipedia.org/wiki/Equation_solving

Back to Syne's link http://www.emc2-explained.info/Time-Dila...9H9bIAnZB1
"This slowing down of clocks due to high speeds is called time dilation and has a precise mathematical relationship." Yup. Unfortunately a claim is not a derivation.

See the link posted by CC for an exemplary derivation of the equation for time dilation from defined assumptions. ( http://www.hep.shef.ac.uk/edaw/PHY206/Si...06lec2.pdf )

From Syne's post:-
"The sum of spatial and time velocity always equals the speed of light."
Citing two crackpot sites doth not a derivation make. Can you (or any link you can find) actually derive a result from your postulate?

C2 seems to be more interested in claiming stuff he doesn't seem to understand is "crackpot" than having any real discussion.

(Oct 25, 2018 08:02 PM)Syne Wrote: C2 seems to be more interested in claiming stuff he doesn't seem to understand is "crackpot" than having any real discussion.

You are totally invited to show that your claims (and sites) aren't "crackpot" - the way to do this is derive time dilation from your (or their) hypothesis. The difference between a claim and a derivation is like the difference between a photograph of a cake and actually making a cake. Make the cake.

(Oct 25, 2018 08:43 PM)confused2 Wrote:

(Oct 25, 2018 08:02 PM)Syne Wrote: C2 seems to be more interested in claiming stuff he doesn't seem to understand is "crackpot" than having any real discussion.

You are totally invited to show that your claims (and sites) aren't "crackpot" - the way to do this is derive time dilation from your (or their) hypothesis. The difference between a claim and a derivation is like the difference between a photograph of a cake and actually making a cake. Make the cake.

That's a lot of talk from someone who has only opined on what others have posted...without deriving anything himself. I'm not impressed with your little homework assignment nor your misunderstanding of pretty basic physics explanations. For example:

"Likewise, a photon has no time. It uses all of its spacetime velocity in the spatial direction and has none leftover for time. There is no time for energy. Zero time has passed for a photon created at the beginning of the Universe."

Since the context of energy is obviously a photon, it can only refer to electromagnetic energy, which moves at c and thus does not "experience" time. That you would be so baffled by that simple statement as to infer crackpottery is a reflection on your knowledge, not that source.

And:
"Nobody with any maths, physics or engineering in their education would refer to this as solving an equation."

Plugging in a mass and solving for its energy is how you solve that equation. The energy is the variable designated as the unknown and cannot be solved for without a known mass. You seem to be talking out of your ass, with zero knowledge of math.



So you've only proven yourself a poser wannabe by trying to call legit sources crackpot, and I never claimed to provide a full derivation, in any of my citations, from my first principle. So quit playing at physics already. It's obviously beyond you.

(Oct 25, 2018 12:20 AM)confused2 Wrote: 1.  All inertial frames are equivalent with respect to the laws of
physics.
2.  The speed of light in a vacuum is the same to all observers.

Personally I feel 2. follows from 1. but I wouldn't argue the point if anyone wanted to disagree.

2 does not follow directly from 1. The laws of physics could easily be the same in all frames without the speed of light being invariant, just like any other relative speed is not invariant between frames. 1 is just Galilean relativity...which basically only means that all velocity is only relative velocity. So without 2, the speed of light could be a different relative velocity depending on the motion of the frame.