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Why this continual resort to individual "reference-frames"?
What have they got to do with physical reality?
I mean, suppose you fell out of an aircraft flying at 20,000 feet..During the time you were falling, you might think " Hey this great! I'm in my own individual reference-frame! Just me! No more aircraft! I'm independent of it! I can move my legs and arms about freely, without even feeling any gravity! There's only air, seeming to rush past, but I can cope with that!Hang on though - what's this underneath me approaching fast - it must be the ground. Well sucks to the ground and its reference frame - I'm in my own individual reference fra.........
Thanks Mike. When you refer to "negative ageing" do you mean that the CMIF method makes people get younger?
Quote from: charles1948 on 14/04/2021 21:49:50Why this continual resort to individual "reference-frames"?Because that's how relativity works.Quote from: charles1948 on 14/04/2021 21:49:50What have they got to do with physical reality?Everything. Times and distances are different for observers in different reference frames.Quote from: charles1948 on 14/04/2021 21:49:50I mean, suppose you fell out of an aircraft flying at 20,000 feet..During the time you were falling, you might think " Hey this great! I'm in my own individual reference-frame! Just me! No more aircraft! I'm independent of it! I can move my legs and arms about freely, without even feeling any gravity! There's only air, seeming to rush past, but I can cope with that!Hang on though - what's this underneath me approaching fast - it must be the ground. Well sucks to the ground and its reference frame - I'm in my own individual reference fra.........What do you think this is supposed to prove?
Perhaps nothing, except that modern physics is losing touch with reality.
I mean, do you really and truly believe that the Higg's Boson and Gravitational Waves have been proved to exist?
Quote from: charles1948 on 14/04/2021 22:15:54Perhaps nothing, except that modern physics is losing touch with reality.You're going to need to explain why someone falling towards to ground is supposed to illustrate that.Quote from: charles1948 on 14/04/2021 22:15:54I mean, do you really and truly believe that the Higg's Boson and Gravitational Waves have been proved to exist?No, because there is no such thing as proof in science. There is very good evidence for them, however.
These days there are no photographs.
The trouble is that the "evidence" for supposed particles like the Higgs Boson, and Gravitational Waves, seems to rely on statistical analysis of "meter readings" and extrapolations from graphical charts.
Quote from: charles1948 on 14/04/2021 22:31:31These days there are no photographs.The other day, you were complaining that we are still talking about wind power. Today you are complaining that we no longer use old methods.When you have finished arguing with yourself, let us know who won.In the mean time, you might want to consider that the half life of the Higgs Boson is about 10^-21 of a second.Travelling at roughly the speed of light, it would cover a ten billionth of a millimetre or about 1/100 of the diameter of a hydrogen atom before it fell apart.How, exactly, would you propose to get a picture of that?
This is very different from the old days when particle physics employed Bubble Chambers, in which the ionised tracks left by particles could be actually seen and photographed.These days there are no photographs.
If I was told that a supposed "particle" couldn't exist long enough to travel across 1/100th the diameter of a hydrogen atom before it fell apart, I would strongly suspect that the "particle" didn't actually exist in the first place.So I wouldn't waste time trying to take a picture of it.
Is that possible, do you think?
So I wouldn't waste time trying to take a picture of it.
'Come to rest' is dang undefined without frame reference. If the ship is constantly accelerating, then it is gaining speed and not coming to rest. It can cease accelerating and therefore be at rest in its own frame, but the clocks will be very out of sync after that.
I HAVE chosen a coordinate system.
The coordinate system I chose defines the spatial origin to be where the observer who sometimes accelerates is. The purpose of the coordinate system is to allow that observer to determine the spatial position and the current age of any distant person of interest.
But the problem of interest to me is that the concept of simultaneity inherent in that definition is not universally agreed upon
The most widely used simultaneity method (by far) is CMIF (co-moving inertial frames) simultaneity.
The well-known physicist Brian Greene is not so disturbed, and gives the most startling example of negative ageing
When you refer to "negative ageing" do you mean that the CMIF method makes people get younger.
Suppose Marconi had been told, as he probably was, that meter-readings of radio-waves conclusively proved that the waves always travel in straight lines.
Quote from: MikeFontenot on 14/04/2021 19:04:45The coordinate system I chose defines the spatial origin to be where the observer who sometimes accelerates is. The purpose of the coordinate system is to allow that observer to determine the spatial position and the current age of any distant person of interest.For there to be a current age of anybody, there needs to be a current time on the preferred worldline (time 0 presumably). Are you asserting a preferred time as well?
I'll elaborate a little.My coordinate system's horizontal axis gives each instant in the life of the observer (he) who sometimes accelerates (or at least the portion of his life we are interested in, like the portion that includes his trip away from the home twin). The vertical axis gives the home twin's (her) age, as a function of his age, according to him.
The other three simultaneity methods have no discontinuities, and no negative ageing.
I actually prefer the CMIF method.