Sujet : Re: [SR] Usefulness of real velocities in accelerated relativistic frames of reference.
De : relativity (at) *nospam* paulba.no (Paul B. Andersen)
Groupes : sci.physics.relativityDate : 12. Mar 2024, 20:20:43
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Den 12.03.2024 10:00, skrev Richard Hachel:
We know that in accelerated frames of reference the average speed is proportional to the instantaneous speed.
Let Vrm=(1/2)Vri
This is meaningless without definition of the entities.
But I can guess:
You are not talking about "speed in an accelerated frame".
You are talking about the speed of a stationary object
in an accelerated frame, measured in an inertial frame.
If the object is instantly at rest at t = 0, and
the coordinate acceleration in the inertial frame is constant a,
Then the speed Vri(t) = at
and the average speed from t=0 to t=t is Vrm(t) = at/2.
So Vrm=(1/2)Vri
We are talking about real relativistic speeds (Richard Verret's hobby).
According to SR:
For the above to be true, the coordinate acceleration must
be constant. This means that the proper acceleration must
increase with time.
Let 1g = 1 c per year = 9.4998 m/s².
To keep the coordinate acceleration a equal to 1 g
the proper acceleration A must be:
at t = 0 year A = 1.00 g
at t = 0.8 year A = 1.65 g
at t = 0.9 year A = 3.33 g
at t = 0.99 year A = 33.4 g
at t = 0.999 year A = 333.5 g
at t = 1.000 year A = infinite
when t ≥ 1.0 year the coordinate acceleration can't
be kept equal to 1 g.
Generally:
The coordinate acceleration a can't be kept equal to n g
when t ≥ 1/n year.
It is obviously normal to keep the proper acceleration constant,
and then Vrm ≠ (1/2)Vri
But we know that relativistic physicists do not use this notion, and it is important to remind them of the relationship between real speed and observable speed.
Vr=Vo/sqrt(1-Vo²/c²)
This is nonsense.
According to "relativistic physicists" there is no difference
between the "real speed" and the "observable (measurable) speed"
in the inertial frame.
This immediately leads us to Vom/sqrt(1-Vom²/c²)=(1/2)Voi/sqrt(1-Voi²/c²)
and therefore to:
Vom²(1-Voi²/c²)=(1/4)Voi²(1-Vom²/c²)
Let Vom²=(1/4)Voi²+(3/4)Voi².Vom²/c²
Hence Vom=(1/2)Voi/sqrt(1-(3/4)Vom²/c²) and, conversely, Voi=2.Vom/sqrt(1+3Vom²/c²)
Thank you for your kind attention.
R.H.
-- Paulhttps://paulba.no/