Absolute Velocity - Meaningful but Useless

Rosnet,
Perhaps some future space ship crew might want to know their absolute velocity with respect to an absolute zero reference frame. The point being invariant is by definiton, absolute zero velocity, isn't it?
Geistkiesel

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SL,
So what do want or need proved, the use of the third C probe? Its, 'res ipsa loquitor', the thing speaks for itself. What is your specific objection here?

As for the acceleration method of adding a measurable amount of speed to a m,oviong frame, are you questioning the ability of a space ship crew to determine a change in speed by the addition of known accelerations?

At least let me know what your specific objections are? This response is the old non-scientific SL that I thought had matured considerably?

There isn't even any SR postulates violated in the steps taken in either case. What is the problem? Personal perhaps?

Geistkiesel

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SL,
As an aside, for the two ships asking for the other to "check my speed", you are really asking for a relative motion measurement aren't you?
Geistkiesel

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Rosnet,
I overlooked something crucial in your statement. When you refer to "two other points in every reference frame", you have not described the absolute zero velocity point I produced. The frame is moving wrt the zero velocity point. The point is frame independent as you can see. The speed of the photons moving as described are the physical entities that define the invariant point. The frame is just there. For sure the frame observers can determine the point, which may be of relatively short duration, but hey, just generate another point from which to make continuous measurements of the ships' speed. If the "device" is assembled in three dimensions one can also obtain direction as well as absolute speed.
Geistkiesel

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Look G (and MacM),

Here's what I want.

Setup two situations with as many observers, extra space probes, and gizmos as you'd like (anywhere you want), scattered around the solar system or wherever.

Put a ship moving at any velocity you wish, anywhere you want.

I want to know it's absolute velocity such that anyone in the universe will calculate the same number. The answer will be in meters/sec and cannot be "with respect to" anything. It's absolute after all.

Make up your own numbers. I don't care.

Let's see what you come up with.

P.S. Geist, my anger is indeed internal and stems from a self knowledge of the masochistic nature of continuing to debate these subjects with you and Mac. It's a form of self abuse.

As far as me being a bad person or not, I'm good when I need to be, and bad when I need to be.

 

Hah, this should be entertaining if either steps up to the challenge. Possibly with the except of G as I can never understand what he is actually saying because he'll say two sequential sentences that contradict each other.

 

I have been asking this in some form for almost a year now. Like I said, it's masochism...

 

SL and Aer, Here goes.
I derived expressions for the difference in speed of the A frame and the B frame assuming the B frame was faster than the A. I also assumed that the speed of the frames from which the relative motion was measured, .2c according to SL were real velocities and nt sme QM like probability function. The speeds were as if they were measured from the embankment.

Ok, the relative speed of the A and B frame is .2c. and as theB is larger this mustg be greagter than .1, so we'll say the measured difference in speed is .09c. therefore Vb = Va + .09. As we had tenetaively set the Va + Vb = Vab = j then Va + Va + k = j, of Va = (j - k)/2. j = .2 and k = .09, so Va = (.2- .09)/2 = .11/2 = .055c. Vb was determiend to be (j + k)/2 = (.2 + .09)/2 or .29/2 = .145. As a check .145 + .055 = .2 in units of C.
j was measured by A and B (per SL). As we don't know what the actual difference of the A and B frame is until measured I had to make this number up.

Any questions or objections?

And of course I thank you for your interest and attention in ths very important matter.

Geistkiesel

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Aer,
You made a statement that I am known by yourself to "contradict" myself in succeeding sentences. Could you give one or two examples please?

From the tone of your statement you made this attribute of myself that you described seem like a frequent occurrance, so would you please justify your statement? I hadn't recognized that I was doing this so I would appreciate your assistance.

Geistkisel

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Here you go:

Relative to what?

How is a real velocity different from a relative velocity?

 

What? You can't do that. Faster wrt what?

What??? No! The 0.2c is one measuring the other! What embamkment?

What the hell? You'll just say?

This is complete nonsense. So, you conclude that the absolute speed of A is .145 and B is .055 ?

It's 0.2c! That's a given!

Ok. Let's redo you "calculations" with my assumption.

Ok, the relative speed of the A and B frame is .2c. and as the B is larger this must be greagter than .1, so we'll say the measured difference in speed is .04c. Let's just say.

therefore Vb = Va + .04. As we had tenetaively set the Va + Vb = Vab = j then Va + Va + k = j, of Va = (j - k)/2. j = .2 and k = .04, so Va = (.2-.04)/2 = .16/2 = .08c. Vb was determiend to be (j + k)/2 = (.2 + .04)/2 or .24/2 = .12. As a check .12 + .08 = .2 in units of C.
j was measured by A and B (per SL). As we don't know what the actual difference of the A and B frame is until measured I had to make this number up.

I got .12 and B is .08.

What do you think?

 

There is no contradiction. I merely said the velocities that ultimately are measured as relative velocity by two inertial frames moving wrt to each other are real velocitities.

Do you have a problem with the concept that relative velocity of inertial frames are wrt each other. Simply said AER, the velocites that are measured as relative are real absilute velocities that aren't measured directly as absolute velocities. This is what I did in my post to SL.

It is clear to me. Do you have any others?
Geistkiesel

 

Is the red the same as the blue?

You just defined your "absilute (sic) velocities" from relative velocity and claimed they are "absolute velocities" and not "relative velocities"

This is stupid.

 

Look what I said . I said the absolute velocities of the frames are real and it is these velocities that are measured as relative velocity wrt each other.

You are both confused and you are manifesting a personal grudge againsgt Geistkiesel. So be it.
Geistkiesel

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Superluminal,
So express your questions and/or objections.

Geistkiesel

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I stand by the post to which you are referring.


Geistkiesel

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Yes Geist, we are aware you stand by your stupidity.

 

I believe the first three statements in my last post are clearly addressable objections:

1) What? You can't do that. Faster wrt what?

2) What??? No! The 0.2c is one measuring the other! What embamkment?

3) What the hell? You'll just say?

And then there's the different numbers we got based on a slightly different assumption made arbitrarily by both of us.

Ok?

 

Geistkiesel,

What you call the 'measured difference in speed' in your example IS the relative velocity of B wrt to A. So where Vab is the relative velocity of B wrt A you should start with Vab = Vb - Va. I don't where you pulled the number .2c from, because all you know is the relative velocity of .09c. That makes the rest of your 'derivation' a bunch of nonsense and rather pointless.

In other words, you haven't measured the absolute velocities of either A or B.

 

I'm not sure whther I understand you properly. Let's see. If you emit two photons in opposite directions, from the same point, you claim that this point is invariant in all frames, since the photons will be emitted from the same point in all frames, and this point, hence, can be taken as an absolute point?

One more thing, please give me a definition of what you mean by an 'invariant point', and what properties it possesses.