Re: What really is "Light" (assuming SR is correct)??
From: JM Albuquerque (jm.aREM.OVE_at_sapo.pt)
Date: 03/11/05
- Next message: kenseto: "Re: What are the SR predictions for these experiments??"
- Previous message: Rafael Valls Hidalgo-Gato: "Re: Hierarchical Inertial System (HIS) and GPS function."
- In reply to: Alex: "Re: What really is "Light" (assuming SR is correct)??"
- Next in thread: Alex: "Re: What really is "Light" (assuming SR is correct)??"
- Reply: Alex: "Re: What really is "Light" (assuming SR is correct)??"
- Messages sorted by: [ date ] [ thread ]
Date: Fri, 11 Mar 2005 19:47:23 -0000
"Alex" <dralexgreen@yahoo.co.uk> escreveu na mensagem
news:1110537918.814725.203970@f14g2000cwb.googlegroups.com...
> You (JM Albuquerque) wrote: "For case 2 my point is that s=0 is
> physically impossible, or else it is a total absurd, since if s=0
> nothing happens at distance so that light speed has to be involved in
> the measurement. "
>
> You are posing the question: is s=0 physically impossible if 's' is the
> space-time interval of a photon?
Yes.
> I'll try to answer this.
>
> Take the Minkowski metric: s^2 = x^2 + y^2 + z^2 - (ct)^2 and simplify
> it as before for a point object moving at velocity v relative to John:
>
> s^2 = (vt)^2 - (ct)^2
>
> John measures the space-time interval of the moving point to be
> composed of BOTH space and time.
Yes.
I assume John is stopped and the point object moving at
velocity v relative to John, so that:
s^2 = (vt)^2 - (ct)^2
> Suppose Bill is actually sitting at the point.
Let me see if I understand it correctly.
I assume that Bill is actually sitting at the object moving at
velocity v relative to John.
We have John and also we have Bill glued with the moving
object.
Both John and Bill are taking measurements of the
distance between both, or what are they measuring ?
I presume that John is trying to measure its distance
relative to the moving object:
s^2 = (vt)^2 - (ct)^2
And Bill is also measuring its distance to the object
where it is sited? Is Bill trying to measure its speed
relative to himself? That's is absurd.
> According to Galilean
> relativity or Special Relativity Bill may think he is not moving and it
> is John who is moving. Bill thinks he is stationary so he measures the
> space-time interval of the same object (himself) as something that ONLY
> moves in time (for T secs).
>
> s^2 = (0)^2 - (cT)^2
I don't think so.
Bill is sitting on the moving object, but Bill thinks he is stationary
and it is John who is moving.
Bill still wants to measure its distance relative to John.
So Bill sees John moving at v by means of light, so that:
s^2 = (vt)^2 - (ct)^2
Both see s^2 = (vt)^2 - (ct)^2
Something must be wrong.
Where did I went wrong?
I guess I cannot understand your following statement:
«««Bill thinks he is stationary so he measures the
space-time interval of the same object (himself) as
something that ONLY moves in time (for T secs).
s^2 = (0)^2 - (cT)^2 »»»
Both John and Bill are trying to measure distance
relative to each other I presume, and there is a
relative speed between both. None of them can
tell whom is moving and whom is stopped
The argument is circular and you cannot say that
Bill's vision is different from John's vision, so that
one measures distance composed by space and
time and the other only sees the same invariant
distance composed by time.
The measurement of a distance must be made
in no time so that both can measure the same value.
If the measurement of a distance takes for instance
one second to be made the distance error will be
of 300,000 km.
Please enlighten me.
> But these intervals apply to the same object. In a four dimensional
> universe 's' would be invariant, apply to the same object and have the
> same value for both Bill and John so:
>
> (0)^2 - (cT)^2 = (vt)^2 - (ct)^2
>
> (cT)^2 = (ct)^2 - (vt)^2
>
> So T = t sqrt(1-v^2/c^2)
>
> Which is the SR transformation for time intervals (not to be confused
> with the Lorentz transformation for absolute times).
Nonsense.
Bill is sitting on the object and he must always measure s=0 between himself
and the object, just because Bill is sited on the object (obvious and
irrefutable).
On the contrary John sees the object at distance, by means of light travel
and so there is always a non-zero distance between John and the object,
except in the precise moment where they all crash against each others.
> It was shown above that the value v=c is the same for all observers so
> t=cx and T=cX are valid for both John and Bill hence:
>
> X = x sqrt(1-v^2/c^2)
>
> This is the SR formula for length contraction. Now lets return to the
> question, is s=0 physically impossible if 's' is the space-time
> interval of a photon? We will suppose Bill is a photon with v=c. John's
> clocks have an interval of 2 secs, John observes Bill's clocks to read
> an interval T where:
>
> T = t sqrt(1-v^2/c^2)
> T = 2 sqrt(1- 1)
> so T =0
>
> John sees Bill's length measurement for distance travelled as
> X = x sqrt(1-v^2/c^2)
> X = x sqrt(1- 1)
> X = 0
>
> So John can only assume that, at the speed of light, Bill finds there
> is indeed no separation between two points on Johns x axis in the
> direction of motion.
At speed of light time stops, distance don't exist and nothing could
possible make any sense at all. No past, no present, no future.
> Now, I suspect you can allow this with the caveat
> that we are just 'trying out' a Minkowski metric. I bet your problem is
> with the other point of view, surely John knows that there is indeed a
> separation between two points on his OWN x axis. Whatever Bill measures
> John is still left with some actual space!
Of course.
That is obvious.
> Of course, John DOES have some actual space, if he measures a length,
> r, he measures both ends of r at the same time. Both ends are measured
> simultaneously so t=0. The space time interval for a length measurement
> is:
>
> given r^2 = x^2 + y^2 + z^2
>
> s^2 = r^2 - (ct)^2
>
> But t=0 so:
>
> s^2 = r^2
>
> In this case, of a PURE LENGTH MEASUREMENT s^2 is never zero.
Of course.
That is obvious.
> So what is the meaning of s^2 = x^2 + y^2 + z^2 - (ct)^2 for John when
> s=0? 's' is not the distance travelled by Bill in his incarnation as a
> photon (this is r) and it is not the time occupied by Bill in John's
> frame of reference (this is t). It is the length of a combination of
> displacements in space and time in the direction of Bill's motion, a
> thing that cannot be measured directly with either a ruler or a clock.
If cannot be measured directly with either a ruler or a clock it has
no physical meaning at all.
> The maths tells us that for John, as for Bill this length is zero.
Maths is nothing for me.
All I care is about physics.
> Your comment that a photon could not measure time intervals of zero is
> quite true.
Indeed.
Believe me, it's quite true.
> This brings us back to the theme of this thread - what on
> earth is a photon? All we know is that it is an interaction between
> two events. We cannot observe it 'in flight', in fact when it is 'in
> flight', according to QM and QED, it seems to explore the whole
> universe simultaneously!
Of course we cannot observe a photon 'in flight'.
Time intervals and distances for a photon 'in flight' are always zero.
A photon has no past, no present and no future.
> I can sense from your comments that you are not going to accept this
> argument because you have an intuitive idea of time. Physicists have
> long been aware of the conflict between our intuitive idea of time and
> Special Relativity. As early as 1918 Weyl noted that SR suggests a
> block time universe where all events coexist.
Indeed.
I agree 100%.
All events must coexist for a photon 'in flight'.
> He proposed that
> 'becoming' is a property of conscious observation. To put this another
> way, there can be no doubt that SR is a provisional theory and equally
> little doubt that it applies within the constraints of a simple
> Minkowskian universe.
No doubt that SR is a provisional theory.
History teach us that no theory is forever.
> It is likely that the universe is far more
> complex than the simple Minkowskian case and we will need to understand
> this complexity to understand the conscious observer.
Of course the Universe is much more complex.
> In this context the recent 'double slit experiment in time' is of huge
> interest because it provides experimental evidence for block time.
> Events are indeed laid out so that they coexist with the present. Our
> problem is how to account for our observation that intuitive time
> passes and to do this we must progress forward from relativity to a
> more complete physics. There is no going back.
I'm starting to think that Physicists are nuts or simple parrots,
I don't know for sure.
Now I'm thinking about two facts that contradict SR and the said
Minkowskian universe.
1 - Pioneer 10/11 anomalous acceleration equal to Hubble's
constant, even with the wrong sign, that can explain the all
misconception when one explains how to convert the wrong
sign into the right sign.
2 - Non aberration of gravity between Sun and Earth, that
will exist and will cause the Earth to slow down, if one assumes
that gravity waves exist and they travel at the speed of light,
for starters.
Best Wishes and congratulations for your clear mind.
> Best Wishes
>
> Alex Green
>
- Next message: kenseto: "Re: What are the SR predictions for these experiments??"
- Previous message: Rafael Valls Hidalgo-Gato: "Re: Hierarchical Inertial System (HIS) and GPS function."
- In reply to: Alex: "Re: What really is "Light" (assuming SR is correct)??"
- Next in thread: Alex: "Re: What really is "Light" (assuming SR is correct)??"
- Reply: Alex: "Re: What really is "Light" (assuming SR is correct)??"
- Messages sorted by: [ date ] [ thread ]
Relevant Pages
|
