Re: The differences between LET, SRT and IRT
- From: kenseto <kenseto@xxxxxxxxxx>
- Date: Tue, 15 Apr 2008 08:03:35 -0700 (PDT)
On Apr 14, 11:19 am, PD <TheDraperFam...@xxxxxxxxx> wrote:
On Apr 14, 9:18 am, kenseto <kens...@xxxxxxxxxx> wrote:
On Apr 11, 7:12 am, PD <TheDraperFam...@xxxxxxxxx> wrote:
On Apr 10, 12:45 pm, kenseto <kens...@xxxxxxxxxx> wrote:
A LET observer makes the following assumptions:
1. A LET observer is assumed to be at rest in the rest frame of the
ether.
Not necessarily. There might be a particular observer that is at rest
in the rest frame of the ether, but an arbitrary observer doesn't make
this assumption in LET. I'll assume this is what you meant.
Ah but a LET observer does assume that he is in a preferred frame, the
ether frame.
No, he does not. In this you are simply wrong. Lorentz, who is the
author of LET, does NOT say that the observer makes any assumption of
being in the ether frame. Lorentz himself says an observer may or may
not be in the ether frame. He did make some remarks about what the one
observer that IS at rest wrt the ether will measure, but he certainly
did not say that any observer makes the same assumption.
Sigh....it is irrelevant what Lorentz said. What is relevant is that
the resulting math (derived from the assumption of physical length
contraction and clock slowing) is the math of the rest frame of the
ether.
As I've told you repeatedly, Ken, it would help enormously if you
would actually read what the originators of the theory said about the
theory, rather than just guessing.
I am not guessing.....the math of LET that says that all clocks moving
wrt the observer are running slow and all rods moving wrt the observer
are physically contracted can only happen if the observer is in a
state of absolute rest in the ether.
That's why he used the ether frame to derive his math
No, he didn't. This is an error of fact. What are you reading about
how he derived his math?
and
the result is that all clocks moving wrt him are running slow an dall
rods moving wrt him are contracted.
2. The speed of light in the rest frame of the LET observer is
isotropic c.
In the rest frame of this particular observer, yes.
Yes he uses the ether frame derive his math.
No, he doesn't.
Yes he did...his math says that all clocks moving wrt the observer are
running slow. This is true only if the observer is at rest in the
ether.
3. All clocks moving wrt the LET observer are running slow by a factor
of 1/gamma. This means that the rate of the LET observer's clock is
the fastest running clock in the universe.
According to LET, all clocks moving wrt to the *ether* are running
slow. If this is what you meant, yes. It means that the rate of the
clock that is at rest with respect to the *ether* is the fastest
running clock in the universe.
Right...so the LET observer uses the ether frame as his frame of
reference to do calculations. That is thwe same as assuming that he is
at rest in the ether frame.
Not so. He also does the calculation for one observer moving wrt the
ether, looking at another clock moving at a different speed wrt the
ether.
No he does not....if he did he would have include the possibility that
the observed clock can run at a faster rate than his clock.
According to LET, all sticks moving wrt to the *ether* are contracted.
This means that the physical length of the meter stick at rest wrt to
the *ether* is the longest stick in the universe.
Right the let observer he is at rest in the ether frame and that's why
all the rods moving wrt him are contracted.
5. Absolute time exists.
An SR observers makes the following assumptions:
1. All inertial frames are equivalent....this includes the ether
frame.
Not quite. All inertial frames are equivalent, period. There is no
ether frame.
Sure quite. SR never said that there is no ether frame.
Yes, it does. It doesn't rule out an ether, but it does say there is
nothing physically special about the frame in which the ether is at
rest. It says that explicitly.
No it doesn't. What is special about the ether frame is that all
clocks moving wrt the ether frame observer are running slow and all
rod moving wrt the ether frame observer are contracted. All other
observers moving in the ether can't make that claim. BTW this claim is
valid mathematically only if the observed clock is in a higher state
of absolute motion than the observer and that's the reason why LET and
SR are incomplete.
IRT is invented to overcome the incompleteness of SR and LET. IT says
that an observed clock can run fast or slow compared to the observer's
clock.
In fact the
ether frame is the only truly inertial frame exists in the universe.
That is CERTAINLY not what SR says.
It is irrelevant what SR says. What is relevant is that no physical
object is in an inertial frame in a gravity environment.
No object in the universe can be considered as an inertial
frame....especially in a gravity environment.
2. The speed of light is isotropic c in all inertial frames.
Yes, and this is experimentally verified.
No the one-way speed of light never been verified experimentally.
That's not what I said. I said is that it has been experimentally
verified that the speed of light is *isotropically* c in all inertial
frames. That HAS been done.
The isotropy (not isotropically c) of the speed of light has been
verified experimentally in the earth frame and the earth frame is not
an inertial frame. So your claim that the speed of light is
isotropically c in all inertial frames is bogus.
Yes. This is more fundamental than an assumption. It's a definition.
This definition for time is flawed. Why? Because it implies that a
clock second is an interval of universal time.
No, it doesn't. It says explicitly the reverse. I don't know how you
get the idea that if a theory explicitly says A, you think the theory
implies B, where B is the opposite of A.
Yes it does. SR says that:
1. The speed of light is a un9iversal constant and thus the clock
second used to define the speed of light must also be a universal
interval of time.
2. In the twin paradox scenario the traveling twin clock second is
compared directly with the stay at home clock second to reach the
conclusion that the traveling twin is younger. This conclusion inplies
that a clock second is an interval of universal time.
In real life a clock
second does not represent the same interval of universal time in
different frames. In fact in SR the passage of a clock second in a
moving clock corresponds to the passage of more than a clock second in
the observer's clock by a factor of 1/gamma. In other words, the
observed clock runs slow by a factor of 1/gamma.
3b
. At the rest frame of a clock, it is running at its proper rate of 1
sec/sec and this is the propert time of the clock. Proper time is
invariant.
Invariant across what? "Invariant" means "doesn't change, regardless
of a change in X" where X is a particular something else. Proper time
is invariant across change in inertial reference frames. It is not
invariant across different paths through spacetime.
That's right....proper time is universal time.
You didn't answer the question: Invariant across what? What is the X
that proper time is invariant when X changes?
Invariant means that the rate of passage of proper time is the same in
all frames.
An SR observer defines
his clock second represents a specific interval of universal time
(proper time)....this specific interval of universal time is
invariant. However this specific interval of universal time (proper
time) is represented by different clock time in different ferames
(different paths through spacetime).
No, different paths through spacetime does NOT mean the same thing as
different inertial frames, Ken. Please bone up on the meaning of the
terms first.
I didn't say that it was. But objects in different paths in spacetime
can certainly be interpreted as in different frame of reference.
No. This is where the theory deviates from LET. LET assumes an
absolute time, and so the fact that a clock at rest wrt the ether runs
the fastest of all clocks is a statement that all observers would
agree on. In SR, this is not something all observers would agree on,
and this is connected to the absence of absolute time. You cannot make
an LET conclusion and force it on SR where it does not apply.
So are you saying that every SR observer doesn't say that all the
clocks moving wrt him are running slow???
Yes, SR says that.
When SR says that it assume that the observer is at rest in the ether
and the reason why it can make this assumption because the PoR says
that all frames are equivalent (including the ether frame).
LET does NOT. LET says that *only* the observer
that is at rest with respect to the ether says that. You made the
additional statement that every LET observer assumes they are at rest
with respect to the ether, but that is an error -- Lorentz did NOT say
that.
LET also says that when its math says that all the clocks moving wrt a
LET observer are running slow.
5. At the rest frame of a meter stick its physical length is its
proper length. Proper length is invariant.
Invariant with respect to a change in what? The same comment applies
here as applies to clocks.
Proper length is the physical length of the rod at the rest frame of
the rod
Yes.
....the physical length of the rod is invariant.
No.
Yes.....there is no length contraction. There is light path
contraction or expansion for a moving rod when the light path length
of the observer's rod is assumed to be the physical length of the rod.
SR missed the
boat by not realizing that it is the light path length of a moving rod
that is changing when the SR observer assumes that the light path
length of his rod is the physical length of his rod.
But what you were talking about was what SR claims, not what it got
wrong. SR does NOT say physical length is invariant. You haven't even
said what you think proper length is invariant with respect to.
6. All meter sticks moving wrt the SR observer are predicted to be
contracted by a factor of 1/gamma.
Yes.
This contraction is a geometric
projection effect. However, SR also claims that contraction is
physically real as in the case of a physically longer pole can fit
into a physically shorter barn.
Yes.
Here you are trying to have your cke and eat it too. Geometric
projection contraction is not physical
Sure it is. Physical length is what's measured.
But the length of a moving rod never been measured.
and therfore you can rotate a
longer rod through a door way.
It is *like* that. It is not the *same* as that.
However, fitting a longer rod into a
shorter barn is physical.
Yes, it is.
This requires physical contraction.
No, it doesn't. No physical process is required to shorten the rod.
The rod is nevertheless physically shorter.
This is stupid..... You are talking with forked tongue. Here's what
you said:
1. You claimed that fitting a longer rod into a shorter barn is a
physical process.
2. You also claim that no physical process is required to shorten the
rod.
Yes.
The IRT definition of simultaneity is much better.
Doesn't matter.
It avoids the
violation of the isotropy of the speed of light in the train frame.
The relativity of simultaneity doesn't violate the isotropy of the
speed of light in the train frame. It *comes from* the isotropy of the
speed of light in the train frame.
No it doesn't come from the isotropy of the speed of ight in the train
frame. Einstein derived RoS from the point of view of the track frame.
This is bogus. The train observer must make his own conclusion whether
the strikes are simultaneous. At the time of the strikes ocuur
simutlaeously the train observer is at equal distance from the strike
and therefore he must also see the strikes to be simultaneous in order
to preserve the isotropy of the speed of light in his frame.
Ken seto
.
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