Re: nonsensical FTL without time travel?

: "WizWom" <wizwom@xxxxxxxxx>
: Well, Wayne, OK, tell me, what will the space compression of the
: frames involved change the time scale, which, according to your little
: simplelistics and wrong charts, gets mucked with?

Are you purposely ignoring what I said? In fact, "space compression"
has nothing to do with it. You seem to think that there's time, and
time dilation, and space, and space compression. But if that were true,
in the lorentz transform there would be only time terms in the time
expression, and space terms in the space expression. Yet that's not
the case, so in fact it isn't true.

If I have x and y coordinates on a plane, and I transform them by
rotation, then in each of those two coordinate systems, the transformed
and untransformed, the other's x-distance between two given points is
larger. Same goes for the y-distance. Yet this "x compression" and "y
dilation" is not the really interesting part of what's going on.
And "time dilation" and "space compression" isn't the really interesting
part of what's going on in special relativity.

This can all be verified by really, really simple diagrams.
So simple, even a caveman could understand it, like Geico insurance.

The lorentz transform in x,t coordinates is

x' = x*cosh(r)-t*sinh(r) = (x-v*t)/sqrt(1-v^2)
t' = t*cosh(r)-x*sinh(r) = (t-v*x)/sqrt(1-v^2)

A rotation in x,y coordinates is

x' = (x-m*y)/sqrt(1+m^2) = x*cos(a)-y*sin(a)
y' = (y+m*x)/sqrt(1+m^2) = y*cos(a)+x*sin(a)

Even simpler, distance in euclidean geometry is x^2+y^2,
and spacetime interval is x^2-t^2. Note the change in sign.
It's the only tricky thing about it.

The analogy is obvious. You merely have to look.
And you don't even need to look at algebraic expressions,
you can simply *draw* the coordinate systems, and it's totally obvious.

Unless you just ignore the issue of simultaneity.
Then you can never even make a start at understanding it.

: I have shown, clearly, that no matter how fast the signal goes, the
: TIME FRAME cannot EVER go into the PAST of anyone.

No, you've shown, clearly, that you don't understand the issue at all.
That you think there is an absolute meaning of "instantly" over a long
distance. Something that is obviously not the case; just look at
the expressions above, or if they confuse you, draw them as graphs.

: Unless, for some bizarre reason, you think that a ship traveling at
: speed is somehow in the past.

I don't even know what you mean by "being in the past". An object is
"in" the past, the present, and the future. That's the nature of
objects; they exist over time. If you mean that what in one frame is a
positive time difference between two events along an FTL trajectory is
negative in another frame, then yes, I "think so", and the reason is
hardly bizarre. You need only look at the expressions above, or better
still, draw the coordinate axes on graph paper, and it's staring you
right in the face.

Again, there is a *reason* that physicists started talking about
"spacetime" and "spacelike intervals" and "timelike worldlines" and all
such manner of things just after Einstein introduced relativity. It's
because, in the special relativistic model, space and time are related
very nearly as tightly as left and forward.

And it's really not that hard to understand, if you simply slow down
and think about it.


Wayne Throop throopw@xxxxxxxxx http://sheol.org/throopw
.

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