What i meant is that space-time is abstract. In relativity, we make extensive use of metric tensors. A tensor is a generalization of a vector to higher dimensions. Vectors have both magnitude and direction. In QFT spinors are used instead of tensors.
In general relativity, metric spaces...
Shadows and light spots can go faster than light but they can't carry physical information. This is confirmed by many experiments, including the spot of a laser which is pointed at the surface of the moon.
This can also be confirmed using logic. Distance and direction are abstract and...
Where is the valid experimental argumentation for space-time, time travel etc?
First of all velocity is a vector and a vector has both magnitude and direction but distance & direction are both abstract (non-physical).
Then you understand that gravity has nothing to do with the curvature...
Causality says that every effect must have a cause (e.g, energy is needed to do work). What we have (and what we are of course) is a proof that causality is never violated.
Like i said, the velocity 4-vector is not a physical velocity. I guess we just have to agree to disagree.
You are wrong. What the guy said is that space-time is a mathematical construct and he's definitely not wrong about that. There's no time axis, it's abstract (non-physical).
Do you...
It's possible to define a 4-vector in special relativity but it's not a physical velocity:
g_{\mu\nu}\eta^{\mu}\eta_{\mu} = \gamma^2 c^2 (1-\frac{v^2}{c^2}) = c^2
If you don't believe in time travel then why are you are arguing with me?
Particle physics says that there are only...
And he almost surely understands it better than you. Relativity does not allow motion in space-time. Why not? Because time is an abstract invariant.
It remains to be seen whether time travel is possible, as you say it is.
How can you say that something is possible if the physical...
Sorry and we could care less about you write. What he writes is not only logical but is also supported by evidence from real life. 4-velocity is not even a physical velocity so why do we call it velocity.
There is no evidence for the physical existence of spacetime and definitely not for...
Few physicists know the complex math of general relativity. What is meant with time-travel? Does this mean that we can run the movie backwards? Can we go back to the stone age?
Anyway, here is a very good argument against time travel.
http://mb-soft.com/public/time.html
Time travel...
What is the difference between v = \frac{dt}{dt} and v = \frac{dt}{d\tau}?
Proper time is time measured when the clock is at rest relative to the observer.
d\tau = \frac{dt}{\gamma}
or
d\tau = dt\sqrt{1-[\frac{v(t)}{c}]^{2}}
He writes that tau is also an invariant evolution...
I'm also working on a theory to combine gravity with magnetism.
I think that the CMBR is not the redshifted photons from the big bang. It's the electromagnetic fields of the quantum vacuum (the ground state of the quantum vaccum). If the sun is charged it really solves the puzzle.
Few physicists know relativity and AFAIK relativity does not allow for time travel. Motion in space-time is itself impossible (by definition). If you are serious about this, then i really doubt the correctness of the theory.
By far the majority of physicists consider time travel as pseudoscience. There just isn't any experimental evidence that it happens.
Relativity does not allow motion is space-time. It allows motion in space. Time is just the abstract inverse of change. Change (or motion) is primary, time is...