reply to post by BiggerPicture
How does a tiny particle travelling so fast (faster than light) goes thru dense matter,
The overwhelming percentage of all material is "empty space." Neutrons have the ability to pass through a lot of matter because of their lack of an
electric charge, high mass, and high energy.
Passing through matter is not much of a problem for neutrons (less for neutrinos).
correlate with time travel?
It doesn't. People simply don't understand the implications of Relativity.
reply to post by chr0naut
If a particle travels faster than light, then it arrives before it was sent, in relativistic terms.
This is quite incorrect.
Based purely upon acoustics, I can conclude that a .50 caliber round arrived more than a second before it was fired.
Why, then, is it any more logical to conclude this must be the case with electromagnetic fields?
Think of it as extreme time dilation where the mathematical function crosses the zero line and therefore becomes inverse.
Is it possible to cool something to such a degree that it has a negative temperature?
The real world doesn't quite behave according to mathematical projections.
Special Relativity is an effect of the propagation of gravitational phenomena. Time dilation in special relativity is exactly the same as time
dilation under general relativity. The cause is merely different.
Gravity propagates at the speed of light. Accelerating, therefore, increases the perceived density of a gravitational field. At the extremes of
velocity, this accounts for time dilation as experienced by relativistic objects.
This is where quantum mechanics come into play ( I know people like to say "they don't play well together" - but that's really their own
silliness) - Planck energy density can never be exceeded. Any massive particle moving near the speed of light will eventually contain enough energy
so as to reach this limit. Only experimentation could really prove what would happen under these circumstances - but it is likely that attempts to
exceed this energy density would result in a burst of Cerenkov radiation with showers of high-energy particles resulting from the evaporation of
quantum singularities.
However, it is possible for spin-zero particles to tunnel through to the "other side" of the classical barrier and continue ahead of the mass (or
what is left of it) at relativistic velocities.
Since time dilation is caused by gravitational density (whatever gravity is), and Planck maximums restrict the amount of time dilation that can be
experienced (likely resulting in an energy-matter conversion process); there is no reason to suspect that moving faster than the speed of light
constitutes a violation of causality (time travel).
For time travel to exist as it is described in relativity would require each Planck-space to exist in its own completely separate time "bubble."
Such a model of time is useless to us, as our concept of time must inherently include 10^mind-shattering number of individual times. This is because
Relativity presumes time is based upon the perception of events - since nonlocal bodies are not allowed to be in communication with each other outside
of light.
It is arguably workable when you treat "whole" objects as a single, indivisible unit. It falls apart when you introduce something like gyroscopic
motion and must figure that each individual particle in that same mass is under different relativistic effects (the particles on the outer edge of a
centrifuge are moving slower as compared to the center). At which time - Special Relativity becomes simply unworkable without a universal frame of
reference.
The problem gets even more crazy when exploring the Twin paradox. According to relativity, each mass perceives itself as stationary. Thus, it should
never experience time dilation positive or negative. When we launch the shuttle into orbit - neither mass has either way of determining who is
undergoing time dilation (the Earth should experience time dilation, according to the shuttle crew). One, however, must have experienced time
dilation.
There are two ways of resolving this under Relativity. Either there is a preferred frame of reference that exists locally and can be accessed by all
mater... or mass is able to "poll" the rest of the known universe to take into account all frames of reference to decide which mass actually
accelerated.
You either accept that there's a preferential reference frame, or accept that there's instantaneous communication between all mass. There's no
other logical alternative to resolving the twin paradox, as only one frame of reference can be true.