And though I .....understand all mysteries, and all knowledge;....and have not Love,
I am nothing.
1 Corinthians 13:2
"General relativity handles the big familiar objects and events of the 
universe, while quantum mechanics covers the invisible and strange
micro-world that surrounds us, where subatomic particles can tunnel
through barriers they have no business getting past, or where two
particles thousands of light-years apart can instantaneously respond to
each other's motions.....a link between special relativity (Einstein’s first
theory describing space and time before he added acceleration in his
general theory of relativity) and quantum mechanics was already well
established. In fact, quantum field theory – which forms the basis for
our modern understanding of how the building blocks of matter interact –
unites quantum mechanics and special relativity. But it does it in a
way that regards them as two independent and distinct pieces of a wider
puzzle.
Dragan felt that this connection must run
deeper: “It's more than just being part of quantum field theory, more
profound,” he says. “It's almost as if quantum theory does exactly what
relativity allows and not a bit more.”
Because there is no physical evidence that anything can
travel faster than the speed of light, the faster-than-light solutions
are always thrown away. But, mathematically, these solutions are still
valid.
So Dragan thought, why not keep the faster-than-light solutions
and see what happens?
When he did, he uncovered a world that would look
more familiar to quantum theorists.In this world,
instead of a particle following a well-defined path, its motion is hard
to pin down, described by layers of complex probabilities that
correspond to different possible outcomes, much like what is known as
superposition in quantum physics. Moreover, if a physicist in this world
tried to measure certain properties of this particle multiple times,
they would not get the same result every time.
Often though, these criticisms boil down to two points:
--that no one has ever detected anything racing beyond light speed, 
--and
that if anything did travel that fast, time travel is possible. Time
travel leads to what is known as causal paradoxes. The most famous of
these is the grandfather paradox — the idea that if you travel back in
time and kill your grandfather, your own birth will be impossible.
Dragan
and Ekert argue that these critics miss the point. “We're not saying
there are any objects that travel faster than light; there might be, but
that doesn't enter our arguments,” Ekert says. “What we are saying is
that you can look on the world from a perspective that is beyond light
speed.”
From this faster-than-light vantage point, you can swap
the order of cause and effect. This is a key result because the
underlying physics must remain the same regardless of whether you’re
watching events unfold above or below the cosmic speed limit.
--And if
this is true, the pair argue that the order of events no longer plays a
fundamental role in the theory.
Dragan says all of
this means that there are no paradoxes to answer for at all. “If you
look at it carefully, you find that the rules of causality are changed.
But they are not completely destroyed, they are modified in precisely
the way quantum theory tells us.”
Wired
