FTL using gravitation 'bubbles' ,(the math is more awesome) exist only the daydreams of theoretical physicists.The conditions in wormholes are only speculation since no wormhole has ever been observed.Even the idea of a wormhole is only theoretically viable mumbo-jumbo.
It is like cavemen who could burn animal fat but not make engines. The basic idea exists but there is lack of any practical design (engine) or even advanced theory (thermodynamics).
In this case we are worse than cavemen with engines, because wormholes are still philosophical speculation
"Heavier-than-air flying machines are impossible."
Lord Kelvin, President, Royal Society, 1895
Well, that was the thinking then! In a little over a century, look where mainstream science has reached! We're not only flying at supersonic speeds, but floating out there in space at a mind boggling 30,000kmh!! And some scientist did mention before Lord Kelvin's gem that it was impossible to travel faster than 100kmh as we would disintegrate!
Fast forward to now....
Particles found to break speed of light.
(Reuters) - An international team of scientists said on Thursday they had recorded sub-atomic particles traveling faster than light -- a finding that could overturn one of Einstein's long-accepted fundamental laws of the universe.
Antonio Ereditato, spokesman for the researchers, told Reuters that measurements taken over three years showed neutrinos pumped from CERN near Geneva to Gran Sasso in Italy had arrived 60 nanoseconds quicker than light would have done. The discovery would undermine Albert Einstein's 1905 theory of special relativity, which says that the speed of light is a "cosmic constant" and that nothing in the universe can travel faster.
When the team of physicists announced that they had proved Einstein wrong, even they werent convinced.
So they ran the test again and broke the speed of light for a second time. Scientists from Cern, the Swiss home of the Large Hadron Collider, sent another beam of subatomic particles over 450 miles to a laboratory in Gran Sasso in the Italian Alps.
And after running the modified follow-up test 20 times, they recorded exactly the same results as before.
But according to Albert Einsteins 106-year-old theory of special relativity, nothing can travel faster than light.
In a little over a hundred we've gone from the theory that traveling faster than 100kmh was an impossibility to seeing Neutrinos traveling at FTL velocities!
And then, Los Alamos National Laboratory (LANL) has several papers on esoteric subjects,
one of which contains details of spacecraft utilizing gravity shielding not only for propulsion but for the internal dynamics within the spacecraft in order to eliminate the effects of massive G-forces on the crew accelerating to near light speeds in the future. And then it has described Quantum Gravitational Antennas for instantaneous communications across the Universe! And theres more
.Like Project 'Looking Glass'... But all this for another thread as we've gone pretty far off topic already!
Remember, what was pure science fiction a few years ago is reality today!
Cheers!
Particles found to break speed of light | Reuters
Einstein and speed of light: 2nd set of scientists find that particles CAN travel faster than light | Mail Online
video perhaps ull understand in brief 
