>Oh yeah I forgot about the study that guy did outside the solar system to detect gravitational waves.
This remark sounds sarcastic. I guess you are opposed to thought experiments.
>Anyone who thinks it's ridiculous to try and find an answer to an impossible situation should think of Einstein's thought experiments.
So now you are for thought experiments? Make up your mind please.
>We can never manipulate space time and will never achieve 'warp speed.'
Thanks for your prophetic insight. Let me add, if man was meant to fly, he would have wings. Also, 640K should be enough for anybody. BTW, I can manipulate spacetime right now by wiggling my finger. The shockwave should reach you shortly.
Let me add the following to the discussion, with the caveat that I'm no expert on relativistic quantum mechanics! In the absence of quantum GR there might not even be a clear understanding to these issues. Please correct me if I'm wrong! These following issues appear to involve superluminal (faster than light) behavior, which is synonymous with causality violation (altering the past). I think items 1, 2, and 3 may have been experimentally demonstrated.
1. Quantum tunneling:
It might be possible for something to "travel" faster than light using quantum tunneling. A particle can be measured on one side of a barrier at one instant and then at a later instance, may be measured on the opposite side of a barrier a considerable distance away. The object could "travel" faster than c.
2. Delayed choice experiment
In the famous two-slit experiment, trying to measure the momentum of a particle (e.g. with the screen attached to springs) destroys the interference pattern. You can choose at the last minute whether or not to measure momentum or position (e.g. you could fix the screen's position), causing a superluminal disturbance and altering the wave function for the particle's past. Note: I don't believe in the Copenhagen interpretation or special "measuring devices", but I think it's commonly accepted and it supports this description of superluminal influence.
3. Related to the EPR paradox
Suppose a particle disintegrates into two other particles, which travel outwards. Measuring the spin of one particle may instantly affect the spin of the distant, entangled particle. This might not be usable as communication, but it still seems to imply superluminal travel of information.
4. Black hole evaporation
A kind of quantum tunneling (item #1), particles can seep out of a black hole, even though light itself isn't fast enough to escape. I think Hawking proposed this, although it's not been experimentally demonstrated.
My opinion is that nothing (objects, influences, information) can travel faster than light. However, causality is not absolute and these things can essentially travel at the speed of light BACKWARD in time. The difference between A causes B vs. A is caused by B, huge on a macroscopic level, is not so important at the most fundamental level. The universe is 4D and is consistent; we do not have an evolving 3D universe based on cause and effect. Superluminal phenomena only appear when we fail to embrace the causality violations, or adhere to awkward dogma like Copenhagen interpretation. I think it's arrogance to insist the universe has randomness; it's easier to accept that we just have a lot of ignorance about things like wave function collapse or how a particle chooses a non-classical path. Bohm proposed a kind of QM which has no randomness and matches experiment exactly (unfortunately it's non-relativistic). For item #3 my opinion is that, in human terms, the final measurement of the particle effectively sends a signal back in time at a mundane speed to the origin of the two particles, instructing them both on which spins to finally show. In the universe's terms, there is no act of "measurement"; consistency is simply maintained without superluminal travel. #1 can be explained using anti-particles travelling backward in time at mundane speeds.