Recent content by AlexDB9

You mean the equations work everywhere over C numbers, except in the reference frame of light (division by 0)?

But Hawking said "It turns out that a mathematical model involving imaginary time predicts not only effects we have already observed but also effects we have not been able to measure yet nevertheless believe in for other reasons." Myself I don't believe in time machines, since I have never seen...

The Alcubierre drive requires negative mass that is hypothetical. However, according to this paper, http://arxiv.org/abs/1407.1457: "We have shown that there exist very physical configurations of an ideal fluid which give rise to solutions of the Einstein equations that correspond...

Alcubierre drive. Also energy estimates I've read go millions of times the industrial energy production to sun's output. Both cases impractical today. But the point is that the AD does not contradict relativity.

I've read that faster than light travel is possible if we manipulate the space around the craft, but the energy needed is on the order of the sun's output. So, even if not practical, since theoretically it is possible I want to ask what happens to our destination's time. As I understand at...

Please elaborate.

The natural expression of speed in relativity (and thus the true meaning of speed) is through the concept of rapidity, which comes from incorporating the gamma factor. It turns out that the rapidity of light is infinite. So the question of whether there can be speeds greater than light becomes...

But I thought it is proven, or at least largely believed, that space expansion is faster than light at the greatest scales. Quote from Wikipedia: "Two reference frames that are globally separated can be moving apart faster than light without violating special relativity". So rapidity ceases to...

I understand that, but how faster than light avoids transfinite, or "more" than infinite, rapidity?

If the expansion of space in the macrolevel is faster than the speed of light then it should have "more" than infinite rapidity. How does that work out? Thanks.