By what means is space expanding? By what means is space expanding?
Can we reproduce the conditions in a laboratory experiment to observe "man made" space expansion?
 A: Had you asked this question a few billion years ago, I might have told you that space is only expanding this second because it was expanding last second. Back then, the expansion of space was decelerating. The only thing that made it keep expanding was that it had been previously expanding and had not yet slowed to a stop. However, in the cosmologically recent past, Dark Energy has become the dominant form of energy in the universe, according to the most widely accepted theories. These theories state that dark energy is a driving force that actually is accelerating the rate of expansion. So, in a way, space is now expanding because dark energy is causing it to (although, even without dark energy, it would still be expanding today, just at a much slower rate).
We cannot reproduce this in a laboratory. By our best understanding, dark energy is spread throughout the universe homogeneously and the density of it, its concentration, is more or less constant no matter how much the universe expands. This means we have no way of manipulating the amount of dark energy in a laboratory. The factors that cause expansion to decelerate are also too weak for us to be able to manipulate them on a scale large enough to affect expansion.
Unfortunately, this all means there will be no man made expansion in the foreseeable future unless some new exotic and unexpected form of energy/matter is discovered or a new theoretical framework is proposed that describes a manipulable mechanism that drives expansion.
