Dark matter is added to the equations to account for the rotational speeds seen in astronomical structures like galaxies.  They should fling apart, even using Einstein's equations, yet they don't.  There is more mass in the galaxy which is holding it together than we can currently directly detect.  These underground sensors will passively detect dark matter.  They are totally safe and emit nothing, unless you feel underground distilled water is dangerous.

What can get out of it if we detect it directly, right now, nothing but that is what they said about electricity too.  

Gaining knowledge about our universe is always a good thing as long as it is properly applied.

Same as weak gravity theory.

String. Brane.

If we can visualize it. It exists. Till then it's theory.

If it exists as a measurable phenomena it can be used to disprove/ prove other theory.

Dark matter may be a resource for many things. Including FTL communication.

In our realm. Nothing can exist that's faster than light. In that matter it may be possible to use parts of it to communicate.

Think about how vibration travels faster in steel than it does in air.

Or

How electricity can flow faster in cold superconductors....

We do not know.... Everything is possible.

I would imagine quantum entanglement would allow FTL commmunication. A very smart PHD student was trying to explain it to me. While nothing can travel FTL, it is still possible to get from point a to b at a speed that would make it seem as if you were traveling FTL.

Problem will be that we have to get off this floating coffin first.

I'm Glad NASA is dead. Now we need a corporation to profit margin exploration of space.

Unfortunately were going to have to stomp a lot of crabs to get out of this bucket...