I'm really into the Mass Effect games and I'm just wondering; if Mass Effect fields really could be created, how useful would they really be? For anyone who doesn't know what a mass effect field is, it's basically a field that either reduces or increases the mass of everything within a certain volume of space; it can be used to reduce the effective mass of a spaceship to near 0.

 

I mean it would certainly allow the colonization of the solar system and maybe even nearby star systems, but could it really allow for faster than light flight?

Such a thing would be amazingly useful, since you could use it to make a perpetual motion machine and get unlimited energy from nothing. I don't see how you would get faster than light travel, though. Just near lightspeed for "free," which is still pretty good! I don't know what would happen at zero mass - the scenario is nonphysical, so there isn't a real answer, I don't think.

I can't really say with certainty whether it might or might not be possible. We don't really know what causes mass, although maybe our shiny new collider might find the answer in a couple of years (the Higgs boson, or not). Once we know what causes mass we might have a better idea of whether it would be possible to change it. It would be a very useful technology for sure, but as Sisyphus noted there's the issue of conservation of energy.

 

For example, if you turn your mass effect field on, accelerate your ship to 0.99c, then to turn it off you'd need an absurd amount of energy, or turning it off would bring your ship to a near halt. And if on top of that you add in conservation of momentum, I think that either you can't have this tech or we'd have to change how we think of momentum.

 

Anyhow, I'm fairly certain it won't work, due to the difficulty of maintaining both momentum and energy in all inertial reference frames, while somehow changing the mass.