astronomers can measure the speed with which stars and galaxies are moving. Most of them are moving away from us. the farther away a galaxy is, the faster it appears to be moving away. this means...
Bigger - the universe is and has been expanding since the Big Bang... although the expansion did slow down for a while, it is now believed to be accelerating
nothing, unless there is some kind of ultimate universe thingy that is like 97143696950917863897256024976209623476801986 light years long. But that's unlikly.LOL