We must not, in trying to think about how we can make a big difference, ignore the small daily differences we can make which, over time, add up to big differences that we often cannot foresee.
That's what Hubble can do for us. It can tell us whether the universe is expanding forever or if one day it's going to come back together.
Marriage is an attempt to solve problems together which you didn't even have when you were on your own.