We already have one of those and it's pretty darn powerful :) of course, if we're talking millennia of technological development, all bets are off - but by then

We already have one of those and it's pretty darn powerful :) of course, if we're talking millennia of technological development, all bets are off - but by then we and the planet will look very different. However, I think this needs to be stretched once more: there will most likely be no advance detection through neutrinos.