Better by far to embrace the hard truth than a reassuring fable - Carl Sagan

Our particular causality scheme has brought us to a modest and rudimentary, although in many respects heroic, series of explorations. But it is far inferior to what might have been, and may one day be.

Consider this claim: as I walk along, time – as measured by my wristwatch or my ageing process – slows down. Also, I shrink in the direction of motion. Also, I get more massive. Who has ever witnessed such a thing? It's easy to dismiss it out of hand. Here's another: matter and antimatter are all the time, throughout the universe, being created from nothing. Here's a third: once in a very great while, your car will spontaneously ooze through the brick wall of your garage and be found the next morning on the street. They're all absurd! But the first is a statement of special relativity, and the other two are consequences of quantum mechanics (vacuum fluctuations and barrier tunnelling, they're called). Like it or not, that's the way the world is. If you insist it's ridiculous, you'll be forever closed to some of the major findings on the rules that govern the Universe.

We can judge our progress by the courage of our questions and the depth of our answers, our willingness to embrace what is true rather than what feels good.