The opening quotation is a question posed to and answered by physicist Stephen Hawking. You can find an excerpt from the interview here at The Guardian. It brings to mind one of the books that is most influential in my thinking these days, which is by philosopher Hilary Putnam and is entitled The Collapse of the Fact/Value Dichotomy and other Essays.* In the book Putnam argues against subscribing to a view of science (and social science in particular) as sustained by a strict metaphysical dichotomy between facts and values. The world simply does not come pre-packaged in that way. Sure we can draw a distinction between the two for specific purposes in particular situations. But that is that. Against those who seek to inflate some such particular distinction into a full-fledged, comfort affording dichotomy, Putnam offers something of a pincer argument. He suggests that (i) on the one hand, most views of "facts" are sustained by suspect philosophical commitments and (ii) values are plural and that they are entangled with our pursuit of scientific knowledge in complex ways. In particular he suggests that we become less pre-occupied with putatively "moral" or "ethical" values and recognize the ubiquity of cognitive and aesthetic values in science. Hence the way Hawking's comment reverberates: simple explanations are beautiful.
Q: What are the things you find most beautiful in science?
Science is beautiful when it makes simple explanations of phenomena or connections between different observations. Examples include the double helix in biology, and the fundamental equations of physics.
* Hilary Putnam. 2004. The Collapse of the Fact/Value Dichotomy and Other Essays. Harvard University Press. I will note too that the color scheme of the cover is consistent with other recent works by prominent pragmatists.