I spend a significant part of my time participating in science communication activities. Many of these involve speaking with schoolchildren. I give a “Tour of the Universe”, which is a guided tour that starts on our planet, travels through the solar system and ends up with pictures taken from the edge of the perceived universe. One of the favourite questions at the end of the talk is “What came before the Big Bang?” – to which I have usually answered, “As time space and time were created with the Big Bang it is hard to talk about a time before time began.” But now scientists are doing just that and postulating what came before. The difficulty is, any evidence that we get is interpreted by the laws of physics of our universe, which may be very different from anything that came before. I stand and possibly hope to be corrected on this.
On the question of if there is anything science should not try to explain, to me, science is a tool that should be used to explain everything, as only understanding can help us decide whether something is worth pursuing or not. However, the chemical nature of the emotions love or hate may be where I draw the line. I would find it too scary to live in a world where we as individuals, groups or even nations could be put into either state synthetically, just by adding something to the water supply.