Science is all about solving riddles, answering questions and generally demystifying this crazy old universe.
So far, we've not done a bad job. We've peered into the furthest reaches of the universe and delved into the weird world of atoms; We've decoded the building blocks of life itself and built a civilisation that has managed to actually leave its own planet with nothing more than a big tin can and lots of flammable fuel.
We've come a long way since ancient times, since Galileo pointed his telescope at the sky in the 16th century, Newton sat under an apocryphal apple tree in the 17th, Darwin formulated his theory of natural selection in the 19th and Einstein started blowing minds in the 20th.
The 21st century, it turns out, is shaping up to be just as exciting in the world of science.
Science loves answers, but it loves questions even more and there are still some mysteries that the universe is not quite ready to give up. These are the big questions and, we can assume, they have big answers. Yes, perhaps a little bit of uncertainty is always healthy, but we'll be darned if we're not going to at least try.
So, what exactly are those scientists thinking about all day?