Forgive us while we get a little philosophical on a Saturday morning, but what the hell is reality anyway? One way of thinking about it is as everything that would be here if we weren't around -- but that's not particularly satisfying as, to the best of our knowledge, we do exist. Or hope we do.
So, instead, reality can be classified as what is most fundamental in the universe. This video takes a dive into that idea, looking at molecules, atoms, quarks, strings and... well, nobody has really found the most fundamental part of the universe yet. Which means that, perhaps, space-time is the ultimate reality. Wait, what? Watch the video to find out. [New Scientist]