Is it more likely you’re a person with a past, or an ephemeral brain in a void?

Are you a person existing within a vast universe, or a brain formed spontaneously in a void, hallucinating this very moment? Your experience would almost certainly lead you to believe the former. However, since cosmologists building on the work of the Austrian physicist Ludwig Eduard Boltzmann (1844-1906) suggested that the latter is actually far more likely, it’s created a complex puzzle for logicians, cosmologists and philosophers to try and untangle. Taking viewers on a mind-bending jaunt through modern cosmology, this brief animation from TED-Ed explains why the ‘Boltzmann brain paradox’ was born, the arguments some thinkers use to counter it, and why it’s a useful thought experiment, even if you didn’t just pop into existence to contemplate a thermodynamic puzzle.