Stephen Wolfram answers general questions from his viewers about science and technology as part of an unscripted livestream series.

Questions include: Why does matter and anti-matter annihilate when they come together? What is the mechanism behind an electron and a positron to convert to energy when they meet? Saying that they are of opposite charges doesn't really explain it - So entropy always tends towards the lowest energy state? - What is the most "scientifically" interesting place you have visited? - How long does the "virtual photon" live before it converts into a pair of particles? - Why do humans have unique fingerprints, iris etc? and do other creatures also have these features?? - What is your favorite unsolved problem? - If you could go back in time and help a legendary scientist solve a problem, who and what would it be? - What is the oldest known and unknown civilization which had the notion of universe and mathematics?

See the full Q&A video playlist: https://wolfr.am/youtube-sw-qa