Motion, Energy, and Evolution

Stephen Wolfram answers general questions from his viewers about science and technology as part of an unscripted livestream series, also available on YouTube here: https://wolfr.am/youtube-sw-qa

Questions include: ​How do galaxies form? - Is it true that animals can sense earthquakes? How? Why can't humans? - ​​I always found it fascinating how birds pick up those fields to "get directions" on where to fly. - People with joint pain can often sense air pressure and humidity changes, and some develop a sense for when the weather will change as a result ("My knee hurts; the weather will change soon."). - What is the difference between speed and acceleration? - If energy is conserved, how we do we run out of it? - How do mutations or radiation effects affect biological evolution? - How size dependent is the universe? Could it be possible to create a mini-galaxy within a controlled environment here on Earth? - Is there fusion going on in a black hole?