Science & Technology Q&A for Kids (and others) [January 26, 2024]

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: ​Can you explain dark matter in layman's terms? - Could dark matter just not be interacting with light/photons? - If our universe is accelerating faster than the speed of light, does that mean we cannot see anything past the speed of light? - So the "viscosity" of the Higgs field gives mass to particles? - How might the topological stability and quantization of skyrmions, initially proposed as models for nucleons, relate to our understanding of gravity, considering their presence in solid-state physics? - Can the probability of a random walk returning to its origin be another way of defining local dimension on a graph? - I'm quite confused with heat/temperature and the general introduction of thermodynamics. Can you explain?