Science & Technology Q&A for Kids (and others) [September 16, 2022]

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 tornadoes form? - Why does a fan create white noise? - Is that how they produced the audio from our galaxy's supermassive black hole? - Fans also generate a different speed of flow radially, as the linear speed is lower closer to the center of the blades than the outside. - I think they were actually to measure distortion in gas. - I thought they were synthetic, but it seems like they managed to actually measure sound waves in distant gas. - Why are roads made of tarmac?-  Is there anything certain modern physics can say about dark matter/energy? What exactly is it? - Does dark matter interact with gravity? - If dark matter particles exist, then why are there no dark matter halos associated with our Sun and with the planet Jupiter? - What's a graviton?