Science & Technology Q&A for Kids (and others) [October 22, 2021]

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: Why do mathematicians create models if machine learning can create more complex and better models? - Hello, can you create gold from lead by having some lead next to a big pile of plutonium? - How proportionate is public opinion of a person to actual achievement of that person generally? - ​How would one go build an UFO? What technology do we need for that? What mathematical achievements/solutions do we need?