Stephen Wolfram Q&A, For Kids (and others) [April 30, 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: Are research papers useful? How should I write them and when? - What do you think of research in engineering. Isn't it better to work in a company that specializes in a certain filed and knows it in and out and come up with something revolutionary instead of working at a university where everything is rather theoretical? - About 20 years ago I heard about holographic storage, what happened with this kind of technology that it didn't went forward? - Why do DVDs need to spin these days? Why not just scan top to bottom directly into memory? scanning optics aren't good enough for that? - How does DVD RW work? never understood that one - ​Follow up question to storing information, is there at present optical end to end computers "not storage" but work memory and the processing unit optical? And would it be easier or harder to have a multi-valued optical computer "not binary" then the electronic?computer "not binary" then the electronic?