Science & Technology Q&A for Kids (and others) [September 10, 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: ​Is there really such a thing as INFINITY or is it just a concept? - ​Does Infinity have a magnitude? - But is infinity really a mathematical object? It has no finite quantity. ​How can something without a finite quantity be used in a calculation/computation? - What's the difference between counting numbers and counting processes? - ​Is Rulial Space likely to be finite or infinite? - ​How is it possible that infinity of integers is smaller than the infinity of floats? - Why can't mules and donkeys reproduce? What are the limits for different species of mammals breeding with one another? - is it 5 crossovers on average for everyone? - Are memes on the internet, conceptually a species? - So how is a specie determined just by visual features? Or maybe defined by breeding? - Last question can genetic traits lay dormant for centuries..? Sort of recurring changes after x generations?