Curious Kids[1] is a series for children of all ages. If you have a question you’d like an expert to answer, send it to This email address is being protected from spambots. You need JavaScript enabled to view it.[2].Why are there small and big black holes? Also, why are some black holes invisible and others
Curious Kids[1] is a series for children of all ages. If you have a question you’d like an expert to answer, send it to