Agreed - we do not even possess the instruments to define the nature of dark matter, and it is only by inference that we can suppose it exists. It is amazing t

Agreed - we do not even possess the instruments to define the nature of dark matter, and it is only by inference that we can suppose it exists. It is amazing that Fermi, Einstein, et al were able to predict what they did without readily available modern computing hardware and search engines. Some things are out of the realm of our perception.