Trying to understand the way nature works involves a most terrible test of human reasoning ability. It involves subtle trickery, beautiful tightropes of logic on which one has to walk in order not to make a mistake in predicting what will happen. The quantum mechanical and the relativity ideas are examples of this.
Racism comes in many different forms. Sometimes it's subtle, and sometimes it's overt. Sometimes it's violent, and sometimes it's harmless, but it's definitely here. It's something that I think we're all guilty of, and we just have to make sure that we deal with our own personal racism in the right way.