Einstein’s special and general theories of relativity make some really odd predictions. Many people don’t care for those predictions, but as a scientist, I have one simple question: Are the predictions confirmed by the data? If the answer is “yes,” the theories are reasonable. The more often the answer is “yes,” the more scientifically sound the theories become. The answer has been “yes” many, many times for these theories, so regardless of how odd their predictions, I have to accept them as sound scientific theories, until another theory becomes even more successful at making such predictions.
While the special theory of relativity is strange enough, the general theory is even stranger. It predicts the existence of black holes, and those black holes have been indirectly observed. It predicts that time speeds up in low gravitational fields and slows down in high gravitational fields. Not only does the global positioning system verify this every nanosecond of every day, but it has been confirmed in the laboratory as well.
General relativity also predicts the existence of gravity waves. A special facility designed to detect such waves, the Laser Interferometer Gravitational-Wave Observatory (LIGO), made headlines last year when it finally confirmed their existence. It has since detected more gravitational waves, but with the help of other facilities, it has now done something truly amazing!