Humans are fascinated with speed. How can we travel faster? First, we domesticated horses. With the invention of the train, people worried that passengers would suffocate at the blistering speed of 30 miles per hour. Of course, we know now that humans can survive much faster speeds than that. The current land speed record is over 700 miles per hour. There is one speed limit we will never break: the speed of light. This cosmic speed limit, roughly 300,000,000 metres per second, is set by the laws of physics.