The combined speed of any object’s motion through space and its motion through time is always precisely equal to the speed of light. ~Brian Greene
I get a little breathy and tingly whenever I think about physics; it’s a nerd thing. Strangely enough this long-exposure shot of a fishing weir in Eastern Canada makes me think about physics. Long-exposure shots like this one create in me a strong appreciation for the passage of time in general and Einstein’s theory of Special Relativity specifically. In 1905 Einstein changed everything when he suggested that the previous giant in the field of physics, Sir Isaac Newton, was not entirely right about time. Newton held that movement through time and movement through space were two entirely unrelated events. Using ingenious thought experiments, Einstein figured out that this couldn’t be true; time and space are linked and what’s more, movement through one affects movement through the other. I mean, this is crazy right? When still, an object is only traveling through time but when it begins to move, some of the travel through time is slowed to compensate for its movement through space; this keeps observations of the speed of light constant ala Brian Greene’s quote above. So that’s what blows my mind–relative to stationary objects, time actually slows a teensy-weensy bit for objects in motion.
This brings me to my favorite experiment in the history of experiments. In 1971 a scientist named Hafele thought of a simple experiment to test Einstein’s theory of Special Relativity. After some hasty calculations he determined that the speed of a jet airplane ferrying an atomic clock would be sufficient to measure the relativistic effects of motion through space. So after meeting up with another scientist named Keating who worked for the Navy as an atomic clock expert, he finally got enough money to by a couple tickets around the world on Pan Am. He placed atomic clocks on the planes and set them off in opposite directions around the globe. In the end, you guessed it, when they checked the time on the atomic clocks that had been in motion and compared them to a stationary atomic clock in the lab, the moving clocks had slowed by exactly the amount that Einstein’s equations predicted. Coolest experiment ever right? Science frigging rocks!
On a related note, I’ve been told that time also slows to a painful degree for those subjected to my prattlings. Sorry about that.