Time…the bane of college students.
There’s never enough, especially the first week back from spring break. Between tests to take and homework to finish, many of us feel like slaves to the clock.
At such moments, it may be comforting to know that there is no such thing as absolute time, and it all depends on your frame of reference. Albert Einstein (whose birthday, by the way, was last week) figured that out 110 years ago when he introduced his theory of special relativity.
Although it sounds intimidating, anyone can grasp the basic ideas of Einstein’s insight, which is outlined in most college physics texts. Knowing something about relativity is handy for sounding smart and making up original excuses. While anybody can get a homework-eating dog, few people think to blame their shortcomings on the fundamental nature of the universe.
Einstein’s theory of special relativity says, among other things, that there is no such thing as absolute time. If a stationary observer and a moving observer measure the time between two events, they will get different answers. The moving observer measures a longer time, and it’s tempting to ask which is right. The answer is surprising: both of them. Each observer is correct in his or her own frame of reference.
This phenomenon, time dilation, is too small to notice in daily life, but scientists have measured it. One such experiment by physicist Joseph Hafele and astronomer Richard Keating was published in “Science” magazine in 1972. They transported accurate cesium clocks on airplanes and compared their time with clocks on the ground; the results were consistent with relativity.
How is this useful to college students? Let’s say you are taking a test, there are just five minutes left, and you need more time. Theoretically, you could get it! In the professor’s frame of reference, you have five minutes. If you accept your fate and sit at the desk staring at a blank page, you still have five minutes. However, if you leap out of the chair and complete the test while racing around the room, five minutes to the professor is a longer time to you. Problem solved!
Of course, nitpickers could say there are difficulties with this scheme. Writing while running takes a steady hand. The professor and other students might object to the disturbance. Finally, to gain a meaningful amount of time, you’d have to be faster than any creature on the planet. It’s possible to calculate that doubling the time from five to ten minutes would require traveling at 584 million miles per hour, almost nine-tenths the speed of light. These, however, are simply public relations and engineering details; the idea is solidly grounded in physics.
Being late is another occasion where relativity could be useful. If your professor objects, simply argue that you were so motivated to show up that you came racing and time dilation occurred. Your watch said you still had time to get there while the classroom clock said you were late. Don’t mention that the effect would be smaller than nanosecond-scale if you were running at top speed, and you could get away with it. At least, you’ll sound original.
