Moving into daylight savings time can be disruptive. I dislike the loss of an hour’s sleep when we spring ahead – admittedly, I never complain about the extra hour the day we fall back. Each year I am also reminded that my mind’s internal clock doesn’t reset as easily or as quickly as my alarm clock or wrist watch. However, collectively changing our clocks provides an opportunity to think about a subject that we very often take for granted― time.
What is time? Saint Augustine answered that question by saying, “if no one asks me, I know what [time] is. If I wish to explain it to the one who asks, I do not know.” Physics tells us that the measurement of time requires the observation of some form of motion. Our ancestors relied on Astronomy and built sundials to record the motion of the Sun during the day and precise markers like Stonehenge to chart the position of the sunrise and sunset to construct the calendar year. At night, the seasonal motion of the stars was used to signal the time to expect the monsoon rains, plant and harvest crops, and celebrate festivals. For instance, this month we see the bright blue star, Spica, in the east. In some depictions of the constellation, including the one we use in our Planetarium, Spica represents a grain of wheat being held by an Angel. Spica rising in the eastern evening sky traditionally signaled the planting of crops for many civilizations in the northern hemisphere, while its setting will signal harvest.
During the Renaissance, the great scientist, Galileo, used the beating of his heart to measure time in his experiments. His observations of swinging chandeliers during mass in the great cathedrals led to another way of measuring time – relying on the regular repeating cycle of a pendulum. Later, the invention of the watch provided humans with an accurate, stable, and inexpensive way to keep track of time. Today we can take the measurement of time for granted, our GPS and cellular phone networks broadcast the time invisibly to our mobile devices – even changing to daylight savings time automatically. We do not have to be aware of the natural cycles of the Sun, Moon, and stars. We do not have to flip an hourglass, set a pendulum clock, or even wind a wrist watch. However, the basic question remains - what is time?
At the beginning of the twentieth century, Albert Einstein showed that the passage of time was not constant. Two people, moving at different velocities, could disagree on the length of one second and whether or not two events were simultaneous. No longer were past, present, and future absolute. Recently some Physicists have argued that time may not exist at a fundamental level (http://discovermagazine.com/2007/jun/in-no-time). Time may be a construction of our consciousness. Our mind attempting to make sense of the world around us.
Whether or not time exists at the most basic physical scales or not, we know that time is a precious gift. We are blessed with only so much and it is up to us to make the best use of it. Neil Pasricha, author of the blog 1000 Awesome Things (http://1000awesomethings.com/) and the New York Times best-selling book, The Book of Awesome, reminds us of the importance of taking the time to appreciate the simple pleasures in life, to maintain a positive outlook, and to remember that we are each given only a short time to enjoy these gifts. His TED talk is one of my favorites and I encourage you to check it out (http://www.ted.com/talks/lang/en/neil_pasricha_the_3_a_s_of_awesome.html).