[This Commentary originally appeared in the October 11, 1990 issue of The Mendon-Honeoye Falls-Lima Sentinel.]
One hundred and eighty six thousand miles per second. It takes light about one and one-third seconds to go from the Earth to the Moon. We know this because scientists have shot lasers at the reflectors the Apollo astronauts left on the lunar surface. The Moon orbits at a distance of 240,000 miles from the Earth.
One hundred and eighty six thousand miles per second. The light emitted from our Sun has aged a little over eight minutes by the time it hits the Earth. The Earth circles the Sun from a span of 93 million miles away.
One hundred and eighty six thousand miles per second. That’s equal to nearly six trillion miles in one year. We refer to this distance as one light-year. The nearest star (Proxima Centauri) looms a mere 4.3 light-years from our Solar System. That translates to just Continue Reading “The Speed of Light”
Journey Beyond The Center Of The ‘Stacks’
Yale’s Astronomy Library was also probably the smallest library on campus. I was the only Astronomy & Physics major in my class. (Back in my day, the only way you could major in astronomy was to double major in physics. It was a lot of classes, with precious little room for elective courses like philosophy, literature, history, and, well, just about everything else.)
My virtually personal reference room was a treasure trove of ancient knowledge. And by ‘ancient’ I mean the actual data is centuries old. Astronomy, for the most part, collects light data from distant stars, galaxies, and nebulae. The objects responsible for these traveling photons lie lightyears distant, sometimes thousands of light years away.
While a light year represents a measure of distance, it also tells you how long ago the Continue Reading “Journey Beyond The Center Of The ‘Stacks’”