An answer to the 24-hour question
The universe in which we live is, the scientists say, 14 billion years old. I'm not that old, but I'm old enough to know some stuff about old.
Age is relative, much like the velocity of light, which, according to Einstein, is also relative -- relative to whomever is seeing the light, along with some other mysterious stuff I think he made up about the space-time continuum, and gravity, and time slowing down if you're moving faster.
Age is relative to whomever is doing the aging. I meet people older than me who consider me fortunate to be so young. Conversely, I meet people younger than me who look at me and hope it doesn't happen to them.
So, age is relative to me as I get older. I've looked into time some, too, which is how Einstein's theories popped up. Once you look up Einstein, the age of the universe pops up. Pop, pop, pop. All these things popping up. Did you know there are 100 billion galaxies? And that each of them has 100 billion suns? Around which a bunch more planets revolve? At my age, when bigger numbers actually boil down to longer life, big numbers have become important.
It's not fair that if, as Einstein states, time slows down if one is moving faster, that just as I begin to hope for more and more days, my body won't stay up to the speed it used to have. Time seemed to progress more slowly when I was younger. Remember summers when you were a kid? They seemed to last forever. Add that to the fact you could move faster back then, and Einstein's theories may in fact have some truth to them. You moved faster; time slowed down.
Now I'm moving slower, and time seems to be speeding up.
A few days ago in class, one of the students asked me, when I was once again explaining the application of the metric system to one of the measurements of vacuum pressure, "How come the day is divided into 24 parts. If the metric system is so great, where'd that come from?"
Good question. I have retained a huge accumulation of useless knowledge, but I had not come across that one yet. So, I told the student that it was probably the Catholic church's fault, and then said wait, no, that that wasn't fair, because although the church needed time by which to schedule worships, long before the church came into being, monks had to know when to worship, which is when time became important. (If you don't know who to blame, blame some church. Oh, and just in case you don't know, democracy is religion's fault; they were the first to structure vertical representation of the masses, back when there were kings and princes and stuff other than democracy.)
Back to the 24-hour question. It has a simple answer. The Sumerians counted with their fingers. They were a tribe that existed 4,000 years ago, which pretty much goes back to when people were first figuring out the act of counting. But getting from 10 fingers to 24 hours? Yeah, I know. That's what I thought at first, too. They used their 10 fingers, but they did it differently than we do.
One more basic fact, first. They knew that day and night were roughly half and half, a fact that will become important in just a bit.
Here's how they did it: First, take your left hand, and, using your thumb, point to the first bottom joint of your pointer finger. That's one. Now point to the second joint. That's two. Now, the final, third joint. That's three. Now, using that same thumb, point to the first joint of your middle finger. That's four. The next joint, that's five, and the next, that's six. Now point to the first joint of your ring finger, seven, go on to eight, and nine, and your little finger, 10, 11 and 12.
Voila! You have just divided half the day into 12 segments. Use your other hand to divide the other half up. Add the two together, you have the 24 hours in a day.
But wait, you ask. Why are there 60 minutes in one of the 24 segments, or hours, of the day? Here we go: Start counting on your left hand again, until you once again get to 12. At that point, fold your right thumb down. Count on your left hand once again to 12, fold your right pointer finger down. You're at 24. Keep doing it until all five fingers on your right hand are down. Bingo! Sixty.
Stuff like this helps time slow down a bit. You never thought of it at all while you were reading this, did you.
Next time, read faster. Live longer.