Closer to Home
December 19, 2012 / Inching Towards the Light
My husband John is the astronomy expert in the family, I mean he understands astronomy stuff really well--far better than I. But that doesn’t stop me at all (nor would he ever discourage me) from appreciating the consequences of celestial machinery. Anybody can do that even if they have never opened a textbook about astronomy or know any science at all.
For instance, right now the planet we are all riding on is just starting to come out of the curvier end of its elliptical trip around the sun and is slowly traveling to the longer side of the ellipse that isn’t quite as curvy. When it gets to the middle of that longer side it’ll be the equinox, June 21. This elliptical path, by the way, is really almost round, hardly an ellipse at all, just like a slightly squashed circle.
I just like to visualize this—the rocky, watery ball we all live out our lives on (as they say, all the people that have ever lived are here on it, in one form or another)—anyhow, this ball is going 67,000 miles an hour around the sun. Think of it! If you are reading this blog at, say, 5 p. m., by the time the 6:00 news comes on you will have gone 67,000 miles through space, traveling along this roundish ellipse!
Another thing to visualize is that our earth doesn’t sit straight up and down, with the poles exactly perpendicular, smack up and down, nor is the equator smack horizontal or straight. If you get what I mean. This is because actually the earth is kind of tilted, as if it were going to tip over a little. It’s not a big tilt, just about 23 degrees of a circle, more or less.
Let’s see, how much is 23 degrees? Well, if you hold your arms out straight from your sides, you’re dividing a circle in half, so that’s 180 degrees above your arms. Now if you point one arm straight above your head, you’ve got 90 degrees between the two arms. OK, now move your lower arm halfway into that space, and it’s 45 degrees. Move the arm halfway into that space, and your arms are about 23 degrees apart.
So now one of your arms is pointing up, and the other is just slanting a little bit. It’s slanting about as much as the earth is tilting. Not much. But it’s enough to make a big difference to us humans, especially those of us who don’t live right near the equator. As we ride around the sun, we keep that same 23 degree tilt. We just keep tilting in that same direction--not like, say, a top winding down out of its spin and tracing a circle with its—um—top. No, we just keep twirling around on our axis always tilting the same 23 degrees off vertical.
So this means that half of the year one hemisphere of the earth gets more direct sunlight, and the other half of the year the other hemisphere gets more direct sunlight. That’s why right now it is winter in the north (when the rays of the sun don’t point very directly onto us) and summer in the south (where the sun rays are pointing pretty directly onto us). And it will be vice versa in six months.
So—if you have got this far, here is my little story. A few weeks ago, right around Christmas, I started keeping track of things like sunrise and sunset, and how much more light we were getting each day; I write these down every morning. I like to use www.wunderground.com for this information. It’s amazing! In the three weeks since the winter solstice on December 21st, we have gained 19 minutes of light! At first we were only getting a few extra seconds a day—12, or 20 or so. But now, well into January, every day we are gaining over a minute and a half of light! I’m so happy!
I especially love it that at what seems the darkest time of the year, December 21st, we are actually starting our turn towards the light. I’m not a religious person much, but the idea of the light that comes in the darkness seems so powerful, because it is real.
I also cherish the fact that no matter what else happens, we will always turn toward the light on December 21st. Joy! To behold it I am here, and you too.