25 December 2011

A gift

Today, many of you are enjoying gifts from other people. I want to talk about one my favourite natural gifts.

For me, the best gifts are the unexpected ones; the ones you didn’t have to get. A present from someone you don’t know all that well, for instance, can be very memorable.

There are many things in nature that are beautiful. But because they lack that unexpected quality, they don’t rank as my favourite natural gifts. Rainbows, for instance. Given water droplets, some light, and the laws of optics, rainbows are inevitable. You can’t not have rainbows. Any planet in the cosmos with water and light will have rainbows.

To me, one of the most astonishing gifts on our planet is this.

The sun and the moon are the same size in the sky.

The sun is huge. Its diameter is about 1,392,000 km.

The moon is small. Its diameter is about 3,474 km.

Yet the sun is so much further away than the moon that it almost exactly compensates for the difference in size. There is no reason that our star and our satellite should match up this way. Either could be a different size or different distance away. There are probably only a small number of planets in the galaxy where you would get this view from the ground.

And that makes this possible:

The best gifts are the ones you didn’t have to get. And this coincidence makes for what may be the best gift from our planet.

Photo by shehal on Flickr; used under a Creative Commons license.

(I was lucky enough to see a total solar eclipse in Manitoba in 1979. They are beautiful in a way that photos and video cannot capture.)

1 comment:

e_journeys said...

I was lucky enough to see the one near Bratsk in 1981. What an extraordinary experience.

More common but still a thrill -- I took this 89-photograph video from my driveway of the total lunar eclipse that occurred on the Dec. 2010 solstice.

Happy Holidays, Peace on Earth, Good Will to All.