Friday, June 23, 2017


This is the Westerlund I Star Cluster, a mere 15,000 light years away.
In it, there is a star so big that if it were in our solar
system it would reach out past the orbit of Jupiter.
See APOD  for more info.

Recent articles have reported that astronomers have now calculated the size of the universe. The long but interesting articles relate how scientists came to their current conclusion that the diameter of the universe is 93 billion light years. (Not miles: light years. A light year is the distance light travels in a year, or about 6 trillion miles. Do the math?) Those of us who remember a bit of high school geometry will realize that nothing was said about the circumference or the area of the universe. 93 billion is a big enough number, especially if it is multiplied by 6 trillion. That comes to a number in the sextillions. When they use the word 'astronomical' they really mean it. Only astronomers can think in that kind of numbers.

Just think on this: it was once believed that our own Milky Way galaxy, which over time has been estimated at various sizes, had the Earth at its center. Our galaxy is now known to be about 100,000 light years across – give or take a few light years - and we are out in its edges. The Andromeda Galaxy, the closest galaxy to ours, it is only 2.54 million light years away.

For those of us who regularly deal in miles or kilometers, or even the length of a city block or a football field, light years are almost mythical. To bring it down to earthly size, I suppose the Earth is not the seed in the watermelon or the flea on the dog, it’s probably not even like the proverbial grain of sand on a coral beach. No, I’d guess we’re more like an atom of carbon in that grain of sand.

In the days before World War II, Winston Churchill was preoccupied with the question of whether we are alone in the universe. In a 1939 essay recently discovered at the Churchill Museum in Missouri, Churchill, a great advocate of science, argued that humans aren’t all that special: “I, for one, am not so immensely impressed by the success we are making of our civilization here that I am prepared to think we are the only spot in this immense universe which contains living, thinking creatures.”

Makes you start thinking about the bigger picture - about all the now seemingly insignificant problems besetting our planet, and the relatively insignificant beliefs we hold. Start thinking about all the beings who most assuredly populate the countless worlds between us and the edge of the known, ever expanding universe. How do they live, what are their problems, who are their gods? Thoughts like this shouldn’t keep you up at night. Maybe, if you pursue them in depth, they'll put you to sleep.

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