Deeper than Deep Space

Let’s review light years, which begin with the speed of light—186,000 miles every second. That’s 671 million miles per hour. If a plane could go that fast, it could circle the earth 7.5 times—in one second. There are 31.5 million seconds in a year, so light goes a long way in a year, about 5,878,499,817 miles.

So if each horizon of the universe is 13.8 billion light years away, that means the observable universe is nearly 28 billion light years wide. But scientists say it is much larger

Behemoth / Christianity Today | 29 October 2015

We were taking an evening walk, my son and I, at the end of a day of fly fishing in Colorado. Embedded in the mountains far from city lights, the sky pulsated with stars, the heavens saturated with millions of pinpricks of light. Overcome with a sense of wonder, I said, “I don’t know how anyone can not believe in God when looking at something like this.”

My son majored in physics at a secular liberal arts college, so he knew better. “A lot of people look at the vastness of space and say it just proves there is no God.”

He had a point, as I have come to more deeply appreciate.

Reading the book The Martian got me thinking about deep space again. One sobering exercise I go through every few years is trying to grasp the size of the known universe. Recently I once again looked up a few astounding astronomy facts, like the size of the observable universe.

The universe, they tell me, is curved, like the earth is round. You can watch a ship sail off into the distance only so far—2.9 miles to be exact—before you lose sight of it as it sinks below the horizon. Similarly, we can only see to “the horizon” of the universe, which is 13.8 billion light years.

Let’s review light years, which begin with the speed of light—186,000 miles every second. That’s 671 million miles per hour. If a plane could go that fast, it could circle the earth 7.5 times—in one second. There are 31.5 million seconds in a year, so light goes a long way in a year, about 5,878,499,817 miles.

So if each horizon of the universe is 13.8 billion light years away, that means the observable universe is nearly 28 billion light years wide. But scientists say it is much larger ...