Have you ever stood out under a star-studded sky and wondered how many stars are out there and do they go on forever? Other people have asked the same questions, some of them smarter than you or me. But first some basics.
We live on a planet. We call it Earth, and at 7,926 miles in diameter, it is not very big in the grand scheme of things. Even so, we have a hard time leaving it, and very few people have been as far as the moon.
Then we live in a solar system with one star, eight planets, lots of asteroids, comets and meteoroids. It is big, but how big exactly depends on what you measure from and to. Here is a nice numbered you can relate to: 18.6 trillion miles. A trillion is a big number. A trillion dollars is a stack of $1,000 bills 64 miles high.
Then we live in the Milky Way galaxy with 300 billion stars, and it is 100 thousand light years across. To convert that into miles multiply 100 thousand times 5.9 trillion. It is a big number!
We also live in a universe and it is 93 billion light years across. Now we are getting somewhere. But wait. That is only the observable universe, the universe we can see with our telescopes. Astronomers agree that it is much bigger than that. It is just that most of the stars are so far away that their light has not had time to get to us yet so we cannot see them.
That may be kind of hard to wrap your head around, but it gets worse. Now we are beyond the range of the James Webb Telescope. If we could somehow travel out there, would we come to an end of it all at some point? Could we part the curtains and take a peek at what is beyond? Or do the stars and galaxies go on and on forever and never ever come an end?
Interestingly enough the theories that astronomers use to predict the size and shape of the universe work for either an infinite one that never ends, or a finite universe, one that has curtains.
Astronomers are leaning towards the infinite variety. It is simpler they say. There is an old saying in science that says if something can happen, give it enough time and it will happen. Does this mean that there are duplicate earths out there and maybe even duplicates of yourself happily living oblivious of you? Deep thinkers are divided on this one. Maybe, maybe not.
But is it real?
There is another possibility for the universe, but to talk about that one, I have to take you on a trip into the Twilight Zone. If you want to sleep soundly tonight , you might want to skip the next couple of paragraphs. Could we be living in a giant simulation? Could we be just bits of information coursing through a universe-sized computer? Could our lives be illusions? Is free will just a cruel joke? Who or what would be running the show?
The idea sounds preposterous of course, but the amazing thing is how many smart people think we cannot rule out that possibility. Elon Musk reportedly says we definitely do live in a simulation. I do not know if that makes you more or less inclined to consider the idea. Then there is our favorite affable astronomer, Neil de Grasse Tyson, who says he would be hard-pressed to rule out the simulation theory.
If all this is just too much, and you need to clear your head, just step outside at night and look up at the stars. Here are a few of my favorites that I say “Hello” to every night. High in the south look for bright and orange-colored Arcturus It is one of the oldest stars we can see at about 7 billion years old.
The three stars of the Summer Triangle, Vega, Deneb and Altair, are coming up in the east. They are a great way to get oriented to the summer sky. Mars is about halfway up from the horizon in the west. You can recognize it by its red color, which really stands out in binoculars.
I am going to leave you with one final question. If it were definitively proven that we live within a computer simulation, would you live your life any differently?
