I sit here and look up into the sky and wonder about how far I can actually see. I can see a few clouds and I can see an airplane streaking across the sky. It's really hard to judge distance when you look straight up without any blockage of your view. When you look out across the land, you can only see so far because the Earth is round and your view is not straight on and on even out in the desert where there are no objects to prevent your view. But when you look straight up into a blue sky, there is nothing to obstruct your view, so how far can I see? I don't really know. I cannot see objects way out into space unless there is some light coming from it or some light be reflected on it from another light source, such as the sun. I can see the moon but it reflects light from the sun or I wouldn't be able to see it. The moon is about 240,000 miles away. I can see the sun and know it's about 93 million miles away, but it's a huge light source. During the day, that's about all I can see, but at night, there are lights everywhere. Most of the lights are stars but there are a few lights that might be reflections of light off nearby planets.
So I started to wonder how far away the stars are because I can see them and they don't look too far away. I looked it up and found that the very closest star is a bit over 4 light years away. OK, that's not so far, but then I looked up a light year and a light year is almost 6 trillion miles. So that makes the closest star over 24 trillion miles away. I can hardly even imagine that I can see an object that is 24 trillion miles away. But there are tons of stars in the sky, so how far away are some of the other stars?
Well, I kept investigating the idea and discovered that the farthest star visible to the naked eye is about 16,000 light years away. Wow. I can see something that is 6 trillion times 16,000 miles away. That's what? 96,000,000,000,000,000 miles. So that's how far we can see, but we can't even see outside of our own galaxy. There are supposed to be something like a 100 billion stars in our galaxy alone but then there are many more galaxies that have been discovered. Actually, there are about 100 billion galaxies, so there could be as many as 100 billion times 100 billion stars in the so called "known" universe. But how far away are these galaxies?
I kept looking up information as another question came up. I found that the most distant galaxy from Earth is known to be 13 billion light years away. Holy cow! That's 13 billion times 6 trillion miles or 78,000,000,000,000,000,000,000 miles away. So now we're getting some where. This is how far away we know there is another galaxy, but the big question I just have to ask is what is beyond that galaxy? Empty space? What is empty space and how far can empty space continue to go away from Earth? Is there a wall or force field that stops us from going beyond the farthest point? Is there another universe that is another trillion-trillion miles from here? Are there trillions of universes that are trillion-trillions of miles apart?
And how far can this keep on going? How many universes might there be in space? Is space flat and does it keep going in every directions for infinity? How is that possible? But then again, how is it possible for there to be a finite universe? Is space rounded and goes back on its self but what's outside the circle?
Does anybody else wonder about space.
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