Is the universe finite or infinite?
Whether the space has a size or not, we will never know. Even if space does have an end to it, we will never know. Space is to big for us to travel out in it and figure out if there is an end. I chose this question because I’ve always had an interest in space and what always made me mad was that I would never know if there was an end to space. If space does have an end, what’s at the end? Is it just like a wall that you can’t go past, and you’re forced to turn around, or is it like a cliff where, if you go past you immediately die?
This is what I found. Nasa was asked if there was an end to space and they said,
Whether space ever ends is a hard question. There is a limit to the space that we can see, because if there is stuff beyond 15 – 20 billion light years (the age of the Universe) the light from there hasn’t reached us yet. So we don’t know.
From what Nasa says, there is a possibility that we will know the answer in the future. But that is a long time from know and until then, we will not know the answer to our question. A light year is the distance light travels in one Earth year (10,000,000,000,000). The size of space is larger than anyone can even imagine. The current view in cosmology is that space was already huge and possibly infinite before the Big Bang.
The universe may be infinite, but we can only see a finite section of it due to the finite speed of light. We can only see those parts from which light has had time to reach us since the beginning of the universe – which means we can (in theory) see a spherical universe with radius of about 15 billion light years.
A youtuber named Vsauce said that, everywhere is the centre of the universe and technically we are also the centre of the universe. He continues to say that the universe is expanding and no matter where you are, it will look like everything is moving away from you at the same speed. He uses a balloon with dots on the surface. The balloon would be the universe and the dots would be galaxies and stars. If you blew up the balloon, all the dots would spread out all at the same rate and there would be no centre unless you focus on one dot and blow up the balloon even more. Then it will appear as if the other dots are moving away from the dot you are focusing on. Watch the video here. He starts talking about the centre of the universe at 8:19.