Welcome to a new series called Steemit Science!

Every week I hope to bring new and amazing science information directly to you on subjects you may have never heard of or ones you may have heard of but wanted to know more. Some subjects you may be an expert in already and we welcome you to share your knowledge, insights and help correct any scientific errors in my posts! I want to make sure all the information I present is easy to understand and scientifically accurate as possible and that will take all of us. Without further ado I present our first topic: The end of the universe!

Theories on the end of the universe

This topic became intresting to me after reading The Last Question by Isaac Asimov. If you have not read the short story before than I would HIGHLY recommend it. A link to the story is below:

http://www.multivax.com/last_question.html

After reading this story it really got me interested in what are some of the current theory's we have about how the universe will end.

I what I have read about current theory I don't think we know enough at this point in time to make any solid assertions in how the universe will end or in that case how it even started but we do have quite a few interesting theory's based on what limited information we do have. As far as how the universe started the current main theory is called the The Big Bang. Most of the theory's on how the universe ends work off of the theory of the Big Bang starting it. So lets look at just three of the theory's on how the lovely little universe we live in may kick the bucket.

Heat death

This theory states that slowly over time all the stars will burn out and collapse into black holes. Then the black holes will slowly collapse until there is pretty much nothing left but diluted gas of protons and leptons. Over a huge amount of time even these will disappear from random collisions. At this point the universe would be almost completely devoid of anything.

This is the theory that The Last Question talks about. The AC in the story still exists in"hyperspace" after complete heat death but since we have no real proof behind anything close to "hyperspace" we don't know if anything could exist in the universe past this point. It seems like a very reasonable theory on the end of the universe. We know our own star will burn out on day so why wouldn't all the other ones eventually do so as well. I personally think this is a rather depressing theory but then again most theory's are depressing when it comes to the end of the universe.

"The Big Chill" or Cold death

This theory is less about the end of the universe and more about the end of life in the universe at which point would pretty much be the end of the universe since there would be nothing left to observe the universe. Basically it states that the universe will continue to expand to from where the Big Bang occurred at such a rate that everything in the universe will become so far separated from from everything else that it will become so cold and empty that it will be unable to support life. Imagine our sun burning out and the next nearest star is so far away and traveling at such a high speed that we would never be able to see let alone reach it. It would get pretty cold pretty fast wouldn't it.

I kind of picture this theory as the night sky being completely empty of stars since they would be so far away that there light would no longer be able to reach us. It already feels like we are unreachable far away from the stars we can let alone not even having stars to see. Of course on the time scales they are talking about the earth would be destroyed by the Sun becoming a Red Giant long before the stars would start disappearing.

The Big Crunch

In this theory the universe is expanding from the point of the Big Bang. At a point the universe will start collapsing back in on itself. It will do this because the theory asserts that universe has too much gravitational attraction to reach escape velocity and thus will start collapsing back in on itself. Now when the universe finally collapses in on itself it will create a new singularity similar to the one that started the Big Bang in the first place. If this new singularity explodes like the Big Bang then the universe will start the same cycle we are currently going through all over again. Our universe would be oscillatory in nature and would continue this cycle of Big Bang and Big Crunch forever or until something stops the cycle.

This seems to be the only theory about the end of the universe that is in the least bit optimistic about the end of the universe. I use the term "optimistic" loosely since it does of course involve the entire universe being destroyed in the process. At the very least the universe wouldn't stop existing it would just create a new one every time the cycle repeats. If you watch Futurama this theory comes up in one of the episodes and they expand it into when the universe is reborn it follows the exact same path it did in the previous cycle so time and space repeat itself infinitely. If you were to move forward through time to the end and start of the next cycle you could end up right back at the same point in time when you left but just in a future universe cycle.

Personally I subscribe to the Big Crunch theory purely based on the fact that it doesn't involve the complete and permanent end of the universe. Of course these theory's will change as our knowledge of the universe grows. I bet in a thousand years we will look back and laugh at how stupid our theory's were on the universe. Maybe we will get to see the end of the universe, maybe not but either way it will happen somehow in one way or another.

Let me know in the comments if you see any inaccuracies, have any questions or have any ideas for future topics you would like me to research and post about. Have a great day and never stop the quest for new knowledge!