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Where Is The Limit of the Universe

Updated on July 23, 2012

Taking it as given that the big bang theory of the universe is broadly correct, the universe is expanding. Searching for images to help us visualize what is happening, scientists have come up with the example of an inflating balloon but the analogy is problematic. A balloon has a limit that separates the air inside from the air outside, but there is nothing outside the universe. That doesn't mean that there is noting in that realm beyond our universe. It means that the phrase beyond our universe is meaningless. The idea of a limit in the sense of a boundary,supposes that there is an outside and an inside to be separated, but there is not outside,so there can be no boundary.

A Limited Extent

Nonetheless ,it is reasonable to ask how far is this expanding universe has expanded. We know that the universe has existed for 13.7 billion years and we know that the fastest anything can travel is the speed of light. The distance that light travels in a year is called a Light-Year , so it might be reasonable to suppose that the maximum radius of the universe is 13.7 billion years..but no. There are two things wrong with that calculation. First, there is no central point from which the radius of the universe can be measured, because of the big bang theory was not like a bomb going off at a point in space. And second, as we learned when discussing space and time, matter is not moving through space in this expanding universe - space itself is expanding and it can do so at a speed that moves galaxies apart faster than the speed of light. The latest to estimate for the distance across the universe is 156 billion light-years!

Dark Energy seen in the present
Dark Energy seen in the present

The Shape of Things to Come

As the universe expands, it does so in opposition to the attractive force of gravity. It was therefore thought that the expansion must gradually slow down and that eventually gravity would take the upper hand , the universe would contract, and everything condensed into a big crunch, returning to a singularity. It might then go bang again, in a scenario that has been called big bounce, although the chances that all chips would fall the same way -that all the particles and forces would be identical to those in the universe - would be infinitely small. However, that was before it was discovered that the rate of expansion is increasing..which brings us to dark matter and dark energy.

  • Einstein recognized that if gravity bends light, celestial bodies could act as lenses, magnifying more distant objects. This phenomenon is now being used to locate the dense masses of dark matter, as these act as lenses in place where no matter can be seen.

The Dark Component

Imagine that not all mater is what we know is matter. Imagine that there's another kind ,the presence of which can only be inferred from unexplained gravitational effects. Well, it seems that this may be the case. This hypothetical invisible matter has been called dark matter, and there may even be more of it than there is ordinary matter. What's more, space maybe filled with a corresponding dark energy that is evenly spread throughout the universe. This would explain why the universe's expansion is accelerating than slowing - it is being powered by dark energy.

How Does It End

If the dark energy hypothesis is correct, the universe will continue to expand at an ever fast rate. The outcome thought most likely is that the universe becomes even colder, a scenario has been described as the big freeze.

If dark energy exerts an even greater force, a big rip could occur, in which the universe expands so fast that the forces holding the matter together are overcome, ripping all particles apart from each other and distributing matter evenly throughout the universe. But don't panic, the universe is expected to last at least one hundred billion years.

The concept of a boundary to the universe is meaningless, as there is nothing outside the universe, but the width of the expanding universe could be as much as 156 billion light years. The universe isn't infinite...yet.

There is a theory which states that if ever for any reason anyone discovers what exactly the universe is for and why it is here it will instantly disappear and be replaced by something even more bizarre and inexplicable. There is another that states that this has already happened

- Douglas Adams (1952-2001) Hitchhiker's Guide to the Galaxy


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  • profile image

    Unster 5 years ago

    Very good hub indeed.

    @dmhenderson You are correct. There is the theory of multiverse, and thus there would be something on the outside, as in, the other universes, each with its own unique constants (light velocity, gravity acceleration and other constants are different).

  • Mr Love Doctor profile image

    Mr Love Doctor 5 years ago from Puerto Rico

    When we talk about something as big as the universe, so many of us have watched a lot of science fiction where wormholes and light drive and hyperspace make going to another galaxy as easy as popping down to the supermarket - and we forget how HUGE it is. Look how intricate and enormous a project it was just to get Curiosity onto Mars - and that's one planet over! This article is a great reminder to us as to why we should be humbled at our tiny place in a big, big universe.

  • ib radmasters profile image

    ib radmasters 5 years ago from Southern California

    The real question is why should we care about the size of the universe.

    Even our own solar system is useless to us.

    Einstein's Space Time theory requires movement, and we can't move through the universe.

    Even if we did come up with a grand unification theory that was real, it wouldn't help us. Chances are based on our history we would probably use it as a weapon, and destroy the universe.

    Our own solar system is playing demolition derby, and we have no say in how to play in that derby.

    My point is that our Solar System is barely useful for us.

  • jolinabetts profile image

    Sunshine Diaz 5 years ago from Wichita, Kansas

    Thanks Mhatter 99 for reading, very much appreciate it.

  • Mhatter99 profile image

    Martin Kloess 5 years ago from San Francisco

    Fascinating report! you did a good job. thank you

  • CrisSp profile image

    CrisSp 5 years ago from Sky Is The Limit Adventure

    Interesting hub! I always wonder where does it end or does it really end? I'm a FA and it always fascinates me to see what's up above the cloud. What's behind and beyond the Universe. Is there anything really? Apparently, it's cloud above the cloud. I think it's infinite. Great read!

  • jolinabetts profile image

    Sunshine Diaz 5 years ago from Wichita, Kansas

    @Robhampton: Thanks for commenting, there's just no limits at all. By the time they discover the light at the end of the tunnel, i hope we're still alive to know the answer. I appreciate your comment, thank you

    @Nothuk - Thank you for saying so, I'm a big fan of Douglas Adams.

    @ dmhenderson : You've got yourself a great idea for another interesting hub!

  • jolinabetts profile image

    Sunshine Diaz 5 years ago from Wichita, Kansas

    @Marcus Faber:

    Thank you for reading my hub, i very much appreciate the comment

  • dmhenderson profile image

    Dave Henderson 5 years ago from Missouri, USA

    Isn't there anything outside the universe? What if there are multiple universes? Wouldn't the other universes exist outside ours? Has this theory been discounted?

  • nothuk profile image

    nothuk 5 years ago from Varna, Bulgaria

    This is a very nicely written hub on a very interesting subject. Congratulations on the nice Douglas Adams finish :)

  • robhampton profile image

    Rob Hampton 5 years ago from Tampa Bay, Florida

    Great hub. I am always fascinated by things like this. My brain hurts sometimes just trying to comprehend the size of the universe.

  • Marcus Faber profile image

    Marcus Faber 5 years ago from London, UK

    Very interesting and well written article, when people think of the universe they think planets, stars, galaxies etc but that is only a tiny fraction of what the universe actually is. Voted up!