# What shape would the Univers be if we could see all of it

1. Jul 24, 2010

### Worzel

I was watching a program some months ago about the Universe and what shape it could be. In the program they used the Atari Asteroids game as an example.

As the spaceship starts to go off the right hand side of the screen it starts to appear on the left hand side. As the spaceship starts to go off the top of the screen it starts to appear at the bottom of the screen.

For the spaceship to do this, the left and right side of the screen must touch each other. like a map of the earth on a sheet of paper. The same goes for the top and bottom of the screen.

This made the games Universe two dimensional. If you travel left, right, up or down you would return to the point you started from. This universe would be toroidal (doughnut shaped). However, I cannot see why it could not be spherical (globe shaped). If you fly north, south, east or west in a plane you will return to the point you started from. Both of these shapes could be elliptical (squashed) in one or both plains.

The programme then posed a question. What would the universe look like if it was three dimensional? Ie. Not only would you return to the same point if you traveled left, right, up or down but you would also return to the same point if you traveled backwards or forwards.

When you look at a banana under a microscope you would have difficulty in telling what shape it is. However, as we can look at the whole of a Banana we know what shape it is.

When it comes to the Universe, we can only see a very, very tiny amount of it and because of this we cannot say that it is shaped like an apple, a pair a doughnut or for that matter a bunch of grapes. It could even be infinite in size and have no shape to it at all.

Anyhow, the programme got me thinking and a thought crossed my mind. What shape would I get if I pulled up the edges of a doughnut and did the same thing pulling the edges down.

In my minds eye, I had turned the outside of the doughnut into a sphere but the middle of the sphere would still have a whole in it (shaped like an apple core).

The simplest way to explain what it looks like is to use a rubber ring, like the ones you can buy for a dog to play with www.valupets.com/pets/rubber-toys/large-rubber-ring-dog-toy/22362.html and a round balloon.

Blow up the balloon so that it has the same circumference as the rubber ring (7 inches) and then put the balloon in to the middle of the ring so that the balloon has the ring running round the middle of it.

I do not think the universe is as uniform as this and the shape may very a lot but this shape simplifies what will happen when a spaceship travels through this universe.

A spaceship is sitting in space above and forward of the Earth, turns right and fires up the engines. It will be traveling in the first dimension. That means the spaceship is traveling round the circumferences of the rubber ring.

If the spaceship points itself upwards and fires up the engines, it will be traveling in the second dimension. That means the spaceship is traveling round the balloon.

If the spaceship just fires up the engines and moves forward, it will travel in the third dimension but this time it will be going round the thickness of the rubber ring.

Compared to the other two, this would be a much, much shorter journey and could be the reason why the universe is thought to be on the flat side.

Comments would be gratefully appreciated but can you please keep them simple enough for me to understand.

To see a cross section of the universe, like cutting an orange in half, follow the instructions below.

Using a pencil, draw a horizontal and vertical line across the middle of an A4 sheet of paper. Put a compass in the middle of the paper and draw a circle with a 50mm radius. For the top right and bottom left quadrants go over the pencil lines with a black pen and the other two with a red pen.

Draw a pencil line from the left edge of the top right quadrant to the left edge of the bottom left quadrant. Find the middle of the line and draw a circle that will touch the end of the top and bottom quadrant. Mark the line of this circle in back ink, where it is inside the first circle and red ink where it is outside the first circle. Now do the same for the other side.

You should now have a black shape that looks like an apple core and two red areas that are crescent shaped. Draw a circle, in black ink, round the whole lot, that just touches the outside edge of the two crescent shapes and then remove all the pencil lines.

The edge of the circle is the outer edge of the universe, beyond which there is nothing and the apple core shape is the inner edge of the universe, again beyond this there is nothing. The red area is the only area where galaxies exist.

Last edited: Jul 25, 2010
2. Jul 24, 2010

### robheus

It looks like a bubble bath, all the bubbles being empty voids, and only where the bubbles connect you find galaxy clusters, etc.

3. Jul 25, 2010

### robheus

And some argue that the universe is shaped dodecahedral