Shape of the universe?

Question

what are the 3 possible shapes of the universe? what shape is indicated by the microwave backround radiation?

Answer 1

Hello Thinking Person...

Let us begin this discussion with the following understanding:
All discussions of "the shape of the Universe" result from the inappropriate idea that someone can stand back and observe the Universe in its totality from a distance and therefore make some educated statement about its shape in relation to things that we know and understand here on Earth... Things like Spheres, Disks, Helixes, Cylinders, Hoops, etc. It is not possible to stand outside the Universe and observe it in totality, so all discussions from that viewpoint are complete conjecture.

What is possible is to state with positive certainty that Astronomers can, today, "see" or "observe" with the very best of optical telescopes, objects in Deep Space at distances of up to 13 Billion Light Years in all directions from Earth.

It is also possible to state with positive certainty that scientists using Radio Telescopes are able to detect objects in Deep Space at distances of 40 Billion Light Years from Earth in all directions.

Therefore, while these statements do not discuss shape, one can state that Astronomers' current technology permits them to "SEE" within an area which approximates a sphere with a radius of 13 Billion Light Years. Radio Astronomers can similarly "SEE" within an area which approximates a sphere having a radius of 40 Billion Light Years. Neither of those two quoted distances are the limits of Space, but rather the limits of the performance of the equipment which they are using to "SEE" or "DETECT" with. Space most certainly continues on far beyond those limitations. We just canot SEE any farther out there than that.

Truths:
1.) No one has ever traveled out to a distance of 13 Billion Light Years from Earth.

2.) No one will ever travel out to distances as vast as that and return with any viable information for us. To do so would require travel at speeds far beyond the capability of mankind at this period in technological development, and a length of time far beyond the expected life span of the planet Earth
(Sun expected to devour Earth in roughly 5 Billion years when it runs out of hydrogen gas supplies).

3.) Communications with any space vehicle ever attempting to make such a voyage would never reach us within our lifetimes so that any information they gain would essentially be lost forever after some point in their travel. Example: travel just one billion light years from Earth would require an EMail Message to take one billion Years to be sent one way to the vehicle, and one billion years for a reply to reach us.

4.) Current space vehicles travel at speeds between 25,000 Miles Per Hour and 50,000 Miles Per Hour. Those speeds are no where close to the speed of light which is
186,000 Miles Per "SECOND."

5.) While many make reference to the size of space as being infinite...At the very least, a depth of 40 Billion light years is so vast that for all intents and purposes, to the average man in the street it might as well be an infinite distance.

Answer 2

Straight Line, Curved Out, Curved in. Steady State, Expanding and Contracting respectively.

Answer 3

It's flat, we know this for sure.