where does the universe end?

Answer 1

Current theory is that the universe is aproximately 92 billion light years across and expanding. Put another way, multiply incredibly large by gigantic and then multiply that by stupendously enormous to the power huge. To answer your question, about 46 billion light years, and expanding, away in any direction. As for what it is expanding into, your guess is as good as mine.

Wikipedia says;

The comoving distance from the Earth to the edge of the visible universe is about 46.5 billion light-years in any direction; this is the comoving radius of the visible universe. It is sometimes quoted as a diameter of 92-94 billion light-years. Since the visible universe is a perfect sphere and space is roughly flat, this size corresponds to a comoving volume of about 4/3 π R3 = 4.0×1032 cubic light-years or 3.4×1080 cubic meters.

The figures quoted above are distances now (in cosmological time), not distances at the time the light was emitted. For example, the cosmic microwave background radiation that we see right now was emitted about 13.7 billion years ago by matter that has, in the intervening time, condensed into galaxies. Those galaxies are now about 46 billion light-years from us, but at the time the light was emitted, that matter was only about 40 million light-years away from the matter that would eventually become the Earth. See comoving coordinates.


Misconceptions
Many secondary sources have reported a wide variety of incorrect figures for the size of the visible universe. Some of these are listed below.

13.7 billion light-years. The age of the universe is about 13.7 billion years, and nothing travels faster than light; does it not follow that the radius of the observable universe must be 13.7 billion light-years? This reasoning might make sense if we lived in the flat spacetime of special relativity, but in the real universe, spacetime (not space!) is highly curved at cosmological scales, and light does not move rectilinearly. Distances obtained as the speed of light times a cosmological time interval have no direct physical significance. [3]
15.8 billion light-years. This is obtained in the same way as the 13.7 billion light-year figure, but starting from an incorrect age of the universe which was reported in the popular press in mid-2006 (e.g. [1] [2] [3]). For an analysis of this claim and the paper that prompted it, see [4].
27 billion light-years. This is a diameter obtained from the (incorrect) radius of 13.7 billion light-years.
78 billion light-years. This figure, as mentioned above, is a lower bound on the size of the whole universe, and has nothing to do with the size of the visible universe.
156 billion light-years. This figure was obtained by doubling 78 billion light-years on the assumption that it is a radius. Since 78 billion light-years is already a diameter (or rather a circumference), the doubled figure is meaningless even in its original context. This figure was very widely reported (e.g. [4] [5] [6]).
180 billion light-years. This estimate accompanied the age estimate of 15.8 billion years in some sources; it was obtained by incorrectly adding 15% to the incorrect figure of 156 billion light-years.

Answer 2

Well....good question. As a child that question drove me nuts because I would image it ending somewhere, but then there is something else behind that and so on. Now I am a senior with half a brain because of it. (The drugs, booze, sex & rock & roll in my youth didn't help either, but it sure was fun.) LOL!!!!!

Answer 3

Where it finishes the substance and the energy it Grande Atom Universe.

Answer 4

Hoboken New Jersey

Answer 5

If Einstein, Hawkins, and most modern theorist are correct, it does not end.
B

Answer 6

Your guess is as good as anyone else's.

Answer 7

It doesn't. That's linear thinking.

Answer 8

It doesn't.