How Deep Does the Multiverse Go?

StartsWithABang writes Our observable Universe is a pretty impressive entity: extending 46 billion light-years in all directions, filled with hundreds of billions of galaxies and having been around for nearly 14 billion years since the Big Bang. But what lies beyond it? Sure, there's probably more Universe just like ours that's unobservable, but what about the multiverse? Finally, a treatment that delineates the difference between the ideas that are thrown around and explains what's accepted as valid, what's treated as speculative, and what's completely unrelated to anything that could conceivably ever be observed from within our Universe.

Math?

[meerling]

"Our observable Universe is a pretty impressive entity: extending 46 billion light-years in all directions, filled with hundreds of billions of galaxies and having been around for nearly 14 billion years since the Big Bang."

The observable universe is observable because there has been time for the light to travel that far, which can not exceed the age of the universe. Therefor, if the universe is 14 billion years old, then the furthest we could see in any direction is only 14 billion light years, giving a maximum, diameter of 28 billion light years.
So why does the summary say it's 46 billion L.Y. across and only 14 billion Y. old?

Re:Math?

[ledow]

If you assume a static, never-changing, fixed space... you might have been right.

Isn't this how we know it's expanding?

Speculative.

[Oligonicella]

Anything dealing with multiverse is speculative. Math does not constitute evidence.

Re:Many worlds

[narcc]

You've missed the point.

Try a different example. Consider that there are an infinite number of values between 0 and 1. While infinite, none of those values will be 2.

If that's not to your liking, consider something like Penrose tiling where a pattern formed from just two shapes can tile infinitely without repeating.

See, when you ask:

What is your criterion for restricting the variations?

There need not be any such criterion. See, just because a thing is possible does not mean it will necessarily be actualized even given an infinite number of universes.

Re:It's turtles all the way down

[Mikkeles]

But, is it turtles all the way up?

Re:Please explain

[pla]

No. Time is a part of this universe. There is no "meta" time, other universes do not necessarily have time. There is no t Minus infinity. We know exactly when time started (ok, to within a few trillionths of a second).

FTA: "The most amazing thing about it, though, is that this is exactly what the Universe was doing before the Big Bang, only with a much greater energy and at a much faster rate! This was the period known as Cosmic Inflation."

Words like "before" presuppose the existence of time. If, as you postulate, time exists only as a function if this universe, then you have just established the de facto existence of "meta time" (at least if you believe TFA).