Space-time is finite, but has no boundaries?

[ComeToTheDarkSideWeHaveCookies]

I had a hard time getting my brain around such concepts back in my Calculus days when we covered Gabriel’s Horn.

Now it is just about the only thing I’ve retained from my excursions into higher math, except for the constant doodling of hypercubes, of course.

[Mathochist]

@Loopydude

Pick up “The Fabric of the Cosmos” by Brian Greene. It’s a good current survey of Cosmology and touches on some of this space-time topology stuff. IIRC, Hawking’s model of the universe that shows up in his diagrams in ABHoT implies a “big crunch” in the future. The jury is still out, but these days the big crunch seems less and less likely to happen. Rather, we’re starting to worry about a “big rip”.

Yes, I’m somewhat aware of the SOTA in cosmology. This answers nothing about my proposal of “antianthropic” boundaries.

[Mathochist]

@honeydewgrrl

except for the constant doodling of hypercubes, of course.

2-d projections of the 1-skeletons of hypercubes, I’m sure.

[Loopydude]

@Mathochist

Yes, I’m somewhat aware of the SOTA in cosmology. This answers nothing about my proposal of “antianthropic” boundaries.

Well, actually I was addressing the OP, since a question was asked about other books.

Does that not not answer your question?

[Lord_Ashtar]

@Loopydude

Pick up “The Fabric of the Cosmos” by Brian Greene. It’s a good current survey of Cosmology and touches on some of this space-time topology stuff.

Thanks, I’ve just added it to my Amazon wish list.

[Mathochist]

@Loopydude

Well, actually I was addressing the OP, since a question was asked about other books.

Does that not not answer your question?

Then why respond to my post?

[Loopydude]

@Mathochist

Then why respond to my post?

I didn’t. :rolleyes:

[tim314]

@Mathochist

2-d projections of the 1-skeletons of hypercubes, I’m sure.

I like doing this too. I’ve been able to draw the 2-d projection of the 1-skeleton of a 7-cube (7 dimensional cube – is that the correct term?) before completely losing track of what was supposed to connect to what.

But I find it saves a lot of time to stick to the 1-d projection.