Is deep Space deep?

[Tormod]

At least we know there is a restaurant there. At the end of the universe, I mean.

[sanctus]

42 should be the answer if I remember right Tormod.

[Tormod]

Originally Posted by sanctus

42 should be the answer if I remember right Tormod.

But is it 42 in time or space?

[DougF]

Ahmabeliever
I think in trying to measure the volume of space we are being as short sighted as the humans who insist the world is flat.

Surely space is infinite. The Big-Bang a miniscule pop in the scope of things and all we know and see but one point in a region that is but one point in a region ad infinitum.

We can't see or detect beyond certain points, or fathom the reach of it, it is not 'a reach' to fathom. We may measure and fathom portions of space for now, between frames of reference we have, I do not think we can measure 'total space' as an area or volume or depth at all.

If there is an end, an edge, then you could measure it. The edge of space, imo, is the proverbial edge of the world.

Good answer! I like it.

[modest]

Originally Posted by UncleAl

The universe has the same geometry as inside a black hole's event horizon. No path leads outward across the event horizon. "Outside" is not meaningful.

1) The geometry of a black hole is different than the approximately flat geometry of the visible universe
2) You can not see out of the cosmological horizon.
3) You can see out of the event horizon.
4) They are not alike, see Eddington/Finkelstein coordinate system

-modest

They say imitation is the sincerest form of flattery

[sanctus]

Modest, are you sure about 3) ?

[modest]

Originally Posted by sanctus

Modest, are you sure about 3) ?

Sure you can see out of a black hole. Photons don't have any trouble getting in. Strictly speaking, I don't think the event horizon is really a boundary condition. The two equations at the bottom of,
Eddington-Finkelstein coordinates - Wikipedia, the free encyclopedia
are maybe insightful.

-modest

[sanctus]

I see your point I never looked at it that way...

[REASON]

Originally Posted by Ahmabeliever

I think in trying to measure the volume of space we are being as short sighted as the humans who insist the world is flat.

Surely space is infinite. The Big-Bang a miniscule pop in the scope of things and all we know and see but one point in a region that is but one point in a region ad infinitum.

We can't see or detect beyond certain points, or fathom the reach of it, it is not 'a reach' to fathom. We may measure and fathom portions of space for now, between frames of reference we have, I do not think we can measure 'total space' as an area or volume or depth at all.

If there is an end, an edge, then you could measure it. The edge of space, imo, is the proverbial edge of the world.

I have always perceived space to be infinite as well, and that the universe is expanding within the void. But I'm sure I recall a theory that suggested that space and time are intertwined such that they were both created simultaneously with the Big Bang, meaning that everything, all matter, energy, space, and time occupied the same initial point, and has expanded outward. This would imply that the there actually is an edge to space.

But then I always wondered, "oh yeah, well what's on the other side then?"

Does anyone know this theory?

[freeztar]

Originally Posted by REASON

But then I always wondered, "oh yeah, well what's on the other side then?"

Does anyone know this theory?

I think UncleAl answered this one well earlier in this thread. He said:
"Outside" is not meaningful.

What he means by this is that our lightcone can never coincide with the photons streaming (and expanding) "outward". We simply can never "catch up" to it.

Here's a much better explanation:
What is at the edge of the universe?