Does Space really go on forever?

[mantajohn9]

I'm not an astronomer but if you google earth it you can find it as part of the alpha centauri system. Apparently it is tiny compared even to our sun and has only a fraction of the luminosity so cannot be seen with the naked eye.

[gaviston]

Until puny humans can think themselves somewhere such stars will be out of reach, which is good if it's a star but not good if it's o.0hu9 or similar class planets.

[Les E]

HI Mantajohn,All,

The Alpha Centauri system which are our nearest stellar neighbours comprise of three members in a binary system.Alpha Centauri A which is almost identical to the Sun.Its slightly more massive 20% larger and half as bright again as our star but has a identical G2 spectrum and surface temperature.Alpha Centauri B is about 3/4 the size of the Sun and is a cooler orange K type star and half the Suns luminosity but still bearably Sunlike.Proxima however is a feeble red dwarf 60,000 times fainter than the Sun.Most of the Galaxy is made up of these red glow worms which are only visible because of their closeness.Most of the bright stars visible in the night sky are distant bright searchlights.
Regards Les

[cat72uk]

its just taken me an infinite time to read all these posts
well 1 1/2 hours

[Flying Astronomer]

But then again if does have a finite shape what is beyond?

A lot of misunderstanding here!

Space is a word we usually take to be synonymous with 'empty space'. We might call 'outer space' empty, because there's no air and no apparent matter present.

But in cosmology, space is a thing - a fabric that has physical meaning and existence. So the universe consists of space and all the things within it. Outside the universe, there is no space. There is nothing whatsoever (not even a vacuum, time, nothing). It is beyond our normal understanding, and I can think of no real analogy, to comprehend in any meaningful way what this 'nothing' is.

Rest assured that the physics and maths are well-understood, and that the universe is in fact not expanding 'into' anything. The problem is that we do not experience such a thing in our lives, so we always imagine this wrongly.

J.

[Flying Astronomer]

Originally Posted by zan

I'm curious as to what's (who's?) in the other 8 dimensions we can't see yet

We are! Those extra dimensions are currently believed to be curled-up into extremely small, complicated spaces that are, like much of cosmology, difficult to comprehend in everyday terms. You can think of them as very complicated origami shapes - but very small. I suppose most of us think of them as somehow being isolated from our normal four dimensions, but they are most certainly not! They are part-and-parcel intertwined and inseperable from the three dimensions of space and one of time. In other words, we don't exist within four dimensions, but, most likely, about 11.

When you move around, you are in fact moving through all these 'extra' dimensions (they're not really extra, only to out historical understanding of space). You don't perceive them because they are incredibly small. If you think deeply about it, you don't actually perceive our normal four dimensions, other than your ability to move through them (in only one direction, in the case of time). You can't touch the three space dimensions, any more than you can touch time. You just move through them.

Again, there are good maths to support the theory, but it doesn't always mean that this is the final solution. There may be others solutions. But it is very likely that there are several more dimensions than the four we are used to (3 of space and 1 of time (time may have emerged from a spatial dimension in the first super-billionths of the universe's history).

[Jim Ford]

The initial event when space-time was created is usually referred to as 'The Big Bang'. I find this really quite unhelpful, partly because as has been previously posted, a bang implies an expansion, and an expansion implies a region into which the expansion is increasingly occupying.

I think that as the initiating event for the creation of our 'dollop' of space-time was a totally unique event for us, it requires a totally unique name that doesn't carry any connotations of any other event since. Ideas for a name, anyone?

Jim

[the young hunter]

'The Big Happening'?

That's the closest thing I can think of to discribe it


mike