Universe

[Homer55]

Is it just me or does anyone else get freaked out and just cant even begin to comprehend the size of the universe, i mean how big is it? is there an end to? whats at the end? owwww my brain hurts!!

[Loosehead]

No not just you. It freaks me out too. The trick is to not try and comprehend it all at once. Mostly it's enough to just "think Local" ie local to sub topic under consideration.

[Homer55]

Thats just confused me even more...im gonna cry

[Loosehead]

sorry Homer, didn't mean to confuse you! What I mean is for example if you are thinking about the planets then try not to think that the solar system is just one of billions of solar systems in our own galaxy and that is just one galaxy out of billions etc. Just think of the solar system in it's own right as an entity.

[Catso]

Are you a rep. trying to sell HHGG?

[Clanad]

There is an end to it... oops it just moved... It might help to understand that it has a measurable size, such as about 15 billion light years. Problem is, and I understand your quandry, is that we have nothing in our life experience against which to measure such distances. Added to the problem is the measurable universe continues to expand, so on one hand it is not infinite yet on the other the inflation continues. Here's a web site that might help you... then again, might not:

http://www.kidsastronomy.com/space_size.htm

... but best of luck!

[Homer55]

Catso were you asking me or loosehead? i dont what HHGG is sorry..

[jake-the-peg]

Whether the Universe is "open" (infinite) or closed (finite) is still the subject of debate. As is it's shape.

Imagine an ant crawnling on a football - he can go left or right or anyway in between. After a while he's back where he started.

We have 3 dimensions - perhaps you could zoom off in any direction and come back to where you started - a closed universe.

Whether it's open or closed ultimately depends on how much gravitational matter is in it.

It's been a while since I was up to date but I think most cosmologists favour an open Universe from current observations

[heathfield]

Homer - The universe ends right where you're sitting. And as for freaking out - try this... 'String Theory' says that all the bits in an atom are made up of 'strings' of energy. It's been calculated that if the solar system was a single atom, a 'string' would be the size of a tree here on earth. Think about the size of the string, and the atom, then think about how the whole universe could be made from them. That's mindboggling!

[curlyfilm]

if i try too imagine whats at the edge, of the universe, it just confuses me, i don't believe the average person can comprehend, what's there, in reality it must go on for ever, because whats at the end nothing? there is no such thing, if you were too travel from one point in space to another, whats between them nothing? there must be something or you would not need to travel between the two points, probably needs a brainier person than me to explain, ouch me head hurts!!!

[Catso]

Homer55, HHGG is Hitchhiker's Guide to the Galaxy.

One famous bit of the guide goes along the lines of 'The universe is big. Very big. So big it's impossible to imagine how big. If you think XXX is big, then this is bigger' etc etc, for several lines, or even paragraphs.

[potterfan3]

The universe is this <---------------------------------------------------> big

[Treenor4ish]

"If you were too travel from one point in space to another, whats between them nothing?"


this is not true. the most mind boggling fact of all is that the universe is expanding at an increasing rate (so its accelerating); so some kind of anti-gravity must be being produced to push the universe outwards. This is called dark energy, it is present all over the universe and takes up about 74% of the universe. It weighs roughly 10^-29 grams per cubic centimeter so its hard to imagine ever being able to 'detect' it with an instrument.

Furthermore, another 22% of the universe is made up of dark matter (leaving only 4% 'regular' matter that we know and can see [things like stars and planets - imagine how heavy they all are and that only being 4% of the universe!]). This is basically invisible, undetectable mass which we know exists due to the effects of centrifugal force on rotating galaxies.

If this all sounds dense, google it: you wont believe how much is still completely unknown about the sheer composition and scale of our universe; in 20 years, textbooks about astronomy and physics will be COMPLETELY rewritten.

[Treenor4ish]

what i would like to know is how fast IS the universe expanding (obviously its always acceleratiing) but how fast roughly is it?


also, what is the mass of light if it is sucked in by a black hole (if it has mass and we can create it, surely we could implement that on a massive scale to fuel energy plants etc [maybe in a few decades obviously])?????