The Universe

[Confidemus]

It still makes no sense though. To be travelling away from something then there must be a vector between you and the "something". Reverse that vector and everything is travelling towards everything else. If that's the case then everything MUST converge at some point.

If you take that vector right back to the big bang, everything in the universe was contained in an infintessimally small singularity, so really the whole universe is the centre of the universe.

You have to remember that the big bang didn't happen in a definable area. It WAS the definable area.

[renton]

I still don't get the expansion into nothing theory. If space didn't exist before the Big Bang then what did?

Something outwith our standard 4 dimensional Universe (or 11, if you like Superstring theory), you may as well say we are expanding into custard for all the good it does. Whatever was there before the big bang it is something that cannot be predicted by our Physics since our physics is bound to the laws of this universe, and only describes and can only describe laws internal to that Universe. We may be expanding into the space occupied by another universe, one offset by a dimension that allow us to pass through it without interaction, it could be that there are thousands of big bangs and thousands of universes caused by the interaction of membranes (M-theory)

[Gnash]

So what if I got on a spaceship and travelled past every star, galaxy, every bit of matter - what would I / the spaceship be in? Ignoring the complications that it would be impossible in practice and assuming the universe is not shaped like a 4 dimensional doughnut.

[Ric]

So what if I got on a spaceship and travelled past every star, galaxy, every bit of matter - what would I / the spaceship be in? Ignoring the complications that it would be impossible in practice and assuming the universe is not shaped like a 4 dimensional doughnut.

In the same 4 dimensions you began in, ergo the Universe.

[cowboy]

Cassini took a picture of Earth on Friday...

might be a silly question, but is that a real picture or one of those nasa kid on pics, where they take a whole load of technical data and make an artists impression?

[cowboy]

I still don't get the expansion into nothing theory. If space didn't exist before the Big Bang then what did?

the egg heads tend to explain it as, the universe is like the surface area of a balloon being blown up. it just gets bigger. the real mind f**k is thinking what is inside and outside the balloon

[Ric]

might be a silly question, but is that a real picture or one of those nasa kid on pics, where they take a whole load of technical data and make an artists impression?

When you say "real" I presume you mean in the visible light spectrum, and in that sense yes it is. Cassini has several imaging cameras on it. If you are interested, the instruments are listed here.. http://saturn.jpl.nasa.gov/spacecraft/cassiniorbiterinstruments/instrumentscassiniiss/

[Ric]

the egg heads tend to explain it as, the universe is like the surface area of a balloon being blown up. it just gets bigger. the real mind f**k is thinking what is inside and outside the balloon

There is "nothing" outside, there is "no" outside.

[djchapsticks]

I've been reading 'A Brief History of Everything' recently. The thing that blew my mind in terms of the 'expansion into nothing' was the question of "what is after the edge of the universe?".

The answer given was that, of course, there is nothing, but it's impossible to even comprehend what complete nothingness is, and is a moot point anyway as even through bending every means of space and time travel, it would be impossible to reach the edge of the actual universe to see through it. You would carry on going and eventually end up back at the point at which you started, i.e. Earth.

The author compared it to walking around the globe in a straight line in search of the horizon and ending up back at your own house. Only the universe isn't spherical like a planet, it's a shape, possibly not even a physical shape, which our minds cannot comprehend.

It's a good read, it gives information on subjects as varied as how people hunt supernovae, to how the Earth's mass was accurately weighed ridiculously accurately, in 1798 by a recluse called Henry Cavendish, who never actually published his works, such was his crippling social anxieties.

The other stand out figure was that the percentage of the entire universe occupied by any kind of matter, is approximately 0.0000000000000000000042%

I recommend giving it a read.

[Confidemus]

The other stand out figure was that the percentage of the entire universe occupied by any kind of matter, is approximately 0.0000000000000000000042%

Yep, as I may have said earlier in the thread, the universe is amazingly sparsely populated by what we perceive to be "matter". So sparse, you could compare it to a building 20 kilometres long, 20 kilometres wide and 20 kilometres high, with just a single grain of rice inside it.

[Ric]

I've been reading 'A Brief History of Everything' recently. The thing that blew my mind in terms of the 'expansion into nothing' was the question of "what is after the edge of the universe?".

I recommend giving it a read.

It is a good book, I found it a little simplified in places but it's certainly one that doesn't race off in a hope that people catch up with the ideas he puts forward.

The other stand out figure was that the percentage of the entire universe occupied by any kind of matter, is approximately 0.0000000000000000000042%

Is that from the book, I can't remember to be honest. I wonder if it is that taking into consideration the amount of "nothingness" inside atoms? The statement is for matter instead of mass, a subtle difference. The "space" inside atoms is equally large in comparison to it's component parts, making it possible that the figure you quoted 4.2^^-21 is an exaggeration and that it's considerably less.

[Confidemus]

Time lapse video of Earth at night from the ISS:

http://www.youtube.com/watch?v=FG0fTKAqZ5g#at=50

[djchapsticks]

It is a good book, I found it a little simplified in places but it's certainly one that doesn't race off in a hope that people catch up with the ideas he puts forward.

That;s why I've enjoyed it and it's the book's intent from the outset, to make it relatively accessible to people who don't have and extensive knowledge of the universe and it's workings.

[~~~]

Cracking picture of the ISS in front of the moon during the day

[Confidemus]

Cracking picture of the ISS in front of the moon during the day

ImageUploadedByPie & Bovril1375401102.529088.jpg

Magic stuff. And here's one of the ISS and Atlantis in transit against the Sun:

[Confidemus]

Here are some contenders for Astronomy Photographer of the Year:

Full list here:

http://www.theguardian.com/science/gallery/2013/jul/30/astronomy-photographer-2013-shortlist-pictures

[tintax]

Anybody had any luck in seeing the Perseid Meteor Shower over the last couple of weeks? It reached its peak last night but I'm still hoping to catch a glimpse over the next few days as it has been to cloudy up here in Inverness to see anything .

[peeeel]

Atheism: The belief that we have a long way to go before we even begin to understand the infinite complexities of the universe.

Religion: "The big magic sky-man made it all, now give me some money."

[WFAANW]

Anybody had any luck in seeing the Perseid Meteor Shower over the last couple of weeks? It reached its peak last night but I'm still hoping to catch a glimpse over the next few days as it has been to cloudy up here in Inverness to see anything .

Me. I was just about to give it up then i seen a white flash across the sky. One right above looked on fire, it was truly amazing. Probably won't see any tonight though as it's cloudy.

[Ric]

Just a couple of months until ISON, fingers crossed... http://en.wikipedia.org/wiki/C/2012_S1

Don't know if it's visible just now with an amateur telescope or not. Has anyone tried to find it?