Earth on the scale of things...

Mobius 1 · 10 Jul 2006 at 12:04

dbmzk1 said:
Antares is 604 light years away from Earth. If it went supernova right this second, we wouldn't be able to tell until 604 years from now because that's how long it would take the light from the explosion to get here. It's far enough away not to kill us.

Good to hear that, lets just hope the sun doesn't go down that road :eek:

well, i would imagine it would do oneday, or it just may collapse on itself, imploding. So reading the above threads... in theory, our space/universe, whatever you wanna call it, is just one universe in a series of universi? (i didnt know what to call it as universes sounded wrong) It's kind of sad and disapointing that the only planet most of us would ever stand on is earth..

D4VE · 10 Jul 2006 at 12:09

johnson said:
all this mass and these massive stars.

Can you REALLY believe all this came from something the size of a pea which went BANG. Can a pea sized object really contain everything from the universe?

I can't really see it like that. These scientists and astronomers keep changing there theories on what is on Saturns moon titan so imagine how wrong they could be regarding the Big Bang theory etc.

Well the theory Ive heard, after the bang there was a uniform spread of particles. Not molecules, not even atoms, but sub-atomic particles. In theory, these began to fuse to form atoms, then again to form bigger atoms and molecules formed from that.
So, in theory it is quite easy to see how everything can be built up and of course this all happened over an immense amount of time.

Vonhelmet · 10 Jul 2006 at 12:11

Sirrel Squirrel said:
amazing how insignificant we really are, with that sort of perspective I don't know how people can argue there isn't other life out there.

Until some of them show up here, I think people are free to argue whatever they like.

Arcade Fire · 10 Jul 2006 at 12:18

sid said:
That doesnt really explain a lot lol so i guess our 3d universe would be a 3-brane unless i've got the wrong end of the stick. These branes exist within the hyperspace.

Some cosmologists postulate that the world we experience fills the three extended dimensions that we are most familiar with, but is localised in some or all of the additional dimensions (known as Kaluza-Klein dimensions) that are required for string theory and M-Theory. So if you like, there are a large (possibly infinite) number of 'universes' each of which is specified by a point, or some other object, in Kaluza-Klein space.

One of the popular theories (i.e. one which predicts something which looks like it might possibly just about approximate real-world physics, in the appropriate limit

) is that which says our universe is a fivebrane, i.e. a five dimensional object that fills the three extended dimensions and two of the Kaluza-Klein dimensions and exists at a specific point in the other four dimensions. It then sweeps out a six-dimensional worldvolume in time, and its interactions with other 'universes' determine facts about our universe, such as observable constants (e.g. the strength of gravity or the cosmological constant) and in turn those determine things such as the rate of expansion of the universe.

Dark_Angel · 10 Jul 2006 at 12:19

Ok, I am aware that the sun is not large enough to turn in to a black hole, but how many more times larger does a star have to be larger than our sun, to collapse and turn in to a Black hole?

Greenlizard0 · 10 Jul 2006 at 12:22

Those pictures are just awesome! Cool find!

sid · 10 Jul 2006 at 12:23

Arcade Fire said:
Some cosmologists postulate that the world we experience fills the three extended dimensions that we are most familiar with, but is localised in some or all of the additional dimensions (known as Kaluza-Klein dimensions) that are required for string theory and M-Theory. So if you like, there are a large (possibly infinite) number of 'universes' each of which is specified by a point, or some other object, in Kaluza-Klein space.

One of the popular theories (i.e. one which predicts something which looks like it might possibly just about approximate real-world physics, in the appropriate limit ) is that which says our universe is a fivebrane, i.e. a five dimensional object that fills the three extended dimensions and two of the Kaluza-Klein dimensions and exists at a specific point in the other four dimensions. It then sweeps out a six-dimensional worldvolume in time, and its interactions with other 'universes' determine facts about our universe, such as observable constants (e.g. the strength of gravity or the cosmological constant) and in turn those determine things such as the rate of expansion of the universe.

Ahh i see, theres no lack of theories in physics? i see you are at cambridge, studying physics by any chance?

sid

squiffy · 10 Jul 2006 at 12:24

johnson said:
all this mass and these massive stars.

Can you REALLY believe all this came from something the size of a pea which went BANG. Can a pea sized object really contain everything from the universe?

I can't really see it like that. These scientists and astronomers keep changing there theories on what is on Saturns moon titan so imagine how wrong they could be regarding the Big Bang theory etc.

And five hundred years ago we didn't understand the Earth was round and orbits around the sun. A few scientists with a "theory" of these now proven facts were scoffed at, and in time other scientists have definiete proof.

Point is a theory can be true, just because we don't fully understand it. You don't fully understand what every single atom is doing in your body at any one time, but you know what your foot is doing when you kick a ball...but perhaps in the future atomic scanners will see such things (ala transporters)

BFCTom · 10 Jul 2006 at 12:58

Aliens so exist.

Visage · 10 Jul 2006 at 13:07

Dark_Angel said:
Ok, I am aware that the sun is not large enough to turn in to a black hole, but how many more times larger does a star have to be larger than our sun, to collapse and turn in to a Black hole?

I cant remember the exact figure, but its not that high - less than 10x, IIRC.

Arcade Fire · 10 Jul 2006 at 13:26

Visage said:
I cant remember the exact figure, but its not that high - less than 10x, IIRC.

I think it's about 3 to 5 solar masses, although black hole formation at such low mass is quite poorly understood - it's unclear whether neutron degeneracy would be able to sustain a 3M star as a neutron star, and it certainly wouldn't be able to sustain a 5M star, but it's possible that other effects (such as quark degeneracy) could kick in at that stage and prevent collapse into a black hole.

Above about 10M the mathematics is unequivocal in predicting that stars will collapse into black holes at the end of their lifetime.

sid said:
Ahh i see, theres no lack of theories in physics? i see you are at cambridge, studying physics by any chance?

I studied mathematics, but I took a lot of courses in theoretical physics, so I have a rough understanding! I guess 'mathematical physics' would be a good name for the aggregate of the courses I ended up taking.

Visage · 10 Jul 2006 at 13:40

I steered clear of mathematical physics - far too scary.....though my MSc was in chaotic physical systems.

I was strangely attracted to it....

Psyk · 10 Jul 2006 at 13:43

The way I understood the whole thing about branes is that our universe is a 3D surface on a sphere that exists in more than 3 dimensions. It's easy enough to picture in your head if you ignore one of our dimensions, then you can picture our universe as a 2D surface on a 3D sphere. That was my understanding from watching a documentary on it (by Brian Greene I think).

G|mp · 10 Jul 2006 at 13:46

BeetleJuice

BeetleJuice

BeetleJuice

Inquisitor · 10 Jul 2006 at 14:12

And at the other end of the spectrum:

http://www.phrenopolis.com/perspective/atom/index.html#electron

Magic_x_uk · 10 Jul 2006 at 14:49

So then, do you think People like 'MIB' dont really excist
and
If there is life on other planets, it will bring a whole new meaning to the Miss World contest!

Dingo · 10 Jul 2006 at 15:31

Fantastic post Phykell

Kaed · 10 Jul 2006 at 15:38

This is a fantastic post...

This is the sort of thing that makes GD for me. You get a lot of spam, but like someone panning for gold, you occasionally find a gold nugget

About a year ago, I wanted to cover my bedroom wall in a homemade poster that was to show the size of our planets and the distance between them, I did a bit or research and realised I was going to need a bigger wall :rolleyes:

Think I read somewhere in Sweden (not sure) there is a long corridor in some museum (ill see if I can get links later - I know im being very vague at the moment) that tries to explain the distance between our planets.

It has Proxima Centauri in another museum in Australia...

*EDIT*

Found it - It's called the Future's museum in Sweden it contains a scale model of the solar system.

The Sun is 105 Metres in diameter, and then the planets range from 5mm to 6km from this 'sun'.

The nearest star Proxima Centauri is situated in the Museum of Victoria Australia.

Unfortunatley, my source for this isn't that interesting, it's 'The book of useless information' and not some article I found :rolleyes:

Arcade Fire · 10 Jul 2006 at 15:39

Visage said:
I steered clear of mathematical physics - far too scary.....though my MSc was in chaotic physical systems.

I was strangely attracted to it....

Haha. Knob.

I'm going to be doing my PhD in a similar kind of thing (nonlinear systems) but at the other end of the spectrum - instead of looking at systems with an (apparent) lack of symmetry I want to look at systems with an uncanny amount of symmetry (things with patterns!) and explore why.

I gave up on mathematical physics too - really interesting, but far too hard. I'll leave that one to the clever people.

Dutch Guy · 10 Jul 2006 at 15:55

What always gets my brain in a twist is when I think about what is behind the space, space is expanding so there is something it is expanding into, but what :confused: