Philosophy is dead...?
- Thread starter Castiel
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It's called iirc the Metric Expansion of Space, I'm not at home right now so can't look it up, but I'm sure a quick google should give you an idea.
Soldato
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I might take some astrology moduels this uni at school so I may be doing about that sorta stuff.
I'd go for Astronomy myself. Tarot cards an stuff is a bit gay...
Seriously though, do it, Cosmology is mad stuff.
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Soldato
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- 2 Dec 2006
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I'd go for Astronomy myself. Tarot cards an stuff is a bit gay...
Seriously though, do it, Cosmology is mad stuff.
Haha, wasn't paying attenchen. I ment stuff bout planets and bright lights in the sky.
Why do you think the Universe is infinite? Genuinely interested as the infinite or finite Universe is an age old argument it's brought up a lot on the Science Forums. Under The Big Bang Model there doesn't appear to be a great deal of supporting evidence for either. What I don't understand is that if the Universe is expanding then surely that would mean the size of infinity is also increasing, which touches on paradoxical. Also under The Big Bang Model the Universe started from a point smaller than an atom, so the Universe hasn't always been in an infinite state and is still expanding.
The boundaries of the Universe also effect the definition of infinite in this instance as well. Say if you travelled extremely far throughout space and eventually ended back where you started, like the spherical geometry Universe, then is the Universe infinite or finite in this definition?
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Whether the Universe is infinite or finite would depend on whether we assume the universe is open or closed.
An open Universe has negative curvature and they are negative in their spacial extent, in other words they have no boundaries. Closed Universes have a positive curvature and are regarded to be finite, there still is no boundary and the common analogy to describe one is that it is like being inside a balloon, wherever you begin you will eventually finish.
From what my brother was telling me, the likely shape of the universe is Flat which has little or no curvature and this is also infinite as it has no spacial boundary. The WMAP probe has given us loads of information and confirmation about the curvature, age and like I said in a previous post the non-zero energy status of the Universe.
http://map.gsfc.nasa.gov/
Expansion of the Universe happens within the Universe as there is no space outside, hence no spacial boundary. If you take a room for example, the walls of that room are not pushing out against anything as there is no such thing as outside the room, but the spacial dimensions inside the room are increasing due to the expansion so the objects within the room get further apart, without moving. It's mind blowing to explain, but it seems that the objects in space are not moving at all, the dimensions of the universe are changing which changes the concentration of mass in the universe which increase the space between those objects and thus the expansion of the universe. We can see this in the expansion of all mass such as Planets and even us on a quantum level.
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wouldnt the drawing of dots on a Balloon then inflating it and seeing the space between each dot increase be a better analogy ?
The Ballon being space and the dots being Galaxies.
wouldnt the drawing of dots on a Balloon then inflating it and seeing the space between each dot increase be a better analogy ?
The Ballon being space and the dots being Galaxies.
See the post above yours...
I thought about this before actually and i think i may have solved the problem, its all a paradox, how can nothing exist and how can something exist?
To solve this paradox quantum fluctuations appeared and eventually after many googol years out of the noise the big bang/s happened creating space, time and matter (which is just energy or quantum fluctuations in stable perpetual motion), everything we know is just the contrast between the two states because given enough time even complex things can happen, like life.
I did but your analogy seemed a bit confusing.
Indeed, but the problem with drawing dot's on the surface of a balloon is that it doesn't represent the fact that there is no spacial boundary as such. The dots would have to be inside the balloon not on the surface.
The really messed up concept is that there is no centre of the Universe, or more precisely everywhere is the centre of the Universe....also each of us is like a mini-expanding universe as all the particles that make us are all slowly expanding away from each other, yet our mass and relative size stays the same...
Indeed, but the problem with drawing dot's on the surface of a balloon is that it doesn't represent the fact that there is no spacial boundary as such. The dots would have to be inside the balloon not on the surface.
The really messed up concept is that there is no centre of the Universe, or more precisely everywhere is the centre of the Universe....also each of us is like a mini-expanding universe as all the particles that make us are all slowly expanding away from each other, yet our mass and relative size stays the same...
I'm pretty sure we arent expanding, its only between large bodies of matter that is expanding. Hence why we see stars moving away from us(redshifted).
If we were expanding, then we would break down, fall apart(the strong force would not be able to hold us together anymore, or is it the electromagnetic).
In one way you are correct, this is because large bodies such as Galaxies only have a weak force between them , Galaxies themselves, Solar systems and such have a stronger force of mavity which is able to overcome the drag of expanding space.
This doesn't mean however that we, or those bodies that inhabit the solar system are not expanding, they are, but all at a uniformly relative rate (which includes the forces which keep us all together). So no, we are not expanding for cosmic reasons, but we are expanding nonetheless, just not the way you think. I can't remember, but I think it was Paul Dirac that put the equations forward. Maybe they have been superseded I don't know.
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Here's a source.
http://www.thenakedscientists.com/HTML/content/latest-questions/question/2727/
Our bodies and constituents require really strict properties for us to exist. Electrons orbit at certain distances from the nucleus. Electrons attract and repel other atoms at certain distances. If we were expanding we would very quickly notice(a tiny change would be catastrophic) through either us falling apart or the properties of the universe changing(which we would notice).
http://www.thenakedscientists.com/HTML/content/latest-questions/question/2727/
Our bodies and constituents require really strict properties for us to exist. Electrons orbit at certain distances from the nucleus. Electrons attract and repel other atoms at certain distances. If we were expanding we would very quickly notice(a tiny change would be catastrophic) through either us falling apart or the properties of the universe changing(which we would notice).
That source is extremely basic and doesn't address the difference between the metric expansion of the universe and the relative expansion of matter.
For example, each atom is expanding exactly relative to the force exerted to keep it together.
Everything is relative to each other, a bit like my room analogy for the expansion of the universe, but all the objects in the room are also expanding relative to it's spacial dimensions so there is no intrinsic change as such. This is seperate from the metric expansion of the universe.
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Just finished the book and to be honest I thought it was pretty weak in some ways. Lots of interesting stuff of course but came across as doing a bit of Dawkins - made great sensationalistic statements outside the area of expertise that were backed by little or no evidence and seemed to miss the fact that the authors acknowledged defects in their arguments that they then had little jbies at religion for. It also reads like one of the authors had a great deal more of the input than the other. But worth reading nevertheless.
Your right that source was pretty weak.
But If what your saying is true then we would notice, surely some distant galaxys coming towards us.
I've never heard of this separate expansion of the universe. If we were expanding and the properties were changing to compensate for that, we would notice, scientists with all their recording equipments would very quickly notice.
What would be catalyst of this expansion? We have a distant galaxy expansion caused by we dont exactly know what(dark matter they say). And this other expansion completely separate to that, does it have the same cause, dark matter, I think there would be a conflict of expansions there. An expansion like what your talking about is a pointless expansion, everything is expanding so nothing is expanding.