The Expanding Universe

[mystomachehurts]

This has got me thinking.

The Universe is expanding right? Expanding into what is not relevant to this post.

I've seen this expansion described as being 'like putting a few ink dots on the surface of a balloon and then inflating the ballon some more. All the dots move away from each other'.

So if the universe is expanding in this manner, does that meean we are all getting bigger? Are the gaps between our atoms getting bigger too?
In fact are the elctrons, neutrons and protons and all the other related bits getting bigger?

What happens when the gaps between the elctrons and a nucleus get to a stage where the forces can't keep the two married? Are the forces expanding too?

Does anyone know about this stuff?

[rhinochopig]

when the gap between the atoms gets too large you need to move on a notch on your belt.

To use your analogy, imagine the ink dots as small ball bearings. The space between the bearings gets further apart, but not the space between the atoms in the metal. Its the difference between the nuclear forces/chemical bonds that hold atoms/molecules together and gravitational forces

Edited by rhinochopig on Tuesday 15th January 14:53

[Chilli]

No idea. But what gets me is that it's "expanding" all the time......into what? what was there beforehand?

Might need Hawkin on this.

[Puggit]

Your atoms are not expanding.

Galaxies are spreading apart from each other , mostly away from the centre of the Big Bang.

[mystomachehurts]

Chilli said:

No idea. But what gets me is that it's "expanding" all the time......into what? what was there beforehand?

Might need Hawkin on this.

I clearly banned the 'expanding into what' portion of the discussion - please see my OP. That's for another quite different thread.

[mechsympathy]

mystomachehurts said:

This has got me thinking.

The Universe is expanding right? Expanding into what is not relevant to this post.

I've seen this expansion described as being 'like putting a few ink dots on the surface of a balloon and then inflating the ballon some more. All the dots move away from each other'.

So if the universe is expanding in this manner, does that meean we are all getting bigger? Are the gaps between our atoms getting bigger too?
In fact are the elctrons, neutrons and protons and all the other related bits getting bigger?

What happens when the gaps between the elctrons and a nucleus get to a stage where the forces can't keep the two married? Are the forces expanding too?

The universe is (alledgedly) expanding, but we are held together by forces between our atoms/subatomic particles, just as we are held on the planet (which in turn is held in an orbit around the sun) by a local gravitational force.

If you blow something up, as a whole it is torn to pieces but those individual bits stay together IYSWIM.

mystomachehurts said:

Does anyone know about this stuff?

No, they're making it up.

HTH

[s2art]

mystomachehurts said:

This has got me thinking.

The Universe is expanding right? Expanding into what is not relevant to this post.

I've seen this expansion described as being 'like putting a few ink dots on the surface of a balloon and then inflating the ballon some more. All the dots move away from each other'.

So if the universe is expanding in this manner, does that meean we are all getting bigger? Are the gaps between our atoms getting bigger too?
In fact are the elctrons, neutrons and protons and all the other related bits getting bigger?

What happens when the gaps between the elctrons and a nucleus get to a stage where the forces can't keep the two married? Are the forces expanding too?

Does anyone know about this stuff?

Metric expansion is a strange thing. The problem with the balloon analogy is that it is just an analogy and if pushed too far is misleading. Another analogy is the 'raisins in dough' analogy. In this case as the bread cooks and expands the raisins move further apart. The raisins being the atoms the dough being space. The raisins are not part of the expansion.
So atoms and stuff are not expanding, just space is. Of course everything will feel a slight force due to the expansion, and if the expansion accelerates enough (the rate of expansion does seem to be accelerating) then eventually the force will be enough to rip everything into its constituent parts (quarks, strings whatever).

[Silverbullet767]

Oh god, not this subject again, my head still hurts from the last time.

[mystomachehurts]

rhinochopig said:

when the gap between the atoms gets too large you need to move on a notch on your belt.

To use your analogy, imagine the ink dots as small ball bearings. The space between the bearings gets further apart, but not the space between the atoms in the metal. Its the difference between the nuclear forces/chemical bonds that hold atoms/molecules together and gravitational forces

Edited by rhinochopig on Tuesday 15th January 14:53

Glad for the edit... you lost me there for a moment.

Thing is in the balloon model the ink-spots expand at the same rate as the gaps between them.

So, one might concur that the atoms and their constituants and the constituants of those constituants, are all expanding.

So, because these constituent parts are expanding are the forces the exhibit expanding too?

I'm not sure how fast this is happening, but consider you could take a tape measure out of the universe for a moment of time and then bring it back again, s othat it didn't expand during this period.

If you measured me with the tape I'd be 6'2", take it out of the unverse for a month and bring it back again - would I be 7 foot tall by then?

[Globulator]

mystomachehurts said:

The Universe is expanding right?

Well, there is a theory that it is, based on some rather dubious assumptions about the red shift and the speed of light being constant (except around gravity wells).
i.e:
Red shift is caused by bodies moving faster.
Faster things seem to be further away.
Therefore things with more red shift are further away.
Astronomers routinely assume distance relates exactly to red-shift now.
I think the assumptions are too big to justify doing that, but who know, they may be right.

mystomachehurts said:

So if the universe is expanding in this manner, does that meean we are all getting bigger? Are the gaps between our atoms getting bigger too?
In fact are the elctrons, neutrons and protons and all the other related bits getting bigger?

An interesting idea, how would you ever be able to measure this though? The theory however just accounts for galaxies - not atoms.

[Silent1]

I reckon it's like a rubber band, at some point it's all going to come hurtling back together. It wont be good when that happens.

[Twincam16]

[mystomachehurts]

s2art said:

Metric expansion is a strange thing. The problem with the balloon analogy is that it is just an analogy and if pushed too far is misleading. Another analogy is the 'raisins in dough' analogy. In this case as the bread cooks and expands the raisins move further apart. The raisins being the atoms the dough being space. The raisins are not part of the expansion.
So atoms and stuff are not expanding, just space is. Of course everything will feel a slight force due to the expansion, and if the expansion accelerates enough (the rate of expansion does seem to be accelerating) then eventually the force will be enough to rip everything into its constituent parts (quarks, strings whatever).

That's another great analogy! (spot on since the Mrs is baking bread at the moment).

But, my concern is that there is 'space' between the electrons and the nucleus. Is that 'space' expanding at the same time as the inter-atomical 'space'?

Surely if the universe ('space') is expanding then the inter and intra atomic space must be changing too? How are the inter and intra atomic forces affected?

[Puggit]

mechsympathy said:

The universe is (alledgedly) expanding, but we are held together by forces between our atoms/subatomic particles, just as we are held on the planet (which in turn is held in an orbit around the sun) by a local gravitational force.

Nothing local about gravity - it's reach is infinite. Your left testicle still has a gravitational pull on Voyager 1...

[Lurker]

Twincam16 said:

This topic is more specifically discussed in Annie Hall.

Mrs Felix: Why don't you do your homework?
Allen Felix: The Universe is expanding. Everything will fall apart, and we'll all die. What's the point?
Mrs Felix: We live in Brooklyn. Brooklyn is not expanding! Go do your homework.

'Explanation' for Brainiacs

After reading it, I still don't understand.

[s2art]

mystomachehurts said:

s2art said:

Metric expansion is a strange thing. The problem with the balloon analogy is that it is just an analogy and if pushed too far is misleading. Another analogy is the 'raisins in dough' analogy. In this case as the bread cooks and expands the raisins move further apart. The raisins being the atoms the dough being space. The raisins are not part of the expansion.
So atoms and stuff are not expanding, just space is. Of course everything will feel a slight force due to the expansion, and if the expansion accelerates enough (the rate of expansion does seem to be accelerating) then eventually the force will be enough to rip everything into its constituent parts (quarks, strings whatever).

That's another great analogy! (spot on since the Mrs is baking bread at the moment).


But, my concern is that there is 'space' between the electrons and the nucleus. Is that 'space' expanding at the same time as the inter-atomical 'space'?

Surely if the universe ('space') is expanding then the inter and intra atomic space must be changing too? How are the inter and intra atomic forces affected?

There is a truly tiny force experienced by the particles due to the expansion of space. It is too small to pull the electrons away from the nucleus (they move in quanta remember). The rate of expansion would need to be huge to effect electron orbitals.

[ATG]

Lets assume that we have a spring in some bit of space. Initially the space is not expanding, then it instantaneously expands quite a bit, and then immediately stops expanding. What will happen to the spring? Initially the spring is not stretched. The rapid spatial expansion stretches the spring, and, once the spatial expansion is over, the spring snaps back to its original length.

Same idea applies to matter in an expaning Universe. As the space between the electrons and nucleus in an atom gets bigger, the forces within the atom pull the particles back towards each other, in a similar way to the stretched spring snapping back to its original length.

Galaxies can be moved away from each other by this expansion because there's nothing much to oppose the expansion .. i.e. they're not linked to each other by anything equivalent to a spring.

Probably.

[mechsympathy]

Puggit said:

mechsympathy said:

The universe is (alledgedly) expanding, but we are held together by forces between our atoms/subatomic particles, just as we are held on the planet (which in turn is held in an orbit around the sun) by a local gravitational force.

Nothing local about gravity - it's reach is infinite.

Fair enough, what I meant was that the universe's expansion continues despite a gravitational pull but our solar system isn't expanding because of gravity.

Puggit said:

Your left testicle still has a gravitational pull on Voyager 1...

That explains a great deal Although, much as I hate to admit it, my left testicle's gravitational pull is pretty insignificant compared to the earth's

[MikeyC]

makes you think tho, that there must be a centre of the universe where said Big Bang started.

Perhaps in future years, there will be tourist trips to said point.
Perhaps the current (and future) faiths will realise this and have pilgrimmages there

jus a thought.....

[Simpo Two]

mystomachehurts said:

Thing is in the balloon model the ink-spots expand at the same rate as the gaps between them.

So, one might concur that the atoms and their constituants and the constituants of those constituants, are all expanding.

The balloon is a bad analogy - it's confusing you - ignore it! You can imagine a car getting further away, right? Well it's like that, only bigger, and with more cars