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Author Topic: Expanding universe  (Read 1448 times)

Offline steelrat1

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Expanding universe
« on: 08/12/2013 15:18:18 »
If the universe is expanding... is the space between the fundamental particles that make up atoms expanding also? so are we expanding? and if not why only the space of the large expands?


 

Offline Pmb

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Re: Expanding universe
« Reply #1 on: 08/12/2013 17:40:52 »
Quote from: steelrat1
If the universe is expanding... is the space between the fundamental particles that make up atoms expanding also? so are we expanding? and if not why only the space of the large expands?

The space between electrons and the nucleus is expanding. However the orbits donít expand because they readjust to the expansion by going back to the same orbits. This people donít get larger.
 

Offline steelrat1

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Re: Expanding universe
« Reply #2 on: 08/12/2013 18:38:41 »
thanks i think i get it, is it the same way the earth and the moon isnt moving away from each other due to the expanding universe but galaxies are moving away from each other ?
 

Offline Pmb

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Re: Expanding universe
« Reply #3 on: 08/12/2013 18:56:21 »
thanks i think i get it, is it the same way the earth and the moon isnt moving away from each other due to the expanding universe but galaxies are moving away from each other ?
Exactly. If you were to calculate the rate at which the distance between the Earth and Moon changed with time due to the expansion you'd see how incredibly small it is.
 

Offline sunshaker

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Re: Expanding universe
« Reply #4 on: 10/12/2013 10:20:25 »
How can we be sure the earth us and our measurements are not also expanding including quantum levels,
Perhaps a cm a billions of years ago would measure only a millimetre now. If everything expands(including our measurements) we have no reference point. "similar to up/down in space",
When we look to a distance, all objects seem smaller, Perhaps this is the same with time.

relative to us the distant earth may have been football size, And in our distant future may be the size of our sun but everything else would also be expanded so we would never know.
 

Offline Pmb

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Re: Expanding universe
« Reply #5 on: 10/12/2013 10:53:12 »
Quote from: sunshaker
How can we be sure the earth us and our measurements are not also expanding including quantum levels,
You can't. And it probably has no meaning to do so either.
 

Offline yor_on

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Re: Expanding universe
« Reply #6 on: 10/12/2013 12:26:08 »
totally true Pete.

My own take on it would probably be that when you define a distance you define it between two reference points. If we treat the universe as consisting of reference points, as stars, CBR, etc, then the distance between those points is what defines that distance (and speed). Assuming it all to magnify (or shrink), but consistently keeping a same equilibrium between your reference points, versus your ruler (and clock), makes it meaningless to define change to a distance. To make it we use some defined length and clock, and if those two archetypes gives us a same answer, then there is no measurable way to prove a difference 'inside' a universe anyhow, as I think. The only way would be if I would assume the universe to be a container of sorts, with a 'inside' and a 'outside', also assuming that I can measure relative some non changing standard at that 'outside'. I don't personally believe in a 'outside' relative a 'inside' though.
« Last Edit: 10/12/2013 19:09:08 by yor_on »
 

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Re: Expanding universe
« Reply #6 on: 10/12/2013 12:26:08 »

 

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