Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: neilep on 04/03/2011 19:10:23
-
As a sheepy I of course know....well...sod all about the expansion of the universe !
look here it is...
[ Invalid Attachment ]
The Universe Expanding Earlier Today!
Does this mean that the fabric of the universe is diluting with every second?..else...where is/are the extra bits of Universe coming from ?.......if it is just diluting does this mean the eventual outcome will be what some people say will be the big rip ?....and if it does rip...does this mean there will be fragments of universe floating about ?.....and what will be left when it's all ripped to nothing ?
sorry....more questions than I planned to ask !!
Thanks
-
Could be! Some theories hold that all matter eventually disintegrates.
Hopefully, it won't happen next Tuesday.
-
Could be! Some theories hold that all matter eventually disintegrates.
Hopefully, it won't happen next Tuesday.
Oh gosh !!..I really hope it does not happen next tuesday......I have a delivery that day !
-
....but disintigrates into what ?
-
does this mean there will be fragments of universe floating about ?
If the Universe is all there is, there would be nowhere for the bits to float about.
-
I am not sure about the possibility of the big rip at the moment but I confidently expect that our universe will expand and fade away slowly for a very long time my guess is probably around the time that it takes all the black holes to evaporate although there is a chance that the big rip will happen before this and leave the black holes (new universes) on their own and slowly evaporating ready to cause the big rip in their universes after they have created a significant number of new universes. i.e. it is a cyclic process based on the creation of and evaporation of black holes.
-
....but disintigrates into what ?
Photons, I think.
-
I confidently expect that our universe will expand and fade away slowly for a very long time
If it is only the galaxy groups that are moving apart, does this not mean that gravitational attraction within the groups will become relatively more dominant? If this is the case, surely, it would draw matter within the groups closer together.
-
"Work is a scalar quantity, obtained from the product of two vector quantities. (As long as the applied force and the displacement are in the same direction, the direction can be ignored in the calculations for work. This is because the calculations yield a vector dot product. Some texts do this implicitly and omit the vector signs in the equation for work.)
Positive work is done when the applied force and the displacement act in the same direction. Negative work is done when the applied force and the displacement act in opposite directions. The positive work done can be combined with the negative work done, to determine the overall work done. Work can be determined graphically by finding the area under an applied force versus displacement graph. Energy is the ability to do work. When work is done, energy is transferred from one object to another. An energy transformation occurs when energy is converted from one form to another. When an energy transformation takes place, not all of the energy is used to produce useful work. Some is converted into heat or other types of energy. Maximizing efficiency during energy transformations makes the best use of the available energy. This helps to conserve valuable resources." From here. (http://www.sasked.gov.sk.ca/docs/physics/u2a3phy.html)
There is only one problem with 'work done'. In a entropic universe ruled by thermodynamics everything is assumed at some point to be 'work done'. But, if so, it can't be photons as photons contains usable energy, neither can it be matter. some refer to it as a 'gluon soup', somehow assuming that gluons do no work? Which would make gluons even more interesting than they already are:)
-
In a entropic universe ruled by thermodynamics everything is assumed at some point to be 'work done'. But, if so, it can't be photons as photons contains usable energy,
They do, but you can't get them to do any work.
http://en.wikipedia.org/wiki/Laws_of_thermodynamics#Third_law
As Sadi Carnot taught us a few years ago, a heat engine can only do work if there is a difference in temperature between its input and its output. As the temperature difference asymptotically approaches zero, so does the capacity for doing work.
-
Against that you might argue that as long as there are photons there are 'interactions'. and that any interaction means a universe that isn't thermodynamically 'dead'. In fact the big bang builds on 'energy' without matter creating ah, matter :). As I see it the only way to assume 'work done' is to pass the idea of a photonic universe. Also it builds on the assumption of the suns transforming all matter. As long as there is any matter left you can't speak of 'work done'. I don't know Geezer, but I don't like the idea of it being all photons. Then again, we don't know how a universe will act if matter disappear. There is the idea of the stress energy tensor being a part of the fabric of SpaceTime of course, so maybe you could assume that the last stage somehow was it all being transfered into its very fabric?
===
What I'm wondering about there is our idea of an arrow, and what will happen with it if matter 'disappear'. It could very well have to do with that. Everything we do we do inside this arrow. Every causality chain we see and deduct we see through that lens, we do not really know if the 'universe' at large 'see' it in the same manner. Times arrow is a very strange phenomena, creating us all.