Dark Energy changes in expansion

Okay accept dark energy asserts a normal gravitational effect on normal matter and energy but not itself. Next accept 80% of teh Universe is made up from it - so there is alot of it!

Adding those two assumptions tells you two important things:

1) The galactic layout / shape / position of all this energy - where, geographically, it resides in the cosmos is critical

2) Unlike normal matter / energy it won't clump because of gravity into suns, planets, people, trees and rocks etc. - it will probably spread our diffusely very, very, very evenly - unbelieveably so.

Visualise this in our own solar system. Most of the Mass is centred in the Sun, then Planets then asteroids, then dust, until you get to a vaccuum where there is generally 1 - 3 hydrogen atoms per cubic metre. But the dark mass is spread evenly and might account for significant equivalent gravitational mass. Next step out side our solar system and proceed to our galaxy, the milky way. There is alot of empy space - potentially chock full of dark energy exerting a gravitational pull.

Now step outside our galaxy and even the galactic cluster containing the Milky Way as one of many galaxies. Between it and the next glactic cluster is a vast amount of empty space - again possible full of dark energy - hence gravity.

As the Universe expands allow the darm energy to expand roughly in proportion with it - allowing it to be evenly distrubuted but still bounded by any edge to our Universe. Well this means dark energy is spread evenly throughout, but normal matter / energy tends to be clustered more towards the centre. So the gravitational effect of dark energy - by location and volume - tends to pulls things out towards the 'edge of the Universe' whilst normal energy / matter tries to pull things all back together back towards a big crunch scenario. Remember from my other thread - gravity isn't quantised - so its effects can apparently go on towards infinity - rather than dwindle to nothing once your distance from a gravitational source is so vast your gravitational force is below the lowest quanta of energy a photon can have.

Finally my own thoughts on what dark energy may be and why it alone is evenly distributed:

M-Theory and superstring symmetry theory postulates we live in a 10 or 11 dimensional rality called a membrane. We commonly observe only 4 of these dimensions space (3) plus mass (=energy) (1). In our reality with our perception time is wrapped into spacetime, although it might be something very different within our reality and across other membranes, but I digress.

The other 6 or 7 hidden dimensions may be so tiny (think Planck level small 10 ^ -35 metre) and subtle its hard to every observe them. But one a galactic of universal scale these dimensions could significantly affect our percieved reality. Possible what we call dark energy is small periodic leakages of regular energy and mass into and out of these hidden dimensions. So I postulate spacetime isn't static - it may be an equilibrium point of normal energy and matter leaking into and back from hidden dimensions. This leakage maybe appearing to us as dark energy and dark matter. Dark matter might just be s-particles or symmetric particles (s-electron, s-neutron, s-proton etc) from string theory.

So that is a theory on what it is (or how it appears). Why is it evenly distributed where nothing else is? Because it's the very fabric of our reality itself - it itself is our dimensional infrastructure, so it has to be everywhere it is by definition. This also adds weight (pun intended) on why dark energy doesn't directly effect itself. Those hidden dimension have their own rules for how they interact - what we postulate as dark energy and dark matter might just be leakage from our realities hidden dimensions!

As I said this is my intuition - arrived at this morning - and if I am right I want the Noble prize please!!! Call it the Kendall conjecture

ROsborne - interesting thread. I'll try to get through the article you linked to.

g_day - thanks for the explanation. So, could this dark energy, then, be related to the hypothetical worm-holes?

Yes if a worm hole is another manifestation of a crossover from our observed normal 4 dimensional reality the those hidden extra 6 or 7 dimensions

And the dark energy could push or pull something through....

At one point in time, gravity dominated the rate of expansion of the universe. It caused a deceleration of expansion. But then around 6billion years ago dark energy began to dominate the expansion, and everything changed from deceleration to acceleration. So there must have been a point in time when deceleration and acceleration were balanced. Apparently this point occurred around 6billion years ago.

If the Universe is 13.something billion years old (which is the most recent estimate), then 6billion is dangerously close to being exactly half the total age of the universe.

Suppose that the change from deceleration to acceleration didin't occur at a linear figure of 6billion years ago, but always occurs at half the age of the universe.

Maybe the point at which deceleration changes to acceleration isn't a finite point in the timeline. Maybe it's more like the "center" of the universe, in a universe which has no "center".

In order to test this theory, the age of the universe would have to be measurable to within a couple of hundred years, and the shift point between deceleration and acceleration just as accurately. Only then would we know if the perceived point of change which we observe, shifts with the timeline.

so, if it were dangerously close to mid-way in a cycle, what next?

We are not dangerously close to the mid-point. The mid-point is always half way between were the observer is and the origin.

I'm wondering if the balance point between decel and accel would always appear to be at the halfway point in the age of the universe, no matter what time period the observer sees it from.

I know that this idea seems illogical, but so does the idea of a universe without a center, until you give up the illusion of three dimensional space. Just as space can exist without a center, so may our timeline exist without a beginning or an ending. Maybe it's an infinite loop punctuated by a defining event? Something about the idea seems to remind me of something, but I'm not sure what yet.

hmmm

Just a quick point or two from the dominate theory:

1) At the Big bang spacetime exploded or unfolded in all directions randomly at around mostly lightspeed

2) during a very brief time in the first moments of after the big bang inflation occured, during which spacetime exploded at 50,000 times the speed of light

Becuase of this if you imagine the early universe as a sphere extremely rapidly expanding, then slice the Universe in any two halves (thru its centre). Well any one half can never see or feel the influence of the gravity from the other half!!!

Why - because the two halves are seperating at lightspeed away from each other, and gravity, light or electricity from one half only travels at lightspeed towards the other half. The gravity wave or light blast from any half can never reach the other half.

This is accepted physics - one element of proof the age of the Universe is best computed to be 13.8 billion years - but the diameter of the Universe is best calculated to be 40 billion light years. Spacetime unfolded in all directions continually at or beyond c - relativistically its a mind bender getting a clear frame of reference on things. You expect teh diameter of the Universe to be about 2 * c * age - about 28 billion lightyears. But i) inflation and ii) the unfolding expansion causes it to be aboit 30% bigger!

g__day, your theory is very interesting, and I enjoyed reading it.

I guess this "dark energy" stuff is not specifically defined yet, and may never be, but density can change with pressure and temperature in normal matter... which is why I'm thinking this "dark energy" hasn't been properly defined.

I wonder about the physicists, though. The basic physics class I had to take, which was calculus based and a year long... well, it was just too basic. There weren't enough variables, but the class would provide a general understanding for future physics classes I'm sure. As it turns out, though, it is hard to win the physicists over with new theories and scientific laws, since they would have to rewrite all their textbooks and equations.

Dark energy is very poorly defined theoretically - if its real that makes it a new scientific frontier to explore - very exciting.

Also this analysis finally answered a big bug bear of mine: at the moment of the big bang, why did everthing explode not implode? After all compress all that mass or energy in such a small area and you'd theoretically expect the biggest black hole every. Hell its event horizon alone would be 20% bigger than our Universe is today!!!

Two factors changed this:

1) Upon creation spacetime didn't exist - so gravity hadn't yet propogated to pull everything in

2) The initial explosion was so clossal that spacetime flew apart so incredibly fast its blast horizon matched or exceeded the propogation of its gravity field. It out ran its own gravity wave!

Once it was flying apart and both sides receeding at c there was no way for the gravity from any half of the big bang to affect most of the other half. Gravity doesn't travel instantly, it travels at c!