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Fermilab Reports Dark Energy Not Needed
An anonymous reader writes "A Fermilab press release
reports that the expansion of the universe may be
explainable without the need for dark energy or a
cosmological constant. Apparently, ripples from
inflation in the early universe may account for
the observed expansion rate of the universe."
From an earlier /.-linked article 13 things that do not make sense:
Also, in the same article, Dark Energy is discussed:Can someone tell me, what's the difference between Dark Matter and Dark Energy?
It doesn't matter.
http://www.hollowdepth.com
Nova did a great piece on the all of physics (a lot on the universe and big focus on Quantum Mechanics and String Theory). It's pretty good if you are trying to find commonplace explanations of some of the theories the article just mentions and doesn't explain.
The rock, the vulture, and the chain
Yes, there is space beyond the cosmic horizon. The horizon on Earth is just the farthest you can see because of the curvature of the planet's surface. The planet keeps going beyond the horizon - the horizon is a function of the observer. The same applies to the universe, although I am not knowledgeable enough to tell you if the cosmic horizon is the limit of what we can see because of the distance, because of a higher-dimensional curvature of the universe, or because of something else.
I've read another hypothesis recently: that gravity slowly "leaks" into other dimensions so that over long distances it's attractive force diminishes, and that is why the universe is flying apart. The average distances between the galaxies has now reached a threashold where the leakage makes a big difference, giving the appearence of a relatively sudden expansion speedup.
Table-ized A.I.
Saw this article a few days ago and it talked about Alpha- raised all sorts of questions for me (being a non-enlightened individual) such as
a) What are the implications if Alpha is 'decaying' with time?
b) What are the implications if alpha is variable with graviational mass?
c) If enough photons were gathered in one location, would they have a 'gravitational' effect... and would that affect any known 'constants'?
Tantalizing and interesting, but I know I lack the education to understand all of the ramifications.
You still need something to push against in order to create those ripples. Unlike vector thrust which only requires a directed force, a ripple requires a reflection of an energy wave.
Let's take a very simple example of a wave in water. It has a wave front and the energy contained in the wave form continues in a straight line until deflected or it runs out of energy due to friction. The only way to get a ripple is to reflect the energy back upon itself (like hitting a solid barrier). But even then, some energy is transmitted to the solid object because the reflected waves do not contain the same amount of energy as the original waves.
So in space, the huge burst of energy at the time of the Big Bang generated ripples, but what was reflecting the energy such that there were ripples, and how much of that energy was transferred to that "external" universe? If we can measure the intensity of the pre-ripple energy and compare it to the energy of the ripples, we can judge how much energy was lost to that "other" universe. But what is that external universe and how can it absorb that energy?
Ripples in our space mean a breakdown in the conservation of momentum, N's 2nd Law. It means that there is a net loss in energy for our single universe. However if we postulate that there is another universe that was able to absorb that lost energy we can trust that our natural laws are still in effect.
Seriously, how did this get a mod as Interesting? He bitches about the arrogance of humans thinking we are the center of everything, then is INSANELY arrogant in stating his own theory as if it were an indisputable fact, while providing NO evidence to support it.
The whole POINT of the term "dark energy" is to say "there's something funny here and we don't know what it is". I'd say that's one regulation shitload less arrogant than camel pilot's claim.
By the way, I'm far from a cosmologist, but the poster clearly has no grasp on the difference between dark matter and dark energy, and therefore has proven he doesn't have a clue what he's talking about.
There's a decent amount of evidence that has been mounting over the past few years that a large component of redshift is in fact intrinsic, i.e. not attributed to the Doppler effect.
In some ways, it seems related to the much-glossed-over "K Effect" of a few decades ago, where it was found that bright, bright blue stars seemed to be systematically redshifted.
Researchers like M. B. Bell are of the opinion that the intrinsic redshifts are superimposed on a Big Bang flow (reducing the actual velocity we should be measuring). Others, like Arp, believe that the Hubble Flow is an illusion, and that the universe is actually relatively static once you take away the intrinsic redshifts.
David Russell's paper that just came out supports either view, and shows that other explanations (like Tully-Fisher Relationship errors or rotational velocities) are far too small to account for the large discrepancies.
(Some more hubbub on the topic.)
In either case, intrinsic redshifts will take a lot of pressure off researchers to find 'dark energy', because the discrepancies of speed/distance are much reduced.
Then, perhaps, we can stop looking for something that isn't there? :)
Binary geeks can count to 1,023 on their fingers
[1]
When his own Theory of General Relativity clearly showed that the universe should expand or contract, Einstein chose to introduce a new ingredient into his theory.
[2]
His "cosmological constant" represented a mass density of empty space that drove the universe to expand at an ever-increasing rate.
[3]
"We realized that you simply need to add this new key ingredient, the ripples of spacetime generated during the epoch of inflation, to Einstein's General Relativity to explain why the universe is accelerating today," Riotto says
Or do physicists still think everything is doomed to continue flying apart until the heat death of the universe in the distant future? Is the Big Crunch back in the picture?
-Joe G.
Get off my virtual lawn, you damned virtual kids!
It's fire.
In the beginning was nothing right? Then a Bang.
I'm thinking about this Bang. Nothing, not absence of something nothing, but Nothing. Nothing exploding.
Fire. An explosion is fire, burning combustible materials and releasing hot gases that expand.
In the middle of Nothing, there was an Explosion.
Is it possible that our universe is bounded, instead of Nothing, by Anti-Energy? The quantum equivalent of reverse-charged light?
Could a single, "mutated" quark, quasar, or thing, become charged the wrong way from subtle interaction with it's surrounding particles?
Matter and Anti-Matter. Touch one to another, and stand well back.
The universe is expanding, and it encompasses all space and time as we know it.
Could it be like a big sheet of paper (paper == anti-energy) and someone (rogue element) "ignites", switches polarity, triggers a "burn"?
When you light the centre of a sheet of paper, it expands, sometimes uniformly.
Are the boundaries of our universe a massive bluish-white of fire? Masses of matter reacting against the inverse Nothing of anti-matter, burning, accelerating like a brush-fire on a hot day.
If the universe is all time and space then it doesn't necessarily have to be planets and stars out there on the boundaries.
It could be the Burn, already moving faster then light from the instant it started, expanding constantly, releasing energy that is recycled back into matter in our own space-time.
His name is Robert Paulsen...