2006-07-20 14:45:28 · 8 answers · asked by huron223 1 in Science & Mathematics ➔ Astronomy & Space
In physical cosmology, dark energy is a hypothetical form of energy which permeates all of space and has strong negative pressure.
Two proposed forms for dark energy are the cosmological constant, a constant energy density filling space homogeneously, and quintessence, a dynamic field whose energy density can vary in time and space.
The exact nature of this dark energy is a matter of speculation. It is known to be very homogeneous, not very dense and presumably does not interact strongly through any of the fundamental forces other than gravity.
The term dark energy was coined by Michael Turner
2006-07-20 14:55:56 · answer #1 · answered by c3llar_door 3 · 0⤊ 0⤋
Dark energy entered the astronomical scene in 1998, after two groups of astronomers made a survey of exploding stars, or supernovas, in a number of distant galaxies. These researchers found that the supernovas were dimmer than they should have been, and that meant they were farther away than they should have been. The only way for that to happen, the astronomers realized, was if the expansion of the universe had sped up at some time in the past.
Quote from www.space.com
In physical cosmology, dark energy is a hypothetical form of energy which permeates all of space and has strong negative pressure. According to the theory of relativity, the effect of such a negative pressure is qualitatively similar to a force acting in opposition to gravity at large scales. Invoking such an effect is currently the most popular method for explaining recent observations that the universe appears to be expanding at an accelerating rate, as well as accounting for a significant portion of the missing mass in the universe.
Taken from http://en.wikipedia.org/wiki/Dark_energy
2006-07-20 22:00:16 · answer #2 · answered by Doodaa 2 · 0⤊ 0⤋
Dark energy is matter suspected by scinetists to be in the universe. It is technically not matter, but more of an area where electrons and protons are reversed. Our galaxy, or at least what's known of it, shows no signs of dark energy, though some spacecraft have stopped sending signals and it is suspected that they crashed into an area of it. This is skeptisized from the hypothosis that when Dark energy and Light matter collide, an awesome explosion occurs. Of course, we won't know for hundreds of years when the light from the explosion gets to us. Some scientists actually think that a few of the recorded supernovas may have been dark energy explosions. So there you have it. Dark energy in a nutshell.
2006-07-20 21:56:24 · answer #3 · answered by shadow6000 2 · 0⤊ 0⤋
Dark Energy is hypothetical energy that forces objects apart and can be used to explain why the universe is expanding at an accelerating rate. Essential we know the universe is getting bigger faster and faster, but do no know why so we make up Dark Energy to explain it.
2006-07-20 21:50:37 · answer #4 · answered by Anonymous · 0⤊ 0⤋
From what I've read, it is either Einstein's cosmological constant or something called "quintessence," but like the first answer it expands the universe.
2006-07-20 21:54:22 · answer #5 · answered by JBarleycorn 3 · 0⤊ 0⤋
Hypothetical substance pushing the universe apart.
2006-07-20 21:49:53 · answer #6 · answered by KM 3 · 0⤊ 0⤋
as someone else cited:
http://en.wikipedia.org/wiki/Dark_energy
there is so much we don't understand, until the theory of everything is solved.
2006-07-20 22:07:42 · answer #7 · answered by Mr X 2 · 0⤊ 0⤋
something you get when you don't pay your power bill.
2006-07-20 21:51:10 · answer #8 · answered by Chris J 1 · 0⤊ 0⤋