Dark Energy

[SinJin]

I've been reading about dark energy. From what I've gathered, this dark energy has a negative pressure which produces the opposite effect of gravity, in turn causing the universe to increase it's rate of expansion. It permeates all of space, and I was wondering if in theory dark energy could be used to propell a space craft, similar to how a cable car is propelled by the electricity in the cable it's attached to. If so, then we could be traveling for free with the only energy we use being empty space! Any thoughts on this?

[harmonygirl]

SinJin, I don't know too much about dark energy, is it related to the aether theory, which seemed (IMHO) to say we are only seeing half the picture right now, that there is balance in terms of the physicality we exist within?

[SinJin]

Dark energy is the energy that occures from vacuum fluctuations. Even when space doesn't contain any matter and appears to be empty, interactions with various fields create these fluctuations, which make up dark energy. So yeah, it says that even though we see space, or aether, as being empty and void of anything, that is only part of the picture. What is really happening is that there are anihilations of particles and anti-particles, which creates this energy.

[ema]

Hi sinjin..

i know only what you say, but i know too that is the dark energy is hypothetical form of energy , just a trial to explain 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...

its just an idea,then don think that we will use it to travel in space in such way you wondred!!..its hypothetical form only..

Best regards maight..
Ema

[harmonygirl]

Sinjin, perhaps I am misunderstanding, but I thought the aether theory dictated NO empty 'space'?

[mkirkpatrick]

Dark energy is just a word coined to explain the reason for some "missing matter"I
see it simply as the etheric plane,existing slightly out of phase with our continuum,and
extemely difficult to detect,usually deduced by inference.


regards michael.

[purveyor of knowledge]

Sin Jin,

Dark energy is the energy of time and space. One of the main breakthroughs of the "theory" of everything is it will equate time/space and energy, much how Einstein's theory equated energy and mass. In other words, for a given amount of time and a given amount of space, at a certain point in time/space, there should be a certain amount of energy contained. The equations that deal with this are waiting to be fleshed. When you consider all of the space/time points together, forming the complete set, the amount of energy present is the number 1/0.

Actually that's only half of the story. 1/0 is both positive and negative. All total there are really two components to the energy of time, which balance eachother. The other component, opposite dark energy, is gravity. Gravity is a contractive force whereas dark energy is an expansive force. Gravity serves to bide time and make it move slower, trying to pull us back to the past, back to the singularity. Dark energy serves to hasten time along, makeing the universe expand and pushing us over the edge, inevitably to the point that is the exact opposite of the singularity. That is what forms an eternity.

You are exactly right in thinking that we should be able to harness this energy of time. That is one of our goals as human beings, and one of the major breakthrougs of the TOE (allthough I can't say it's the greatest: there are lots of great breakthroughs of the TOE). But as I was saying, all technology of the future will be based on utilizing the energy of time. That is because this energy is completely free and inexhuastble. Truly an ideal situation for what we need. That is what will allow us to travel faster than the speed of light.

[neutralino]

Dark energy is just a word coined to explain the reason for some "missing matter"

Actually, this is incorrect. You are perhaps thinking of dark matter. Dark energy is a blanket term used by cosmologists to describe whatever is causing the acceleration of the expansion of the universe. We don't know what this is; it could be some sort of vacuum energy, or could be a constant on the energy-momentum side of Einstein's field equations, or could be something else completely different.

As an aside, it seems strange to me that one of your moderators in a cosmology forum does not know basic cosmology!