Until 1998 it was theorized that the universe was expanding but that at some point gravity would slow it’s expansion and then would cause the universe to collapse upon itself.
In 1998 observations from the Hubble Telescope found that in the distant past the universe was actually expanding more slowly than it is now – which means that the universe’s expansion has actually sped up. This was a completely unexpected finding. The most likely explanation for the increase in the rate of expansion is some sort of force that is creating the expansion. This mystery force is referred to as Dark Energy.
Scientists have calculated how much Dark Energy is necessary to cause the accelerated expansion of the universe but they don’t know really anything else about it. Based on calculations about 68% of the universe is Dark Energy, another 27% is Dark Matter and only about 5% is normal matter that we can see and detect. IFOD on Dark Matter: http://www.theifod.com/what-is-dark-matter/
There are a few theories about what Dark Energy might be:
- One of the characteristics of space proposed by Einstein is that it has its own energy. Additionally, he also proposed that additional space comes into existence as the universe expands. Thus, as the universe expands more space comes into existence and with that new space comes new energy.
- Another explanation is based on the fundamentals of quantum mechanics which says that space is full of temporary virtual particles that pop in and out of existence and that these virtual particles are providing the energy for cosmic acceleration.
- Another explanation for dark energy is that it is a new kind of energy field, something that fills all of space but something whose effect on the expansion of the universe is the opposite of that of matter and normal energy.
- Finally, maybe Einstein’s theory of gravity is not correct and that we need a new theory of gravity.
Dark energy is when you have a black 62 Chevy 2 door hard top with a 409 engine, 2 four barrel carburetors, 4 speed stick on the floor, and your main squeeze is setting close. you are lined up at the stop sign with a Volkswagen Beatle and he tries to beat you off the line. That is when you got dark energy. Teds theory of reality.