Dark energy has been described as everything from a fifth force to a new form of matter, but so far, no direct evidence has been found of its existence. “I have absolutely no clue what dark energy is,” says Nobel-Prize winning physicist Adam Riess . “Dark energy appears strong enough to push the entire universe – yet its source is unknown, its location is unknown and its physics are highly speculative.”
“We now think that both dark matter and dark energy can be unified into a fluid which possesses a type of ‘negative gravity’, repelling all other material around them,” said Jamie Farnes from the Oxford University e-Research Center in 2018 about the what is perhaps the great unsolved mystery of the Universe. “The outcome seems rather beautiful: dark energy and dark matter can be unified into a single substance, with both effects being simply explainable as positive mass matter surfing on a sea of negative masses.”
What if gravity is an illusion, a cosmic side effect of something else going on at deeper levels of reality? The classical theory of gravity is in dire need of new approaches, since it doesn’t combine well with quantum physics. Both theories, crown jewels of 20th century physics, cannot be true at the same time. A Dutch theoretical physicist and string theorist, Erik Verlinde, proposes a starkly different theory – the theory of emergent gravity. “For me gravity doesn’t exist,” he says. “We might be standing on the brink of a new scientific revolution that will radically change our views on the very nature of space, time and gravity.”
Welcome to the biggest mystery in physics: one of the great known unknowns of the universe is the nature of dark energy, an antigravitaional force field making the universe expand faster. Current theories range from end-of-the universe scenarios to dark energy as the manifestation of advanced intelligent life. It is the proverbial elephant in the “cosmic” room. (more…)
Something is messing with our universe, and that something is the enduring mystery astronomers have dubbed dark energy –which comprises about two-thirds of the mass and energy in the universe.