“Once an axion is detected,” astrophysicist Raymond Co at the University of Minnesota wrote in an email to The Daily Galaxy, “the implications to cosmology will be profound. For instance, signals from experiments with different search strategies will determine whether the axion is dark matter. If it is, with the measured axion properties, one can narrow down its possible cosmological origins.
“We actually saw this decay happen. It’s the longest, slowest process that has ever been directly observed, and our dark matter detector was sensitive enough to measure it,” said Ethan Brown, an assistant professor of physics at Rensselaer Polytechnic Institute about a process that takes more than one trillion times longer than the age of the universe. “It’s amazing to have witnessed this process, and it says that our detector can measure the rarest thing ever recorded.”
“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.”
“I spent an hour just staring at this image,” lead researcher, astronomer Pieter van Dokkum of Yale University says as he recalls first seeing the Hubble image of NGC 1052-DF2, a galaxy completely void of dark matter. “This thing is astonishing, a gigantic blob so sparse that you see the galaxies behind it. It is literally a see-through galaxy. It’s so rare, particularly these days after so many years of Hubble, that you get an image of something and you say, ‘I’ve never seen that before.”
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.”