Dark matter was recently discovered to cause the universe to be twice as cold as what scientists originally thought. Dark matter is talked about as a, “cloud of invisible particles,” by astrophysicist and NPR Blogger, Adam Frank. He also says, “It’s fascinating that dark matter is everywhere but not traceable.” The reason why it’s not traceable is because dark matter doesn’t release electromagnetic radiation, or any light that would make it detectable. Regarding the search for dark matter, Frank says, “When it comes to the direct detection, there’s no real progress. We’re doing lots of interesting studies and we’re putting limits on them but nobody has found a direct detection.” He says that these experiments bring them one step closer to truly understanding dark matter.
The team that conducted the experiment included Alan Rogers, a researcher at MIT’s Haystack Observatory, and his colleagues. This experiment, conducted in Australia, involved being as far from radio signals as possible and not having any connection. The device made to detect a signal is called the ‘EDGES ground-based radio spectrometer.’ They discovered that the signal they received was larger than what they initially thought it was. The larger signal means that hydrogen gas was twice as cold as they had previously thought. This was discovered by the radio antenna that received signals from early stars.
Theorists predicted that the temperature was -454 degrees Fahrenheit, rather than it being roughly -227 degrees, which was the predicted temperature. Rennan Barkana, of Tel Aviv University in Israel, was trying to figure out how the temperature could be completely off from what they had predicted. He says, “Then it hit me that there’s only one candidate for some component of the universe that can actually be even colder, and that’s dark matter.” Barkana also included how he thinks that the hydrogen gas could’ve been cooled by the dark matter.
Dark matter is known as just, “sitting there and gravitating.” So this new evidence about interactions with dark matter is a huge step in the properties of dark matter. “If that’s the case, then we’ve detected the first non-gravitational interaction between dark matter and anything.” says Mack.