Over 50 years ago, the theoretical physicist and mathematician Freeman John Dyson – an expert in astronomy, nuclear engineering, solid-state physics and quantum electrodynamics – theorized that a highly advanced “extraterrestrial civilization would harvest most of its energy from their star, which would both limit the amount of visible light expelled outward and increase the levels of infrared radiation.” It was a fascinating idea but not one that could be put to the test – until now.

Today (April 15, 2015), the Astrophysical Journal Supplement Series has published the results of research conducted by scientists at Penn State’s Center for Exoplanets and Habitable Worlds. The article, “Alien Technologies Survey (G-HAT),” presents the findings of their exhaustive review of nearly the entire catalog of data provided by the infrared telescope on NASA’s space-based WISE observatory.

The lead author of the paper, researcher, Roger Griffith, looked through nearly 100 million entries from WISE for galaxies that emitted high levels of mid-infrared radiation. From there, he took a closer look at 100,000 of the most ‘promising’ galaxy images.

Previous searches for signs of alien civilizations in other galaxies looked at only 100 galaxies. And researchers were not looking at the levels of heat they emitted. So this research was groundbreaking.

Jason T. Wright, an assistant professor of astronomy and astrophysics at the Penn State’s Center for Exoplanets and Habitable Worlds and lead researcher, explained in a press release that "The idea behind our research is that, if an entire galaxy had been colonized by an advanced spacefaring civilization, the energy produced by that civilization’s technologies would be detectable in mid-infrared wavelengths — exactly the radiation that the WISE satellite was designed to detect for other astronomical purposes."

No startling revelations were reported in today’s article. However, 50 galaxies with unusually high levels of mid-infrared radiation were identified. And research will continue in order to discover what the probably natural causes.

"Our results mean that, out of the 100,000 galaxies that WISE could see in sufficient detail, none of them is widely populated by an alien civilization using most of the starlight in its galaxy for its own purposes. That’s interesting because these galaxies are billions of years old, which should have been plenty of time for them to have been filled with alien civilizations, if they exist. Either they don’t exist, or they don’t yet use enough energy for us to recognize them," Wright said.

The research team also discovered mysterious new phenomena in our own Milky Way galaxy. Stay tuned.