Alone in the galaxy

The universe is an even bigger waste of space than we had imagined. Some scholars at Oxford reconsider the famous Drake Equation — an attempt at estimating the number of intelligent civilizations in our galaxy — and find that the number of civilizations in the Milky Way is likely no more than one (emphasis mine):

When we take account of realistic uncertainty, replacing point estimates by probability distributions that reflect current scientific understanding, we find no reason to be highly confident that the galaxy (or observable universe) contains other civilizations, and thus no longer find our observations in conflict with our prior probabilities. We found qualitatively similar results through two different methods: using the authors’ assessments of current scientific knowledge bearing on key parameters, and using the divergent estimates of these parameters in the astrobiology literature as a proxy for current scientific uncertainty.

When we update this prior in light of the Fermi observation, we find a substantial probability that we are alone in our galaxy, and perhaps even in our observable universe (53%–99.6% and 39%–85% respectively). ’Where are they?’ — probably extremely far away, and quite possibly beyond the cosmological horizon and forever unreachable.

Thus, the study suggests that we shouldn’t be terribly surprised if we fail to detect any signs of intelligent life in the universe. In a sense, this is reassuring. If the Drake Equation amply explains the cosmic silence, then we can worry a bit less about the hypothesis of a universal Exterminator that wipes out all life forms that get too smart for their own good.

On the other hand, the strong possibility that we are literally alone in the observable universe makes it all the more necessary for humanity to start pushing out into other neighborhoods. So says Musk:

Elon Musk

@elonmusk
· 25 Jun
This is why we must preserve the light of consciousness by becoming a spacefaring civilization & extending life to other planets https://twitter.com/worldandscience/status/1011081640158945280 …

Elon Musk

@elonmusk
It is unknown whether we are the only civilization currently alive in the observable universe, but any chance that we are is added impetus for extending life beyond Earth
10:15 AM – Jun 25, 2018

The USG will likely be too preoccupied with its own problems over the rest of the century to even think about interplanetary colonization. Can the private sector handle it? Or will the US pass the torch of space exploration to its global competitors?

An awful waste of space

The silence of the cosmos continue to be, well, deafening:

After searching 100,000 galaxies for signs of highly advanced extraterrestrial life, a team of scientists using observations from NASA’s WISE orbiting observatory has found no evidence of advanced civilizations in them. […]

Roger Griffith, a postbaccalaureate researcher at Penn State and the lead author of the paper, scoured almost the entire catalog of the WISE satellite’s detections—nearly 100 million entries—for objects consistent with galaxies emitting too much mid-infrared radiation. He then individually examined and categorized around 100,000 of the most promising galaxy images. Wright reports, “We found about 50 galaxies that have unusually high levels of mid-infrared radiation. Our follow-up studies of those galaxies may reveal if the origin of their radiation results from natural astronomical processes, or if it could indicate the presence of a highly advanced civilization.”

In any case, Wright said, the team’s non-detection of any obvious alien-filled galaxies is an interesting and new scientific result. “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.

“This research is a significant expansion of earlier work in this area,” said Brendan Mullan, director of the Buhl Planetarium at the Carnegie Science Center in Pittsburgh and a member of the G-HAT team. “The only previous study of civilizations in other galaxies looked at only 100 or so galaxies, and wasn’t looking for the heat they emit. This is new ground.”

Why should you care? Because these non-findings strengthen the case for the Great Filter — the hypothesis that some sort of cosmic barrier is preventing the rise of advanced, technological civilizations, a barrier that some believe could take the form of an Exterminator that eats intelligent life for breakfast.

The Great Filter is coming for you. Repent!