Have We Already Been Visited by Aliens?
Elizabeth Kolbert
Elizabeth Kolbert
Quote:An eminent astrophysicist argues that signs of intelligent extraterrestrial life have appeared in our skies. What’s the evidence for his extraordinary claim?
Quote:Far from being deterred, Loeb doubled down. Together with Thiem Hoang, a researcher at the Korea Astronomy and Space Science Institute, he blasted the frozen-hydrogen theory. In another equation-packed paper, the pair argued that it was fantastical to imagine solid hydrogen floating around outer space. And, if a frozen chunk did manage to take shape, there was no way for a block the size of ‘Oumuamua to survive an interstellar journey. “Assuming that H2 objects could somehow form,” Hoang and Loeb wrote, “sublimation by collisional heating” would vaporize them before they had the chance to, in a manner of speaking, take off.
Loeb has now dispensed with the scientific notation and written “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” (Houghton Mifflin Harcourt). In it, he recounts the oft-told story of how Galileo was charged with heresy for asserting that Earth circled the sun. At his trial in Rome, in 1633, Galileo recanted and then, legend has it, muttered, sotto voce, “Eppur si muove” (“And yet it moves”). Loeb acknowledges that the quote is probably apocryphal; still, he maintains, it’s relevant. The astronomical establishment may wish to silence him, but it can’t explain why ‘Oumuamua strayed from the expected path. “And yet it deviated,” he observes.
In “Extraterrestrial,” Loeb lays out his reasoning as follows. The only way to make sense of ‘Oumuamua’s strange acceleration, without resorting to some sort of undetectable outgassing, is to assume that the object was propelled by solar radiation—essentially, photons bouncing off its surface. And the only way the object could be propelled by solar radiation is if it were extremely thin—no thicker than a millimetre—with a very low density and a comparatively large surface area. Such an object would function as a sail—one powered by light, rather than by wind. The natural world doesn’t produce sails; people do. Thus, Loeb writes, “ ‘Oumuamua must have been designed, built, and launched by an extraterrestrial intelligence.”
'Historically, we may regard materialism as a system of dogma set up to combat orthodox dogma...Accordingly we find that, as ancient orthodoxies disintegrate, materialism more and more gives way to scepticism.'
- Bertrand Russell
- Bertrand Russell