The Best Way to Find Aliens: Look for Their Solar Power Plants
By Ross Anderson | The Atlantic
—
A team of astronomers is now looking for Dyson Spheres, massive star-scale solar power plants that extraterrestrial hunters hope alien civilizations employ.
A portion of the Wide-field Infrared Survey Explorer (WISE), NASA’s all-infrared survey of the sky.
In 1960, mathematician, physicist, and all-around genius Freeman Dyson predicted that every civilization in the Universe eventually runs out of energy on its home planet, provided it survives long enough to do so. Dyson argued that this event constitutes a major hurdle in a civilization’s evolution, and that all those who leap over it do so in precisely the same way: they build a massive collector of starlight, a shell of solar panels to surround their home star. Astronomers have taken to calling these theoretical megastructures Dyson Spheres. Dyson’s insight may seem like nothing more than a thought experiment, but if his hypothesis is sound, it has a striking implication: if you want to find advanced alien civilizations, you should look for signs of Dyson Spheres.
Last month a trio of astronomers led by Penn State’s Jason Wright began a two-year search for Dyson Spheres, a search that will span the Milky Way, along with millions of other galaxies. Their project was just awarded a sizable grant from the Templeton Foundation, a philanthropic organization that funds research on the “big questions” that face humanity, questions relating to “human purpose and ultimate reality.”
So how do Wright and his team aim to find a Dyson Sphere? Though the word “sphere” summons to mind a solid structure, Wright says his team won’t be looking for solid shells. “Even though there is enough mass in our solar system to construct a solid sphere, such a structure would not be mechanically feasible,” Wright told me. “It would probably have to be more like a swarm of collectors.”
This wild speculation about futuristic alien tech probably seems unscientific, but the search for extraterrestrial civilizations has always depended upon such speculation. Think of all the predictions that are baked into SETI, the Search for Extraterrestrial Intelligence, which uses telescope arrays to scan the heavens for alien radio communications. At present, humans have nowhere near the excess energy you’d need to send the kind of radio signal that SETI is looking for. Earlier this year, astronomer Robert Gray told me that “to operate a radio beacon that is on all the time, broadcasting in all directions, strong enough to be picked up from many light years away, you need an enormous amount of energy — something in the range of thousands and thousands of big power plants.” SETI is betting that advanced civilizations will value communicating with other civilizations a lot, or at least enough to justify huge energy expenditures. It’s also betting that such civilizations will communicate via radio waves, and that they will transmit their signals on one of the frequencies that we monitor. For us to find intelligent extraterrestrials, it’s not enough that they exist; they have to develop and use technology in predictable ways.
—
Read the rest of the article here: The Atlantic
