March 10, 2017

Harvard scientists: ‘Fast radio bursts’ might come from alien spaceships

From time to time, the world is treated to a genuine theory from respected experts on subjects that are usually confined to science fiction. Take Elon Musk's suggestion that our world is probably a simulation or Stephen Hawking's idea that AI really could take over the world.

Similarly, Havard scientists have posited that fast radio bursts (FRBs) are caused by aliens traveling around space.

FRBs are intense blasts of radio waves lasting a very short time, from 1 to 5 milliseconds. They were only discovered in 2007, and it was in early 2017 that astronomers pinpointed one for the first time in a galaxy three billion light years from Earth.

Rotating magnetars that hammer surrounding material with their vast magnetic fields, superluminous supernovae explosions, or immensely volatile cosmic events like supermassive black holes ejecting material are among the theories of what causes FRBs.

Harvard-Smithsonian Center for Astrophysics (CfA) scientist have now sensationally added to the list with the notion that FRBs could come from structures created by alien beings to power their spacecraft.

"Fast radio bursts are exceedingly bright given their short duration and origin at great distances, and we haven't identified a possible natural source with any confidence," said Harvard professor Avi Loeb. "An artificial origin is worth contemplating and checking."

Light sails

The function performed by the imagined structures is to move alien vehicles using light sails, in which powerful light beams propel a reflective surface in the vacuum of space. Humans are currently experimenting with light sail technology that uses light from the sun.

Another fascinating project involves the development of a global system of lasers that are used to move nanoprobes at around 20 percent the speed of light. Known as photonic propulsion, this technology could send a probe to the closest star system to us, Alpha Centauri, in just two decades.

Loeb and fellow Harvard researcher Manasvi Lingam propose that if alien spacecraft were being propelled by a vast system that converted solar power into energy for laser beams, that system could be twice the size of Earth. The radio emissions from an entity of such a size would be detectable even across billions of light-years, they suggest.

The spacecraft, incidentally, could be a million tons (roughly 20 cruise ships) and still be propelled by the system.

"That's big enough to carry living passengers across interstellar or even intergalactic distances," says Lingam.

The beams that would have to be regularly targeted at the craft could, the theory goes, move far beyond and reach Earth intermittently as FRBs, disrupted by the movement of distant galaxies and planets.

A little like Elon Musk suggesting that Earth being a simulation is the only logical conclusion, Loeb said, when asked how much he believes in his theory, that: "Science isn't a matter of belief, it's a matter of evidence. Deciding what's likely ahead of time limits the possibilities. It's worth putting ideas out there and letting the data be the judge."


Image credit: M. Weiss/Center for Astrophysics