Space

Alien technology? Harvard scientists propose source for fast radio bursts

Alien technology? Harvard scie...
Artist's depiction of a light sail powered by a radio beam (in red) generated on the surface of a planet
Artist's depiction of a light sail powered by a radio beam (in red) generated on the surface of a planet
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Dish at Parke Observatory in Australia, where the first fast radio burst (FRB) was discovered in 2007
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Dish at Parke Observatory in Australia, where the first fast radio burst (FRB) was discovered in 2007
Artist's depiction of a light sail powered by a radio beam (in red) generated on the surface of a planet
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Artist's depiction of a light sail powered by a radio beam (in red) generated on the surface of a planet

There are plenty of strange phenomena lurking in the universe, and fast radio bursts are among the more mysterious. So named for their less-than-5-millisecond duration, the source of these intense, high-energy light bursts continues to elude scientists. Now researchers from the Harvard-Smithsonian Center for Astrophysics are proposing they could have "an artificial origin," specifically from planet-sized alien transmitters for powering interstellar spacecraft.

Fast radio bursts (FRB) were first discovered in 2007 at Parkes Observatory in Australia, with several dozen or so detected since. The initial discoveries showed FRB to be seemingly random one-off events coming from distant galaxies, leading some to hypothesize they were the result of cataclysmic cosmic events, like the merging of black holes or a massive supernova.

But in 2015, an astronomer from McGill University found 11 bursts that not only originated from the same location in space, but were repeating. More repeating FRB were discovered in 2016, which were tracked to a dim dwarf galaxy 3 billion light-years away, poking holes in the cosmic cataclysm idea.

With no consensus on the source of these puzzling phenomena, Avi Loeb and Manasvi Lingam from the Harvard-Smithsonian Center have offered another possibility: advanced alien technology in the form of a solar-powered radio transmitter. These beams of light, they say, could be used to power giant light sails in a "photonic propulsion" system, transporting spaceships or probes through interstellar space that approach the speed of light.

"The system is comprised of two distinct components," Lingam told New Atlas. "The first is a means of harnessing the stellar energy, via photovoltaic arrays for instance. The second is the actual radio-wave beam emitter, which powers the light sail. And the energy for generating the beam comes from the star."

The beam emitter, or transmitter, envisioned by the team is powered by stellar energy, but could conceivably be juiced up through other alternatives. The light reaching Earth as an FRB from such a system would simply be energy leakage, which would mean the gadget would have to be enormous – as much as twice the Earth's diameter. The device would cover a large fraction of the surface of the planet, while Lingam said it's possible the emitter could also be an artificial free-floating structure, like a Dyson sphere.

"The reason for this size is that it enables the effective harnessing of stellar energy and the use of water as coolant," said Lingam. "If the transmitter were smaller, it would undergo more severe heating and would thus be harder to cool. Similarly, if it were smaller, there would not be enough area to tap the stellar energy and power the beam." Lingam added that the coolant would be part of the beam-emitting device, similar to how one uses water as a coolant for lasers.

Informed speculation

The researchers say it's all within the realm of possibilities, at least according to the laws of physics, even if it's far beyond our own technological abilities. It's a no-stone-left-unturned type of suggestion, though Loeb argues that "deciding what's likely ahead of time limits the possibilities. It's worth putting ideas out there and letting the data be the judge."

At the same time, researchers are currently limited by such a small sample size and their ability to detect FRB, according to Roger Romani, professor of physics at Stanford University. "The rarity [of FRB] is not really clear yet – we have only detected a handful, but even the largest surveys sensitive to these events covered only a small fraction of the sky," Romani told New Atlas. "If extrapolated to the full sky, there should be many FRB per day, but the exact rate is unclear. A number of current experiments are seeking to pin this rate down."

As far as Loeb and Lingam's alien-technology idea, he tends to agree that every possibility should be considered, no matter how improbable it might seem. "I do not think that more prosaic astrophysical origins should yet be eliminated," he told us. "Most would concur that exotic, but astrophysical events likely cause FRB. So I would not sign up for the alien interpretation at this juncture. That being said, this sort of informed speculation is good fun, as long one retains appropriate skepticism."

The research has been accepted for publication in the Astrophysical Journal Letters.

Source: Harvard-Smithsonian Center for Astrophysics

12 comments
RXStephen
Its Alcubierre drive space ships coming out of warp and obliterating their destinations.
McDesign
Think of it metaphorically. This approach moves the weight of the heavy energy storage (gasoline or hydrogen or batteries, etc.) from the moving vehicle to the ground. Then, the energy to move the vehicle is conveyed to the vehicle with massless, essentially lossless photons/electrons/radio waves, much in the same way that an electric train is powered. Super idea.
Techtwit
I have always wondered, when reading of "sails" being pushed through space by solar wind, laser beams, and now a radio transmitter, how do the occupants get back home again. Haven't puzzeled out how they turn around, or engineer a reverse gear.
Douglas Bennett Rogers
Maybe we are looking as exhaust from highly time dilated space ships, the actual exhaust being in the gamma ray region.
VOMIChairman
Perhaps it could be some SETI signals that are being broadcast out in the universe in the hope that some "extraterrestrial" intelligence would find it. No different than what we are doing.
Bonzadog
Oh deary me, immature speculation written large...just where is scientific impartiality...
Brooke
The best possible way to beam light is with something like a laser, but even there the spot size far from the source depends on the diameter of the objective lens. This is why the lasers used to measure distance to the moon have their beams expanded using a telescope in reverse. But even with a planet sized "lens" the range where most of the power gets to the spacecraft would be limited. After that the efficiency would be poor.
Nik
Given that they are 3 billion years old, perhaps past tense throughout the article, would be appropriate. Modern electronic communication transmissions also use compressed information pulses. So maybe if these pulses were 'uncompressed' it may be found that they contain information, that is, if they are not purely natural events, like pulsars.
Christopher Nigel Phillips
Random wideband em radiation in any form is to be expected from an Electric Universe. All visible (and many invisible) phenomena in space can be explained by plasma discharge. Nothing else, except an electricity supply is needed. Who the heck needs gravity to make x-rays, radio, UV and of course light? What a waste of space is the Standard Model, so far!
StevenR01
It would make sense. There is no faster-than-light drive. Einstein was right. The only way to go interstellar is using light sails as proposed by Stephen Hawking, et al. Multiple civilizations come to the same conclusion and build the same kind of craft. We see their gasp at immortality as the civilizations flash into existence, reach their zenith and decay into extinction. This happens on millions and billions of worlds and this is the result. I guess we should get building one...