Scientists from Applied Physics, an independent group that advises businesses and governments on science and technology, have developed a new method for detecting extraterrestrial vehicles. This is based on gravitational waves, which they believe could be the signatures of advanced technologies such as warp drives potentially used by other civilizations.
Gravitational waves, first detected in 2015 by the Laser Interferometric Gravitational Wave Observatory (LIGO), are generated by the collision of massive objects such as black holes or neutron stars. These cosmic events do cause a fluctuation in the curvature of space-time, which extends over long distances, all the way to terrestrial interferometric detectors. Scientists show that technologically advanced alien civilizations could create similar ripples using warp drives.
A warp drive, or warp drive, is a hypothetical propulsion technique that would allow travel at near-light speed, even FTL, by locally warping the fabric of spacetime; specifically, space will shrink in front of the ship and lengthen behind it while the ship is in the “warp bubble”. These space-time warps can also generate gravitational waves potentially detectable by ground-based observatories.
Explore the entire galaxy in search of technosignatures
Are we alone in the universe? This is perhaps one of the greatest mysteries of science, and astrophysicists have been trying for decades to find any signs of extraterrestrial life. However, the technology currently used to explore the galaxy is limited: as ScienceAlert explains, the types of electromagnetic waves we use to communicate weaken as they travel, making it virtually impossible to filter out noise beyond a few hundred light-years away.
This limitation does not arise in the case of gravitational waves, which can propagate over much longer distances. The first waves, detected in 2015, were caused by the collision of black holes located at a distance of 1.3 billion light years! “Because gravitational waves experience much less attenuation than radio or optical signals, they are ideal for covering large volumes of the universe,” the statement explains.
According to the researchers, their approach will expand the search for extraterrestrial intelligence far beyond Earth’s nearest neighbors. “This new method is not limited to the traditional range of electromagnetic signals; so we already have the ability to scan all 1011 stars in the Milky Way for warp drives, and soon we will be able to survey thousands more galaxies,” said Gianni Martire, CEO of Applied Physics.
If an extraterrestrial civilization were to use technology capable of producing gravitational waves, they would still need to be powerful enough to be detected by our instruments. In an article (the first in a series) to be published in the Monthly Notices of the Royal Astronomical Society, the researchers estimated the size and speed of this hypothetical craft.
“At the moment, our methods are applicable to the general class of fast and/or strongly accelerating spacecraft (RAMAcraft) far from the Earth. In the future, we also hope to extend these methods to smaller and closer objects to the Earth,” says Luke Sellers from the Applied Physics Advanced Engine Laboratory.
Jupiter mass vessels can be detected at speeds up to 100 kpc
The authors of the paper calculated that LIGO is theoretically capable of detecting a RAMA with a mass equivalent to that of Jupiter (i.e. approximately 1.9 x 1027 kg), accelerating at 10% of the speed of light, up to about 100 kiloparsecs (326,000 light-years from us) – which would cover our entire galaxy and beyond. They add that smaller objects could also be detected if they were closer: Moon-sized objects could be detected up to 10 pc away, which is in the range of nearby stars such as Proxima Centauri.
It should be noted that Applied Physics is already collaborating with scientists at Carnegie Mellon University in Pittsburgh to develop the first machine learning model that is sensitive enough to detect these distortions and distinguish them from background noise, according to a press release.
Scientists believe that current and future gravitational wave detectors will soon be a great addition to SETI’s efforts. Observatories LIGO, Virgo and KAGRA can now search for evidence of the presence of RAMAcraft, becoming “the first devices RAMADAR (RAMAcraft Detection And Ranging)”.
However, some improvements are expected (and needed) before the search for extraterrestrial warp drives continues. “Detection of gravitational waves is still in its infancy. Future experimental improvements will open the door to new discoveries,” said Manfred Paulini, professor of physics and associate dean at Carnegie Mellon University.
Detection capabilities will obviously increase as low frequency spatial detectors are developed and improved. Future observatories such as Japan’s DECIGO (Decihertz Gravitational Wave Interferometer Observatory) project and the European Space Agency’s (BBO) Big Bang Observer will be about 100 times more sensitive than LIGO in detecting RAMAcrafts, increasing search volume by a million times!