In an interview last night, I was asked two scientific questions.
First, there was the news report about the discovery of the `strongest evidence yet’ of life on a distant planet, K2–18b. I was asked: “If life is confirmed there, what would be the next step? Should we try to establish some sort of contact? Generally, do you think it is a good idea to reach out to extraterrestrials once we know where they are?”
I explained that the new paper is based on the JWST detection of the spectral fingerprint of a single molecule, dimethyl sulfide, in the atmosphere of the exoplanet. This molecule is not a reliable biomarker according to another paper, which shows that it is found in the interstellar medium without the presence of life. On Earth, this molecule is produced by microorganisms in the oceans.
Inferences based on the detection of molecular biomarkers in the atmospheres of exoplanets are indirect. However, as I suggested in a paper with my former student, Henry Lin and Gonzalo Gonzalez, the detection of molecules associated with industrial pollution, such as CFCs, will be far more indicative, not only of life but also of the technologies it developed. I find microbes to be much more boring than intelligent life. Microbes are probably very abundant, but we can learn much more from a smarter kid on our cosmic block.
If we ever discover conclusively life on an exoplanet, we should definitely listen to any technological signals it transmits. But a dialogue would be challenging. For example, this planet K2–18b is 124 light years away. If we send a communication signal towards it right now, the earliest time for us to receive a response at the speed of light is 248 years from now, in the year 2273. I am not that patient and would love to learn more about it by observing it in great detail over the centuries before the year 2273.
Because of the large distances to stars, I am not worried about predators. Those who can reach us are likely far more advanced technologically than we are. They will probably not view us as a serious threat. In fact, my concern is that they will ghost any direct message (DM) we send them because they will not find us particularly intelligent given the geopolitics on our planet.
In a second news item, the new director of the Office of Science and Technology Policy (OSTP) in the White House, Michael Kratsios, gave his first public talk in which he remarked that “our technologies permit us to manipulate time and space.” This statement was part of a broader discussion on how regulatory frameworks since the 1970s have potentially hindered technological advancements, urging for a reevaluation to enhance American productivity and innovation. I was asked whether Michael’s statement indicates that the U.S. Government has secret knowledge about how to manipulate spacetime, garnered from years of reverse engineering of alien spacecraft that were recovered on Earth.
In response, I explained that the field equations formulated by Albert Einstein in 1915, relate the curvature of spacetime on their left-hand-side to the mass or energy density of matter or radiation on their right-hand-side. The distortions of time or space are miniscule unless one concentrates a huge amount of mass within a small volume. For example, the Sun distorts spacetime at a minuscule level of one part in 10⁸ at the position of Earth. The resulting tiny curvature is sufficient to make the Earth move in a circle around the Sun. When black holes with tens of solar masses collide at cosmological distances, they produce small ripples in spacetime of one part in 10^{21} near Earth, as first detected by LIGO in 2015. The immediate vicinity of black holes is characterized by large spacetime distortions, but the U.S. government does not have access to such environments. We use Einstein’s equations to acquire precise navigation with GPS systems. If these equations were wrong, we would get lost.
I also clarified that any experimentation by the U.S. Government does not reach the energy densities accessible at CERN’s Large Hadron Collider by many orders of magnitude. This implies that if there is any new physics regarding the manipulation of spacetime, it would have been noticed in unclassified data shared by the international community of physicists at CERN. Secrets were leaked out of the Manhattan Project and physicists worldwide would have known of any major advance in the theory of gravity.
If we ever learn how to bottle the “dark energy” that causes the accelerated expansion of the Universe, we might have access to repulsive gravity that could propel a craft without fuel. Discovering a more advanced civilization with this knowledge would unleash a new wave of American innovation, which Michael Kratsios will greatly appreciate. But we have to find these alien technologies first. For that to happen, NASA and NSF need to allocate billions of dollars to the search for extraterrestrial techno-signatures and not invest only, as they do now, in the search for bio-signatures. Hopefully, someone out there is listening!
ABOUT THE AUTHOR
Avi Loeb is the head of the Galileo Project, founding director of Harvard University’s — Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, and the former chair of the astronomy department at Harvard University (2011–2020). He is a former member of the President’s Council of Advisors on Science and Technology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” and a co-author of the textbook “Life in the Cosmos”, both published in 2021. The paperback edition of his new book, titled “Interstellar”, was published in August 2024.
