Transitions in Gaining New Knowledge

Avi Loeb
5 min readJun 8, 2024


Fritz Zwicky at the Schmidt telescope of the Palomar Observatory, California, in the 1930s. (Image credit: Palomar Observatory/Caltech)

The philosopher Arthur Schopenhauer had a brilliant observation: “All truth passes through three stages. First, it is ridiculed. Second, it is violently opposed. Third, it is accepted as being self-evident.” During the forty years of my career in astrophysics, I had witnessed these phases in frontiers of research that were initially ridiculed and eventually recognized as self-evident.

One such frontier involves the search for the first galaxies that formed when the Universe was a few percent of its current age. My graduate student on this topic three decades ago, Zoltan Haiman, currently a tenured professor at Columbia University, was challenged by a thesis committee member who argued forcefully that there is no basis for predicting the properties of the first stars from first principles at redshifts beyond 10. Last week, a research team reported the discovery of a galaxy named JADES-GS-z14–0 at redshift 14.3 in the Webb telescope data with properties consistent with our expectations from 30 years ago. Haiman’s thesis examiner, who is alive and well as one of the world leaders in observational cosmology, must be treating the latest Webb data as self-evident now.

Similarly, in the 1980s the possible existence of exoplanets was regarded as a fringe topic or an extraordinary claim that requires extraordinary evidence. The evidence was not easy to come by because members of time allocation committees for major observatories were reluctant to allocate precious telescope time to the risky search for exoplanets. By now, more than 5600 exoplanets have been discovered and some of these early gatekeepers take credit for the success of this research frontier.

When the physicist turned astronomer, Fritz Zwicky, suggested in the early 1930 that most of the matter in the Universe is invisible, his claims were ignored. Today, the search for dark matter is a mainstream research frontier. We are still searching for the nature of this unknown substance. In contrast to exoplanet search, the legitimacy given to the search does not stem from us knowing for sure that it exists and that gravity is not modified at low accelerations.

In the early years of a new research frontier which advocates reasonable possibilities but is being ridiculed, the act of collecting evidence is blocked and these possibilities remain fringe. This self-sustained cycle of ignorance slows down the rate of acquiring new knowledge. Extraordinary evidence requires open minds, supported by extraordinary funding.

This historic perspective shielded me from critics who argued that sensors aboard U.S. Government satellites overestimated the speed of a meteor detected on January 8, 2014 by a factor of two. The authors could not fit the satellite data by their standard model for stony meteorites from the solar system, and so they dismissed this data which did not conform with past knowledge. By downgrading the data, the anomaly disappeared in their mind. This is a well-known manifestation of cognitive dissonance in psychology. As it turns out, their rejection of the meteor velocity data was refuted in a recent paper, and was not consistent with our material findings from the meteor site . Another argument by naysayers that an ocean expedition to the meteor site recovered coal ash rather than meteoritic material, was refuted by analysis of 55 elements from the periodic table. Finally, some critics claimed that the meteor may have been a truck, even though it was the fireball’s flash of light — equivalent to a few percent of the Hiroshima atomic bomb energy, which was used to localize our meteoritic survey site.

How will the search for extraterrestrial technological objects near Earth gain traction within the scientific mainstream? Most likely, in the same way that the searches for the first galaxies, exoplanets or dark matter did. As of now, the Galileo Project’s research on this topic is received with enthusiasm from many young scientists who are waiting for the right moment to act on it. They witness the thought-police of naysayers and are careful to speak their mind. Many young scientists approach me routinely to say how inspired they are by the Galileo Project research.

The phase transitions outlined by Schopenhauer are psychological. As soon as the naysayers are marginalized and free academic discussion on a topic of great interest and importance is legitimized, scientists get the courage to study the unknown and search for the related evidence. My goal is to bring the search for extraterrestrial artifacts near Earth to the mainstream of astronomy. Once the discussion is legitimized at the level of the search for extraterrestrial microbial life, the transition into the mainstream will be rapid.

Next Thursday, I will be speaking about this topic at a public forum on Capitol Hill in Washington DC. If the U.S. government has relevant information about cosmic neighbors beyond the solar system, I will be glad to learn about it. Otherwise, researchers can find the answers through the standard scientific process of searching for the evidence.

Two days ago, Japanese lawmakers established a group to investigate Unidentified Anomalous Phenomena (UAP). The investigation comes less than a year after the U.S. Department of Defense classified Japan a “hotspot” for UAP sightings. Now, a non-partisan group of more than 80 Japanese lawmakers, including former defense ministers, plans to investigate sightings of UAP, citing concerns about possible national security issues.

If some UAP are extraterrestrial, they would not adhere to national borders because they originated from interstellar space where terrestrial politics is irrelevant. Studying them should be a matter of science based on international cooperation. Sharing scientific information openly is particularly important in this context which carries major implications for science, religion, politics and our aspirations for space.

In studying anomalous near-Earth objects, the Galileo Project’s observatories and expeditions are taking a path not taken previously by scientists, and may discover low-hanging fruits. As in the searches for the first galaxies, exoplanets and dark matter, the only requirement for success is genuine curiosity.


(Image credit: Chris Michel)

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. His new book, titled “Interstellar”, was published in August 2023.



Avi Loeb

Avi Loeb is the Baird Professor of Science and Institute director at Harvard University and the bestselling author of “Extraterrestrial” and "Interstellar".