My scientific career started in the Institute for Advanced Study at Princeton, where the official seal depicts the image of truth and beauty holding hands.
A recurring question in physics is whether mathematical beauty can guide us in finding the truth about the physical world. My take is that beauty might be wishful thinking but reality is under no obligation to be as beautiful as we imagine it to be.
An imagined beautiful symmetry of nature could guide us to invest ten billion dollars in the Large Hadron Collider (LHC) at CERN. But when the LHC tested Supersymmetry in its popular parameter space, no evidence was found to support its imagined beauty of new physics. Experiments resemble blind dates. Sometimes they reveal a reality that is more exciting than we hoped for, but most of the time they disappoint us.
Beauty is highly valued among members of academia because it provides a framework for mathematical or intellectual virtuosity that carries accolades and awards if proven real. The premature popularity of beautiful ideas in academia stems from trendy fashions. Without experimental evidence to support them, plausibility arguments in academia could be as misleading as faith-based ideas in political or religious communities.
Another way to evaluate the merit of ideas is by common sense rather than by the criterion of beauty. For example, it is entirely reasonable to search for technological signatures of other civilizations in the universe, given that there are sextillion (10 to the power of 21) stars in the observable universe and most of them formed billions of years before the Sun. Although common sense is often valued by the general public, it could be undervalued relative to “beauty” by scientists who argue that “extraordinary claims” require “extraordinary evidence” where the label “extraordinary” is assigned to ideas that excite the public. But is the idea that a civilization like ours exists elsewhere truly more extraordinary than the idea of Supersymmetry? In reality, the search for other technological civilizations was never funded beyond a percent of the cost of the LHC. This is awkward given that the public pays the taxes that fund science.
Actually, the situation is even more awkward. SETI scientists were engaged for seven decades in the search for technological radio signals without success. Yet, in their conferences they ban discussions on the alternative techno-signature of extraterrestrial objects near Earth, which they regard as more extraordinary than radio signals. The situation is akin to experimental physicists banning discussions on direct detection of supersymmetric particles from the sky because they focused traditionally on the alternative method of finding them through particle accelerators.
The likelihood of extraterrestrial life is increased if life could be transported between planets. The spread of biological wealth could be mediated by the exchange of rocks through a process called panspermia.
We know that Martian rocks were delivered to Earth. One of them, ALH84001, was never heated to more than 40 degrees Celsius. It could have transported microbes as tiny astronauts, billions of years before Elon Musk dreamed of traveling between these planets.
This type of panspermia is limited to the speed of rocks, which is typically less than one part in ten thousand of the speed of light. Could panspermia be accelerated to the speed of light? If we ever establish a conversation with sentient members of another civilization, we could send them the recipe for reproducing “life-as-we-know-it” out of the raw materials on their exoplanet. This would resemble explaining the recipe for a cake through a phone conversation.
As of now, we have no idea where to send the recipe and whether anyone out there would cooperate. The chances are slim that any transmission would be acted upon, given the tiny window of time that it occupies relative to the age of the Universe. Our recipe is unlikely to arrive to the right place at the right time. But even if we succeed, it would take a while before we would know it because most Milky-Way stars are at distances of tens of thousands of light years.
Technological panspermia could also be delivered by probes equipped with artificial intelligence and 3D printers. The scientific search for interstellar probes is the goal of the Galileo Project. We are currently collecting data and searching for anomalous objects near Earth.
For those who favor the scientific method over trendy fashions, I recommend the following guiding principles:
1. Follow scientific evidence by collecting data with state-of-the-art instruments that are fully under control and are well calibrated.
2. Follow the principle of the international football association FIFA: “Listen to eyewitness testimonies but use cameras to make up your mind.”
3. Follow the principle advocated by basketball coaches: “Keep your eyes on the ball, not the audience.”
4. Unfriend “pro-science” pretenders who ignore facts that disagree with their models.
5. Avoid mud wrestling because it will get you dirty.
6. Rise to the greatest heights of scientific practice, where the oxygen level is too low for your critics.
Here’s hoping that the future will promote the long-lasting value of truth over the temporary fashions of beauty. Whereas the passion for beauty is transient, the value of truth is eternal.
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 chairs the advisory board for the Breakthrough Starshot project, and 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.