Why SETI might be our most humbling science | Jill Tarter: Full Interview
Quick Read
Summary
Takeaways
- ❖SETI's mission is to detect technosignatures, not "intelligence," focusing on signals nature can't produce (e.g., narrow-band radio, nanosecond optical pulses).
- ❖The discovery of thousands of exoplanets and extremophiles has made the universe appear "bio-friendly," transforming the search for life into a scientific imperative.
- ❖A successful SETI detection would offer statistical proof that long-lived technological civilizations are possible, providing inspiration for humanity's future.
- ❖SETI encourages a "cosmic perspective," shifting human identity from national to "earthling," which is crucial for addressing global challenges.
- ❖Future SETI will leverage AI for bias-free pattern recognition in vast datasets and utilize next-generation telescopes like the Square Kilometre Array.
- ❖Jill Tarter was a partial inspiration for Ellie Arroway in Carl Sagan's "Contact," reflecting her prototypical journey as a woman in STEM.
Insights
1Evolution of SETI's Scientific Basis
The field of SETI has transitioned from a speculative belief system to a rigorous scientific exploration, largely due to the discovery of exoplanets and extremophiles, which demonstrate the universe's potential for life. This shift makes the question "are we alone?" an empirically answerable one.
Over my career, I've been able to watch the universe appear to become more bio-friendly... now we know that in the Milky Way Galaxy, there are more planets than there are stars. And additionally, we now know about organisms that we call extremophiles... two big game changers. We've gone from belief to scientific exploration over the past 400... and I think that's the right trajectory.
2SETI's Focus on Technosignatures, Not Intelligence
SETI specifically searches for "technosignatures"—evidence of technology that nature cannot produce—rather than attempting to define or detect "intelligence" directly. This involves looking for highly compressed signals in frequency (radio) or time (optical) that indicate artificial origin.
We don't know how to define intelligence. We certainly don't know how to detect it at a distance. What we can perhaps do is find evidence of someone else's technology... So we should actually call it SETT. We're specifically looking for the kinds of signals that as far as we know, nature can't produce, but our technologies do it all the time.
3AI's Role in Future SETI
Artificial intelligence and machine learning are poised to revolutionize SETI by enabling bias-free pattern recognition in vast datasets, moving beyond pre-defined signal types to detect "any pattern" indicative of non-natural origins.
Now we're on a threshold where we can begin to think about using artificial intelligence to help us with this search... now we wanna use machine intelligence to look at the data in a bias-free way and say, not is there this pattern, but is there any pattern? Is there anything other than noise in these data?
4The "Long Future" Imperative
A successful SETI detection would provide crucial statistical evidence that it is possible for technological civilizations to achieve a long, sustainable future, offering inspiration and hope for humanity to overcome its current global challenges.
The real reason to work on this question is to know whether it's possible for us to have a long future... if we detect a signal, then we know it is possible to have a long future... a successful detection means that it's possible to have a long future as a technological civilization.
Bottom Line
Advanced extraterrestrial civilizations might geo-engineer planets within their systems, making them appear unnaturally uniform or altered in ways detectable by future imaging telescopes.
This suggests a novel technosignature beyond traditional radio or optical signals, expanding the search parameters for life.
Future large-scale optical and infrared telescopes (30-meter class) could serendipitously detect such planetary modifications, opening new avenues for SETI.
Humanity is "too young" to broadcast signals into space; broadcasting requires a commitment to transmit continuously for cosmic timescales, implying a stable, long-lived civilization.
Premature or short-term broadcasting is ineffective and potentially unwise, suggesting a focus on listening until humanity achieves greater stability.
This perspective frames broadcasting as a long-term goal for a mature civilization, guiding future policy on interstellar communication.
Key Concepts
Cosmic Perspective
Viewing humanity from an extraterrestrial viewpoint (as "earthlings" on a single planet) can foster unity and motivate global solutions to shared challenges, moving beyond national boundaries.
Technological Adolescence
The concept that a civilization must outgrow aggressive, self-destructive behaviors (its "technological adolescence") to achieve a long, stable future, implying that any detectable advanced civilization would likely be "kinder and gentler."
Lessons
- Cultivate a "cosmic perspective" to foster global unity and address shared planetary challenges, recognizing humanity's common identity as "earthlings."
- Support long-term scientific endeavors like SETI, understanding that their success may span generations and require stable funding, but offer profound insights into humanity's potential future.
- Approach unexplained phenomena (like UFOs) with scientific skepticism and a demand for verifiable data, rather than immediate conclusions about extraterrestrial origins.
Notable Moments
Jill Tarter's scholarship was revoked by Procter & Gamble in her junior year of engineering at Cornell because she planned to marry, with the company stating she wasn't "serious" about a scientific career and would "just go be a housewife."
This highlights the significant gender discrimination faced by women in STEM fields in the past, and Dean Dale Corson's intervention demonstrates the importance of supportive mentors in overcoming such barriers.
Tarter recounts a personal "UFO experience" while flying with her husband, where they saw a bright, unidentifiable light that ground control couldn't detect on radar. It was later explained as the moon shining through a hole in the clouds.
This anecdote illustrates the psychological impact of unexplained phenomena and reinforces the scientific principle of seeking evidence and explanations before attributing events to extraordinary causes, even for a seasoned SETI researcher.
Tarter describes a "false positive" SETI detection where a strong, artificial-looking signal appeared to come from a star but disappeared when the telescope moved. It was eventually traced to the SOHO spacecraft entering a weak side lobe of the telescope.
This demonstrates the rigorous process of verifying potential extraterrestrial signals and the constant challenge of distinguishing between terrestrial interference and genuine technosignatures, emphasizing the need for robust verification methods like multiple telescopes.
Quotes
"If you're willing to work really hard, then you can do anything you wanna do."
"We've gone from belief to scientific exploration over the past 400 or actually much longer ago in terms of asking the question. And I think that's the right trajectory."
"On a finite world, a cosmic perspective is a necessity and not a luxury."
"If you're going to broadcast, you need to start and not stop."
Q&A
Recent Questions
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