Why Don't We See Robotic Civilizations Rapidly Expanding Across the Universe?

The central region of the Milky Way, also known as the Zone of Avoidance. Credit: ESO/S. Brunier

In 1950, while sitting down to lunch with colleagues at the Los Alamos Laboratory, famed physicist and nuclear scientist Enrico Fermi asked his famous question: “Where is Everybody?” In short, Fermi was addressing the all-important question that has plagued human minds since they first realized planet Earth was merely a speck in an infinite Universe. Given the size and age of the Universe and the way the ingredients for life are seemingly everywhere in abundance, why haven’t we found any evidence of intelligent life beyond Earth?

This question has spawned countless proposed resolutions since Fermi’s time, including the infamous Hart-Tipler Conjecture (i.e., they don’t exist). Other interpretations emphasize how space travel is hard and extremely time and energy-consuming, which is why species are likely to settle in clusters (rather than a galactic empire) and how we are more likely to find examples of their technology (probes and AI) rather than a species itself. In a recent study, mathematician Daniel Vallstrom examined how artificial intelligence might be similarly motivated to avoid spreading across the galaxy, thus explaining why we haven’t seen them either!

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Maybe We Don’t Hear From Aliens Because They Choose To Go Silent

Artist impression of an alien civilization. Image credit: CfA

How will humanity meet its end?

That’s only a depressing question if you think that humanity will go on forever. Alas, nothing lasts forever, and if something could last forever, it probably wouldn’t be our struggling primate species.

But we’ll likely be around for a while yet, pondering things as we do. One of the things we love to ponder is: why don’t we hear from any other alien civilizations?

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If Aliens Were Sending us Signals, This is What They Might Look Like

For over sixty years, scientists have been searching the cosmos for possible signs of radio transmission that would indicate the existence of extraterrestrial intelligence (ETI). In that time, the technology and methods have matured considerably, but the greatest challenges remain. In addition to having never detected a radio signal of extraterrestrial origin, there is a wide range of possible forms that such a broadcast could take.

In short, SETI researchers must assume what a signal would look like, but without the benefit of any known examples. Recently, an international team led by the University of California Berkeley and the SETI Institute developed a new machine learning tool that simulates what a message from extraterrestrial intelligence (ETI) might look like. It’s known as Setigen, an open-source library that could be a game-changer for future SETI research!

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Why Would an Alien Civilization Send Out Von Neumann Probes? Lots of Reasons, says a new Study

Artist's concept of the New Horizons spacecraft encountering a Kuiper Belt object, part of an extended mission after the spacecraft’s July 2015 Pluto flyby. Credits: NASA/JHUAPL/SwRI

In 1948-49, mathematician, physicist, computer scientist, and engineer John von Neumann introduced the world to his idea of “Universal Assemblers,” a species of self-replicating robots. Von Neumann’s ideas and notes were later compiled in a book titled “Theory of self-reproducing automata,” published in 1966 (after his death). In time, this theory would have implications for the Search for Extraterrestrial Intelligence (SETI), with theorists stating that advanced intelligence must have deployed such probes already.

The reasons and technical challenges of taking the self-replicating probe route are explored in a recent paper by Gregory L. Matloff, an associate professor at the New York City College of Technology (NYCCT). In addition to exploring why an advanced species would opt to explore the galaxy using Von Neumann probes (which could include us someday), he explored possible methods for interstellar travel, strategies for exploration, and where these probes might be found.

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If Alien Probes are Already in the Solar System, Maybe we Could Detect Them Calling Home

Artist's impression of the Milky Way Galaxy. Credit: ESO

It’s been seventy years since physicist Enrico Fermi asked his famous question: “Where is everybody?” And yet, the tyranny of the Fermi Paradox is still with us and will continue to be until definitive evidence of Extraterrestrial Intelligence (ETI) is found. In the meantime, scientists are forced to speculate as to why we haven’t found any yet and (more importantly) what we should be looking for. By focusing our search efforts, it is hoped that we may finally determine that we are not alone in the Universe.

In a recent study, two researchers from the University of Liège and the Massachusetts Institute of Technology (MIT) recommended that we look for evidence of transmissions from our Solar System. Based on the theory that ETIs exist and have already established a communications network in our galaxy, the team identified Wolf 359 as the best place to look for possible interstellar communications from an alien probe.

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Beyond “Fermi’s Paradox” XVII: What is the “SETI-Paradox” Hypothesis?

The Arecibo Radio Telescope in Puerto Rico was the site of NASA's High Resolution Microwave Survey, a search for extraterrestrial radio messages. Credit: Unites States National Science Foundation

Welcome back to our Fermi Paradox series, where we take a look at possible resolutions to Enrico Fermi’s famous question, “Where Is Everybody?” Today, we examine the possibility that we haven’t heard from any aliens is because no one is transmitting!

In 1950, Italian-American physicist Enrico Fermi sat down to lunch with some of his colleagues at the Los Alamos National Laboratory, where he had worked five years prior as part of the Manhattan Project. According to various accounts, the conversation turned to aliens and the recent spate of UFOs. Into this, Fermi issued a statement that would go down in the annals of history: “Where is everybody?”

This became the basis of the Fermi Paradox, which refers to the disparity between high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Since Fermi’s time, there have been several proposed resolutions to his question, including the possibility that everyone is listening, but no one is broadcasting – otherwise known as the “SETI-Paradox.”

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If Aliens Are Out There, We’ll Meet Them in a Few Hundred Million Years

An artist's conception of how common exoplanets are throughout the Milky Way Galaxy. Image Credit: Wikipedia

Seventy years ago, Italian-American nuclear physicist Enrico Fermi asked his colleagues a question during a lunchtime conversation. If life is common in our Universe, why can’t we see any evidence of its activity out there (aka. “where is everybody?”) Seventy years later, this question has launched just as many proposed resolutions as to how extraterrestrial intelligence (ETIs) could be common, yet go unnoticed by our instruments.

Some possibilities that have been considered are that humanity might be alone in the Universe, early to the party, or is not in a position to notice any yet. But in a recent study, Robin Hanson (creator of the Great Filter) and an interdisciplinary team offer a new model for determining when the aliens will get here. According to their study, humanity is early to the Universe and will meet others in 200 million to 2 billion years from now.

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Beyond “Fermi’s Paradox” XVI: What is the “Dark Forest” Hypothesis?

The Full Moon at 10:30 p.m. last night (Aug. 30). Even at 25 altitude, it glowed a deep, dark orange due to heavy smoke from western forest fires. Credit: Bob King

Welcome back to our Fermi Paradox series, where we take a look at possible resolutions to Enrico Fermi’s famous question, “Where Is Everybody?” Today, we examine the possibility that Earth hasn’t been visited by aliens because interstellar travel is not very practical!

In 1950, Italian-American physicist Enrico Fermi sat down to lunch with some of his colleagues at the Los Alamos National Laboratory, where he had worked five years prior as part of the Manhattan Project. According to various accounts, the conversation turned to aliens and the recent spate of UFOs. Into this, Fermi issued a statement that would go down in the annals of history: “Where is everybody?

This became the basis of the Fermi Paradox, which refers to the disparity between high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Since Fermi’s time, there have been several proposed resolutions to his question, which includes the Dark Forest Hypothesis, where extraterrestrial civilizations are deliberately avoiding contact.

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Beyond “Fermi’s Paradox” XV: What is the Percolation Theory Hypothesis?

Artist's impression of the Milky Way Galaxy. Credit: ESO

Welcome back to our Fermi Paradox series, where we take a look at possible resolutions to Enrico Fermi’s famous question, “Where Is Everybody?” Today, we examine the possibility that Earth hasn’t been visited by aliens because interstellar travel is not very practical!

In 1950, Italian-American physicist Enrico Fermi sat down to lunch with some of his colleagues at the Los Alamos National Laboratory, where he had worked five years prior as part of the Manhattan Project. According to various accounts, the conversation turned to aliens and the recent spate of UFOs. Into this, Fermi issued a statement that would go down in the annals of history: “Where is everybody?

This became the basis of the Fermi Paradox, which refers to the disparity between high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Since Fermi’s time, there have been several proposed resolutions to his question, which includes the very real possibility that interstellar colonization follows the basic rule of Percolation Theory.

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Beyond “Fermi’s Paradox” XIV: What is the Aurora Hypothesis?

Credit and Copyright: Stefan Payne-Wardenaar; Magellanic Clouds: Robert Gendler/ESO

Welcome back to our Fermi Paradox series, where we take a look at possible resolutions to Enrico Fermi’s famous question, “Where Is Everybody?” Today, we examine the possibility that the reason for the Great Silence is that colonizing other star systems is hazardous to our health!

In 1950, Italian-American physicist Enrico Fermi sat down to lunch with some of his colleagues at the Los Alamos National Laboratory, where he had worked five years prior as part of the Manhattan Project. According to various accounts, the conversation turned to aliens and the recent spate of UFOs. Into this, Fermi issued a statement that would go down in the annals of history: “Where is everybody?

This became the basis of the Fermi Paradox, which refers to the disparity between high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Since Fermi’s time, there have been several proposed resolutions to his question, which includes the Aurora Hypothesis that states that just because planets are habitable doesn’t mean that intelligent life can colonize there.

Continue reading “Beyond “Fermi’s Paradox” XIV: What is the Aurora Hypothesis?”