ETI Archives

October 5, 2022October 5, 2022 by Evan Gough

How Should the World’s Governments Respond if We Detect an Alien Civilization?

The Search for Extraterrestrial Intelligence. Image Credit: SETI

Science fiction is the realm where people traditionally wrestle with the idea of contact with an ETI (Extraterrestrial Intelligence.) But now, those discussions are migrating from science fiction into more serious realms. Academics are going back and forth, one paper at a time, concerning the response and geopolitical fallout from potential contact with an ETI.

The discussion is interesting whether you think it’s likely or even remotely possible that humanity ever contacts an ETI. And it might tell us more about humanity than it does about an ETI.

March 20, 2022March 20, 2022 by Matt Williams

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.

March 12, 2022December 24, 2023 by Matt Williams

What is the Kardashev Scale?

Nikolai Kardashev (1932-2019), Credit: IAU

Are we alone in the Universe? Could there be countless sentient life forms out there just waiting to be found? Will we meet them someday and be able to exchange knowledge? Will we even recognize them as intelligent life forms if/when we meet them, and them us? When it comes to astrobiology, the search for life in the Universe, we don’t know what to expect. Hence why all the speculation and theoretical studies into these questions are so rich and varied!

One such study was conducted by famed Soviet and Russian astrophysicist and radio astronomer Nikolai Kardashev (1932 – 2019). While considering an important question related to the Search for Extraterrestrial Intelligence (SETI) in 1964, Kardashev proposed a classification scheme for ranking a civilization’s development. This would come to be known as the Kardashev Scale, which remains one of the most influential concepts in SETI to this day.

August 10, 2021August 11, 2021 by Matt Williams

We’ll Have to Wait About 3,000 Years for a Reply From Intelligent Civilizations

Artist’s impression of CSIRO’s Australian SKA Pathfinder (ASKAP) radio telescope finding a fast radio burst and determining its precise location. The KECK, VLT and Gemini South optical telescopes joined ASKAP with follow-up observations to image the host galaxy. Credit: CSIRO/Dr Andrew Howells

As a field, the Search for Extraterrestrial Intelligence suffers from some rather significant constraints. Aside from the uncertainty involved (e.g., is there life beyond Earth we can actually communicate with?), there are the limitations imposed by technology and the very nature of space and time. For instance, scientists are forced to contend with the possibility that by the time a message is received by an intelligent species, the civilization that sent it will be long dead.

Harvard astronomers Amir Siraj and Abraham Loeb tackle this very question in a new study that recently appeared online. Taking their cue from the Copernican Principle, which states that humanity and Earth are representative of the norm (and not an outlier), they calculated that if any transmissions from Earth were heard by an extraterrestrial technological civilization (ETC), it would take about 3000 years to get a reply.

April 28, 2021April 28, 2021 by Matt Williams

We Could Detect Alien Civilizations Through Their Interstellar Quantum Communication

The Parkes radio telescope at Parkes Observatory in New South Wales, Australia. Astronomers using the telescope detected what appeared to be a radio signal coming from the direction of Proxima Centauri in April and May 2019. Image via Daniel John Reardon/ Wikimedia Commons.

Since the mid-20th century, scientists have been looking for evidence of intelligent life beyond our Solar System. For much of that time, scientists who are engaged in the search for extraterrestrial intelligence (SETI) have relied on radio astronomy surveys to search for signs of technological activity (aka. “technosignatures“). With 4,375 exoplanets confirmed (and counting!) even greater efforts are expected to happen in the near future.

In anticipation of these efforts, researchers have been considering other possible technosignatures that we should be on the lookout for. According to Michael Hippke, a visiting scholar at the UC Berkeley SETI Research Center, the search should also be expanded to include quantum communication. In an age where quantum computing and related technologies are nearing fruition, it makes sense to look for signs of them elsewhere.

January 17, 2021January 17, 2021 by Matt Williams

According to the Math, it’s Highly Unlikely That an Intelligent Civilization is Located at Alpha Centauri

In December of 2020, the world got a bit of a pre-holiday surprise when it was announced that astronomers at the Parkes radio telescope in Australia had detected a “tantalizing” signal coming from Proxima Centauri (the red dwarf companion of the Alpha Centauri system). Afterward, researchers at Breakthrough Listen consulted the data on the signal – Breakthrough Listen Candidate 1 (BLC1) – and noted the same curious features.

However, the scientific community has since announced that the signal is unlikely to be anything other than the result of natural phenomena. This was also the conclusion reached by Amir Siraj and Prof. Abraham Loeb of Harvard University after they conducted a probability assessment on BLC1. Like the vast majority of candidate radio signals discovered to date, this one appears to be just the forces of nature saying hello.

January 7, 2021February 7, 2022 by Matt Williams

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.

December 25, 2020August 22, 2024 by Matt Williams

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

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

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.

August 7, 2020February 7, 2022 by Matt Williams

Beyond “Fermi’s Paradox” V: What is the Aestivation Hypothesis?

An illustration of cosmic expansion. Credit: NASA's Goddard Space Flight Center Conceptual Image Lab

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 we’re not hearing from aliens is that they’re asleep and waiting for the Universe to get better.

This became the basis of the Fermi Paradox, which refers to the high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. But despite seventy years of looking, we still haven’t been able to answer Fermi’s question, leading to multiple proposals as to why this is. Today, we look at the “Aestivation Hypothesis,” which argues that aliens are not dead (or non-existent), they’re just resting!

March 10, 2020March 10, 2020 by Matt Williams

Seti@home is on Pause. Unfortunately, it’s not Because They’ve Discovered Aliens

A home PC running SETI at Home helping to churn through observational data Credit: SETI@home

In May of 1999, the Berkeley SETI Research Center launched a citizen-science program that would make the Search for Extra-Terrestrial Intelligence (SETI) open to the public. The brainchild of computer scientist David Gedye, this program would rely on large numbers of internet-connected computers to sort through the volumes of data collected by institutions participating in SETI efforts.

The program was appropriately named SETI@home and would rely on the computers of volunteers to process radio signals for signs of transmissions. And after twenty years, the program recently announced that it has gone into hibernation. The reason, they claim, is that the program’s network has become too big for its own britches and the scientists behind it need time to process and share all the results they’ve obtained so far.