Robin Hanson Archives

August 7, 2024August 9, 2024 by Matt Williams

New Study Suggests that Our Galaxy is Crowded or Empty. Both are Equally Terrifying!

Gaia's all-sky view of our Milky Way Galaxy and neighbouring galaxies, based on measurements of nearly 1.7 billion stars. The map shows the total brightness and colour of stars observed by the ESA satellite in each portion of the sky between July 2014 and May 2016. Brighter regions indicate denser concentrations of especially bright stars, while darker regions correspond to patches of the sky where fewer bright stars are observed. The colour representation is obtained by combining the total amount of light with the amount of blue and red light recorded by Gaia in each patch of the sky. The bright horizontal structure that dominates the image is the Galactic plane, the flattened disc that hosts most of the stars in our home Galaxy. In the middle of the image, the Galactic centre appears vivid and teeming with stars. More information on: http://sci.esa.int/gaia/60169-gaia-s-sky-in-colour/

Is there intelligent life in the Universe? And if so, just how common is it? Or perhaps the question should be, what are the odds that those engaged in the Search for Extraterrestrial Intelligence (SETI) will encounter it someday? For decades, scientists have hotly debated this topic, and no shortage of ink has been spilled on the subject. From the many papers and studies that have been written on the subject, two main camps have emerged: those who believe life is common in our galaxy (aka. SETI Optimists) and those who maintain that extraterrestrial intelligence is either rare or non-existent (SETI Pessimists).

In a recent paper, David Kipping (Prof. “Cool Worlds” himself) and Geraint Lewis examined this debate more closely and offered a fresh take based on a form of probability analysis known as Jayne’s Experiment. By applying this method to astrobiology and the Drake Equation, they concluded that the existence of intelligent life in our galaxy may be an “all or nothing” proposition. To quote the late and great scientist and science fiction author Arthur C. Clarke: “Two possibilities exist: either we are alone in the Universe, or we are not. Both are equally terrifying.”

August 11, 2021August 11, 2021 by Matt Williams

Avoiding the Great Filter. How Long Until We’re Living Across the Solar System?

An edge-on view of a spiral galaxy. Credit: ESO

If you’re a fan of the Search for Extraterrestrial Intelligence (SETI) and the Fermi Paradox, then it’s likely you’ve heard of a concept known as the Great Filter. In brief, it states that life in the Universe may be doomed to extinction, either as a result of cataclysmic events or due to circumstances of its own making (i.e., nuclear war, climate change, etc.) In recent years, it has been the subject of a lot of talk and speculation, and not just in academic circles.

Stephen Hawking and Elon Musk have also weighed in on the issue, claiming that humanity’s only chance at long-term survival is to become “interplanetary.” Addressing this very possibility, a research team led by NASA’s Jet Propulsion Laboratory (JPL) recently created a timeline for potential human expansion beyond Earth. According to their findings, we have the potential of going interplanetary by the end of the century and intragalactic by the end of the 24th!

July 23, 2020February 7, 2022 by Matt Williams

Beyond “Fermi’s Paradox” III: What is the Great Filter?

The Karl Jansky Very Large Array at night, with the Milky Way visible in the sky. Credit: NRAO/AUI/NSF; J. Hellerman

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 there is something in the Universe that prevents life from reaching the point where we would be able to hear from it.

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 high probability estimates for the existence of extraterrestrial intelligence (ETI) and the apparent lack of evidence. Seventy years later, we still haven’t answered that question, which has led to many theories as to why the “Great Silence” endures. A popular one is that there must be “Great Filter” that prevents life from reaching an advanced stage of development.