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.

Continue reading “What is the Kardashev Scale?”

Could our Universe be Someone’s Chemistry Project?

This is a rendering of gas velocity in a massive galaxy cluster in IllustrisTNG. Black areas are hardly moving, and white areas are moving at greater than 1000km/second. The black areas are calm cosmic filaments, the white areas are near super-massive black holes (SMBHs). The SMBHs are blowing away the gas and preventing star formation. Image: IllustrisTNG

It is a pivotal time for astrophysicists, cosmologists, and philosophers alike. In the coming years, next-generation space and ground-based telescopes will come online that will use cutting-edge technology and machine learning to probe the deepest depths of the cosmos. What they find there, with any luck, will allow scientists to address some of the most enduring questions about the origins of life and the Universe itself.

Alas, one question that we may never be able to answer is the most pressing of all: if the Universe was conceived in a Big Bang, what was here before that? According to a new op-ed by Prof. Abraham Loeb (which recently appeared in Scientific American), the answer may be stranger than even the most “exotic” explanations. As he argued, the cosmos as we know it may be a “baby Universe” that was created by an advanced technological civilization in a lab!

Continue reading “Could our Universe be Someone’s Chemistry Project?”

China’s FAST Telescope Could Detect Self-Replicating Alien Probes

One of the most challenging questions to answer when confronting the Fermi Paradox is why exponentially scaling technologies haven’t taken over the universe by now.  Commonly known as von Neumann probes, the idea of a self-replicating swarm of extraterrestrial robots has been a staple of science fiction for decades.  But so far, there has never been any evidence of their existence outside the realm of fiction.  That might be because we haven’t spent a lot of time looking for them – and that could potentially change with the new Five-hundred-meter Aperture Spherical Radio Telescope (FAST).  According to some recent calculations, the massive new observational platform might be able to detect swarms of von Neumann probes relatively far away from the sun.

Continue reading “China’s FAST Telescope Could Detect Self-Replicating Alien Probes”

We Could Detect Extraterrestrial Satellite Megaconstellations Within a few Hundred Light-Years

A map of space debris orbiting Earth. Credit: European Space Agency

Starlink is one of the most ambitious space missions we’ve ever undertaken. The current plan is to put 12,000 communication satellites in low-Earth orbit, with the possibility of another 30,000 later. Just getting them into orbit is a huge engineering challenge, and with so many chunks of metal in orbit, some folks worry it could lead to a cascade of collisions that makes it impossible for satellites to survive. But suppose we solve these problems and Starlink is successful. What’s the next step? What if we take it further, creating a mega-constellation of satellites and space stations? What if an alien civilization has already created such a mega-constellation around their world? Could we see it from Earth?

Continue reading “We Could Detect Extraterrestrial Satellite Megaconstellations Within a few Hundred Light-Years”

Beyond “Fermi’s Paradox” VII: What it the Planetarium Hypothesis

A new study considers what life could be like for civilizations 1 trillion years from now, when every star in the Universe will expand beyond the cosmic horizon. Credit: ESO/S. Brunier

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 can’t see them because they have us all inside a massive simulation!

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. Seventy years later, we are still trying to answer that question, which has led to some interesting theories about why we haven’t. A particularly mind-bending suggestion comes in the form of the Planetarium Hypothesis!

Continue reading “Beyond “Fermi’s Paradox” VII: What it the Planetarium Hypothesis”

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.

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

How an Advanced Civilization Could Stop Dark Energy From Preventing Their Future Exploration

This illustration shows the evolution of the Universe, from the Big Bang on the left, to modern times on the right. Image: NASA

During the 1930s, astronomers came to realize that the Universe is in a state of expansion. By the 1990s, they realized that the rate at which it is expansion is accelerating, giving rise to the theory of “Dark Energy”. Because of this, it is estimated that in the next 100 billion years, all stars within the Local Group – the part of the Universe that includes a total of 54 galaxies, including the Milky Way – will expand beyond the cosmic horizon.

At this point, these stars will no longer be observable, but inaccessible – meaning that no advanced civilization will be able to harness their energy. Addressing this, Dr. Dan Hooper  – an astrophysicist from the Fermi National Accelerator Laboratory (FNAL) and the University of Chicago – recently conducted a study that indicated how a sufficiently advanced civilization might be able to harvest these stars and prevent them from expanding outward.

Continue reading “How an Advanced Civilization Could Stop Dark Energy From Preventing Their Future Exploration”

Construction Tips from a Type 2 Engineer: Collaboration with Isaac Arthur

Type 2 Civ Tips!
Type 2 Civ Tips!

By popular request, Isaac Arthur and I have teamed up again to bring you a vision of the future of human space exploration. This time, we bring you practical construction tips from a pair of Type 2 Civilization engineers.

To make this collaboration even better, we’ve teamed up with two artists, Kevin Gill and Sergio Botero. They’re going to help create some special art, just for this episode, to help show what some of these megaprojects might look like.

Continue reading “Construction Tips from a Type 2 Engineer: Collaboration with Isaac Arthur”

Maybe the Aliens Aren’t Hiding, they’re Sleeping, Waiting for the Universe to Get Better

A new study has offered a new take on the Fermi Paradox - alien civilizations are not visible to us because they are sleeping. Credit and Copyright: Kevin M. Gill

When you consider that age of the Universe – 13.8 billion years by our most recent counts –  and that which is “observable” to us measures about 93 billion light-years in diameter, you begin to wonder why we haven’t found signs of extra-terrestrial intelligence (ETI) beyond our Solar System. To paraphrase Enrico Fermi, the 20th-century physicists who advanced the famous Fermi Paradox – “where the heck are all the aliens?”

Naturally, Fermi’s Paradox has attracted a lot of theoretical explanations over the years – which include ETI being very rare, humanity being early to the Universe, and the aliens being extinct! But a new study by a team of scientists from the Future of Humanity Institute (FHI) offers a different take on this age-old paradox. According to their study, the key to answering this question is to consider the possibility that the aliens are engaged in “aestivation”.

Continue reading “Maybe the Aliens Aren’t Hiding, they’re Sleeping, Waiting for the Universe to Get Better”

Finding Alien Megastructures Around Nearby Pulsars

Artist's representation of a Dyson ring, orbiting a star at a distance of 1 AU. Credit: WIkipedia Commons/Falcorian

During the 1960s, Freeman Dyson and Nikolai Kardashev captured the imaginations of people everywhere by making some radical proposals. Whereas Dyson proposed that intelligent species could eventually create megastructures to harness the energy of their stars, Kardashev offered a three-tiered classification system for intelligent species based on their ability to harness the energy of their planet, solar system and galaxy, respectively.

Continue reading “Finding Alien Megastructures Around Nearby Pulsars”