Extraterrestrial: The First Sign of Intelligent Life Beyond Earth

by Avi Loeb

It was also at this time that I started to realize that while philosophy asked the fundamental questions, it often couldn’t resolve them.

There is so much we do not know that I often wonder whether another civilization, one that had the benefit of pursuing science for a billion years, would even consider us intelligent.

Given so many worlds—fifty billion in our own galaxy!—with similar life-friendly conditions, it’s very likely that intelligent organisms have evolved elsewhere.

Those three traits—orbit, shape, and reflectivity—do not exhaust ‘Oumuamua’s weirdness, as we know.

But they also found that the number per unit volume of interstellar material necessary to have ‘Oumuamua be a random rock requires “mass ejection rates” that far exceed expectations, up to a quadrillion (1015) ‘Oumuamua-size objects per star,

In two follow-up papers, my former collaborator Amaya Moro-Martin showed that the natural abundance of ‘Oumuamua-like objects on random orbits falls short of the required value by several orders of magnitude, even if every planetary system ejected all of the expected solid material in it.

In short, if ‘Oumuamua was a natural object, it had to have been generated by planet formation. It also has to belong to an unknown class of objects generated by planet formation whose size, shape, and composition make them deviate from a path shaped solely by our Sun’s gravity without any visible outgassing. At the time of this writing, we know of no other object that fits the second set of criteria. But we know of at least one that fits the first.

When scientists double down on supersymmetry despite the Large Hadron Collider finding no evidence for it or when they insist that the multiverse must exist despite there being no data to support the theory, they are wasting precious time and money and talent. And we have not only finite funds to spend, but finite time.

Once the universe ages by a factor of ten, all distant galaxies will be pulled away from us faster than the speed of light, and humanity will be able to observe only the stars in our own galaxy.

We date the birth of the universe, the Big Bang, to some 13.8 billion years ago.

Earth is only about 4.5 billion years old and that we believe the planet has supported life for only 3.8 billion of those years.

Even though life as we know it and life as we do not know it may exist on numerous other planets, it is most likely that we will encounter relics of extraterrestrial technologies before establishing contact with any living civilization.

After the Big Bang, hydrogen was the most abundant element in the universe by a wide margin; the early universe was about 92 percent hydrogen atoms and 8 percent helium atoms.

Frank Drake, whose famous equation quantifies our chances of detecting a light signal from an advanced civilization in space—is that most of the technological civilizations that ever existed might now be dead.

The very moment when a civilization reaches our stage of technological advancement—the window where it can signal its existence to the rest of the universe and begin to send craft to other stars—is also the moment when its technological maturity becomes sufficient for its own destruction, whether through climate change or nuclear, biological, or chemical wars.

It is quite conceivable that if we are not careful, our civilization’s next few centuries will be its last.

Of all the lessons we can learn from ‘Oumuamua, the most essential might be that we cannot allow the smaller filters of war and environmental degradation to grow into a great filter.

What if in the 1940s humanity had instead spent that $1.3 trillion—not to mention the skill, expertise, muscle, and minds of between forty and one hundred million people—on the exploration of the universe?

We are greatly in need of a new branch of astronomy, what I have termed space archaeology.

First, the Sun’s mass—330,000 times that of Earth—makes it more massive than 95 percent of all known stars.

Identifying planets at the Goldilocks distance from a star, that zone in which water neither freezes nor evaporates, is the astro-archaeologist’s starting point in the hunt for alien civilizations.

that about a quarter of all stars are orbited by planets of Earth’s size and surface temperature, planets that might have liquid water—and the building blocks of the chemistry of life—on their surfaces.

Of course, the coordination of effort required to present the universe with a more nuanced, uniform message from human civilization presupposes a civilization capable of unity.

The history of the universe indicates a trend toward extinction—of stars, of planets, of solar systems, and, perhaps, of the universe as we know it.

Youth is a matter not of biological age but of attitude.

But the moment we know that we are not alone, that we are almost certainly not the most advanced civilization ever to have existed in the cosmos, we will realize that we’ve spent more funds developing the means to destroy all life on the planet than it would have cost to try to preserve it.

Currently, we keep all our eggs in one basket—the Earth. As a result, humanity and our civilization are extremely vulnerable to catastrophe. By spreading multiple copies of our genetic material through the universe, we could guard against that risk.

“In the sciences, the authority of a thousand is not worth as much as the humble reasoning of a single individual.”

Then, too, scientists owe the public—literally. We are funded by the public.

Just like the biblical story of Saul finding his kingdom by chance while searching for his father’s lost donkeys, Paul and I stumbled on an unexpected insight while pursuing a completely different goal. By aiming to better understand black holes, we uncovered a mechanism for explaining our accelerating universe.