ADVERTISEMENT

Scientists use this formula, called the Drake equation, to explore the chance we'll make contact with intelligent aliens

Nearly half of Americans believe aliens have visited Earth, but there may be a roughly 38% chance humans are alone in the universe. That conclusion is based on research using the Drake equation: a formula with seven variables that explores the chance detectable extraterrestrial civilizations exist.

  • Nearly half of Americans believe
  • The
  • While some predictions that use the equation are optimistic, a comprehensive new study suggests a strong likelihood that we're alone in the
  • There's also a roughly 38% chance that humans are completely alone in the
ADVERTISEMENT

A majority Americans believe in UFOs and just under half think extraterrestrial beings have visited Earth, according to a 2015 poll of about 1,000 adults in the US.

Though people in the US can barely pass a basic science quiz created by the government, it's tempting to climb aboard the extraterrestrial train: There are hundreds of billions of galaxies in the visible universe, hundreds of billions of stars per galaxy, and untold numbers of planets around each star. It's easy to imagine that alien life, perhaps an intelligent kind, is out there somewhere.

But scientists aren't sure one way or the other.

ADVERTISEMENT

Their go-to expression for this alluring possibility — and deep-seated doubt — is the Drake equation.

Astrophysicist Frank Drake drew up the famous formula on a chalkboard in 1961. This was at the dawn of a worldwide search for extraterrestrial intelligence (SETI), and his thinking continues to influence the use of astronomical observatories to this day.

The equation is more of an argument wrapped in seven variables. Multiplied together, these variables yield a calculation of the possibility that humanity might someday hear from an intelligent civilization.

"Although there is no unique solution to this equation, it is a generally accepted tool used by the scientific community to examine these factors," the SETI Institute says of the Drake equation.

ADVERTISEMENT

The first letter of the Drake equation, on the far left, is "N." It represents the number of intelligent alien races within the Milky Way that could be broadcasting signals detectable to Earth.

As you move right in the equation, the variables grow increasingly difficult to estimate.

The SETI Institute defines the seven variables in this way:

Scientists have a good handle on the first two variables, R and f, and are increasingly certain about the third, n.

ADVERTISEMENT

However, the other variables farther to the right all deal with the bold hypothetical of life actually existing elsewhere in the universe. This is something we have no definitive proof of — not even for a bacterium.

As a result, all solutions to the Drake equation are enormously uncertain.

Scientists' uncertainty about intelligent alien life is illustrated by their extraordinary variety of solutions to the Drake equation.

In a draft study posted online in June, three researchers at Oxford University's Future of Humanity Institute looked at all the studies they could find that touched on Drake equation variables. Then they crunched some numbers.

ADVERTISEMENT

The researchers found that about two thirds of studies guess that some 100 advanced alien civilizations might exist in the Milky Way galaxy.

However, the highest estimates come in at 100 million civilizations per galaxy, and the lowest guesses are as low three civilizations per 10,000 Milky-Way-like galaxies. That is a 100-billion-fold difference in predicted abundances of intelligent, communicating beings.

"It is common to see carefully estimated astrophysical numbers multiplied by these ad hoc guesses," the authors wrote. "It has been noted that the final results seem to depend heavily on the pessimism or optimism of the authors."

In hopes of better lessening that uncertainty, the Oxford researchers — Anders Sandberg, Eric Drexler, and Toby Ord — reformulated each Drake equation variable as a range of uncertainties. Their work produced a bell-curve-like distribution of results. And they were bleak.

The average probability (toward the middle of the curve) that we're alone in the Milky Way came to about 52%, with a 38% average chance that we're alone in the entire observable universe.

ADVERTISEMENT

Even the most optimistic, better-than-average values were depressing: The authors calculated that there's a 41% chance we're alone in the galaxy and a 32% chance we're alone in the visible universe.

"We find a substantial probability that we are alone in our galaxy, and perhaps even in our observable universe," they said.

So the next time you gaze at the stars and wonder if aliens are out there waiting to be found, flip a coin. That may be our best representation of the chances we're alone — and perhaps all the more reason to seed the cosmos with human life.

FOLLOW BUSINESS INSIDER AFRICA

Unblock notifications in browser settings.
ADVERTISEMENT

Recommended articles

10 most dangerous African countries in 2024

10 most dangerous African countries in 2024

Russia’s nuclear influence expands further north of Africa

Russia’s nuclear influence expands further north of Africa

Navigating the future: How AI transforms selling on Amazon

Navigating the future: How AI transforms selling on Amazon

Wall decor tips: Transforming your space with style and creativity

Wall decor tips: Transforming your space with style and creativity

Putin's African diplomacy: Security talks with West, Central Africa take centre stage

Putin's African diplomacy: Security talks with West, Central Africa take centre stage

Infinix users get over 35% exclusive discount on Showmax premier league & general entertainment subscription

Infinix users get over 35% exclusive discount on Showmax premier league & general entertainment subscription

10 longest bridges in Africa

10 longest bridges in Africa

India issues free heart surgeries to 150 Ugandan children

India issues free heart surgeries to 150 Ugandan children

Ethiopians voluntarily give back 80% of the money they had illegally taken

Ethiopians voluntarily give back 80% of the money they had illegally taken

ADVERTISEMENT