The Drake Equation: A Stoner’s Guide to Alien Theory

Smoking a bowl of weed at night, gazing at the stars, have you ever wondered the theory of alien life being out there somewhere? Well, you’re not alone. In fact, scientists have been trying to answer this question for decades, and one of the most well-known methods for estimating the likelihood of extraterrestrial civilizations is the Drake Equation.

But what exactly is the Drake Equation, and how does it work? Keep reading, my fellow stoners, and we’ll dive into the theory behind this famous equation.

What Is the Drake Equation?

The Drake Equation is a mathematical formula that was developed in the 1960s by astronomer Frank Drake. It’s used to estimate the number of civilizations in the Milky Way galaxy that might be capable of communicating with us.

The equation is written as:

N = R* • fp • ne • fl • fi • fc • L

where:

• N represents the number of civilizations that might be able to communicate in the Milky Way galaxy (i.e. the number we’re trying to estimate).
• R* is the star formation rate in the Milky Way galaxy.
• fp represents the fraction of stars with planets.
• ne is number of planets that are in the “habitable zone” (i.e. the distance from the star at which liquid water would be able to exist on the surface of the planet).
• fl is the fraction of habitable planets that develop life.
• fi is the fraction of those planets with life that develop intelligent life.
• fc is the fraction of intelligent civilizations that develop the technology for interstellar communication.
• L is the average lifetime of a communicating civilization.

Let’s break down each of these variables and see how they contribute to the final estimate of N.

R* – The Rate of Star Formation in the Milky Way Galaxy

In the equation, the first term represents the average rate of star formation in the Milky Way galaxy. This is an important factor because, if there are a lot of stars being formed, there’s a greater chance that some of them will have planets that could potentially support life.

To estimate the value of R*, scientists look at data on the number of stars that have been formed in the past, as well as current rates of star formation. Based on this information, it’s estimated that there are about 10 new stars being formed in the Milky Way galaxy every year.

fp – The Fraction of Stars With Alien Planets

The next term in the equation is the fraction of stars that have planets. This is an important factor because, if a star doesn’t have any planets, then there’s no chance for life to develop.

Thanks to advances in technology, scientists have been able to discover thousands of exoplanets (planets outside our solar system) in recent years. Based on this data, it’s estimated that about 1/3 of all stars have planets.

ne – The Number of Habitable Planets Per Star

The third term in the equation is the number of planets per star that are in the habitable zone. This is the range of distances from a star where liquid water is likely to exist on the surface of a planet.

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To estimate the value of ne, scientists use data on the characteristics of exoplanets that have been discovered, as well as models of how planetary systems form. Based on this information, it’s estimated that there are about 2.2 wearable planets per star on average.

fl – The Fraction of Viable Planets That Develop Life

In the equation, the fourth term represents the fraction of habitable planets that develop life. This is an important factor because, even if a planet is in the habitable zone, it doesn’t necessarily mean that life will emerge.

To estimate the value of fl, scientists look at data on the conditions that are thought to be necessary for life to emerge, such as the presence of water and certain chemical elements. Based on this information, it’s estimated that about 1/4 of habitable planets will develop life.

fi – The Fraction of Planets With Life That Develop Intelligent Alien Life

The fifth term in the equation is the fraction of planets with life that eventually develop intelligent life. This is an important factor because, even if life exists on a planet, it doesn’t necessarily mean that it will evolve to the point of becoming intelligent.

To estimate the value of fi, scientists look at data on the evolution of life on Earth and try to understand what factors might have contributed to the development of intelligence. Based on this information, it’s estimated that about 1/100,000 of planets with life will develop intelligent life.

fc – The Fraction of Intelligent Alien Civilizations That Develop Interstellar Communication

The sixth term in the equation is the fraction of intelligent civilizations that develop the technology for interstellar communication. This is an important factor because, even if an intelligent civilization exists, it doesn’t necessarily mean that it will have the means to communicate with other civilizations.

To estimate the value of fc, scientists look at data on the development of communication technology on Earth and try to understand what factors might have contributed to its advancement. Based on this information, it’s estimated that about 1/10 of intelligent civilizations will develop the technology for interstellar communication.

L – The Average Lifetime of a Communicating Alien Civilization

The final term in the equation is the average lifetime of a communicating civilization. This is an important factor because, even if an intelligent civilization exists and has the means to communicate with other civilizations, it doesn’t necessarily mean that it will last forever.

To estimate the value of L, scientists look at data on the lifespans of civilizations on Earth and try to understand what factors might have contributed to their longevity (or lack thereof). Based on this information, it’s estimated that the average lifetime of a communicating civilization is about 10,000 years.

Putting It All Together: The Final Estimate of N

Now that we’ve broken down each of the variables in the Drake Equation, let’s put it all back together and see what the final estimate of N is.

Using the estimated values for each of the variables, we can calculate the number of civilizations with which communication may be possible in the Milky Way galaxy.

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Plugging in the values, we get:

N = 10 • (1/3) • 2.2 • (1/4) • (1/100,000) • (1/10) • 10,000

which simplifies to:

N = 22

So, according to the Drake Equation, there might be about 22 civilizations in the Milky Way galaxy with which communication might be possible.

It’s important to remember that these estimates are just that – estimates. The values for each of the variables are based on current data and our best understanding of how the universe works, but they are subject to change as we learn more.

Conclusion

The Drake Equation is a powerful tool for estimating the likelihood of extraterrestrial civilizations in the Milky Way galaxy. By considering factors such as the rate of star formation, the number of stars with planets, and the average lifetime of a communicating civilization, scientists are able to make educated guesses about the number of civilizations that might be out there.

While the final estimate of N according to the Drake Equation is just an estimate, it helps to illustrate the complex factors that go into determining if we’re alone in the universe. And who knows – as we continue to learn more about the universe and develop new technologies, we might one day be able to communicate with these hypothetical extraterrestrial civilizations.

Until then, keep looking up at the stars and wondering – you never know what you might find out there.