The man who wrote the second most famous formula in science, and who opened the era of extraterrestrial civilizations, has passed away

On September 2, 2022, American astronomer Frank Drake passed away. He opened the way for mankind to explore extraterrestrial civilizations and will be remembered forever.

Written by Qu Lijian

Frank Donald Drake (May 28, 1930 – September 2, 2022)

Drake believed that there were aliens in the universe and that humans would eventually establish contact with them. More importantly, he turned his ideas into action and into a scientific problem that could be solved step by step. He did not see the solution to the problem and died at home on September 2, 2022.

Drake once asserted that humans would establish contact with aliens during his lifetime. In his later years, he admitted that he would not be able to wait for that day. He did not live to see this historic moment, but he planted the seeds of the scientific field of searching for extraterrestrial life, which now blooms all over the cliffs. He should have left this world with relief rather than regret.

Childhood Dream

Drake was born in Chicago in 1930. His father was a chemical engineer and his mother was a housewife. Drake was interested in chemistry and electronics since he was a child. Drake's interest in astronomy and extraterrestrial civilizations began when he was 8 years old. His father told him that there were other worlds in the sky, meaning other planets, but Drake's thinking went further. He imagined that there were earth-like planets with intelligent civilizations distributed in many corners of the universe, each with its own version of cars, streets, and neighborhoods.

Drake's parents are Baptists who are very strict with their children, and their family life seems miserable. Drake has hated religion since he was a child, and has a profound view of religion that is inconsistent with his age. He believes that the worldview of religion is narrow and is shaped by the specific environment of its origin.

When Drake was a child, he often rode his bike to the Chicago Museum of Science and Industry to linger over the various exhibits. There he learned that the sun is just an inconspicuous one among the countless stars in the Milky Way, and he even felt that alien life existed in the Milky Way.

The Museum of Science and Industry, which Drake often visited as a child, is one of the largest science museums in the world and one of Chicago's most famous cultural attractions.

At the age of 17, Drake received a scholarship from the Naval Reserve Officer Training Corps (similar to our country's national defense students) and enrolled at Cornell University, intending to become an aircraft designer after graduation. Drake took an astronomy course during college. In 1951, Russian-American astronomer Otto Struve (1897-1963) gave an academic report at Cornell University. In the report, he said that based on his observations, it can be inferred that there are many stars with planets in the Milky Way, so there should be extraterrestrial life in the Milky Way. This had a great impact on Drake who was listening to the report. His ideas since childhood were similar to those of the great astronomical heroes. Since then, he has taken the issue of extraterrestrial life and extraterrestrial civilization more seriously.

In 1951, Drake received a bachelor's degree in engineering physics and then served in the U.S. Navy. In 1955, Drake entered Harvard University for graduate studies. In 1958, he received a doctorate in astronomy and then joined the National Radio Astronomy Observatory. While engaged in astronomical observation, he still kept in mind his childhood dream - to find aliens.

Project Ozma

In April 1959, Drake persuaded the director to launch Project Ozma, a radio telescope to search for extraterrestrial radio signals. Ozma is the princess of Oz in the American fairy tale The Wizard of Oz.

Drake and the telescope he used to conduct Project Ozma, the Tatel Telescope

Project Ozma was carried out in secret because Drake and his colleagues were afraid of being laughed at. In September 1959, Italian particle physicist Giuseppe Cocconi (1914-2008) and American physicist Philip Morrison published an article in Nature, describing their ideas on the search for extraterrestrial civilizations, and the research proposal was similar to Project Ozma. Drake no longer kept it secret and made public their ongoing plan.

In 1960, the telescope assembled by Drake officially began observations, and Project Ozma finally came to fruition. Project Ozma ultimately did not find any traces of extraterrestrial civilizations, but it attracted the attention of the public, including a young graduate student named Carl E. Sagan (1934-1996), who began their lifelong collaboration. Project Ozma attracted many big names to the observatory where Drake worked to discuss the search for extraterrestrial life.

Carl Sagan (left) and Drake (right) in 1994. Carl Sagan is a famous American astronomer, astrophysicist, cosmologist, science fiction and popular science writer, and pioneer astrobiologist.

Drake Equation

In the summer of 1961, Drake received a call from JPT Pearman of the Space Sciences Committee of the National Academy of Sciences. Pearman said he was particularly interested in Project Ozma and suggested that Drake organize a conference to promote research on the search for extraterrestrial life.

In 1961, the first academic seminar on the search for extraterrestrial civilizations began. There were 10 participants, including Pearlman and Drake, Carl Sagan, Cocconi, Morrison, and Drake's academic mentor in the search for extraterrestrial civilizations, Struve, a Chinese astronomer Su-Shu Huang (1915-1977), and several "fans" of extraterrestrial civilizations: neurologist John Lilly, inventor and co-founder of HP Computer Bernard Oliver, Nobel Prize winner in Chemistry Melvin Calvin (1911-1997), businessman and amateur radio expert Dana Atchley. They named their small group "Dolphin Society" because John Lilly, a participant, studied how dolphins communicate with each other. He believed that if the dolphin language could be cracked, it would also help understand the communication methods of aliens.

At this conference, Drake proposed the equation that was later named after him - the Drake equation.

A plaque on the wall of the conference room of the first-ever Search for Extraterrestrial Intelligence symposium in 1961 commemorates the meeting.

The Drake equation has the following form:

This equation can be used to estimate the number of extraterrestrial civilizations in the Milky Way. Different estimates of the variables in the equation can lead to different results, ranging from a few to billions.

The Drake equation has become a landmark equation in astronomy, especially in the field of search for extraterrestrial intelligence, and like Maxwell's equations, it has captured the public's imagination. It is known as the "second most famous equation in history," second only to E=mc^2.

This equation still guides the search for extraterrestrial intelligence (SEI) today. The search for extraterrestrial intelligence (SEI) is actually the study of one or several terms in the Drake equation.

In 1963, Drake joined the NASA Jet Propulsion Laboratory (JPL) as the head of the lunar and planetary science department. But the following year, Drake resigned because there were too many administrative affairs and no time to conduct research that interested him.

After that, Drake returned to his alma mater, Cornell University. Drake continued to achieve many influential results in the field of astronomy, but he never stopped thinking about searching for extraterrestrial civilizations. He had a new idea to send a message to extraterrestrial civilizations to tell them that they are not alone in the vast universe and that the earthlings are here.

Talking to aliens

In 1972 and 1973, the United States launched the Pioneer 10 and 11 unmanned spacecraft in succession. They were the first and second man-made objects in history to leave the solar system.

Drake and Carl Sagan designed a gold-plated aluminum plate that was installed on Pioneer 10 and Pioneer 11. The gold-plated aluminum plate has some patterns engraved on it, indicating where the spacecraft took off from, and also depicts the image of the highest life on Earth: a man and a woman. The background of these two people is the outline of the Pioneer spacecraft itself, which clearly shows that the height of a person is about 2/3 of the width of the spacecraft. A schematic diagram of the ground state hyperfine transition of the hydrogen atom is also drawn.

Pioneer pattern on gold-plated aluminum plate

This gold-plated aluminum plate wanders in the vast universe like a drifting bottle, waiting to be captured by aliens and let the aliens know that there is a civilization in the universe that wants to establish contact with them.

However, this possibility is too slim, and Pioneer 10 will not reach the first star ahead, Aldebaran, until 2 million years later.

The fastest way to communicate is electromagnetic waves. With the help of Carl Sagan and others, Drake designed an electromagnetic wave message to send to aliens and sent it to the universe using the radar of the Arecibo telescope on November 16, 1974.

Since then, humans have sent electromagnetic wave information to aliens in the universe many times, and most of the content is improved on the basis of Arecibo message, including the latest improvement in 2022. (For the interpretation of Arecibo message and the latest improvement, please refer to "In order to let aliens understand the information of the earth, they desperately came up with these "garbled codes"")

Graphical illustration of the Arecibo information

In 1977, Drake and Carl Sagan designed a golden record for the Voyager 1 and 2 spacecraft, which included sounds and images that represent various cultures and life on Earth, including the Chinese guqin piece "Flowing Water".

Although the ultimate purpose of the gold-plated aluminum plates on Pioneer 10 and 11 and the golden records on Voyager 1 and 2 is to communicate with aliens, they actually mean more to humans on Earth, symbolizing the relationship between humans and the universe.

The Golden Record carried by Voyager 1 and 2

In 1984, Drake moved from Cornell University to the University of California, Santa Cruz, where he served as chairman of the board of directors of the SETI Institute (SETI, which stands for Search for Extraterrestrial Intelligence) and director of the Carl Sagan Center, a research institute under the SETI Institute. In 1996, Drake retired from the university and stepped down as director of the Carl Sagan Center in 2010.

On September 2, 2022, Drake passed away peacefully at his home in California at the age of 92.

SETI Institute's logo

heritage

Standing under the starry sky, wondering: Are there aliens? Where are they?

Whenever people in ancient and modern times look up at the starry sky, they can't help but ask themselves, what's there? Are there other stars like the sun, planets like the earth, and intelligent life? Over the past thousands of years, especially in the past few hundred years, with the development of astronomy and astrophysics, our knowledge of the universe has greatly increased, and we can even infer the initial origin and final fate of the universe, but our curiosity about extraterrestrial life has never diminished.

In 1961, Drake wrote down his equation for estimating the number of extraterrestrial civilizations, turning the existence of aliens from a philosophical question into a scientific one. He was also the first person to search for alien signals, a pioneer in the field of Search for Extraterrestrial Intelligence (SETI), and participated in the design of the images and electromagnetic wave information that humans eventually sent to aliens... Drake revolutionized the way we think about and search for extraterrestrial life and civilizations.

After Drake, we no longer passively wait for extraterrestrial life and extraterrestrial civilizations, but take the initiative, but not recklessly, because this is a solid scientific issue to explore. Although we have not yet achieved any results, perhaps in the future, we will look back and find that Drake actually brought a revolutionary leap to the civilization of the earth.

Now that he is gone, let us honor his legacy by seeking the answer to the big question:

Who else is there in the universe?

Produced by: Science Popularization China

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