THE GREAT SILENCE

Is it a good idea to try and contact alien civilisations? The answer could be a big fat no

- Varun Ramesh Balan

Where is everybody? This was a question physicist Enrico Fermi asked in 1943, in a cafeteria at the Los Alamos Laboratory, one year into the Manhattan project developing the world’s first nuclear bomb. He wasn’t asking about human beings.

The somewhat atavistic tendency to zoom out and imagine one’s place in the universe is something that affects many who look at the sky, count the stars, and wonder if anything is living out there. Of the ~1024 stars (a septillion—a “trillion trillions”) in the universe, up to seven per cent in our neighbourhood alone are of the G-type category that our sun falls into.

Based on the latest data from the Kepler space telescope, which can peer up to 3,000 light years away, the Search for Extraterrestrial Intelligence (SETI) estimated 300 million potentially habitable planets in our galaxy. Writing in the Astrophysical Journal in 2020, Tom Westby and Christopher J. Conselice speculated that there may be as many as 36 Communicating Extra-Terrestrial Intelligent (CETI) civilisations in the Milky Way alone, based on the Strong Astrobiological Copernican limit that estimates habitable conditions would tend to generate life in under 4.5 to 5.5 billion years.

If by now, we could estimate this number within our galaxy alone, imagine how much larger it could become when you consider that there are around 100 billion galaxies in the universe. It is likely, isn’t it?

The Drake Equation and Fermi’s not-so-Paradox