The Fermi paradox

Recursive RNA revealed??

• There are roughly 200 to 400 billion stars in the Milky Way, and an estimated 2 trillion galaxies in the observable universe.

• Many of these stars are billions of years older than our Sun and are orbited by Earth-like planets.

• If life follows a similar evolutionary path to Earth’s, some civilisations would likely develop interstellar travel.

• Even at sub-light speeds, a civilisation could colonise the entire Milky Way in a few million years (basically a blink in the cosmic timescale)

Given these factors, the Earth should have already been visited or at least detected life outside it.

This is known as the Fermi paradox.

One of the most prominent attempts to reconcile this paradox is the Great Filter theory. It suggests there is a specific stage of evolution or technological development that is almost impossible to surpass, and hence why the universe is silent. There are two possibilities:

• The Filter is behind us: We may have already passed a “needle-threaded” moment, such as the transition from prokaryotic to eukaryotic life or the development of intelligence. If this is true, we are among the first to pass through the ‘filter’.

• The Filter is ahead of us: This suggests that all civilisations eventually reach a point where they self-destruct before achieving interstellar travel. This could be due to war, nuclear weapons, AI, climate change etc.

The potential explanations:

1. The Rare Earth Hypothesis:

   • This theory posits that the conditions required for complex life are so specific (the right distance from the Sun, a large moon for tidal stability, specific size, etc) that Earth might truly be a statistical anomaly.

2. The Zoo Hypothesis:

   • Advanced civilisations may be aware of us but have all agreed to a directive of non-interference. They treat Earth like a zoo, waiting for us to reach a certain level of technological or cultural maturity before making contact.

   • I personally believe this solution (although it isn’t the consensus opinion currently).

3. The Dark Forest Theory:

   • Popularised by Liu Cixin’s ‘3 Body Problem’ trilogy (highly recommend btw!!), this theory suggests that the universe is a “dark forest” where because resources are finite and another civilisation’s intentions are unknowable, the most logical survival strategy is to remain silent and destroy anyone who reveals their location.

4. Technological Mismatch

   • We have only been using radio waves for about a century. An advanced civilisation might communicate using neutrinos, gravity waves, or quantum entanglement technologies (also explored in 3BP) we aren’t yet capable of detecting.

A couple of days ago, scientists found an RNA sequence only 45 nucleotides long that’s capable of self-replication under certain conditions.

the RNA sequence. also i’d bet on this winning a Nobel.

This lends credence to the idea that life isn’t rare, and that the filter lies ahead of us. With the acceleration of science and technology over the past decades, we are potentially reaching a singularity where we face the ‘filter’ within our lifetimes.

I’m excited for the future!

Hope you guys enjoyed, don’t forget to like and subscribe!!