ENGLISH VERSION
To this day, we have known only one type of life. The one that was born on Earth, the one made possible by our chemistry. A life built on precise foundations: left-handed amino acids (L), right-handed sugars (D), a double-helix DNA whose logic is universal... to us.
But what is now called "mirror life" is something else. It is the bold idea that there could exist — or that we could create — a form of life similar to ours in its organization but reversed in its matter. A chirally opposite life, as if every molecule had been turned over in a mirror.
Imagine: proteins made of right-handed amino acids, a genome built on left-handed sugars. A cell, a living machine, made of the same building blocks as ours — but all reversed. And most importantly: able to replicate, metabolize, grow, die... without ever being able to interact with our own biology.
That is what mirror life is.
A life outside of life, but built on the same laws, reversed.
If you had to describe terrestrial life with a single rule, it would be this: life is chiral. In other words, life makes a choice between right and left — and it sticks with it.
All the proteins in our body are made of L-amino acids, as if nature had systematically favored the left hand. On the other hand, our DNA is built on D-sugars, the right-handed version. And this asymmetry is not just a detail: it conditions everything.
No natural enzyme knows how to recognize a right-handed amino acid. No ribosome assembles proteins backwards. It’s a closed world: our biology knows only one language.
This lock — biological, but not physical — has fascinated researchers for more than a century. Why has life chosen only one direction? Nothing in the fundamental laws of the universe seems to impose it. Chirality here appears as an original roll of the dice, an asymmetry born somewhere in the primordial soup, never questioned since.
From there, the idea of "mirror life" becomes a fundamental experiment. What if we rewrote life by reversing all its rules? What would happen? Could it work? Adapt? Evolve? Survive?
It’s no longer just a question of science. It’s a metaphysical provocation.