Morning! Ya huele a feria.
(Music-matching! Thanks, Iker, for all of those immersive moments on the radio. You and your show played a huge role during my childhood).
I’ve always got fascinated by the night sky and outer space. I remember the first time I went with my parents and cousins to night-hunting shooting stars, and I couldn’t believe how cool it was. Since then, I’ve always tried to follow all significant sightseen events, from eclipses to meteor showers or just plain and regular constellation findings. I was lucky to even watch the northern lights the past year —easily the most spectacular natural event I had the pleasure to witness.
Related to all of this is the timeless attraction to outer civilizations. In the same way, space exploration was a family matter —my cousin even saved for and bought an excellent telescope. It was just great spending those fresh summer nights around it observing moon craters as close as you can imagine— mystery in general and supernatural phenomena was a recurrent topic. I bet they are probably still getting goosebumps when remembering that bright green ball dividing in two above the sea horizon or that guy floating over the sand and moving so fast on that same beach —early 2000’s when none had a camera in the pocket, and the only thing left to do was immerse yourself in the tales with curiosity and naivety.
A few months ago, I got interviewed, and they asked me what historical event I would want to witness. Automatically I thought about the first human contact with intelligent alien life. They released that interview this week. Also, two of the podcasts that I usually follow have treated the extraterrestrial life topic (Heavy Mental and Lex Fridman’s), and I couldn’t resist following the pattern in this letter.
Today, I want to introduce you to the Assembly Theory by Sara Walker, Leroy Cronin, and many others (you can see them all in the original paper). It is a framework that tries to explain the phenomena that we call life by determining how likely it is for a specific object to be made by a life form.
Said another way, after an object’s analysis, a molecular assembly number (MA) is assigned to that object. The higher the number, the more likely that the object results from some sort of living form. Even though the theory is highly focused on molecular combinations, it can be applied to any ‘object’ understanding object either as a physical one (a pencil) or abstract (an idea).
You might be wondering how that number is calculated. Oversimplifying and taking molecules as an example, 1st they start with the basic building blocks, bonds in the case of the paper, and combine them to create sub-units. Those sub-units can be combined again with other sub-units or basic blocks to recursively generate larger structures until getting the desired object. Out of all pathways leading into the same object, the shortest one is chosen, and that is the MA number.
As you can see, the only limitations are those building blocks. Applied to chemistry-extraterrestrial life discovery would be contingent on being based on molecule structures.
I guess the other big question yet to answer is what’s life. I’ll leave you here the three definitions that Sara mentioned so you can give them a thought.
Life is how information structures matter across space and time.
Life is simple machines constructing more complex machines.
Life is the physics of existence, the mechanism the universe has to explore the space of what’s possible.
Suppose you are still here and your brain hasn’t melted yet. In that case, I highly recommend you to follow up and listen (or watch) to the Lex Fridman’s podcast, where Sara and Lee explain everything by themselves and ramble around other philosophical topics. I can assure you that this is the most mind-blowing topic I’ve heard about in a while.
Have you ever seen a UFO? Have you made contact with some sort of alien form? Did you get abducted and were the subject of sassy experiments? Let me know by replying to this mail or leaving a comment on the web version.
¡Ten un buen día!