**🧬 What *Is* Life, Really? And Could We Build It From Scratch?**
What if the key to understanding life… is not *what it’s made of* — but *how it assembles*?
Ask ten scientists “What is life?” and you’ll get a thousand different answers. But **Lee Cronin**, the chemist behind **Assembly Theory**, offers a radical simplification:
> **Life is any system that can produce complexity at scale.**
Not DNA, not metabolism — just *non-random complexity*, multiplied.
### 🔧 Enter “Assembly Theory” — Life by the Numbers
Instead of asking “Does it have genes?” Cronin asks:
**How much *selection* went into producing these objects?**
- **Assembly Index**: How complex is an object — how many steps to make it?
- **Multiply that by how many copies of it exist**, and you get a system’s *Assembly*.
- The more **non-random complexity** at scale? The more likely you’re looking at life.
In essence:
> **Life is what happens when the universe gets choosy — and does it over and over again.**
### 🌌 Why This Changes Everything
1. **We can *measure* life**, not just define it vaguely.
2. **We can trace its evolution** anywhere — even on other planets.
3. **We might even build it.**
Yep — **we might be close to creating life in a lab.**
### 🧪 The “Origin of Life” Machine
Cronin and his team are building a **selection engine** — a machine designed to sift through random chemistry and spot the emergence of life-like behavior.
They're targeting three critical time factors:
1. **Time to create** the object.
2. **Time until it decays** if left alone.
3. **Time it can persist** through generations in a living system.
If a molecule scores high on all three? It might just be alive — or close.
### 🚀 How soon will we create synthetic life?
No one knows.
But Cronin believes it's not decades away.
> “We now know what we’re looking for — and we’re building the tools to find it.”
**✨ Big Idea:**
What if “life” isn’t some magical property… but an **inevitable result** of chemistry and selection?
If so, life may not be rare. It may be **written into the fabric of the universe**.
About Lee Cronin:
Leroy Cronin has one of the largest multidisciplinary, chemistry-based research teams in the world. He has given over 300 international talks and has authored over 350 peer-reviewed papers with recent work published in Nature, Science, and PNAS. He and his team are trying to make artificial life forms, find alien life, explore the digitization of chemistry, understand how information can be encoded into chemicals, and construct chemical computers.
He went to the University of York where he completed both a degree and PhD in chemistry and then went on to do postdocs in Edinburgh and Germany before becoming a lecturer at the Universities of Birmingham, and then Glasgow where he has been since 2002, working up the ranks to become the Regius Professor of Chemistry in 2013 at age 39.
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