What Alice did not find out when Humpty disintegrated was why all the kings men couldn’t do anything about him.

Maybe it never occurred to her to ask the question. It is, after all, in the nature of Humptys to break. Just as, before Newton asked his question, heavy things fell because it was in their nature to fall.

Humpty broke because, over time, left to themselves, complex things change to more simple things. That is how we sense time; it is how we know that time is not running backwards. And putting Humpty together again requires energy; so much that even all the Kings men didn’t have enough between them.

This is the Second Law of Thermodynamics. Complex ordered things left to themselves become simple random things. Look in your sock drawer. Entropy is the word given to the degree of complexity; or more correctly, absence of complexity. Entropy naturally increases; order naturally changes to disorder.

Life is complex. It is highly ordered. It has low entropy. When NASA asked James Lovelock (of the Ghia hypothesis) how they might detect life on another planet his answer was simple; make a device for measuring entropy. And he quickly knocked one together for them.

What does low entropy look like? It looks like Humpty Dumpty; a collection of small bits put together in an ordered fashion likely to fall at any moment. It is the presence together of complex molecules that would naturally react to form much simpler less ordered, more random, ones. Like the highly ordered particles in cellulose (wood) in an atmosphere of oxygen. When they change to their high entropy state–when Humpty breaks–they burn together to become carbon dioxide particles flying around randomly.

Our atmosphere is 22% oxygen in the presence of lots of plants made of complex carbon-containing molecules, but with only 0.04% carbon dioxide. Low entropy. Mars’ atmosphere is 95% carbon dioxide and only 0.1% oxygen and no plants. High entropy. The difference between the two is life. And making life on earth has been a long, difficult, massively energy consuming process.

Life on Earth is a massive Humpty waiting to fall.