Carl Sagan's Model

Carl Sagan’s Model

Carl Sagan is a collection of water, calcium and organic molecules called Carl Sagan. You are a collection of almost identical molecules with a different collective label. But is that all? Is there nothing in here but molecules? Some people find this idea somehow demeaning to human dignity. For himself, Sagan finds it elevating that our universe permits the evolution of molecular machines as intricate and as subtle as we.

But the essence of life is not so much the atoms and simple molecules that make us up as the way in which they are put together. Every now and then we read that the chemical which constitute the human body cost ninety-seven cents or ten dollars or some such figure; it is a little depressing to find out our bodies valued so little. However, these estimates are for human beings reduced to our simplest possible components. We are made mostly of water, which costs almost nothing; the carbon is cost in the form of coal ; the calcium in our bones as chalk ; the nitrogen in our proteins as air (cheap also), the iron in our blood as rusty nails. If we did know better, we might be tempted to take all the atoms that make us up, mix them together in a big container and stir. But in the end all we have is a tedious mixture of atoms. We can do this as much as we want. How could we have expected anything else?

Harold Morowitz has calculated what it would cost to put together the correct molecular constituents that make up a human being by buying the molecules from chemical supply houses. The answer turns out to be about ten million dollars, which should make us all feel a little better. But even then we could not mix those chemicals together and have a human being emerge from the jar. That is far beyond our capability and will probably be so for a very long period of time. Fortunately there are other less expensive but still highly reliable methods of making human beings.

Is there nothing inside us but molecules? Image: Lilac © Megan Jorgensen (Elena)