What is Life? summary

OK, let’s sum up what we’ve learned so far: any living organism, along with every biologically relevant process it undergoes, must be composed of a huge amount of atoms. This is a safeguard against the potential for single atoms, which can behave erratically, to influence the overall behavior of the organism.

So far, so good. But now we run into a problem, which is this: tiny groups of atoms –⁠ much too small to display exact statistical laws –⁠ do, in fact, have an enormous influence over everything that occurs within a living organism! 

So, we just learned that genes contain not only the blueprint for any living organism but also the instructions for how to build it. And we’ve learned that individual genes are far too small for the atoms they’re made up of to obey any statistical laws. Add to this the fact that genes are remarkably stable over time. How do we square these things?

To answer this question, let’s first clear up a common misconception about evolution. The famous naturalist Charles Darwin famously theorized that natural selection occurs through small, continuous, accidental variations. He was wrong.

The molecule we’re describing here is nothing short of a masterpiece. It’s incredibly small, yet remains highly ordered over long periods of time. The classical laws of physics don’t seem to apply to it at all! This, however, shouldn’t surprise us. In fact, this is always true when it comes to discussions of life.

For example, take entropy, the tendency of an isolated, inanimate system to decay into a state of thermodynamic equilibrium –⁠ basically, into what we can call disorder. Normally, matter quickly decays into this state. Life, on the other hand, repeatedly feeds upon negative entropy –⁠ that is, order –⁠ inside of the food it eats. By doing so, it avoids death, the state of maximum entropy, and continuously generates order from order. The classical laws of physics would call that impossible.

Now let’s turn to the second series of lectures, where Schrödinger starts off by exploring a more philosophical question: What, exactly, is consciousness?

You’ve probably heard the classic conundrum, “If a tree falls in the forest and no one is around to hear it, does it still make a sound?”

At first, it may seem that by becoming conscious beings we humans have effectively escaped the classic Darwinian survival of the fittest. After all, most people dislike seeing their fellow humans suffering and dying. So societies have developed ethical codes and laws that simply don’t allow people to let others die –⁠ instead, they help them survive, whatever their physical or mental conditions might be. Darwin's theory doesn’t allow for the inheritance of learned traits, either. For instance, a person can’t learn how to play the piano and then pass that skill on to his daughter purely through genetics.

Together, these facts raise the following question: Given the absence of evolutionary pressure, is humanity doomed not to advance any further biologically? The answer is no.

In this last blink, let’s turn to another deeply mysterious question about consciousness – namely, the question of sensual qualities. What, Schrödinger asks, makes yellow yellow?

Ask a physicist how she conceives of yellow light and chances are she’ll throw a bunch of big and complicated words at you: Yellow light consists of transversal electromagnetic waves of wave-length around 590 millimicrons.