The opposite of entropy is order, an unlikely state like an unbroken egg, but if order inevitably declines, why is it all around us? Day follows night, seasons cycle, and plants produce not only food but also the air we breathe, in a synergistic, self-regulating system that some call Gaiea.
Is the web of life on earth then just a local anomaly that bucks the universal trend to disorder? For example, a fridge that keeps beer cold on a hot day doesn’t deny the second law because it gets energy from electrical power, and our earth has the sun to power it. But our earth isn’t the only planet that orbits a star, they all do, so it may be lucky but it isn’t unusual. And its order requires order above it. For life to evolve on earth, the sun had to keep its planets in order, and the galaxy had to keep its stars in order, so if earth’s order comes from a cosmic order, it isn’t a local anomaly.
Hence, the only explanation that current physics allows is that the big bang was highly ordered, so life is still possible because our universe is still only half-way through its devolution:
“The ultimate source of order, of low entropy, must be the big bang itself. … The egg splatters rather than unsplatters because it is … the drive toward higher entropy … initiated by the extraordinarily low entropy state with which the universe began.” (Greene, 2004), p173-174.
In this reverse logic, our universe began very ordered because the second law is true, but that the initial chaos was highly ordered makes no sense at all. How is the white hot plasma that came before atoms and molecules formed, let alone stars, very ordered? If there was a prize for backward thinking (Note 1), this would surely be a top contender.
How then did life on earth begin? Our earth was born about four and a half billion years ago but for over half that time, only single cell organisms existed. As continents formed and volcanoes erupted, they produced the oxygen needed by plants and animals later. Primitive archaea and bacteria merged into the modern cells that led to plants, animals, and us (Lane, 2015), but in the earth’s timeline, the latter only began to proliferate about half a billion years ago. Nature’s order has been a long time coming, so to call it a devolution based on a heat engine law is ridiculous.
Modern humans arose about three million years ago, so bacteria that have been on our planet for billions of years are still poorly understood. For example, bacteria in boxes placed outside the International Space Station for a year were seen to come back to life when they returned to earth. Under harsh conditions, bacteria can form spores that are dead metabolically but revive under the right conditions, even after millions of years, so they could hitch a ride on a meteor to travel between planets. The panspermia hypothesis, that life can evolve on one planet and spread to another, means that bacteria from mars might have colonized the earth.
Whether this is true or not, bacteria exist on earth, so of the mind-boggling 160 billion planets thought to exist in our galaxy, many others may host them too. If so, a galaxy teeming with life isn’t what the second law predicts after 14 billion years of decay!
Clearly, order is possible, but if the second law predicts only disorder, what caused it?
Note 1 Backward thinking explains an already known answer, by tweaking it to fit the facts, or the facts to fit it, so it doesn’t produce new knowledge. In contrast, forward thinking begins with a question and lets the evidence lead to an answer, so it can produce new knowledge. Science is based on forward thinking not backward thinking (see Research Roadmap).