Brian Greene is an American theoretical physicist, mathematician, and string theorist who writes books about science for the general public.
Author Brian Greene
In this tome, Greene contemplates the universe, from it's inception to it's inevitable demise. Greene writes, "Planets and stars and solar systems and galaxies and even black holes are transitory. The end of each is driven by its own distinctive combination of physical processes, spanning quantum mechanics through general relativity, ultimately yielding a mist of particles drifting through a cold and quiet cosmos."
We don't need to worry much about the end of the universe because it probably won't happen for trillions and trillions of years. On the other hand, the end for an individual living creature - like a human being - is much closer.
Greene suggests that the knowledge of inevitable death drives people to leave a mark, to accomplish something that lasts beyond themselves. This may be the impetus that inspires scientists, scholars, artists, musicians, writers, etc.
In fact it's what drives Greene himself. He writes, "I've gone forward with an eye trained on the long view, on seeking to accomplish something that would last."
The decay of the universe is driven by the second law of thermodynamics, which says that the production of waste is unavoidable. Greene notes, "The second law describes a fundamental characteristic inherent in all matter and energy, regardless of structure or form, whether animate or inanimate. The law reveals (loosely) that everything in the universe has an overwhelming tendency to run down, to degrade, to wither." In other words, disorder is more likely than order.
Greene provides simple examples to demonstrate this. For instance, if you vigorously shake 100 coins and throw then down, it's a hundred billion billion billion times more likely that you'll get 50 heads and 50 tails (a high entropy, low order configuration) rather than all heads or all tails (a low entropy, high order configuration).
So going from the past to the future, entropy is overwhelmingly likely to increase.
You may ask, 'How then did organized things like stars, planets, bacteria, rhododendrons, dogs, humans, etc. come to be'?
Greene explains that (temporary) organization occurs via the entropic two-step, which is a "process in which the entropy of a system decreases because it shifts a more than compensating increase in entropy to the environment." To use humans as an example, we take in energy (food, air) to sustain our bodies, but we give off even more energy as waste products (heat).
A burning question for scientists, philosophers and much of the general public is 'How did life begin?' In the eyes of physicists like Greene, the 'molecular spark' that animated a collection of particles to 'come alive' is explainable by natural laws we haven't yet discovered. The particles themselves slowly formed after the Big Bang, eventually organizing into proto DNA-like molecules that could reproduce themselves....
......and finally into RNA, DNA, proteins, and other molecules that make up living things. Greene explains all this in detail, and - for me - was among the most interesting parts of the book.
As masses of particles that follow universal laws, do we have free will, unlike a rock for example? This is a question of great interest to many philosophers and scientists. Greene observes that, "as living creatures [our] particles are so spectacularly ordered, so breathtakingly configured, that they can undertake exquisitely choreographed motions that are not possible for [rocks]." So we can walk, cook, read, play computer games, go shopping, play sports, and so on. Though our particles ARE bound by physical laws, and we DON'T have free will, we apparently CAN control our behavior. Greene is a bit murky about this, and I would have liked a better explanation. 😏
Greene explains how Darwinian evolution drove the development of living things, from the simple to the complex. For instance, animal life advanced from single celled organisms,
to primitive creatures like sponges,
to more complex organisms like fish,
to land animals like salamanders,
and on and on to VERY intelligent primates (us).
It all happened because of Darwin's law of natural selection or 'survival of the fittest.'
For humans, natural selection favored physical traits - including our big brains - that allowed us to use tools; run from danger; kill prey; make fires; build shelters; etc. Greene posits that more nebulous human endeavors, like language; story-telling; art; religion; music; and so on ALSO helped us survive.
Greene's lengthy discussions about this are a little cloudy, but I got the jist....such behaviors cement us into communities, which are adaptive for survival. In any case, they fit into the 'survival of the fittest' scenario.
Getting back to the fate of the universe, Greene mentions various theories about the destiny of the cosmos. Scientists have observed that the universe is expanding at an ever increasing rate. No one knows what will happen in the future, but various possibilities are suggested, such as: the rate of expansion will speed up even more and the universe will rip apart;
the expansion will slow down and the universe will collapse with a big crunch;
the universe will collapse and expand over and over again...like a sort of cosmic yoyo; and more.
These discussions include consideration of gravity, repulsive gravity; dark energy, electromagnetic and nuclear forces, the Higgs field, and other such things that physicists love. No matter what, however, the universe will ultimately disintegrate into widely separated teeny tiny particles that are randomly drifting around.
As for humanity, we won't be around forever. Greene writes, "The entire duration of human activity - whether we annihilate ourselves in the next few centuries, are wiped out by a natural disaster in the next few millennia, or somehow find a way to carry on until the death of the sun, the end of the Milky Way, or even the demise of complex matter - would be fleeting."
So, does human life matter. If we won't survive for eternity, should we sit back and do nothing? Greene doesn't think so. He writes "our moment is rare and extraordinary" and "it's utterly wondrous that a small collection of the universe's particles can rise up, examine themselves and the reality they inhabit, determine just how transitory they are, and with a flitting burst of activity create beauty, establish connection, and illuminate mystery."
So go on and do your thing. 😊
Greene includes the work and opinions of many scientists and philosophers in his discussions, and tells personal anecdotes to illustrate some points - like the time he blew up the oven at the age of ten; or was thrilled by the aurora borealis; or saw his daughter let go of a soaring swing and tumble to the ground.
Greene has the rare ability to make difficult concepts accessible to non-specialists, and for science and math nerds, there are extensive notes (and a few equations) at the end of the book. All in all, a book worth reading for people interested in the subject.
Rating: 4 stars
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