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“What’s the meaning of the universe?” asked Joseph Campbell, a scholar of myth and religion. “What’s the meaning of a flea? It’s just there, that’s it, and your own meaning is that you’re there.”
Joseph Campbell writes: “As the consciousness of the individual rests on a sea of night into which it descends in slumber and out of which it mysteriously wakes, so, in the imagery of myth, the universe is precipitated out of, and reposes upon, a timelessness back into which it again dissolves.”5
Maybe the difficulty is logical. Stephen Hawking argues that the question of beginnings is just badly put. If the geometry of space-time is spherical, like the surface of Earth but in more dimensions, then asking what existed before the universe is like looking for a starting point on the surface of a tennis ball. That’s not how it works. There is no edge or beginning to time, just as there is no edge to the surface of Earth.6
phase changes.
Within a billionth of a billionth of a billionth of a billionth of a second after the big bang, energy itself underwent a phase change. It split into four very different species. Today, we know them as gravity, the electromagnetic force, and the strong and weak nuclear forces.
Today, the mass of this energy may account for as much as 70 percent of the total mass of the universe. But even if it is beginning to dominate our universe, we don’t yet understand what this energy is or how it works, so physicists call it dark energy. The term is a placeholder. Watch this space, because understanding dark energy is one of the great challenges of contemporary science.
The first law of thermodynamics tells us that the ocean of energy is always there; it’s conserved. The second law of thermodynamics tells us that all the forms that emerge will eventually dissolve back into the ocean of energy. The forms, like the movements of a dance, are not conserved.
If there is a bad guy in the modern origin story, it is surely entropy, the apparently universal tendency for structures to dissolve into randomness.
Joseph Campbell described entropy’s role poetically in a book on mythology: “The world, as we know it… yields but one ending: death, disintegration, dismemberment, and the crucifixion of our heart with the passing of the forms that we have loved.”12
This explains a fundamental aspect of our universe: almost three-quarters of all the atoms in it are hydrogen, and most of the rest are helium.
heat is really a measure of the motion of atoms.
the more distant an object was, the faster it was moving away. And that seemed to mean that the entire universe was expanding.
“To do anything requires energy. To specify what is done requires information.”3
Living organisms consist of cells enclosed by semipermeable membranes. 2. They have a metabolism, mechanisms that tap and use flows of free energy from their surroundings so they can rearrange atoms and molecules into the complex and dynamic structures they need to survive. 3. They can adjust to changing environments by homeostasis, using information about their internal and external environments and mechanisms that
allow them to react. 4. They can reproduce by using genetic information to make almost exact copies of themselves. 5. But the copies differ in minute ways from the parents, so, over many generations, the features of living organisms slowly change as they evolve and adapt to changing environments.
Here is how Darwin put it in The Origin of Species: Can it… be thought improbable [that] variations useful in some way to each being in the great and complex battle of life, should sometimes occur in the course of thousands of generations? If such do occur, can we doubt (remembering that many more individuals are born than can possibly survive) that individuals having any advantage, however slight, over others, would have the best chance of surviving and of procreating their kind? On the other hand, we may feel sure that any variation in the least degree injurious would be rigidly destroyed.
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rejection of injurious variations, I call Natural Selection.9
In 1885, Eduard Suess suggested that about two hundred million years ago, all the continents had been joined together in one supercontinent.
The basic rule is that the more divergence there is between two genomes, the longer it’s been since those two species shared a common ancestor, and we know roughly the speed at which different types of genomes diversify.
Oxygen levels plummeted to about 1 or 2 percent of the atmosphere, and there followed a long period, almost a billion years, during which oxygen levels remained low and climates remained warm. Earth’s ancient thermostats seemed to have been reset to cope with the presence of significant levels of atmospheric oxygen produced by cyanobacteria.
Little life ruled the biosphere for three and a half billion years and still rules much of it. It took three billion years to get from Luca to the first specimens of big life—the first multicellular animals, or metazoans. That tells us that evolving multicellular organisms was much trickier than evolving prokaryotes.
Dictyostelium tells us several important things. First, multicellularity has evolved many times and is still evolving today in some groups of organisms. Second, multicellularity, like life, has a gray border zone of organisms that are hard to classify.1 Third, multicellularity multiplies the computational power of individual cells, increasing their ability to manage information about their environments.
