The Universe: A Guide for Short-Term Visitors; Claude Bernard, PhD

Perhaps the two most fundamental questions that humans face are: “Why are things the way they are?” and “How should we behave.” Traditional religions answer the first question with creation stories. Think of the Biblical Genesis:

In the beginning God created the heaven and the earth. And the earth was without form, and void; and darkness was upon the face of the deep. And the spirit of God moved upon the face of the waters. And God said let there be light….

Or from the Hindu Satapatha Brahmana:

Verily, in the beginning, this universe was water, nothing but a sea of water. The waters desired, “How can we be reproduced?” They toiled and performed fervid devotions: when they were becoming heated, a golden egg was produced…. In a year’s time… Prajapati [the first being] was produced from the egg. Desirous of offspring he went on singing praises and toiling. He laid the power of reproduction into his own self. By the breath of his mouth he created the gods…

These creation narratives do more than just respond to the question of why things are the way they are. The stories also serve as a basis for guiding behavior: they attempt to explain where good and evil come from and what actions are correct — in other words “How should we behave.” Think of the Judeo-Christian story of original sin in the Garden of Eden. That sin is supposed to explain why this life is full of toil and suffering. Only by faith and obedience can we be forgiven and enter heaven after death.

The Hindu scripture has a simpler explanation of evil. After Prajapati created the gods by his breath, he created the demons by his flatulence.

From our modern perspective, we recognize that the creation stories told by traditional religions are myths: narratives invented to explain what was otherwise unexplainable. The fact that the narratives are invented implies a more important problem: Each story is different, a narrative of creation and history of one particular group of people. Each group sees themselves as the focus of creation, the “chosen” ones. And we know what that can — and often does — lead to: intolerance, persecution, war. The God of one group of people will smite the infidels, the enemies of that group. Here is just one recent example, from the New York Times, Nov. 22, 2000:

“In the name of the holy Torah, we are warning you, Arafat…,” said Israeli Rabbi Elnekave, “dare not touch… anyone among us… [or] we will pray to our Creator that He take you away.”

The scientific story provides an alternative explanation for why things are as they are. It has two advantages over the religious creation myths: It is true and it is universal. I should qualify the first of these: science does not give us Truth with a capital T. It is a self-correcting process that gets closer and closer to a true description of reality, but never actually arrives at some ultimate, absolute Truth. Yet even its relative truth is certainly universal: The scientific story of the origins of the universe, the earth, life, consciousness is the same for all of us.

Before telling this scientific story, let me start with a brief guide to our universe. We live on a planet that is 25,000 miles in circumference. That is so big that few of us make the journey in a lifetime. Yet our nearest neighbor, the moon is about 10 times further. Going to the moon gave us some perspective. Views of the Earth from space have, I believe, changed forever the way we view ourselves.

The sun is about 400 times further away than the moon. In fact it is so far that it takes light, moving at the incredible speed of 186,000 miles/second, about 8 minutes to get to us from the sun. The sun is just an ordinary middle-aged star, but it is important to us because we are close to it. The nearest star other than the sun is Proxima Centauri, about 24 trillion miles away. It takes light 4 years to get to us from Proxima Centauri — in other words, we say Proxima Centauri is 4 light years away. Let me give you some sense of how big that distance is: A trip to Proxima Centauri at the speed of the Apollo rocket (25,000 MPH) would take 100,000 years — about as long as our species, Homo Sapiens, has existed. Or another way: if you stood on Proxima Centauri and looked at the Earth, it would appear the same size as a penny viewed from 100,000 miles away.

About 100 billion stars like our sun or Proxima Centauri make up our galaxy, the Milky Way, which is about 70,000 light years across. The nearest other galaxy to ours is Andromeda, about 2.5 million light years away. Since Andromeda is 2.5 million light years away, we see Andromeda as it was 2.5 million years ago — when our ancestors were still coming down from the trees and developing the ability to walk upright. We believe Andromeda looks very much like our own galaxy. Galaxies themselves are grouped in huge clusters. We are part of the so-called Virgo cluster, whose center, a large concentration of galaxies, is about 60 million light years away.

The light we see now from galaxies 8 to 10 billion light years distant, left them well before our own sun or Earth had formed. All told there are may be 100 billion galaxies like this in the “observable universe.” We are clearly a very small part of the whole scheme of things.

Distant galaxies, like the ones we just saw, are moving away from us and from each other. We know this from the Doppler effect on their light — the same effect that makes the sound of a speeding ambulance siren decrease in pitch as it passes us. In fact, the further a galaxy is from us, the faster away it’s moving. This is the so-called “expansion of the universe.” Now imagine that someone took a movie of the expansion. If you ran the movie backwards, you would see the galaxies coming closer and closer together. In fact, the current speeds imply that at some time in the distant past — about 14 billion years ago — the galaxies were all in the same place at the same time. Indeed, they would have been crammed so closely together that they wouldn’t have been galaxies at all, just a very dense concentration of matter and energy. And it would have been incredibly hot; because when matter is compressed it heats up. (Think of how warm a bicycle pump gets when you use it to compress air into a bicycle tire.) The hot, dense concentration of matter and energy exploded in what we call the Big Bang, the start of our universe.

So, “In the beginning was the Big Bang.” Well, not quite. At some very early point, the universe would have been too dense and too hot for our current understanding of the laws of physics to be applicable. We cannot say what happened before that time. As I mentioned before, science can’t give us ultimate answers to questions — only relative ones. There is always a “what caused that?” that can come before.

So a better start is “Shortly after the beginning, there existed a state of matter and energy that we understand, and whose future evolution we can explain.” How much understanding you want determines how early you are willing to go. I like to start at about 10-32 (decimal point followed by 31 zeroes and a 1) seconds after the beginning. Our current observable universe was at that time about the size of a beach ball, and the temperature was 3×1026 (3 followed by 26 O’s) degrees Celsius. It was much too hot for normal matter to exist: everything was broken into its tiniest components. (This is the same effect that makes the molecules of liquid water separate and make up a gas (steam) when the temperature gets high enough.) Quarks, the constituents of protons and neutrons, moved around freely — not bound together at all. Indeed, protons, neutrons, atomic nuclei, and atoms would not exist at that time. Aside from esoteric particles that need not concern us here, there were just quarks, electrons, and radiation — electromagnetic waves of all frequencies, including what we call “light.”

At that early time, the universe was expanding at an enormous rate. And as it expanded, it cooled. A hundred thousandth of a second later, it was already 100 times the current earth-sun distance in size, and would have cooled to a temperature of a mere 10 trillion degrees. It was then cool enough that protons and neutrons could form out of the quarks. A little while later, 3 minutes after the Big Bang, it cooled enough for protons and neutrons to join together. About 1/7 of the protons joined with neutrons to make helium nuclei, which are combinations of 2 protons and 2 neutrons. But, interestingly, no larger nucleus than helium — nothing with more than 2 protons and 2 neutrons — was made at this time: no carbon, no oxygen, no iron. This is because the expansion of the universe soon separated the protons and neutrons and helium nuclei enough to isolate them and prevent further joining together.

The next important event occurred about 300,000 years after the Big Bang. At that time, it was cool enough — about 5000 degrees — for normal, neutral atoms to form for the first time. These were atoms of hydrogen, which has one electron orbiting a single proton, and helium, which has 2 electrons orbiting its nucleus. A neutral atom is a combination of negatively charged electrons and an equally positive nuclei; it has no net electric charge. Since light and other electromagnetic waves interact with electric charges, they have only a tiny probability of interacting with neutral atoms. Thus most of the light that existed at that time just continued moving in straight lines from then to now, without hitting anything. The glow from the hot matter that existed previously is thus still present today. All that has happened in the meantime is the electromagnetic waves have been cooled — reduced in frequency — by the expansion of the universe. The white-hot glow 300,000 years after the Big Bang cooled first to red hot, and then cooled below the visible range. So an imaginary observer at that time would see the glow disappear, and the universe cloaked in blackness. Today the glow still exists as microwave radiation, well below the visible range. It was discovered in 1964 by researchers at Bell Laboratories trying to study microwave emission in our galaxy. They found a glow coming equally from all directions. At first they attributed it to some problem with their antenna — perhaps the pigeon droppings on it — but when it persisted after they cleaned the antenna, they began to think it was real. Today we are sure that the so-called Cosmic Microwave Background exists. Indeed, some of the static seen on a TV tuned to an unused channel is due to that microwave radiation left over from the Big Bang. The Cosmic Microwave Background has now been measured very accurately and is an invaluable source of information about our universe at the young age of 300,000 years.

After the glow became invisible, the universe was dark for a long time. In the dark, gravity did its long, slow, silent work, pulling clumps of matter together. About a billion years later, scattered points of light started to appear — these were the first stars, gradually winking on like city lights at dusk. Gravity had produced enough heat in the compressed clumps of matter to reignite the nuclear ovens.

Inside big stars, the small nuclei made earlier were pushed close enough together to make heavier nuclei — first carbon, then oxygen, neon, magnesium, silicon, sulfur, upwards toward iron, that most stable of all nuclei. The biggest stars burned the fastest, going through the whole chain up to iron in as little as 25 or 50 million years. Such stars would then explode in an enormous dying gasp — a supernova explosion — blowing the newly made elements back out into space.

The heavier elements, made in stars and blown out into space by supernova explosions, then mixed with the hydrogen and helium already there, and some of that gas and dust condensed by gravitational attraction into new stars. The larger new stars would explode once again, repeating the cycle many times. After about 8 billion years of such element cooking, about 4.5 billion years ago, a moderate sized, run-of-the mill star condensed in our neighborhood. This was our sun. As a moderate sized star, it has a relatively long lifetime — about 10 billion years — so it is not quite middle aged yet. From left-over gas and dust condensed several planets, including our Earth. The atoms that make up our Earth — carbon, oxygen, silicon, sulfur, iron — are those that were formed inside stars. So our Earth is in fact made of stardust — and so are we.

The birthright of the Earth also includes relatively small amounts of heavy, radioactive elements such as uranium, made in the supernova explosions themselves. Decay of these elements heats the Earth, keeping it on a slow boil. Where the hot rock reaches the sea floor are so called “hydrothermal vents.” Although it is by no means proven, current theory says that life began about 4 billion years ago at one of these hydrothermal vents. The high temperature and pressure and the presence of facilitators — catalysts — like iron and sulfur produced complex molecules out of the available carbon, oxygen, phosphorus, nitrogen and hydrogen. Those molecules included nucleic acids as well as pyruvate, a fatty substance that would have joined to form soap-bubble-like enclosures. At some point, the nucleic acids in one of these enclosures combined to make chain-like molecules, called RNA, that could facilitate the copying of molecules like themselves. That was the beginning of life.

Once life existed, the immensely powerful forces of mutation and natural selection would come into play. Inaccurate copying — either through flaws in the copying mechanism or through environmental insults — would necessarily occur, producing new versions of RNA. Most of these variations would be worse than the original and be unsuccessful in copying themselves in turn. But once in a while the new version would be better at copying itself and would proliferate at the expense of the original.

After some time, the more efficient modern version of life evolved, with DNA taking the role of the “blueprint,” while proteins became the facilitators of chemical reactions like copying and metabolism. About 2.4 billions years ago modern photosynthesis evolved, producing free oxygen in the atmosphere for the first time, making possible life on land and setting the stage for the evolution of modern animals and plants. The production of oxygen was obviously crucial to our evolution, but it should be kept in mind that it was an environmental disaster for many of the pre-existing creatures for whom free oxygen was a poison.

During the course of evolution, the surface of the Earth has been continually changing. Kept “on the boil” by radioactive elements deep in its interior, the Earth bubbled and cracked — and still does today. Pieces of the Earth’s crust slide around like the surface of a thick bubbling pot of soup. That is “continental drift.” It is slow by human measure — St. Louis, as part of the North American continental plate, is moving westward at about the rate a fingernail grows. Yet continental drift, coupled with the effects of volcanoes and the impact of meteors, has been continually rearranging old environments and creating new ones — leading to the incredible variety of life on Earth.

The first multi-cellular organisms appeared a mere 600 million years ago. The division of labor that multi-cellularity made possible led to a proliferation of new life forms. Within 50 million years the first predatory weapons — jaws and teeth — appeared, and in response, the defensive weapons of shells and spines. This was the start of the “arms race” between predator and prey that has continued up the present. Twenty million years later, the first representative of the phylum chordata, of which we are a member, shows up in the fossil record. This creature was very similar to Amphioxus. It had a notochord, the stiffening rod that a hundred million years later would become the backbone of vertebrates, and a tiny nerve chord, which later evolved into a spinal chord, and ultimately, a brain. Indeed the brain has proved the most powerful weapon in that arms race between predator and prey, making possible rapid, coordinated movements, and, in more recent times, strategy and planning.

The most important division of labor brought on by multi-cellularity was the division between the “soma” (the body) and the “germ line” (the cells) that make eggs and sperm. The germ line takes on the responsibility of reproduction itself, while the soma does everything else that life does: breathing, moving, finding and eating food, thinking, finding a mate, raising young. This division of labor makes possible the enormous variety and adaptability that we see in multi-cellular animals, but it also comes at an enormous cost: death. One-celled creatures like bacteria or amoebae do not die, except by accident. They just keep growing and dividing — in principle forever. But once the soma lost its direct reproductive function, there was no longer an evolutionary requirement that it live forever. The “immortality” function has been taken over by the germ line alone — our genes live forever through our children. That is all evolution pushes for, after all — that genes be passed on to offspring. Our bodies and our consciousness are indeed just short-term visitors to the universe.

As Ursula Goodenough likes to say, “Death is the price we pay for having a brain.” Looked at this way, it’s a bargain. Most would agree that life in what doctors call a “persistent vegetative state” is not worth living. And none of us would trade places with an immortal bacterium.

OK. That, in brief, is the scientific story of why things are as they are. Can this guide to our universe also be a guide to our actions, an answer to the question of how we should behave? Robert Wright, in his book The Moral Animal, discusses the evolution of altruism in our species. Initially altruism was directed only at relatives: our kin share many of the same genes with us, so by helping our relatives we help our own genes. This kin-directed altruism is what drives the apparently selfless behavior of social insects like bees. Later, altruism extended to members of the same group or tribe, even if they were not directly related. This so-called “reciprocal altruism” is based on a “tit for tat” mechanism — “I’ll scratch your back if you scratch mine.” Since reciprocal altruism would leave both people better off, it had an evolutionary advantage. According to Robert Wright, our feeling of gratitude when someone does us a good turn is merely evolution’s way of enforcing reciprocal altruism, making sure we repay a favor with a favor. But there is also a stick with this carrot: We have a feeling of righteous indignation, leading to a desire for revenge, when people transgress against us. This “Eye for an eye, tooth for a tooth” heritage is deeply ingrained in us. It finds expression, for example, in our punitive criminal justice system.

In the end, I don’t think one can base a morality on reciprocal altruism. Reciprocal altruism is really just enlightened self-interest, but driven by emotions created by evolution, rather than reason. Morality should be something more than that — we believe that truly moral actions are done for their own sake, not for what they will buy us. Indeed, I don’t think you can logically deduce ethics from science at all. Attempting to do so would make us guilty of what philosopher G. E. Moore called the “Naturalistic Fallacy” — trying to deduce what should happen from what does happen. But I do think that the scientific narrative can be a starting point from which we can develop a true Morality.

For one thing the scientific story is universal, unlike the proliferation of creation stories that come from traditional religions. As Loyal Rue says in his book, Everybody’s Story, “the photo [of the earth] from space has taught us one thing for sure: there is only one story.” If we’re all in the same boat, then perhaps we can see each other as spiritual sisters and brothers and treat each other with true altruism. In fact, we humans differ in less than 1% of our genes. When we realize that we really are sisters and brothers in this genetic sense, maybe our kin-directed altruism can be put in service of all humanity. It is believed that the word “religion” comes from the Latin root, “religare,” meaning to bind together. A religion grounded in the scientific story could truly bind us all together.

And finally, science shows us the incredible beauty of the universe. Some might say that rational, scientific understanding of the mechanisms of the universe diminishes our spiritual connection to it. I think the reverse is true: science gives us a front row seat from which to observe and appreciate the majesty and mystery of the universe. The resulting awe and wonder are reasons enough to feel a gratitude to nature for our existence. And as we know, gratitude is nature’s way of getting us to repay a favor. So let us repay it by treating all of creation with respect and love.