Primordial Light: Science is...

•Science is a means of obtaining knowledge about the World* based on a system of investigation called the scientific method. Scientific inquiry proceeds from the assumption that the physical World behaves in a regular and largely predictable manner.** Try to imagine a world that was not regular and predictable: what if Newton sat under the apple tree and watched as one apple fell down, the next fell upward, the next fell sideways, the next stood still, and so on, in a random order. It would have been impossible to devise a theory of gravity under those circumstances (but there would be no need for a theory of gravity because life could not have evolved in a Universe with no fixed laws).***

You can find many treatises on the scientific method on the Web, so I’m not going to offer my own meager understanding of the method. Instead, I will point out a few very basic things about how science works.

Science deals with assertions and observations about the World that can be tested and either verified or falsified. That excludes many (but not all) religious claims from the realm of science. A question that cannot be investigated by application of the scientific method falls into the realm of the supernatural (beyond the natural), in which science has no legitimate interest because the supernatural presents no physical evidence to investigate. That a scientific claim must be falsifiable is very important, because it is what separates scientific inquiry from ordinary inquiry. Walk into your office soaking wet and say that it’s raining outside and people will nod and perhaps show some sympathy. Walk into a physics colloquium soaking wet and say that it’s raining outside and everyone will proceed to try to prove that it isn’t raining; there must be some simpler explanation for why you are wet. Only after every other conceivable explanation has failed to explain your dampness—and several of the physicists have personally gone outside and gotten soaking wet in the rain—will your claim be accepted as possibly true. The foregoing is an exaggeration, but it is in the ballpark.

Beliefs that are held to be incontrovertibly true even if they are not supported by evidence are based on dogma or ideology, and not on reality. A belief system built on dogma, be it political or religious, is a weak one because it rarely consists of a single dogma, but of a series of interrelated dogmas—it is a house of cards. Disprove one element of the system and the rest come crashing down. Not all dogma is outside the realm of science. That the heavens are perfect and unchanging and that the Earth is the center of the Universe was once dogma to the Church of Rome. When these dogmas were shown to be false by Copernicus and Galileo the Church did not accept the proof, but punished the messengers**** because the Church was aware that a dogma is a house of cards. The former dogma, concerning the immutability of the heavens, is an interesting one because throughout human history anyone who looked at the sky (including the ecclesiastics who fabricated the dogma) could tell that it wasn't true. Meteors light the sky for a brief instant. There have been supernovae—exploding stars—that were so bright they could be seen in daylight. The supernova that formed the Crab Nebula was first seen on Earth on July 4th, 1054, and it was visible in daylight; in Europe, Johannes Kepler saw a supernova in 1604. Comets may light the sky for months (Galileo probably observed Halley’s Comet in its 1607 apparition). Galileo observed sunspots, and Chinese astronomers saw sunspots in 1077. Chinese astronomers recorded a number of astronomical events that were not reported in Christian Europe. These phenomena were certainly visible to European observers, but in some cases the observers were loath to risk being burned at the stake for telling the truth about what they had observed.

There is another interesting—and profound—effect of the Church of Rome’s adherence to dogma. It is dogma in the Church that the Pope is infallible in matters of faith and morals. It has been proven repeatedly over the centuries that that cannot be true—if one accepts certain other things as true. When a Pope defends a faith in a false dogma such as a geocentric cosmos, and orders or sanction the persecution and murder of persons who know that that dogma is false, then that Pope has made egregious errors in matters of faith and morals (but only if one accepts that a) the Universe is not geocentric and b) murdering people for telling the truth is an immoral act). Likewise, if one accepts, as many do, that the rape of helpless children, and complicity in protecting the perpetrators are both immoral acts, then the incumbent Pope, who has been shown by the Church’s own records to have protected persons known to him to be child rapists, cannot be infallable in questions of morality. To believe otherwise is to believe that child rape and the abetting of child rape are moral acts.

* World: In this sense, World means the entire observable, material Universe.

** But the Heisenberg Uncertainty Principle, which is a principle in quantum mechanics, postulates that the stuff that makes up the Universe cannot be precisely measured at the subatomic, or fundamental, level. Nonetheless, quantum mechanics is able to reliably predict the statistical probability that matter will behave in such-and-such fashion at the fundamental level. Those predictions are sufficiently accurate to have allowed the invention of transistors and integrated circuits, quantum devices that power our lives in the 21st century.

*** The common cold provides a rough example of what such a Universe would be like. The common cold cannot be prevented, cured, or even treated (except for its symptoms) because it is caused by a variety of rapidly evolving viruses. The cold you had last winter is not the same as the cold your spouse had. It is not the same as the cold you will have this winter. If all pathogens worked in that insidious way we would not be here.

**** The Church apologized 350 years later. Anyway, the Church has come a long way in Astronomy and Cosmology since the 17th century. Today the Vatican Observatory is a world-class research institution.

Other religious dogmas that have been repudiated to the satisfaction of rational people everywhere are the young-earth dogma and the biblical Creation Myth.

Generally, however, scientific theories are more easily overthrown than false religious or political dogmas. It is known that the dinosaurs flourished for nearly 200 million years before they became extinct about 65 million years ago.* (The cause of the extinction is still the subject of a lively and fascinating debate among scientists.) Humans similar to us did not appear until about 100,000 years ago; in other words, modern humans arrived on the scene 65 million years after the dinosaurs disappeared. Compared to the time the dinosaurs roamed the Earth** we have been here for the merest blink of an eye. These are known facts (though they are denied by anti-rationalist, anti-science religious fanatics, which caused a comedian to quip that creationists must think that The Flintstones is a documentary). But these are scientific facts, and that means that they could be falsified. All that is necessary to falsify the above statements (and cause a rethinking of the Theory of Evolution, but not its demise) is for a paleontologist to find T. Rex tracks in a human settlement, or the chewed-up remains of a hapless primate in a T. Rex’s belly! This will not happen. Likewise, the theory of gravity, handed down to us by Newton and Einstein,*** is also falsifiable. All it needs is for one apple to fall upward from a tree in the absence of forces other than gravity acting on the apple. This will not happen, either.

* In fact, the dinosaurs may not be extinct at all; many (though not all) students of the subject believe that birds are the living descendants of dinosaurs.

** I purposely avoided the cliché “dinosaurs ruled the Earth” because the dinosaurs did not rule the Earth. Since the beginning of life on Earth the Earth has been ruled by bacteria. It is likely that the bacteria will continue to rule so long as life persists on Earth.

*** Newton’s theory of gravity was superseded by Einstein’s General Theory of Relativity, which he published in 1916. The General Theory of Relativity is a theory of gravity that incorporates and expands on Einstein’s 1905 work, The Special Theory of Relativity. Newton described gravity as an attractive force between two bodies, while Einstein showed that gravity is a curvature in the fabric of spacetime that is caused by the presence of matter. Newton’s theory, however, is good enough for all practical purposes on Earth and through most of the Solar System and beyond. It can even predict the motions of galaxies containing hundreds of billions of stars. Where Newton’s theory breaks down, and is superseded by General Relativity, is in the vicinity of very massive bodies such as stars (including our Sun) and black holes. In the presence of such massive bodies the curvature of spacetime becomes significant (though less massive bodies such as grains of sand also create a curvature in the fabric of spacetime). A certain anomaly (precession) exists in the orbit of the planet Mercury, which is the closest planet to the (massive) Sun. The anomaly had been known for about 100 years before Einstein’s General Theory, but Newton’s theory of gravity could not explain it. General Relativity explains the anomaly beautifully. It is thought, however, that General Relativity will also be superseded one day by a new theory. The problem with our current understanding of gravity is that many theorists are convinced that the four fundamental forces in the Universe are manifestations of a single force that had effect for just an instant in the infinite energy and gravity that existed during the first few millionths of a second of the age of the Universe. Thus far, theorists can unite only three of the four forces, with gravity as the exception. The theory they seek is variously called the Theory of Everything (TOE) or the Grand Unification Theory (GUT) because the four fundamental forces account for everything that exists or occurs in the Universe, and if those forces could be shown to be different aspects of a single force, one equation would suffice to explain everything. The fundamental forces are 1) the strong nuclear force, which holds the nucleus of the atom together. This force is so strong that if you break its grip and split the nucleus you have a nuclear explosion, and if you break its grip by fusing two atomic nuclei you have a vastly more powerful thermonuclear explosion, but the strong force only acts over the smallest of distance scales; 2) the electromagnetic force, which is responsible for electricity and magnetism; 3) the weak force, which is behind radioactive decay, and 4) gravity. Gravity is by far the weakest of the four forces, but it has by far the longest reach: its effect can be felt across the Universe.

• We’ve been talking about theories. The Theory of Gravity. The Theory of Evolution. What is a theory?

The popular notion that a theory is a guess, a conjecture, or an opinion is far removed from the meaning of theory in science. Persons who refuse to acknowledge the fact that evolution is a property of life on Earth like to say that “Evolution is only a theory.” They’re being disingenuous, because they know what a scientific theory is, but they are attempting to mislead others as to the meaning of theory in science in order to convince them that a myth is the truth and the truth is a lie. Why do they not say “Gravity is ‘only’ a theory!?”

A theory is a logical and self-consistent description of observed facts or of the observed behavior of a set of natural or social phenomena. It is been observed frequently enough to be taken as fact that if you drop an object near the surface of the Earth that object will always fall down toward the Earth (absent external forces such as wind acting on a dropped sheet of paper). It was from this observed fact that Isaac Newton derived his theories of motion and gravity. A theory is held to a very high standard in science and it signals a high level of confidence; the word is sometimes used interchangeably with fact or law—the popular name of Newton’s theory of gravity is the Law of Gravity. To declare something to be a theory in science is to raise it to the highest level of confidence—knowing that it can never be proven. In order for the result of a line of research to be raised to the exalted status of theory it must pass endless, rigorous tests.

A theory must make predictions, and those predictions must be correct every time they are tested. Newton’s theory predicts that all falling objects accelerate at the same rate, regardless of their masses. Observations show that a brick and a feather dropped from the same height at the same instant will strike the ground at the same instant. The feather, at least, has to be dropped in a vacuum for this to work; otherwise the laws of aerodynamics will confound the law of gravitation—temporarily. (I did say that gravity is a very weak force.) The predictions of Newton’s theory have been tested over and over again, always with confirming results. As noted above, the limitation of Newton’s theory is not that it offers faulty explanations, but in what it cannot explain.

Steven Hawking wrote in A Brief History of Time “a theory is a good theory if it satisfies two requirements: It must accurately describe a large class of observations on the basis of a model which contains only a few arbitrary elements, and it must make definite predictions about the results of future observations”. He also said, “any physical theory is always provisional, in the sense that it is only a hypothesis; you can never prove it. No matter how many times the results of experiments agree with some theory, you can never be sure that the next time the result will not contradict the theory. On the other hand, you can disprove a theory by finding even a single observation which disagrees with the predictions of the theory”. This goes back to what I said above: if one apple falls upward from its tree the Theory of Gravity is in trouble. Hawking was being very rigorous, as he should have been. Pin him down, however, and I’ll bet that he would admit that, as a practical matter, some theories may rightly be accepted as established facts.

There are a few theories that have been the subject of so many challenges and test, and that have passed those tests, that they may rightly taken as being true. Those theories include gravity (even though our understanding of gravity is incomplete); the theory of evolution; the germ theory of disease, and, more recently, the theory of climate change in which human activity plays a role. These are probably the most tested and most trustworthy theories in science; scientists have spent more time (and money) trying to disprove these theories than they have spent on all other theories. The theories continue to pass the tests, and the emphasis has shifted from trying to overthrow them (because it isn’t going to happen, though it could, because they are scientific theories) to trying to refine them. This may seem to contradict what I said above about the General Theory of Relativity being superseded one day. The discovery of a Grand Unified Theory, if it happens, will be a truly monumental achievement, but General Relativity will remain valid in its realm, just as Newtonian Mechanics is valid in its realm, and General Relativity will not be proved utterly false in the way that the Copernican Revolution invalidated Ptolemy’s cosmology.

This treatise is not about climate change, but here is an aside on that subject. There are economic powerhouses—the global energy industries and the automobile industries in particular—that deem it to be in their interest to claim that global climate change is not happening, or that human activity—specifically, the combustion of hydrocarbon fuels and the concomitant release of vast quantities of carbon into the atmosphere—is not at least in part responsible. They can produce scientists—real, legitimate, scientists—who will confirm the assertions of these for-profit industries. Some of these scientists are the same ones who confirmed for the tobacco industry that smoking does not cause cancer, heart disease, or other illnesses. This is bogus science, paid for by people with a political and financial ax to grind. The evidece for global warming does not come from TV weathermen (climate and weather are not the same thing; a cold spell in January in south Florida, for example, has nothing to do with climate and does not in any way disprove the theory that the earth’s climate is changing in an unprecedented way due largely to human activity. The anti-climate-change claque are a paid lobby, not a scientific community with a set of testable claims. One can, incidentally, also find authentic, PhD-level scientists who do not believe the theory of gravity, the theory of evolution, or the germ theory of disease. None of them, however, has testable evidence to support their claims. They may be scientists, but they are making non-scientiic claims.

The lack of even a basic understanding of science among the American people is appalling. Most people can’t answer the most basic questions about the world around them. How long does it take for the Earth to complete one rotation on its axis? (Hint: it’s not 24 hours.) Why do we have seasons? What are the equinoxes? The solstices? (Hint: they're tied to the reason we have seasons.) What is a molecule? How do airplanes manage to fly? How do we know what distant stars are made of? A quarter of Americans believe in astrology, which has no basis in reality. A third believe in UFO’s, the existence of which is not supported by even the tiniest bit of evidence. 28% believe that witches exist (ditto). 21% believe in reincarnation (ditto). An amazing 40% believe in ghosts (ditto); and an even more amazing 73% believe in medical miracles. Even many doctors say they believe in medical miracles. The next time you run across someone who believes in medical miracles, ask them these questions: Why has no amputee ever had a limb miraculously restored? Why does the medical literature contain no record of a baby born with Down Syndrome miraculously becoming healthy? What about babies born with physical defects incompatible with life—anencephaly, for example? Does the Bestower of Miracles have something against amputees and tragically deformed babies? Does that make sense in a world where medical miracles are said to occur? The answer is no, it doesn’t make sense, and I believe that the World either makes sense or it doesn't, and if it doesn't, then all bets are off; all that we think that we know about the World is wrong. This does not disprove the occurrence of miracles, for as we have seen, with no evidence to test, that cannot be disproved. But rational people have good reason to disbelieve in miracles—because there are no miracles. Everything that happens has a physical cause, whether we know that cause or not. Here’s something that does make sense: People ascribe to the supernatural those things that they cannot—or will not—understand. Among other things, that liberates people from the burden of thinking and learning, and it keeps their minds uncluttered by even an elementary understanding of the World they live in. Unfortunately, this ignorance, which is part of the scientifically measurable phenomenon known as “the dumbing of America,” is a primary contributor to the political, economic, and social decline of America. The problem is exacerbated by the fact that certain commercial interests have found that having an uneducated public can be very profitable, and those commercial interests have found a powerful ally in one of our two main political parties.

So. Is that it, then? Do we know everything there is to know about the origin and evolution of the Universe? Physicists have been declaring “the end of physics;” i.e., that we know all there is to know on the subject, for some hundreds of years. Not quite, I'm afraid. There are many deep mysteries in physics, and every answer raises new questions. Here are just a few of the myriad things that physicists don’t know (yet):

• The Big Bang Theory is a description of the events that occurred beginning a few billionths of a second after the origin of the Universe. What happened during those first billionths of a second?

• What, if anything, came before the Big Bang; i.e., what caused the the Universe to come into being, and where did it happen, since there was no “where” yet in which any events could happen? The Universe did not appear and begin to expand into pre-existing empty space; space itself originated at the instant of the Big Bang, and the expansion of the Universe includes the expansion of space itself.

• Did time have a beginning? Did time exist before the Universe came into existence, or did it begin with the Big Bang? Theistic religions usually claim that their gods are eternal, and at least one faction—the Church of Rome—says that while their god existed for an infinite amount of time before he created the Universe, it is forbidden to ask what he was doing before he created the Universe. I think that’s a perfectly valid question, because if the Roman god is eternal, he spent an infinite amount of time nowhere. Why did he suddenly create the Universe after an infinite time nowhere, doing nothing? How did he decide when to create the Universe? (I don't know if the Church really considers its god to be a male, but they have to use some pronoun. "It" seems too impersonal, and the Church is a male-dominated institution, so it is hardly surprising that they don’t represent their god as a goddess.) But I digress.

• What is time, anyway? The laws of physics show no preference for the direction of the flow of time; the laws work equally well whether time is seen to flow forward or backward, yet the psychological arrow of time—the way we perceive time—moves only forward. Why do we remember yesterday and not tomorrow? (Yes, that is a valid scientific question. See also thermodynamics and the arrow of time.)

• Why should there be a thing we call mathematics that can describe with such elegance the workings of the Universe?

• Is M Theory—the extension of String Theory that asserts that all of the fundamental particles and forces in the Universe are made up of infinitesimally small, vibrating strings of energy—correct? We experience three dimensions and Einstein showed that, while it is not obvious, time is our fourth dimension, with the three spatial dimensions (x, y, z) and time comprising a continuum called “spacetime”. M Theory could be the foundation of a Grand Unified Theory, yet it predicts that there are 10 or 11 dimensions. What are we to make of that? (The notion that space and time are aspects of the same thing can be a difficult concept to grasp. As far as is known, everything in the Universe except mathematical points and imaginary lines exists in three spatial dimensions. Consider a tree, perhaps. It has width x, height y, and depth z, but it also exists during a certain period in time, and a complete description of the tree would include all four of those dimensions.)

• It is a widely held principle of science that the most elegant answer, meaning the simplest answer, to a question is very probably the correct answer. See Occam’s Razor. While current theories such as General Relativity, M Theory, and quantum mechanics may be said to be mathematically elegant, the mathematics is complex, and only a handful of people understand these theories. Could it be that we will never understand the Universe at its most fundamental level, either because in the 13.75 billion years since the beginning of the Universe critical evidence that would enable us to explain the fundamentals has become blurred and diluted, or because the answer is so complex that the human mind will be unable to formulate a coherent description (theory) of the Universe’s basic laws? It is my belief that the Universe ought to be accessible to the average person (practically anyone who knows arithmetic can achieve an understanding of Newtonian mechanics) and I will be very disappointed if a Theory of Everything is derived and that theory is too complex for ordinary people like me to comprehend. There are not very many mathematical physicists in the world. Why should the workings of the Universe be accessible to only an extremely tiny fraction of the human population? My belief, that an understanding of the Universe should be accessible to everyone, has no basis other than the fact that it is the way I would like for the Universe to be. Thus, my belief is based on wishful thinking; it is not a theory.

• Organic molecules (molecules that contain carbon and that are necessary for the existence of all life that we know about) are very common throughout the Universe. Will these organic molecules always interact in such a way as to produce life if conditions in a certain place (most likely, but not necessarily, a planet) are right, i.e., if conditions are warm and wet, as they have been for most of the history of the Earth? In other words, is life common in the Universe?

• Extending the previous question—Is anyone out there? Are there other self-aware beings in the Universe? It seems that everyone says there must be, and serious scientists have invented equations showing that it is mathematically certain that there are. The reality, however, is that we have not seen any evidence whatsoever that sentient beings exist elsewhere. In the foregoing link, the physicist Enrico Fermi counters Drake’s equation by famously asking “Where are they?” Where, indeed! The size of our galaxy, not to mention the size of the Universe, makes it very possible, if not probable, that we will never know if there is anyone out there. Equally unappealing is the probability that even if we found proof (radio signals, most likely) that another civilization exists, the distance between them and us would make it impossible for us to converse with them. If they were 50,000 light-years from us and we sent a friendly greeting via a sufficiently powerful radio signal, they would receive the signal 50,000 years later. If they replied immediately we would receive the answer 100,000 years after we sent the greeting; if they were contemplative beings they might think for another 50,000 years before replying. Would the knowledge that we had sent a greeting persist on Earth for 100,000 years or more so that someone here would know to turn on a radio at the right time to listen for an answer? Consider, too, the possibility that there is an advanced civilization much closer to us—say, no more than 100 light-years away. If they're listening, they already know about us, because they have received radio signals from Earth. They could, in theory, visit us within perhaps a couple of thousand years. Would we want that? What if they are in a situation that is a popular, and quite plausible, science-fiction theme—their home planet is threatened by natural phenomena (the aging of their sun, planetological activity, climate change) or by their own actions (pollution, war). Suppose they are looking for a new home and a good supply of cheap labor. Or food. Suppose they carry pathogens that could kill us all. It has been suggested that we need to consider whether we should take steps to prevent other civilizations from detecting our presence, at least until we have detected them and had an opportunity to assess their civilization first through the study of their unintentional radio emissions. Alien visitors, too, might face risks. Perhaps our message would be a declaration of jihad or a promise of eternity in hell if the aliens aren’t the right color or of the right religion. In a world where we kill people by the hundreds of thousands over the mistaken belief that they are different from us in some way, imagine how we might react to beings who were really different from humans in their appearance and their philosophy. I think it would be a shame if a group of non-human diplomat-scientists traveled thousands of years to deliver wondrous offerings of peace and friendship to the people of Earth, only to land and promptly get lynched or imprisoned. This, too, is a plausible science-fiction theme.

Develop a theory—not a guess, but a theory—that answers any one of the questions raised above and you will have a good shot at winning the Nobel Prize in something or other.

Finally, just for fun, here are two things we know. I think they are both fascinating and disappointing.

Time travel into the future is possible so long as your frame of reference is the time on Earth at which you began your journey. Einstein showed that as objects move faster, their clocks run slower compared to those of a stationary observer. This is called time dilation. This phenomenon has been measured in the every-day world by extremely precise clocks, but the effect isn’t significant until you approach the speed of light (about 186,000 miles per second in a vacuum). Speeds approaching the speed of light are called relativistic speeds because General Relativity describes the effects of traveling at such speeds. If you could leave the Earth and travel at perhaps 99% of the speed of light and return to Earth two weeks later (by your clock) you would find that more than two weeks had passed on Earth—in other words, you would have traveled into the future. You would not have noticed this as a slowing of time because within your frame of reference your clock, your calendar, the growth of your hair and nails, would all have been normal. But when you got home your friends would have aged more than you. Your friends would not have noticed anything different, either, but compared to you they would have marked off more days (or months, or years) on their calendars. If you traveled at an acceleration rate of 1g you could, in your lifetime, return to Earth billions of years later (by Earth time) than when you left. You would have traveled billions of years into the future.

• Now the bad news: After traveling into the future you couldn’t return to your own time to be reunited with your loved ones. Travel backward in time will never be invented. How can we be sure of that? Stephen Hawking has written some highly technical papers on the subject, but he also put it in practical terms: If travel backward in time will ever be invented during the span of human habitation of the Earth, we would have had visits by researchers, and probably tourists, from the future. There have been no such visitors. Can we be sure of that? Yes, quite sure. One might argue that a visitor from the future could appear at a remote point in the Gobi desert in the middle of the night and spend a few minutes and then return to her own time without being detected, but what would be the point? To see what sand looked like in the past? The first visitors from the future, before the tourists began arriving, would be researchers and they would want to see people, and they would be noticed. There is a logical conundrum here, as well. How can someone who hasn't been born yet appear among us as a tourist? Consider, too, the murder paradox: What if someone traveled into the past and encountered himself as an infant and killed the infant that is himself? Travel into the past seems to present insurmountable paradoxes.

Nature and Nature's laws lay hid in night;
God said, Let Newton be! and all was light
Alexander Pope
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