Drawing Philosophy from Physics: Richard Feynman’s Messenger Lectures

Why Does the Universe Act as It Does?

Why does the world behave as it does?  Why do planets go around the sun?  Why do satellites travel in elliptical orbits?  Why?  To any parent of a young child, the rabbit hole of endless questions will sound familiar.  Although your preschooler seems to be never satisfied with answers, we often reach a point in mature life, when we stop asking questions and instead accept the visible world around us as stable and obvious and unchanging.  If we can resist this tendency to stop questioning, we realize that the chain of explanation never ends.

I left hard sciences behind when I chased Dickens down the path to an English degree and Atticus Finch to law school.  But I’ve kept up a casual interest in physics and cosmology topics since.  During a recent dinner party conversation with friends more accomplished in scientific fields than I, I commented that one of my recurring frustrations with law practice is the fungibility of argument and the lack of firm answers.  My (uninformed) view was that scientific study must offer a respite from a world of uncertainty and imprecision. One friend recommended that I read Richard Feynman’s Cornell University lectures, telling me that even among the work of Noble laureate physicists, “there is no ‘there,’ there.”

Richard Feynman on What Scientists Do

In 1964, the then 46-year old physicist Richard Feynman gave a series of seven Messenger lectures at Cornell University.  They were then transcribed and published under the title The Character of Physical Law. Feynman would win the Nobel Prize the next year for his work in quantum electrodynamics, which tied together all the varied phenomena present in light, radio, magnetism, and electricity.  The lectures had been established as a course “on the evolution of civilization for the special purpose of raising the moral standard of our political, business, and social life.”

On their face, Feynman’s lectures provide a broad overview of major topics of physics and scientific inquiry: gravitation, conservation, symmetry, past and future, and probability and uncertainty.  At the heart of each of these lectures, however, are the unifying questions of “what does a scientist do,” and “how does a scientist know what he’s doing is valid?”

Through these lectures, Feynman explains that scientists find explanations satisfying when they cease to be random but instead rely upon a generalized, unifying law. Recalling our opening question, “why do the planets go around the sun?,” Feynman explains that all objects travel in a straight line when left alone, but when that unchanging motion is combined with a gravitational force – the law of gravitation – the result is an ellipse and a planetary orbit.

Doubt and the Beauty of Nature’s Fabric

Feynman’s lectures contain an unexpected and marvelous surprise by acknowledging and embracing the role that doubt and uncertainty play in our relationship with the Universe. While I came to this book expecting concrete explanations and unraveled mysteries, Feynman makes the point again and again that while we may have figured out how the Universe works, we can have no insight into why it works the way it does.

In pondering the mathematical reality of gravity, that gravitational force between two objects is directly proportional to their masses, but inversely proportional to the square of the distance between them, Feynman states that there is no way to understand this mystery other than with mathematics.  The formula, F=M1M2/r2 explains the reality of gravity, but with no further explanation of the mechanism.  This can cause frustration, until we accept that the same impenetrable problem of mathematical truths is universal:

If this were the only law of this character it would be interesting and rather annoying.  But what turns out to be true is that the more we investigate, the more laws we find, and the deeper we penetrate nature, the more this disease persists.  Every one of our laws is a purely mathematical statement in rather complex and abstruse mathematics.  Newton’s statement of the law of gravitation is relatively simple mathematics.  It gets more and more abstruse and more and more difficult as we go on.  Why?  I have not the slightest idea.  It is only my purpose here to tell you about this fact.

Feynman encourages us to become comfortable with doubt throughout the seven lectures. Once we become comfortable with the existence of doubt, we can appreciate what it is that can be said for certain about the known laws of the Universe.  First, they are simple. Feynman makes this point about gravity:

But the most impressive fact is that gravity is simple. . . . It is simple, and therefore it is beautiful.  It is simple in its pattern.  I do not mean it is simple in its action – the motions of the various planets and the perturbations of one on the other can be quite complicated to work out, and to follow how all those stars in a globular cluster move is quite beyond our ability.  It is complicated in its actions, but the basic pattern or the system beneath the whole thing is simple.  This is common to all our laws; they all turn out to be simple things, although complex in their actual actions.

Second, the laws of the Universe are constant and (pun intended) universal.  Our lives contain information streams of such complexity that for all our ability to decipher them, they might as well be random.  And yet, beneath the visible chaos are simple patterns.  We know this to be true because of the universality of these systems:

Finally, comes the universality of the gravitational law, and the fact that it extends over such enormous distances that Newton, in his mind, worrying about the solar system, was able to predict what would happen. . . ., where [a] little model of the solar system, two balls attracting, has to be expanded ten million million times to become the solar system.  Then ten million million times larger again we find galaxies attracting each other by exactly the same law.  Nature uses only the longest threads to weave her patterns, so each small piece of her fabric reveals the organization of the entire tapestry.

Multidisciplinary Thinking and the Universe of Ideas

On a basic level, Feynman’s lectures discuss the laws of physics and the mathematical underpinnings of those laws.  But the reason that Feynman is so compelling on these topics is that he understands the greater human point to the intellectual struggle.

Feynman notes that, “we have a way of discussing the world, when we talk of it at various hierarchies, or levels.”  At the most basic level are the fundamental laws of physics.  Next are the properties of substances, such as surface tension or the manner in which they might bend light.  Continuing to increase in complexity are collections of phenomena, such as a weather storm or a star.  Next lie things like a muscle twitch, or nerve impulse, which is an “enormously complicated thing in the physical world.”  Beyond that lie the organization of matter in even more elaborate complexity, like living beings.  Finally are the highest level concepts, like man, history, evil, beauty, and hope.

Feynman asks us to consider what is the most beautiful, perfect, and mysterious?  Is it the world of greatest complexity, or the most fundamental laws?

Which end is nearer to God?  Beauty and hope, or the fundamental laws?  I think that the right way, of course, is to say that what we have to look at is the whole structural interconnection of the thing; and that all the sciences, and not just the sciences but all the efforts of intellectual kinds, are an endeavor to see the connections of the hierarchies, to connect beauty to history, to connect history to man’s psychology, man’s psychology to the working of the brain, the brain to the neural impulse, the neural impulse to the chemistry, and so forth, up and down, both ways….

And I do not think either end is nearer to God.  To stand at either end, and to walk off that end of the pier only, hoping that out in that direction is the complete understanding, is a mistake.  And to stand with evil and beauty and hope, or to stand with the fundamental laws, hoping that way to get a deep understanding of the whole world, with that aspect alone, is a mistake.

It is, according to Feynman, those who are struggling to understand the world from both extremes who are making meaningful progress towards insight.

The great mass of workers in between, connecting one step to another, are improving all the time our understanding of the world, both from working at the ends and working in the middle, and in that way we are gradually understanding this tremendous world of interconnecting hierarchies.

If you haven’t jumped down the rabbit hole of Feynman’s writing yet, don’t wait any longer.  I think Surely You’re Joking, Mr. Feynman is a great place to start, but you can’t go wrong with any choice.  Pair with Richard Feynman on the Value of Straight Talk.

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Dark Matter and the Dinosaurs: Harvard Physicist Lisa Randall on Our Place in the Universe

If there is a connecting theme in my intellectual pursuits, it is the goal of finding connections between ideas that open up a new window of perception and expose some hidden truth. Harvard physicist Lisa Randall has written a stunningly beautiful example of the creativity that comes from the study of the intersection of great ideas, in Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe.

Did Dark Matter Cause the Extinction of the Dinosaurs?

Sixty-six million years ago, an object the size of a small city crashed into what is now the Yucatan Peninsula in Mexico.  The cataclysmic event, known as the K-Pg Extinction, killed off the dinosaurs and 75% of the remaining life on Earth. Randall’s book presents a hypothesis that seems simple, but quickly reveals massive complexity: that “dark matter might ultimately (and indirectly) have been responsible for the extinction of the dinosaur.”

To test this theory, Randall weaves an explanatory narrative that is approachable enough for readers unfamiliar with cosmology and particle physics, but thorough enough to satisfy the more curious.  Dark matter makes up 85% of the matter in our universe, but we cannot see or touch it.  It interacts with gravity, but not with light or visible matter. The theory that Randall and her colleagues have advanced is that the K-Pg impact was caused by a comet passing through a disk of dark matter on the horizon of our galaxy. When the cosmic wrecking ball touched the dark matter, it was deflected toward Earth and its dinosaur inhabitants.  It left a changed world, the death of the dinosaurs, and new evolutionary opportunities for mammals and their descendants.

The book succeeds on a fundamental level for its historical explanation of the theories of dark matter and the extinction event. But Randall excels in using this scientific explanation as a point of departure for bigger themes about the limits of our perception and our place in the Universe.

We See Very Little of the Universe

Our powers of observation are weak and contain massive blind spots.  As Randall reminds us, “the Universe contains a great deal that we have never seen – and likely never will.” The dark matter that Randall studies composes up to 85% of the matter in our Universe, and yet no one has ever seen it, or felt it, or heard it.  Physicists know that it is there because of its gravitational pull, but otherwise have been unable to conduct experiments on it.

At first mention to the uninitiated, this idea might seem contrary to the natural order. Why would there be matter that we cannot see or touch?  Randall points out that this is nothing more than a bias on our part in favor of overestimating our capacities:

People ask how it can possibly be that most matter – about five times the amount of ordinary matter – cannot be detected with conventional telescopes.  Personally, I would expect quite the opposite…. Why should we have perfect senses that can directly perceive everything?  The big lesson of physics over the centuries is how much is hidden from our view.

We rely on our senses every day.  Without confronting evidence to the contrary, we fall into the easy trap of believing that we can perceive and understand all around us.  But our blind spots are huge, and making sense of our relationship to the Universe requires us to confront this point and embrace uncertainty.

Telescopic image revealing the gravitational pull of dark matter.
Telescopic image revealing the gravitational pull of dark matter

Finding Freedom in the Cosmic Order

The greatest lesson I found in Randall’s book is the realization that we are central to nothing in the Universe of any cosmic significance, and that there is unparalleled freedom in embracing our insignificance.

Between 1500 and 1950, humanity fought against, and then accepted, three great intellectual revolutions.  First, Copernicus taught us that we are not the center of the Universe.  Centuries later, Darwin taught us that we are not the center of life on Earth. Shortly thereafter, Freud taught us that we are not even at the center of our own minds. Randall proposes that modern physics should cause us to undergo a “Fourth Revolution,” in which we realize that our fundamental physical makeup is not aligned with the majority of the Universe:

Not only is the Earth not physically the center of the Universe, but our physical makeup is not central to its energy budget – or even to most of its matter.

Theists sometimes advance an argument for intelligent design that supposes that the fact that the Universe is “something,” rather than “nothing,” is of some cosmic significance tending toward the existence of God.  At the very least, they argue, it is evidence that the Universe is not a random occurrence.  According to Randall, the idea that “something” is special doesn’t hold true under mathematical scrutiny.

One question I frequently hear is why there is something rather than nothing…. I just think something is more likely.  After all, nothing is very special.  If you have a number line, “zero” is just one infinitesimal point among the infinity of possible numbers you can choose.  “Nothing” is so special that without an underlying reason, you wouldn’t expect it to characterize the state of the Universe.

At first glance, one might consider these notions of insignificance to be depressing or saddening.  I don’t. One of the unavoidable conclusions of any consideration of the K-Pg event is that death and destruction lead to new life.  The K-Pg comet destroyed the dinosaurs and three-quarters of the Earth’s life, and yet without that extinction, it is likely that birds, mammals, and humans would never have had the evolutionary opportunity to exert their influence on the world.  As Randall puts it, “extinctions destroy life, but they also reset the conditions for life’s evolution.”

It’s worth remembering that the K-Pg extinction was not the first time the Earth had experienced an extinction event.  In fact, it was the Fifth Great Extinction.  Four times before, the Earth and its cosmic environment turned hostile to its global set of inhabitants, destroying and paving the way for new evolutionary paths.  We are the beneficiaries of the K-Pg extinction.  And if Randall’s theory is true, our entire race’s birth, development, and eventual extinction are the product of the seemingly random interaction of a comet and a disk of imperceivable dark matter on the edge of our galaxy. That random collision, some 65 million years ago, is responsible for the Mona Lisa, Hamlet, the Magna Carta, Taco Bell, and the Macarena.  All is Stardust, after all.

These things, of course, have a finite life.

In another four billion years or so, the Sun will turn into a red giant, and a few billion years after that, it will burn out completely.  According to current models, no forms of Earth-bound life – simple or complex – will survive in that distant future.

So what do we make of this?  The conclusion I keep returning to is that the bad day at the office doesn’t matter.  A disappointing outcome on a business deal doesn’t matter.  The things that cause  stress and anxiety and jealousy, that make me compare myself and my accomplishments to those of other people, that make me feel like I have failed in some way – they don’t matter.  They are of such infinitesimal consequence that they are not worth mental energy or focus.  The time we have is short and beautiful, and we should fill it with all of the love and charity and teaching and learning that we can.

I don’t know if Lisa Randall considered this type of impact when she wrote her book.  I have to believe that she considered its possibility.  In relying on lessons from cosmology, particle physics, biology, environmental science, geology, and contemporary culture, she has created a multidisciplinary masterpiece that gives a markedly unique perspective on our place in the cosmos.  Highly recommended.