Tag: physics

Canali, Aristocrats, Ant-Men: David Baron on Mars

Posted on by David Kordahl

by David Kordahl

This article is a lightly edited transcript of a conversation with David Baron about his new book, The Martians: The True Story of an Alien Craze that Captured Turn-of-the-Century America. A video of this conversation is embedded below.

Intro and Percival Lowell Background (0:00)
Origins of the Canal Craze (6:39)
Gathering Evidence for the Canals (10:41)
Scientific Debate with Astronomers (14:02)
Thinking about “Outsider Scientists” (23:35)
Influence of Canals on Culture (27:45)
Reflections on Mars and the Future (32:33)

Intro and Percival Lowell Background

Today I’m speaking with David Baron, a seasoned science writer who has contributed to many major American journalism outlets, including the New York Times, the Washington Post, and the Wall Street Journal. He was a longtime science correspondent for NPR, and his TED Talk on the experience of solar eclipses has been viewed millions of times. His last book, American Eclipse, won the American Institute of Physics Science Writing Award in 2018. Today we’ll be discussing his new book, The Martians: The True Story of an Alien Craze that Captured Turn-of-the-Century America.

The “alien craze” in the subtitle of your book is the story of how, for about a decade at the beginning of the twentieth century, many people came to believe that the planet Mars held not only life, but a complex civilization. The person most responsible for popularizing this view as an established scientific fact was Percival Lowell. Lowell functions as a main character in your book.

I want to thank you for joining me today. At what point in your reporting for this book did it become clear that Lowell would function as a central figure in your story?

Oh, pretty much I knew that from the start. I first learned about the so-called “canals on Mars” from Carl Sagan, when I was in high school and watched the Cosmos series on PBS. On an episode about Mars, Sagan talked about this astronomer, Percival Lowell, who at the turn of the last century saw these weird lines on Mars that he believed were irrigation canals. It’s remembered as one of the great blunders in science, because it was an idea that really took off.

What actually surprised me was not that Lowell was my main character, but just how many other people got swept up in this craze—some of them quite prominent, famous scientists and inventors who totally believed that in fact there was the civilization on Mars. It was not just Percival Lowell. It was quite a collection of interesting characters. Read more »

Tuesday, October 28, 2025

Why AI Needs Physics to Grow Up

Posted on by Ashutosh Jogalekar

by Ashutosh Jogalekar

There has long been a temptation in science to imagine one system that can explain everything. For a while, that dream belonged to physics, whose practitioners, armed with a handful of equations, could describe the orbits of planets and the spin of electrons. In recent years, the torch has been seized by artificial intelligence. With enough data, we are told, the machine will learn the world. If this sounds like a passing of the crown, it has also become, in a curious way, a rivalry. Like the cinematic conflict between vampires and werewolves in the Underworld franchise, AI and physics have been cast as two immortal powers fighting for dominion over knowledge. AI enthusiasts claim that the laws of nature will simply fall out of sufficiently large data sets. Physicists counter that data without principle is merely glorified curve-fitting.

A recent experiment brought this tension into sharp relief. Researchers trained an AI model on the motions of the planets and found that it could predict their positions with exquisite precision. Yet when they looked inside the model, it had discovered no sign of Newton’s law of gravitation — no trace of the famous inverse-square relation that binds the solar system together. The machine had mastered the music of the spheres but not the score. It had memorized the universe, not understood it.

This distinction between reproducing a pattern and understanding its cause may sound philosophical, but it has real consequences. Nowhere is that clearer than in the difficult art of discovering new drugs.

Every effective drug is, at heart, a tiny piece of molecular architecture. Most are small organic molecules that perform their work by binding to a protein in the body, often one that is overactive or misshapen in disease. The drug’s role is to fit into a cavity in that protein, like a key slipping into a lock, and alter its function.

Finding such a key, however, is far from easy. A drug must not only fit snugly in its target but must also reach it, survive long enough to act, and leave the body without causing harm. These competing demands make drug discovery one of the most intricate intellectual endeavors humans have attempted. For centuries, we relied on accident and observation. Willow bark yielded aspirin; cinchona bark gave us quinine. Then, as chemistry, molecular biology, and computing matured in the latter half of the twentieth century, the process became more deliberate. Once we could see the structure of a protein – thanks to x-ray crystallography – we could begin to design molecules that might bind to it. Read more »

Monday, September 15, 2025

Little Cousin Bernie Swears He Can Fly Like Buck Rogers — The Memoir of a Free-Range Professor Continues

Posted on by Barbara Fischkin

by Barbara Fischkin

Buck Rogers wearing his flying belt. Vintage comic strip panel.

Eight weeks have passed since I wrote about my Cousin Bernie—and how, posthumously, he adds to my own memories of him. As readers may remember from my last offering, Cousin Bernie’s widow, Joan Hamilton Morris, sent me the pages of an incomplete memoir her late husband pecked out on a vintage typewriter in an adult education class he took after retiring as a university professor of psychology and mathematics.

If Cousin Bernie were alive today he would be 102. Those pages of memoir chapters, some more worn than others, remain in a place of honor, tucked into a corner of my own writing table. I feel that “Cousin Joanie,” as I call his widow, sent them to me for safekeeping—and for presentation to the world. Originally I thought I could do this in one or two chapters. A deeper read has revealed a surprising amount of insight. Here is my fourth take on my cousin, who fascinates me despite his evergreen persona as a nerdy, chubby, lost boy from Brooklyn. There will be a fifth offering and probably a sixth. If it seems Bernie is taking over my memoir, I am fine with this. I have written a lot about my mother’s side of the family. Now it is my father’s family’s turn.  And what better way to bring them into the light, than through Cousin Bernie?

What follows is Cousin Bernie, Part Four. I’ve only edited it slightly, less so I think than his Adult Education teacher. So far, my minor editing has provoked no lightning bolts from the heavens. I have discovered another Bernie, a child who believed he could fly like his comic strip hero.

“I was eight years old, and my sister, Gertie, six. We had just been transplanted to Bridgeport, Connecticut from Brooklyn, New York. My father, a home painter and decorator, felt that he could do better in terms of finding work in a smaller city.

“Here, a whole new set of stimuli presented itself: A Benjamin Franklin stove in the kitchen, a gas water heater in the bathroom, which had to be lighted so we could bathe, and a coal bin on the back porch. There was a scuttle for bringing in coal for the stove. The Saturday Sabbath meal preparations—gefilte fish, stewed chicken and beef, challahs, cookies and pies—began as early as Wednesday night. The stove was banked and allowed to go out on Saturday night.

“We slept as the stove died down and, on Sunday mornings, my sister and I would climb into my parents’ big bed. Pop got up wearing his union suit, put on a robe, removed the ashes, kindled a new fire in the stove and came back to bed with us for my reading of the Sunday comics. My sister, Gertie, pointed to each speech bubble, as I read them. It seemed to me that Andy Gump’s nose or chin was strange looking. I disliked it when the bubbles were long. But it was here in the Sunday comics that I encountered the adventures of ‘Buck Rodgers in the Twenty-Fifth Century.’  Read more »

Wednesday, August 6, 2025

Activists and stewards in the shadow of Hiroshima

Posted on by Ashutosh Jogalekar

by Ashutosh Jogalekar

Eighty years ago on August 6, 1945, a blinding flash of light changed the world forever. The shadow of Hiroshima and Nagasaki has been with us ever since. Scientists struggled to make sense of the milennial force they had unleashed on the world. While science had always had some political implications, the advent of nuclear weapons took this relationship to a completely new level. For the first time humanity had definitively discovered the means of its destruction, and the work of scientists had made this jarring new reality possible. Scientists struggled with the new reality just like everyone else. Suddenly they were cast into the limelight as the new mandarins, becoming the politicians’ most important resource almost overnight. They were asked to offer advice on matters of seismic political and world significance for which they had not equipped themselves through their education and research.

Generally speaking, scientists who responded to this new reality fell into two camps. Let’s call them activists and stewards. Neither is meant to be a derogatory description. Neither group is “good” or “bad”, and both were important. To make the distinction clear, let’s consider some concrete examples. Robert Oppenheimer was an activist; Hans Bethe was a steward. Carl Sagan was an activist; Sidney Drell was a steward. Edward Teller was an activist; Herbert York was a steward. Leo Szilard was an activist; Enrico Fermi was a steward.

The primary difference between the two groups was that activists were revolutionary while stewards were evolutionary. Activists believed that the new age of nuclear weapons demanded urgent changes; stewards shared in the activists’ sense of urgency but believed that as painful as reality was, change needed to be worked from within, through institutional structures, through compromises and gradual advances.

The careers of Oppenheimer and Bethe provide a striking and instructive contrast between the two groups. Read more »

Monday, July 14, 2025

A Quantum Correspondence

Posted on by David Kordahl

by David Kordahl

Peter Morgan has worked for decades to appreciate the underlying structures of physics. But can he convince others he is right?

Magritte, Le fils de l’homme (1964).

When I receive unsolicited scientific communication, I bin writers into two crude categories: Possible Collaborators, and Probable Crackpots. Of course, these categories may overlap. Ted Kaczynski, after all, taught at Berkeley before he made those bombs.

When I first received a message from Peter Morgan, I wasn’t sure where to slot him. The fact that he was listed as a lab associate for the Yale University Physics Department pushed the needle of my prior judgment toward Collaborator. But the fact that he was cultivating journalists to promote his ideas about quantum theory…well, that swung my needle far the other way.

Morgan first contacted me on X.com (the website formerly known as Twitter) on December 9, 2024. I had posted the review of Escape From Shadow Physics: The Quest to End the Dark Ages of Quantum Theory that I had written for 3 Quarks Daily, and he posted a short comment in response. Seeing Morgan’s frequent physics posts, I followed him. Minutes later, he pitched me a column idea.

Morgan suggested that I write about his ideas:

I hope that if there are any of the ideas that deserve to go viral, they will do so sooner rather than later, then I can admire what better mathematicians and physicists than I am can do with whatever survives the winnowing. There are quite a few people who react positively to how different this is (for one thing it’s not a ToE, and the data and signal analysis aspect is met almost joyfully by some people), but I’m so far out in left field that nobody quite believes that I’m not making some obvious mistake. It’s always embarrassing to be the person who champions nonsense, right?

Right. I went to Morgan’s profile and watched one of the talks on his YouTube channel. After realizing I had no immediate way of assessing whether there was any there there, I sent him a polite but noncommittal reply, and placed a mental bookmark, thinking I might contact him again once I had time to spare. Read more »

Monday, June 9, 2025

Richard L. Garwin (1928-2025): Force of Nature

Posted on by Ashutosh Jogalekar

by Ashutosh Jogalekar

There are physicists, and then there are physicists. There are engineers, and then there are engineers. There are government advisors, and then there are government advisors.

And then there’s Dick Garwin.

Richard L. Garwin, who his friends and colleagues called Dick, has died at the age of 97. He was a man whose soul imbibed technical brilliance and whose life threaded the narrow corridor between Promethean power and principled restraint. A scientist of prodigious intellect and unyielding moral seriousness, his career spanned the detonations of the Cold War and the dimming of the Enlightenment spirit in American public life. He was, without fanfare or affectation, the quintessential citizen-scientist—at once a master of equations and a steward of consequence. When you needed objective scientific advice on virtually any technological or defense-related question, you asked Dick Garwin, even when you did not like the advice. Especially when you did not like it. And yet he was described as “the most influential scientist you have never heard of”, legendary in the world of physics and national security but virtually unknown outside it.

He was born in Cleveland in 1928 to Jewish immigrants from Eastern Europe, and quickly distinguished himself as a student whose mind moved with the inexorable clarity of first principles. His father was an electronics technician and high school science teacher who moonlighted as a movie projectionist. As a young child Garwin was already taking things apart, with the promise of reassembling them. By the age of 21 he had earned his Ph.D. under Enrico Fermi, who—legend has it—once remarked that Garwin was the only true genius he had ever met. This was not idle flattery. After Fermi, Dick Garwin might be the closest thing we have had to a universal scientist who understood the applied workings of every branch of physics and technology. There was no system whose principles he did not comprehend, whether mechanical, electrical or thermodynamic, no machine that he could not fix, no calculation that fazed him. Just two years after getting his Ph.D., Garwin would design the first working hydrogen bomb, a device of unprecedented and appalling potency, whose test, dubbed “Ivy Mike,” would usher in a new and even graver chapter of the nuclear age. Read more »

Wednesday, October 16, 2024

What Tangled Webs: The Hopf Fibration And Physics III

Posted on by Jochen Szangolies

by Jochen Szangolies

The Bloch sphere, the state space of a single qubit, as the Hopf fibration. To every point, a circle is associated which keeps track of the phase degree of freedom, according to the matching colors.

In the previous two installments of this series ([1], [2]), I have been engaged in the project of communicating a bit of the intuition behind the abstract notions of physics (and the necessary mathematics). My guiding principle in this attempt (essay in the literal sense) has been a famous quote of Hungarian mathematician and polymath John von Neumann: “In mathematics you don’t understand things. You just get used to them.”

This is an initially surprising notion. Mathematics, it seems, is the domain of pure intellect, where great minds wrestle with arcane concepts to squeeze droplets of eternal truth from Platonic realms of pure form. How does this square with ‘just getting used to it’?

I think that the poles of this apparent dichotomy are not as far removed as it might seem. The traditional view seems to emphasize singular mental effort, while von Neumann intimates, rather, repeated exposure—training, or diligent practice. The first is the province of what Daniel Kahnemann calls ‘System 2’, the effortful, explicit, step-by-step mode of reasoning that is often implicitly meant simply by ‘thought’. We analyze novel concepts, break them down into their components, resolve them into a step-by-step, algorithmic sequence, much like taking apart a watch to find what makes it tick.

But practice targets a different, implicit and automatic mode of thought: that of ‘System 1’, the associative, fast and heuristic mode of cogitation at work when you perform activities that require little explicit thought. Take riding a bike: there is no hope to learn it purely via the System 2-mode—that is, you can’t read a book on bike-riding, hop on and be off on your merry way. You need, rather, to train—to try, fail, and try again, until you get it right; and once you do, you’ll find yourself at a loss explaining exactly how. But after you have learned to do it, it ceases to become an explicit effort, instead happening apparently ‘by itself’, without you having to attend to the precise sequence of motions that keep your feet cranking the pedals, your arms turning the handles, and your entire body holding the balance.

Practice imparts an understanding that can’t be achieved by direct instruction. Getting used to something is a way to understand it that bypasses and complements the step-by-step process of analytical reason, a way to appreciate it at an intuitive Gestalt level rather than from the bottom up in terms of its individual components.

This is of course well appreciated by working physicists and mathematicians. But both popular science writing and popular culture at large paint a radically different picture. Read more »

Tuesday, July 23, 2024

The Wormhole Fiasco

Posted on by Eleni Petrakou

by Eleni Petrakou

Front page of journal Nature featuring the mentioned article

It’s late 2022. Scientists announce the creation of a spacetime wormhole. A flurry of articles and press releases of the highest caliber spread the news. Involved researchers call the achievement as exciting as the Higgs boson discovery. Pulitzer-winning journalists report on the “unprecedented experiment”. US government advisory panels hear it is a poster child for doing “foundational physics using quantum information systems”. Media the world over are on fire.

All the while, the scientific community is watching, dumbfounded.

Because, of course, nobody had created any spacetime wormhole.

*

Now that all the rage is well gone, it’s probably worthwhile to revisit that episode with the proverbial hindsight.

Specifically, the events of November ’22 kick off with an article in Nature detailing the creation of a “holographic wormhole” in Google’s quantum labs. On the same day, the prescheduled publicity by respected science outlets is crazy –the announcements by participating elite universities don’t hurt either– and sure enough the story quickly makes headlines all across muggle media.

To keep things in context: in case you are wondering if wormholes are something whose existence would shake a large part of what physics we know and, even if they exist, we might be technological centuries away from their handling, you are right. This is why all experts not connected to the study reacted with unbridled skepticism. Read more »

Monday, April 22, 2024

Physical Analogies and Field Theory

Posted on by David Kordahl

by David Kordahl

In popular media, physics often comes up for one of two competing reasons. The first is to introduce a touch of mysticism without labeling it as such. Whether it’s Carl Sagan talking about our bones as stardust, or Lisa Randall suggesting some extra dimensions of space, these pronouncements are often presented to evoke the listener’s primal awe—an ancient and venerable form of entertainment. The second reason is just as venerable, and often as entertaining. Sometimes, physics just gets results. Think of MacGuyver in MacGuyver, Mark Watney in The Martian, or those stunt coordinators in Mythbusters—characters whose essential pragmatism couldn’t be further from the tremulous epiphanies of the theorists.

Dramatically, the esoteric and the everyday can seem like opposites, and many fictional plots seem to advise against bringing them together. Mad scientists, those cautionary anti-heroes like Drs. Frankenstein and Manhattan, are often characters who both stumble upon hidden truths and put them to terrible use. But in the real world of physics, it’s common to forge connections between the realms.

Physical analogies, examples that link unfamiliar physics to everyday experience, are important in forging such connections. Waves in an Impossible Sea: How Everyday Life Emerges from the Cosmic Ocean, a new book by the physicist Matt Strassler, is an impressive attempt to explain contemporary physics using little math but many analogies. Strassler mainly goes against the archetype of the theoretical physicist as the purveyor of primal awe. Instead, he’s a practiced teacher, more interested in accuracy than amazement. In seven concise sections—Motion, Mass, Waves, Fields, Quantum, Higgs, and Cosmos—he covers the basics of physics with minimal fuss, but with a charmingly dorky earnestness. Read more »

Monday, March 18, 2024

Jack Dunitz (1923-2021): Chemist and writer extraordinaire

Posted on by Ashutosh Jogalekar

by Ashutosh Jogalekar

Jack Dunitz during a student outing at Caltech in 1948 (Image credit: OSU Special Collections)

Every once in a while there is a person of consummate achievement in a field, a person who while widely known to workers in that field is virtually unknown outside it and whose achievements should be known much better. One such person in the field of chemistry was Jack Dunitz. Over his long life of 98 years Dunitz inspired chemists across varied branches of chemistry. Many of his papers inspired me when I was in college and graduate school, and if the mark of a good scientific paper is that you find yourself regularly quoting it without even realizing it, then Dunitz’s papers have few rivals.

Two rare qualities in particular made Dunitz stand out: simple thinking that extended across chemistry, and clarity of prose. He was the master of the semi-quantitative argument. Most scientists, especially in this day and age, are specialists who rarely venture outside their narrow areas of expertise. And it is even rarer to find scientists – in any field – who wrote with the clarity that Dunitz did. When he was later asked in an interview what led to his fondness for exceptionally clear prose, his answer was simple: “I was always interested in literature, and therefore in clear expression.” Which is as good a case for coupling scientific with literary training as I can think of.

Dunitz who was born in Glasgow and got his PhD there in 1947 had both the talent and the good fortune to have been trained by three of the best chemists and crystallographers of the 20th century: Linus Pauling, Dorothy Hodgkin and Leopold Ruzicka, all Nobel Laureates. In my personal opinion Dunitz himself could have easily qualified for a kind of lifetime achievement Nobel himself. While being a generalist, Dunitz’s speciality was the science and art of x-ray crystallography, and few could match his acumen in the application of this tool to structural chemistry. Read more »

Monday, January 1, 2024

The Posthumous Trials of Robert A. Millikan

Posted on by David Kordahl

by David Kordahl

Millikan and EinsteinThe photograph beside this text shows two men standing side by side, both scientific celebrities, both Nobel prizewinners, both of them well-known and well-loved by the American public in 1932, when the picture was taken. But public memory is fickle, and today only the man on the right is still recognizable to most people.

Albert Einstein, Time Magazine’s “Man of the Century,” the father of special and general relativity, has a place in science that remains secure, regardless of what one thinks of his life as a whole. Despite activist efforts at demystification, Einstein the scientist is unblemished by any misgivings about his personal life or political activities. Robert A. Millikan, the bow-tied man on the left, is far less secure. The posthumous charges against Millikan have been against his scientific integrity and his political sympathies, and his detractors have made headway.

In 2020, Pomona College changed the name of their Robert A. Millikan Laboratory, noting Millikan’s “history of eugenics promotion,” along with his purported sexism and racism. In 2021, the California Institute of Technology, the institution that Millikan spent decades building, followed suit, renaming Millikan Hall as Caltech Hall, and discontinuing the Millikan Medal, previously the Institute’s highest honor. Citing Caltech’s precedent, the American Association of Physics Teachers (AAPT) renamed its own Millikan Medal later that same year.

Since I spend most of my time teaching physics, and since I am myself a member of the AAPT, it was the last of these name changes that rankled me the most. These allegations bothered me because I suspected that they weren’t quite fair. Read more »

Monday, September 11, 2023

The Philosopher of Quantum Reality

Posted on by David Kordahl

by David Kordahl

This column is ultimately a review of A Guess at the Riddle: Essays on the Physical Underpinnings of Quantum Mechanics, the short new book by David Z Albert, a philosopher at Columbia University and (as I found out last week) the graduate advisor of the founding editor of 3QuarksDaily, S. Abbas Raza. Unlike Raza, I have never met Albert, but my parasocial relationship with his work is midway through its second decade, which I am now acknowledging upfront.

I first became aware of David Z Albert when I was an undergraduate at a small Lutheran college in rural Iowa. On its top floor, the Wartburg College library had a large painting of Martin Luther, our hero, overseeing a bonfire of Catholic theology. But in the basement, where the unburnt books were held, I found a copy of Albert’s 1992 debut, Quantum Mechanics and Experience. The book’s style seemed wholly unusual to me. As a physics student, I wasn’t accustomed to books that were at once about science but somehow separate from it. I was impressed how Albert had retained only enough detail for a conceptual critique. I didn’t know, then, that its peculiar patois was just that of the analytic philosophers, with Albert merely adopting an eccentric dialect of that communal tongue.

In my last column for 3QD, I wrote about how quantum models work. A physical system is associated with a quantum state. As time passes, the quantum state changes according to a deterministic rule, the Schrodinger equation, branching smoothly into distinct outcomes. At the end, you compare how much of the wave-function—what percentage of its total squared amplitude—is parked in each possible branch, and this gives you the probability of observing each outcome.

Quantum Mechanics and Experience is a book about the measurement problem in quantum mechanics, which (roughly) is the question of how nature decides which one of the predicted possibilities within the final quantum state we actually end up observing. Albert’s book wasn’t my first exposure these issues—I had read Nick Herbert’s 1987 book, Quantum Reality, a few years earlier—but it represented the first time I got the sense that these issues were still debated, and still up for grabs. Read more »

Monday, July 17, 2023

How Quantum Models Work

Posted on by David Kordahl

by David Kordahl

A notable theorist visits a notable laboratory (Stephen Hawking at CERN, 2013)

The science lab and the theory suite

If you spend any time doing science, you might notice that some things change when you close the door to the lab and walk into the theory suite.

In the laboratory, surprising things happen, no doubt about it. Depending on the type of lab you’re working in, you might see liquid nitrogen boiling out from a container, solutions changing color only near their surfaces, or microorganisms unexpectedly mutating. But once roughly the same thing happens a few times in a row, the conventional scientific attitude is to suppose that you can make sense of these observations. Sure, you can still expect a few outliers that don’t follow the usual trends, but there’s nothing in the laboratory that forces one to take any strong metaphysical positions. The surprises, instead, are of the sort that might lead someone to ask, Can I see that again? What conditions would allow this surprise to reoccur?

Of course, the ideas discussed back in the theory suite are, in some indirect way, just codified responses to old observational surprises. But scientists—at least, young scientists—rarely think in such pragmatic terms. Most young scientists are cradle realists, and start out with the impression that there is quite a cozy relationship between the entities they invoke in the theory suite and the observations they make back in the lab. This can be quite confusing, since connecting theory to observation is rarely so straightforward as simply calculating from first principles.

The types of experiments I’ve had been able to observe most closely involve electron microscopes. For many cases where electron microscopes are involved, workers will use quantum models to describe the observations. I’ve written about quantum models a few times before, but I haven’t discussed much about how quantum physics models differ from their classical physics counterparts. Last summer, I worked out a simple, concrete example in detail, and this column will discuss the upshot of that, leaving out the details. If you’ve ever wondered, how exactly do quantum models work?—or even if you haven’t wondered, but are wondering now that I mention it—well, read on. Read more »

Monday, May 22, 2023

Oppenheimer II: “Work…frantic, bad and graded A”

Posted on by Ashutosh Jogalekar

by Ashutosh Jogalekar

“Oppenheimer, Julius Robert”, by David A. Wargowski, December 7, 2018

This is the second in a series of posts about J. Robert Oppenheimer’s life and times. All the others can be found here.

In the fall of 1922, after the New Mexico sojourn had strengthened his body and mind, Oppenheimer entered Harvard with an insatiable appetite for knowledge; in the words of a friend, “like a Goth looting Rome”. He wore his clothes on a spare frame – he weighed no more than 120 pounds at any time during his life – and had striking blue eyes. Harvard required its students to take four classes every semester for a standard graduation schedule. Robert would routinely take six classes every semester and audit a few more. Nor were these easy classes; a typical semester might include, in addition to classes in mathematics, chemistry and physics, ones in French literature and poetry, English history and moral philosophy.

The best window we have into Oppenheimer’s personality during his time at Harvard comes from the collection of his letters during this time edited by Alice Kimball Smith and Charles Weiner. They are mostly addressed to his Ethical Culture School teacher, Herbert Smith, and to his friends Paul Horgan and Francis Fergusson. Fergusson and Horgan were both from New Mexico where Robert had met them during his earlier trip. Horgan was to become an eminent historian and novelist who would win the Pulitzer Prize twice; Fergusson who departed Harvard soon as a Rhodes Scholar became an important literary and theater critic. They were to be Oppenheimer’s best friends at Harvard.

The letters to Fergusson, Horgan and Smith are fascinating and provide penetrating insights into the young scholar’s scientific, literary and emotional development. In them Oppenheimer exhibits some of the traits that he was to become well known for later; these include a prodigious diversity of reading and knowledge and a tendency to dramatize things. Also, most of the letters are about literature rather than science, which indicates that Oppenheimer had still not set his heart on becoming a scientist. He also regularly wrote poetry that he tried to get published in various sources. Read more »

Monday, March 27, 2023

Quantum Field Theory, “Easier Than Easy”

Posted on by David Kordahl

by David Kordahl

The book under review.

I began reading Anthony Zee’s most famous book, Quantum Field Theory in a Nutshell, at Muncher’s Bakery in Lawrence, Kansas, where, as a would-be quantum field theorist in 2010, Zee’s book taught me to evaluate Gaussian integrals. Zee made it all seem almost trivial, but his fast style belied the true expectation that his book would be read slowly, pen in hand, the reader studiously working their way from one line to the next. You couldn’t escape the sense that Zee was a very clever man, if not a very sympathetic teacher. This was a book whose readers would select it. If they couldn’t proceed, well, who was really to blame?

I never did become a quantum field theorist, though that’s hardly Zee’s fault. (At that point, I barely had the patience to sit and eat a donut.) Thankfully, Zee has now published an even swifter book, Quantum Field Theory, As Simply as Possible, which readers of this column will be happy to know I actually finished.

On the first page, Zee comments wryly that popular physics books jumped straight from quantum mechanics to string theory—so this book fills the quantum field theory gap. Now, if you are not a physicist, you may not know what quantum field theory is. This review is for you. Unfortunately, Zee’s new book probably isn’t. For whom then, is QFT, as Simply as Possible (henceforth: QFT, ASAP) written? My own answer is that it’s perfect for a past version of myself, just way too late for that bakery. Read more »

Monday, August 8, 2022

As simple as possible, but no simpler

Posted on by Ashutosh Jogalekar

by Ashutosh Jogalekar

Physicists writing books for the public have faced a longstanding challenge. Either they can write purely popular accounts that explain physics through metaphors and pop culture analogies but then risk oversimplifying key concepts, or they can get into a great deal of technical detail and risk making the book opaque to most readers without specialized training. All scientists face this challenge, but for physicists it’s particularly acute because of the mathematical nature of their field. Especially if you want to explain the two towering achievements of physics, quantum mechanics and general relativity, you can’t really get away from the math. It seems that physicists are stuck between a rock and a hard place: include math and, as the popular belief goes, every equation risks cutting their readership by half or, exclude math and deprive readers of a deeper understanding. The big question for a physicist who wants to communicate the great ideas of physics to a lay audience without entirely skipping the technical detail thus is, is there a middle ground?

Over the last decade or so there have been a few books that have in fact tried to tread this middle ground. Perhaps the most ambitious was Roger Penrose’s “The Road to Reality” which tried to encompass, in more than 800 pages, almost everything about mathematics and physics. Then there’s the “Theoretical Minimum” series by Leonard Susskind and his colleagues which, in three volumes (and an upcoming fourth one on general relativity) tries to lay down the key principles of all of physics. But both Penrose and Susskind’s volumes, as rewarding as they are, require a substantial time commitment on the part of the reader, and both at one point become comprehensible only to specialists.

If you are trying to find a short treatment of the key ideas of physics that is genuinely accessible to pretty much anyone with a high school math background, you would be hard-pressed to do better than Sean Carroll’s upcoming “The Biggest Ideas in the Universe”. Since I have known him a bit on social media for a while, I will refer to Sean by his first name. “The Biggest Ideas in the Universe” is based on a series of lectures that Sean gave during the pandemic. The current volume is the first in a set of three and deals with “space, time and motion”. In short, it aims to present all the math and physics you need to know for understanding Einstein’s special and general theories of relativity. Read more »

Monday, June 27, 2022

The Ur-Alternative: Quantum Mechanics As A Theory Of Everything

Posted on by Jochen Szangolies

by Jochen Szangolies

Figure 1: The fundamental inventory of the world, as currently known. Image credit: Cush, CC0, via Wikimedia Commons

At the close of the 20th century, the logical end-point of physics seemed clear: unify all physical phenomena under the umbrella of a single, unique ‘Theory of Everything’ (ToE). Indeed, many were convinced that this goal was well within reach: in his 1980 inaugural lecture Is the end in sight for theoretical physics?, Stephen Hawking, the physicist perhaps most closely associated with the quest for the ToE in the public eye, speculated that this journey might be completed before the turn of the millennium.

More than twenty years after, a ToE has not manifested—and moreover, seems in some ways more distant than ever. Confidence in the erstwhile ‘only game in town’, string/M-theory, has been waning in the face of floundering attempts to make contact with the real world. Without much hope of guidance from experiment, some have even been questioning whether the theory is ‘proper science’ at all—or, conversely, whether it requires a reworking of scientific methodology towards a ‘post-empirical’ framework from the ground up. But in the wake of string theory’s troubles, no other contender has risen up to take center stage. Read more »

Monday, May 16, 2022

Physicists and Fugues: A Well-Tempered Pairing

Posted on by Ashutosh Jogalekar

by Ashutosh Jogalekar

Sergei Rachmaninoff and John Wheeler were both masters of their art, equally at home with details and wild speculation, both seeing their disciplines as holistic ones encompassing all of human experience and the universe

As someone who has been interested in both classical music and the history of physics for a long time, I have been intrigued by comparison of the styles between the two art forms. I use the term “art form” for physics styles deliberately since most of the best physics that has been done represents high art.

Just like with classical music, physics has been populated by architects and dreamers, careful workmen and inspired explorers, bursts of geniuses and sustained acts of creativity. It is worth spending some time discussing what the word “style” might even mean in a supposedly objective, quantitative field like physics where truth is divined through precise measurements and austere theories. The word style simply means a way of thinking, calculation and experiment, an idiosyncratic method that lends itself individually or collectively to figuring out the facts of nature. The fact is that there is no one style of doing physics, just like there is no one style of doing classical music. Physics has blossomed when it has benefited from an unpredictable diversity of styles; it has stagnated when a particular style hardened into the status quo. And just like classical music goes through periods of convention and experimentation, deaths and rebirths, so has physics.

If we take the three great eras of classical music – baroque, classical and romantic – and the leading composers pioneering these styles, it’s instructive to find parallels with the styles of some great physicists of yore. Johann Sebastian Bach who is my favorite classical musician was known for his precise, almost mathematical fugues, variations and concertos. Read more »

Monday, January 10, 2022

Mind And Tense: Zombies In The Here And Now

Posted on by Jochen Szangolies

by Jochen Szangolies

Figure 1: A philosophical zombie is a being physically/behaviorally identical to a human, but lacking any ‘inner’ experience.

Zombies have become a mainstay of philosophy as much as of pulp fiction—a confluence that it would be fallacious to assume implies some further connection between the two, naturally. Zombies are beings that act in many ways like living humans—they move around, they interact with the world, and they, to generally horrific effect, consume resources for sustenance—not ending up as which is the typical goal of the protagonists of various kinds of zombie media. Yet, they lack the crucial quality of actually being alive, instead generally being considered merely ‘undead’.

Zombies are thus creatures of lack, creatures that have been robbed of some quality we otherwise think essential. Consider, for instance, the notion of the soulless zombie: a being which, despite acting and reacting just like any other human being—in fact, we might stipulate, in a way exactly paralleling your actions and reactions—lacks a ‘soul’ of any kind. If this is imaginable, then, the argument goes, there’s nothing that you’d actually need a soul for—and hence, we can strike it from the list of essential qualities without any resulting deficit.

A counterpoint to this particular argument is the floating man thought experiment of Ibn Sina (often Latinised as Avicenna), the eleventh century Persian polymath and physician. Ibn Sina imagines being created ‘at a stroke’, fully formed, in a state of free fall, and in darkness. Lacking any external sensory impression, one would still be certain of one’s own existence. But if there is nothing physical one could be conscious off absent such sensory data, then that sensation of being aware of one’s own self must be a sensation of something non-physical—the soul, or Nafs in the Quran. To Ibn Sina, then, the soulless zombie would merely show that the world is not exhausted by the physical, by our behaviors and reactions to external stimuli. Read more »

Monday, January 3, 2022

Which Scientific Bets Should Be Declined?

Posted on by David Kordahl

by David Kordahl

Imagine, if you will, that I own a reliably programmable qubit, a device that, when prepared in some standard and uncontroversial way, has a 50/50 probability of having one of two outcomes, A or B. Now imagine also that I have become convinced of my own telekinetic powers.

Suppose that the qubit has been calibrated within an inch of its life, and I have good reason to believe that the odds for the two possible outcomes, A or B, are in fact equally matched. My telekinetic powers, on the other hand, are weak—not strong enough to make heads explode like that guy in Scanners, nor strong enough to levitate chalk like in Matilda. Yet neither am I powerless. If I reign myself in—no more than a few attempts per night (I take care not to tire myself), and no counting tries when my juju’s off (remember, my gifts are unremarkable)—then I have been able, through intense concentration and force of will, to favor outcome A just slightly, just barely bumping its odds up, let’s say, from 50.0% to 50.1%.

Squinting, I claim statistical significance. But when I share these findings with you, my scientifically trained colleague, you are unimpressed.

Okay, but why not? I might insist that experimental controls have been properly implemented. I might even allow you to propose a list of criteria for a follow-up experiment. I might grow impatient, and thrust papers at you on meta-analyses of the para-psychological literature, and pass you a copy of Synchronicity—or at least my review of it—showing how the founders of quantum mechanics were themselves interested in psi effects. Look, I might huff, have you not read Freeman Dyson on the possibility of ESP? Have you not noticed that even critics suggest further study?

I hope this description does not describe the way that I actually behave. But why not? What about this response, rudeness aside, would be so bad? Read more »