Posts Tagged ‘Physics’
“Merely fact-minded sciences make merely fact-minded people”*…
As we float awash in the debate over who/what is conscious (only humans? animals? plants? AI? everything?), we might take a moment to ponder the role of consciousness. For example, in science.
Harald A. Wiltsche argues that physicists, and scientists in general, attempt to paint an objective picture of reality. Consciousness, experience, and subjectivity are forcibly pushed out of the picture. Indeed, even where science is empirical, this empiricism rarely involves a consideration of human consciousness, but rather the readings of some mechanical measuring device, or some hypothetical abstracted sum of all perspectives – a God’s eye view or view from nowhere.
A phenomenologist of science, Wiltsche paints a different picture. Physics, even in the form of quantum mechanics, has its origins in the phenomenology of human consciousness. No matter how hard scientists try, it can never escape those origins, and to truly move forward, it must understand and embrace them…
Physics and phenomenology are usually taken to inhabit different worlds. Physics aims at a description of objective reality in mathematical terms. Phenomenology—the philosophical movement inaugurated by Edmund Husserl—is an a priori investigation into consciousness and into the ways things appear in experience. Physics deals with equations, invariants, and symmetries, aiming to represent reality minus observers; phenomenology seems to concern precisely what physics leaves out: subjectivity, consciousness, meaning. If the two meet at all, it is only in polite, but ultimately inconsequential, interdisciplinary dialogue.
My claim is that this picture is mistaken. Physics does not stand outside phenomenology. It presupposes the very structures phenomenology seeks to analyse—above all, the structured correlation between subject and object through which objectivity first becomes intelligible. The task, therefore, is not to unite two distant domains, but to recognize a relation that has been there from the beginning…
[Wiltsche makes his point first with reference to spacetime physics, then to quantum mechanics. He concludes…]
… The question, then, is no longer whether physics and phenomenology should be united. As physics confronts its own conceptual foundations, the challenge is to bring into view the structures phenomenology has analyzed since its inception—and to explore how they can illuminate the meaning of objectivity in modern theory.
Eminently worth reading in full.
Physics cannot escape its roots in phenomenology: “Consciousness is the hidden architecture behind fundamental and quantum physics” (or archived version here) from @haraldwiltsche.bsky.social in @iai.tv.
Bonus question: if Wiltsche is right that consciousness is essential to advancing our understanding of reality, and consciousness is something that other things, living and “inanimate,” (do or can) possess, what does that mean for our quest to understand realit(ies)?… Or does a question like this simply (albeit implicitly) affirm anthropocentrism? How will we know?
See also: “A physicist is just an atom’s way of looking at itself“
* Edmund Husserl
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As we contemplate consciousness, we might note that it was on this date in 1977, at the High Wyncombe Town Hall in England, that the Bunch of Stiffs tour kicked off. It featured Nick Lowe’s Last Chicken in the Shop, Elvis Costello and The Attractions, Ian Dury and the Blockheads, Wreckless Eric and The New Rockets, and Larry Wallis’ Psychedelic Rowdies– acts managed by Dave Robinson and Jake Riviera before they formed the Stiff Records label, which released a live album of the festivities in February of 1978.
“A physicist is just an atom’s way of looking at itself”*…
Encouraged by successes in understanding black holes, theoretical physicists are applying what they’ve learned to whole universes. As Matt von Hippel explains, what they’re finding has them questioning fundamental assumptions about how physics ought to be done…
Tinkering at their desks with the mathematics of quantum space and time, physicists have discovered a puzzling conundrum. The arcane rules of quantum theory and gravity let them imagine many different kinds of universes in precise detail, enabling powerful thought experiments that in recent years have addressed long-standing mysteries swirling around black holes.
But when a group of researchers examined a universe intriguingly like our own in 2019, they found a paradox: The theoretical universe seemed to admit only a single possible state. It appeared so simple that its contents could be described without conveying even a single bit of data, not even a choice of a zero or a one. This result clashed with the fact that this type of universe should be capable of hosting black holes, stars, planets — and people. Yet all those rich details were nowhere to be seen.
“We look around, and certainly the world seems more complex than that,” said Rob Myers, a theoretical physicist at the Perimeter Institute for Theoretical Physics in Waterloo, Canada, who has not been directly involved in this research.
Physicists have good reason to trust the calculation, which builds on fundamental physical ideas. The math implies a universe with only one state; our universe is clearly not like that. Now a team of theorists has floated a possible answer. The paradoxical result occurred when physicists sought an objective description of the state of an entire universe. But a description like that might not be possible, even in principle. It implicitly assumes a universe that exists without an observer to observe it. And perhaps without observers, the complexity of the universe loses its meaning…
[von Hippel unpacks the scientific thinking that led to this conundrum. He concludes with an account of recent work by Ying Zhao that hints at a resolution…]
… Quantum mechanics requires a distinction between an observer — such as the scientist carrying out an experiment — and the system they observe. The system tends to be something small and quantum, like an atom. The observer is big and far away, and thus well described by classical physics… Perhaps an observer could do the same to these closed, impossibly simple-seeming universes?
In 2024, Zhao moved to the Massachusetts Institute of Technology, where she began to work on the problem of how to put an observer into a closed universe. She and two colleagues —Daniel Harlow and Mykhaylo Usatyuk — thought of the observer as introducing a new kind of boundary: not the edge of the universe, but the boundary of the observer themself. When you consider a classical observer inside a closed universe, all the complexity of the world returns, Zhao and her collaborators showed.
The MIT team’s paper came out at the beginning of 2025, around the same time that another group came forward with a similar idea. Others chimed in to point out connections to earlier work.
At this stage, everyone involved emphasizes that they don’t know the full solution. The paradox itself may be a misunderstanding, one that evaporates with a new argument. But so far, adding an observer to the closed universe and trying to account for their presence may be the safest path.
“Am I really confident to say that it’s right, it’s the thing that solves the problem? I cannot say that. We try our best,” Zhao said…
“Cosmic Paradox Reveals the Awful Consequence of an Observer-Free Universe,” from @quantamagazine.org.
Apposite: “Biology Might Not Be Quantum, but Its Math Is Quantumlike“
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As we keep an eye out, we might send cosmological birthday greetings to Enrico Fermi; he was born on this date in 1901. A physicist and Nobel Laureate (1938) for his discovery of nuclear reactions brought about by slow neutrons, he is best remembered for (literally) presiding over the birth of the Atomic Age. Fermi was perhaps especially remarkable as the last “double-threat” in his field: a genius at creating both important theories and elegant experiments. As observed before (and illustrated above :), the division of labor between theorists and experimentalists has since been pretty complete.
The novelist and historian of science C. P. Snow wrote that “if Fermi had been born a few years earlier, one could well imagine him discovering Rutherford’s atomic nucleus, and then developing Bohr’s theory of the hydrogen atom. If this sounds like hyperbole, anything about Fermi is likely to sound like hyperbole.”
“Great inventions are never, and great discoveries are seldom, the work of any one mind. Every great invention is really an aggregation of minor inventions, or the final step of a progression. . It is not usually a creation, but a growth, as truly so as is the growth of the trees in the forest.”*…
Our old friend (and here and here) Brian Potter thinks deeply about scientific and technological advance. Here, he ponders the pace of progress…
In her book on the history of the laser, historian Joan Bromberg notes that the technological and scientific predecessors of the maser (which itself preceded the laser – two critical technologies whose developmental histories I sketched in this piece two months ago) were in place for decades before physicist Charles Townes had the insight to combine them…
… This sort of decades-long wait between when a technology first becomes possible, and when it actually appears, seems common, or at least seems like it might be common. I’ve previously written about why it took so long for wind power to be widely deployed after it became technologically possible, and people often idly speculate whether inventors in the Roman Empire could have built a steam engine, or why we waited so long to put wheels on luggage.
Knowing how long this gap between when an invention becomes possible, and when it actually appears, is useful, because it tells us something about the nature of technology and technological progress. What factors govern whether some new technology appears? How much does mere technical possibility matter, and how much do things like cross-pollination of knowledge, economic feasibility, and political factors contribute? Knowing more about how long it takes for an invention to appear once it becomes technically possible can help us answer these sorts of questions.
I wanted a better sense of how long it takes for some technology to appear once its necessary predecessors are in place. So I used AI to try and find out…
[Potter explains his method, then unpacks his results…]
We can clearly see a few trends on this graph. One is that for most inventions, the gap between when it could have been invented and when it was actually invented is not particularly large. Of the 166 inventions Claude estimated a date for, 107 of them (64%) had an “earliest plausible” date 50 years or less from the actual date, and 150 of them (90%) had an “earliest straightforward” date 50 years or less from the actual date. For more than half the inventions, the average earliest straightforward date of invention was 10 years or less from the actual date.
Conversely, there were a relatively small number of inventions where the gap between “could have been invented” and “was invented” was very large. 30 inventions (18%) had an average gap of more than 100 years between “earliest plausible” and actually invented, and eight inventions had a gap of more than 1000 years. You can see this clearly on a histogram, which shows a large bump of small time gaps, and a long tail of fewer, larger gaps.
The inventions with the longest period between “could have been invented” and “was invented” are below.
There’re a few interesting trends observable here. Many of the longest-delayed inventions — the hypodermic needle, general anaesthetic, stethoscope — are medical inventions. (You could argue the surgical mask could be in this category as well). For the hypodermic needle, this probably needed to wait until the existence of some substance that needed to be injected (such as morphine, first synthesized in 1804), but for other medical inventions this possibly also reflects folks’ reluctance to do inventive-tinkering in a medical context. For general anaesthetic, for instance, the trial and error of getting the dose right was incredibly dangerous, and the inventor Hanaoka Seishu “crippled his mother and blinded his wife perfecting the dose.”
Several of the longest-awaited inventions are ones where the version in the list is an early, impractical version of the one that actually solved a problem. So the “dandy horse” — a two-wheeled, wooden vehicle that was a predecessor of the bicycle — could have been built in antiquity, but the dandy horse wasn’t particularly practical as a means of transportation, and actually useful bicycles had to wait for the improved manufacturing technology of the later 19th century. Likewise, the version of the ballpoint pen that Claude thinks could have been invented much earlier is John Loud’s 1888 version, but Loud’s pen worked poorly and wasn’t successful. Actually useful ballpoint pens are surprisingly difficult to manufacture (China famously couldn’t manufacture them until very recently), and credit for the “useful ballpoint pen” is usually given to Lazlo Biro in 1938. (Claude correctly notes that “useful” versions of both these inventions would need to wait until much later.) Judson’s early zipper and de Martinsville’s early sound-recording device are also examples of early, not-particularly-useful inventions.
Other inventions on this list seem like they might be a case of the surrounding social or technological conditions needing to be right for the invention to appear. So Otis’ elevator safety brake needed to wait until elevators were in higher demand, which probably didn’t occur until steam engines or some other similar power source came along (though maybe you could have water-driven elevators much earlier). Barbed wire perhaps needed to wait until enclosing very large areas of land for grazing became something people needed to do.
And some inventions seem like they might have been genuinely useful had someone thought of them earlier, and simply nobody did. Blanchard’s pattern-tracing lathe, Neilson’s hot blast, and the safety pin all seem like they fall into this category, though perhaps there were good reasons these didn’t appear earlier.
Going back to the scatterplot, the other obvious trend on this chart is that the gap between when an invention becomes possible and when it appears has narrowed over time. If we graph the average and median gaps for inventions by 20-year time periods, we can see that they have fallen over time.
For the 60 post-1900 inventions, every one has a “straightforward” invention date of 50 years or less than the actual date, and 75% of them have a straightforward date of 10 years or less before the actual date. Of the 30 inventions with a gap of more than 100 years between when they could have been invented and when they actually appeared, 29 of them were invented before 1900. So the process for creating new inventions seems to be getting more and more efficient — opportunities are getting noticed and exploited sooner and sooner, up through 1970 at least (which is when the list of major inventions extends to).
We can also look at how wait times vary by type of technology. The chart below shows average wait times by different categories, for both inventions overall and for just post-1900 inventions. We can see that medical inventions have the longest wait, while electronic inventions have the shortest wait…
… We can also look at what types of factors tend to be bottlenecks. For some inventions, the bottleneck is primarily scientific: the limiting factor for the transistor is the band theory of quantum mechanics, and the limiting factor for the radio was Hertz’s demonstration of electromagnetic waves. But for other inventions, it’s primarily technological: the turbojet had to wait not for some new physical theory, but until compressor technology and high-temperature steels appeared; likewise the airplane had to wait not for some novel theory of aerodynamics but until a light enough engine appeared. The chart below shows how often “science” or “technology” was the limiting factor for a given invention, for both inventions overall and post-1900 inventions.
In both cases, technology is the bottleneck far more often than science (though of course if you removed enough technological bottlenecks eventually you’d hit a scientific one, and vice versa).
There is of course only so much you can learn from this sort of exercise: at the end of the day, this is based on an AI’s best guess, not a thorough analysis of the various controlling factors by experts. But while I wouldn’t swear to its accuracy, I think the answers are probably mostly pretty good, and enough for us to draw some general (if tentative) conclusions about the nature of technological progress.
My main takeaway is that we mostly don’t wait all that long for new inventions. Since 1800 most inventions have appeared within a few decades of when it was possible to build them, and since 1900 these gaps been even narrower. It also seems likely that medical inventions are more likely to have long wait times than other types of inventions, and that the limiting factor for how early some new technology could appear is most likely to be technological, rather than scientific.
On the (maybe suprisingly) quick– and quickening– pace of progress: “How Long Do We Wait for New Inventions?” from @constructionphysics.skystack.xyz
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As we analyze advance, we might send inventive birthday greetings to William Webster (W. W.) Hansen; he was born on this date in 1909. A physicist and one of the founders of the technology of microwave electronics, he had a central hand in the development of klystron technology (essential to high frequency amplification, thus central to microwave technology, radar, and UHF television transmission), and linear accelerators (he led the development of SLAC), and along with the Varian brothers and Edward Ginzton, co-founded Varian Associates (in 1948)–one of the first high-tech companies in Silicon Valley.
“Reality is that which, when you stop believing in it, doesn’t go away”*…
Particles are nature’s smallest constituents, but that doesn’t mean they’re fundamental. So of what, physicist Felix Flicker asks, does the Universe consist?…
What is the world made of? For centuries, people have believed that matter is constructed from tiny, indivisible parts. Some of the earliest known references come from the Greek philosopher Democritus, who taught that the Universe was composed of atoms the size of dust motes floating in sunlight. Theravada Buddhism developed the concept of kalapas, indivisible bundles of properties fleeting into and out of existence. Alchemy’s description of fundamental ‘corpuscles’, expounded by Isaac Newton and others, derived from translations of Aristotle by mediaeval Islamic scholars. And Hideki Yukawa, winner of the 1949 Nobel Prize in Physics for his work developing the modern theory of elementary particles, took inspiration from a passage in the Zhuangzi, a Daoist text written during China’s warring states period, in which fast-moving entities puncture holes within formless chaos. Yukawa saw a parallel to particle collisions.
The concept of a particle, as we now refer to these indivisible parts, has therefore been repeatedly re-introduced in contradictory ways. The modern view continues this tradition. In late-19th-century physics, particles were tiny indivisible objects with well-defined positions and momenta. The advent of quantum mechanics led these clear waters to become muddied. But the basic idea persists: we are taught from a young age that matter is made of atoms, built from particles such as electrons, and electrons are not built from anything else. For this reason, these particles are sometimes said to be fundamental. But are they? Is the Universe really made from the smallest constituents, as a beach is made from sand?
The answer to this question, I will contest, is perhaps a surprising one: yes, the Universe is built from fundamental units – but fundamental need not mean smallest. This view is generally adopted by those physicists, such as myself, who work in the largest discipline within the subject: quantum matter. This is the study of quantum behaviours that manifest on everyday scales: the attraction of iron to a magnet, the flow of electricity along a wire, or the passage of sound through a crystal. In these settings, too, we find particles. But these particles are not elementary, like the electron: they are emergent.
The distinction can be pictured as follows. Imagine a lightbulb, its rays of light travelling to your eyes. We can ask what those rays are made of. Quantum mechanics has an answer: a ray of light is a stream of individual particles called photons. In turn, we can ask what the photons are made of. The answer this time is that they are not made of anything else: they are elementary. Now imagine that this lightbulb is of a vintage sort, and gives off a gentle hum. It emits waves of sound that travel to your ears. We can again ask what those waves are made of. And, once again, quantum mechanics has an answer: a wave of sound can be described by individual particles called phonons. Now, if you are familiar with the Standard Model of particle physics, you will know that it contains photons but not phonons. The reason is that phonons are not elementary. If you ask what a phonon is made of, there is an answer: it is a pattern of vibrations of the atoms in the air. In the study of quantum matter, however, we say it is an emergent particle.
So what are emergent particles? Are they as real as elementary particles? And, perhaps most importantly, can they tell us anything new about the nature of reality?…
[Flicker answers the first two of those questions, then turns to the third…]
… So, are elementary particles emergent? Even if we can ever answer this, we will be faced with the same question, whatever we find. In the end, whether you like the idea comes down to personal taste and, perhaps, a degree of cultural upbringing. The more widely publicised attempts at a ‘theory of everything’ always struck me as suspiciously similar to themes in the Old Testament: the Universe was once describable by a single mathematical formula, but that one, true quantum field spontaneously broke in a cataclysmic event that resulted in the messy collection of particles we find before us. I find that the quantum matter perspective, on the other hand, resonates with me in a similar manner to the Daoist texts such as the Zhuangzi. From this new perspective, it is our current world that is beautiful. It grew from a swamp of possible theories, each ugly in its arbitrariness: it doesn’t matter which way we followed, as they all lead here…
A physicist argues that our universe is more than the sum of its particles: “Reality Emerges,” from @aeon.co.
Resonant: “There Is No ‘Hard Problem Of Consciousness’,” from Carlo Rovelli
Also apposite (and fascinating): “Physicists just found a tiny flaw in time itself,” from ScienceDaily.
* Philip K. Dick
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As we muse on materialization, we might send insightful birthday greetings to Jack Steinberger; he was born on this date in 1921. An experimental physicist, he worked on sub-atomic particles– the “elementary” constituents of matter discussed above– at Columbia, UC Berkeley, and CERN. He shared the 1988 Nobel Prize in Physics (with Leon M. Lederman and Melvin Schwartz) for the discovery of the muon neutrino.
“The mind is not a vessel to be filled, but a fire to be kindled”*…
(Roughly) Daily is, in effect, a kind of notebook, a commonplace book. So it will be no surprise that your correspondent found today’s featured piece fascinating.
Jillian Hess, a professor who studies the history of note-taking, shares the lessons she took from her review of the papers of the remarkable Richard Feynman…
Formal education, at its best, prepares us for a life of learning. After all, we are only in school for a fraction of our lives and there is so much to learn!
Richard Feynman (1918-1988) understood the value of self-education. He was a Nobel Prize-winning theoretical physicist, a member of the Manhattan Project at the age of 25, and a dynamic public intellectual who never stopped learning.
Often touted as one of history’s greatest learners, Feynman taught himself a dizzying amount of science. I wanted to see his notes for myself—to observe the great autodidact thinking on the page. So, I visited his archives at Caltech in February…
… In the archives, I saw… for myself: Feynman’s notebooks contain imprints of thinking in real-time—the work as it happened. They were instruments for thinking through uncertainty.
What follows is a list of note-taking principles for self-education that I gathered while studying Feynman’s notebooks.
Start with First Principles: Feynman’s “Things I Don’t Know About” Notebook
Discussions about Feynman’s learning process usually draw from this notebook, which he compiled as a Ph.D. student at Princeton. The contents include mechanics, mathematical methods, and thermodynamics. Clearly, he knew something about these topics, but he found his understanding superficial. So, his response was to take the subject apart—to break it down into “the essential kernels” …
[Hess illustrates this principle, then unpacks two others: “create a reading index” and “keep learning.” She continues…]
… Uncertainty is Interesting
This is my biggest takeaway: We should fear certainty more than doubt. Learning to live with uncertainty is an essential aspect of learning, as Feynman said in 1981:
You see, one thing is, I can live with doubt and uncertainty and not knowing. I think it’s much more interesting to live not knowing than to have answers which might be wrong.
And then, in an echo of his “Notebook of Things I Know Nothing About,” compiled four decades prior, he adds:
…I’m not absolutely sure of anything, and there are many things I don’t know anything about.
If a man as celebrated for his genius as Feynman felt that way, certainly the rest of us have a lot more to learn…
[And she concludes…]
… Notes on Feynman’s Notes:
Use notes to think: Feynman didn’t think through problems in his head and then turn to his notebooks. Instead, he used his notebooks to think through problems. His thought process required paper.
Start with first principles: “Why” is a very powerful question. And asking why can lead us back to the fundamentals and help us understand them in an entirely new light. This applies to any subject. Feynman has helped me think of note-taking as a kind of expedition. Use your notes to dig deeper into topics you think you already understand.
Never stop learning: How wonderful would it be if we could hold onto the excitement of learning we had as children? After all, the world didn’t get less interesting. It’s worth returning to the note-taking methods you used in school to see if they are still useful in adulthood. I particularly like Feynman’s high school method of taking 30 minutes to understand a subject before he allowed himself to take notes on it.
[Then leaves us with the man himself, “in all his radiant, enthusiastic, brilliance”…]
On “Richard Feynman’s Notes For Self-Education.”
Pair with: “Curiosity Is No Solo Act“: “it gains its real power when embedded in webs of relationship and shared meaning-making”… something that Feynman’s life also demonstrated (as you can see in his autobiography and/or in James Gleick‘s biography, Genius)
* Plutarch
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As we light that fire, we might spare a thought for Jeremy Bernstein; he died on this date last year. A physicist who woked on nuclear propulsion for Project Orion and held research and teaching positions at Stevens Institute of Technology, the Institute for Advanced Study, Brookhaven National Laboratory, CERN, Oxford University, University of Islamabad, and École Polytechnique, he is better remembered as a gifted popular science writer and profiler of scientists.
Bernstein wrote 30 books, and scores of magazine articles for “general readers”– for The New Yorker, where he was a staff writer from 1961 to 1995, and for The Atlantic Monthly, the New York Review of Books, and Scientific American, among others.
Of Feynman, Bernstein wrote “[his] Mozartean genius in physics seemed to be combined with an almost equally Mozartean urge to play the clown.” (in which, of course, Feynman was in the good company of Einstein, Claude Shannon, and others :-)
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