Stephen Jay Gould said: "I am, somehow, less interested in the weight and convolutions of Einstein's brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops."
This quote really drives home the point that the overwhelmingly vast majority of scientific discovery and progress throughout history has come with humanity's entirely self-inflicted handicapping, like a V8 engine running on only 1 cylinder. Can't help but wonder what our knowledge here in 2025 would be like had we, as a species, tapped into our full potential by empowering women and people of color (to name just a few categories) earlier. You can almost see it in action with the people mentioned here as time went on.
I believe that geniuses like Einstein are just the tip of the iceberg. We need them, but they are not the limiting factor, and producing more of them may not have that much of an influence on scientific progress.
What really drives progress, I think is production and technology. Like better telescopes. For the cosmic distance ladder, the clever mathematical tricks are nice, and necessary, but the real important part is the precise measurements. And for that, we need precise instruments. And precise instruments need good quality materials, skilled tradesmen, good tools, etc... The tools themselves need the same, and the tools to make the tools, etc... A lot of the measurements involve travel and long distance communication, which wasn't trivial either. Mounting an expedition to the other side of the world requires a ship, a crew, etc... Then we need to collect these data, and people have to write these books, we need librarians, archivists, etc... All that so that finally, one guy can look at the data and do the maths.
And all that is far from the whole story. Skilled craftsmen and sailors need food and shelter, and the raw materials to practice their craft of course. They need farmers, miners, lumberjacks, etc... Farmers, miners and lumberjacks need their tools too. Advancing in the cosmic distance ladder is the work of millions of people over several lifespans, and some of them worked in cotton fields. We could wish the guy in the cotton fields was treated better, but it doesn't change the fact that in order to advance science, we actually need more people in cotton fields than people doing maths.
With technological progress, we can afford to have more people doing maths and provide them with enough data to be useful, but that's a very recent development.
A better theory is that it is legal innovation. If the wealthiest and most powerful are threatened by progress ... there will be no progress. If the wealthiest and most powerful get more power and status from progress, there will be progress. Without insurance, for example, it isn't possible to run serious sea trade. Without the joint stock corporation, it isn't feasible for the British to organise and conquer India. It takes democracy to really align the political class with increasing prosperity for the median citizen; otherwise states tend towards tinpot dictatorships.
There isn't a shortage of smart people or opportunities to make technological progress. The handicap is powerful humans looking at new approaches and saying "No" with the firmness of a man who sees a threat to their position. Even today I have a list of things that from an engineering perspective would probably result in improved prosperity, it just isn't possible to get them through the political process (nuclear power springs to mind, but I'm sure there are less controversial examples - Uber v. the Taxi industry maybe).
I get your point about not being able to do everything in a vacuum, but I think there's also just a very limited set of geniuses that are of the Einstein/Newton level that might only exist once a century if you're lucky. We have millions in academia now and how many more physicists than the 1800s? There has certainly been progress, but it seems diminished.
There's a lot of discussion on this online and some folks speaking past each other. Yeah, there has been the invention of the internet, faster computers, the blue LED, sequencing the human genome...etc, but that is argued to mainly be engineering innovations on already understood physics. Where is the next discovery on the level of general relativity? Are we just at diminishing returns now where all the low hanging fruit has been found? How many physicists wasted away researching string theory? Were we just putting resources in the wrong place?
I do strongly think that modern research has become so beauracratic that it gets in the way of actual progress. The endless paperwork, presentations, teaching...etc isn't very conducive to discovery. Your average professor is more like a project manager than what Newton did.
The physics of the 1800s had a lot of low hanging fruit. Most undergrads in physics can show you a derivation of Maxwell's equations from first principles, and I think a fair few of them could have come up with it themselves if they were in Maxwell's shoes. The hard truth is that the physics/math of today is just much further afield, and much harder.
Very little of the stuff physicists came up with in the 19th century was obvious or low hanging at the time. And no your undergrads would likely have never came up with Maxwell's equations on their own.
Yeah, I agree with you on this one. It's kind of easy once you understand it, but it took Maxwell to figure it out. I might not have figured that out in ten centuries by myself lol.
I definitely think it takes a Maxwell to describe the physics behind displacement current (which I think was not around in Maxwell's initial drafts), but the derivations of the four classic Maxwell equations are fairly straightforward multivariable calculus problems that start with fairly simple assumptions. Multivariable calculus was relatively young in his era, but I think a motivated student from the current era could discover it given a summer of thought experimentation.
That's a highly biased opinion. The Newtonian conception of physics is trivial for us, and we can say that most people could come up with the ideas by their own, but that's because our world conception is based on those ideas; it's already implicit in how we understand the world. That's why Newton was so important, there was a shift in the whole conceptualization of the physical world. With Maxwell's equations is similar. The interpretation as waves, the fact that the equations are Lorentz symmetric but no Newton symmetric, etc. All that is free for us, and it is not obvious at all.
Spend a trillion dollars building a bigger supercolider if you want more fundamentals. I think the application of these discoveries is much more important at this point. What do we actually use GR for? Corrections to gps, and ... it's not like it's gonna cure cancer. Technology will do that. We've exhausted all the fundamentals that we can access, that's what's happened. You want more fundamentals, you need more access. You want more access, Get ready to ride the exponential curve of costs
That is pretty contentious even in physics circles (from what I've heard in videos). The build me a bigger particle collider might not have any impact. We might not see any of the hypothetically proposed stuff.
You need a certain amount of motivation, grid, etc. If these skills would be broadly available and the situation also, we would have a lot more Einsteins today.
There is plenty of things which do not require global projects building multibillion devices.
I'm not so sure. It seems these kinds of people are exceedingly rare that grasp a fundamental truth we've all missed. ChatGPT is really cool, but building a really really big neural network and training it off all the stuff on the internet certainly seems less impressive than discovering calculus. I mean ..LLMs are impressive and magical of course.
The the single best way to drive science and technology: teach everyone to format a json string share it via a URL.
The people on the bleeding edge of science and technology aren't just sitting in futuristic labs, surrounded by holograms and AI tech assistants, spouting one brilliant insight after another.
They are spending most of their days arranging various types of poorly formatted data, be it scientific metadata, purchase orders, journal proofs, grant proposals, interview schedules, their shopping list, or maybe (for a brief moment) actual scientific data. The real productive geniuses are the ones who figure out a way to ignore all this noise for along enough to get something done. It all comes down to logistics in the end.
A huge fraction of this work could conceivably be automated, or just trivial if people migrated to a better data structure. Maybe LLMs will help us bring order here, but that's only half the battle: part of learning to format data is thinking about the formal structure, what consumers will actually need, what parts are duplicated, etc.
20 years ago Tim Burners-Lee was advocating to clean this up via a better structured web [1], but, for various reasons, we haven't made much progress. I suspect a big reason is that the vast majority of people would struggle to understand the purpose of structured data: like basic literacy it's only useful if other people in your community use it.
I love Scott, but I think OP's meaning is not about verifying discoveries, but rather having the tools necessary to create discoveries in the first place. You can't invent an electric motor without electricity. Alternatively, think about how Da Vinci has many notebooks full of ideas- but lacked the resources to create them.
Scott's article is mostly on point here, but he dismisses the "respect" idea too quickly. As humans we are confronted with an overwhelming array of information and opinions from a huge number of sources. It's natural to apply a filtering based on our perceived reputation of said sources. And hearing that someone does not believe that HIV causes Aids despite extremely compelling evidence to the contrary is good cause for decreasing that reputation value.
My view of genius has changed quite a bit as I've gotten a bit older.
I think the word "genius" best describes a body of work, or an accomplishment that changes the world in a surprising way, that is, genius is not just intelligence, it is being in the right place at the right time, with the right people around you (Einstein's wife was reportedly brilliant as well), and then being driven to understand and describe the world back to people through new science or art. It means that a person has enough resources and few distractions that occupy their minds.
In other words, 'genius' to me describes a situation, not just the person.
> genius is not just intelligence, it is being in the right place at the right time, with the right people around you
Intelligence + circumstance is key, I agree, but I don't think you should devalue the intelligence part. Plenty of people face similar circumstances but don't move the world.
I liken intelligence to a catalyst in chemistry: nothing happens if the ingredients aren't there, but if they are, it's remarkable. Without the catalyst, the progress of a reaction that has all of the right ingredients might not even be perceptible.
If we're going to talk seriously about intelligence, I think we need to have a multi-factor understanding of intelligence. Too many people think that intelligence means doing well on tests (this was my view as I grew up).
In the SciFi book "Children of Memory", Tchaikovsky at least splits intelligence into reasoning and recall. People also talk about system size and working set.
Persistence is another thing I've come to view differently. The mind is willing to entertain a problem as long as progress feels possible. I wonder if that feeling of possible progress is trainable. Another view of 'possible progress' is rational faith (lower case f, sorry I don't have a less loaded term, after all, many consider faith to be irrational).
But mainly, I think we are still in the dark ages of psychology, brain function, and theory of the mind. Thus it is important to me to be humble about how I talk about what intelligence might mean.
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By the way, I love the Children of Time series, but I had to really defocus my mind and suspend my disbelief and scientific critique to try to imagine other intelligences.
> Tchaikovsky at least splits intelligence into reasoning and recall.
I'm not sure these are cleanly separable or observable. Reasoning is assisted by recall, and if there is some distinct reasoning ability then one can use it to make up for poorer recall by deriving knowledge.
In computational terms: you can gain speed up computation via memoization (trade off memory for more computation), but you can also trade off computation speed for memory with suitable compression. If you only had a black box, how would you distinguish these different internal mechanisms? I don't think you can, increasing either recall or reasoning ability will both improve performance on any conceivable intelligence metrics.
Agreed. I do not mean that these facets are completely separable, but that they can be evaluated as their own "thing"/schema/clade/subgens. After all, even though a von Neumann computer needs both memory and computation to function, you can benchmark them separately.
I really wish I had better ontology words. Ontolographs.
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Also, I'm doing the book a great disservice by simplifying it so much.
I wonder. I'm against wealth inequality, but for thousands of years, the human labor required to feed, clothe, and shelter a family wouldn't have allowed anyone to learn, preserve, and advance human knowledge without the labor of many being exploited one way or another by an elite few. That's not to justify anything or argue against egalitarianism today.
A great point! I beleive today the main problem is no longer the amount of human labor needed to feed or clothe, but to have access to those universities/labs/companies that have the necessary resources to enable meaningful research that humanity values.
Costs of creating food and clothe have plummeted - this is good from any possible point of view, and clearly shows we do no longer "need" inequlity from these perspectives.
However, access to human institutions does not follow the same democratization and pricefall. In several fields (space, medical and material sciences), advances we yearn for require lots of capital/military power. In many fields, innovations are tied to huge amounts of money to be spent (mostly accessible only in one particular capital market of the world).
But even in "cheaper" fields (like mathematics, economics etc.) simply being heard requires working in prestiguous universities. And many of those have no choice but to select and hire people based on their previous work or their financial capabilities.
Thus, reinforcing the same stratification as we've seen with food and clothing, and slowing the process of finding the right bright minds to do what they excel at in greater numbers.
It's quite unlikely we will solve any major part of this social problem before 2086 (or any projected population peak)... People seem to be still stuck in celebrity culture in politics and everywhere.
It's hard to differentiate between transients and steady-state on a short time-line. The "research factory" model, I believe, is a transient, at least in physics, sustained by the low-hanging fruit left between industrialization and now. Progress is slowing down asymptotically approaching zero. And I think that's okay - consider that the progenitors of the current approach all had day jobs, all of them did this in addition because they HAD to do it. As long as society allows people to have sufficient free time, we'll still get progress in the foundations of physics. (Note that this argument does NOT apply to capital intensive experimentation, e.g. the LHC, space telescopes, or fusion research).
Journeyman physics isn't all bad, and in fact can be quite good. Not only do you not have to worry about the social, administrative, political and funding headaches of academia, you are also not suffused in the always reasonable-sounding groupthink that persistently tells you what can and cannot be done, what should and should not be questioned. I strongly believe that the next truly big shift in physics, if it ever comes, must come from an outsider. (And if that happens, ironically, we'll have another period of fruitful professional academic physics, and later another iteration of this same discussion).
I don't know where this viewpoint comes from where, even though a cursory look at history gives counter evidence. We have ample anthropological evidence of societies engaging in labor that is beyond eat, cloth and shelter.
The biggest such evidences are still there: The pyramids and other huge monuments, which took 100s of thousands or more of manhours to build. Many cultures had temples with ample evidence that people spent a lot of time engaging in religious activities there. Everywhere you evacuate, you see art pieces that had to be made by people spending time. The dead were often buried with weapons and food. There is plenty of evidence of people engaging in massive yearly festivals with lots of food, drinks and music.
How is all of this happening if humans were like cattle spending all their looking for food?
The pyramids is a perfect example of an elite few exploiting the labor of many. All that labor to build tombs for a small handful of people looking for an advantage in the after-life.
Sure, in some places and times there was enough slack to allow common people to celebrate festivals or partake in elaborate religious activities. But I think you underestimate how costly education was when every book had to be painstakingly copied by hand.
None of us is making cloth, working in fields or even baking.
We are so good, that we have an epidemic of people consuming too many calories.
There is no way for me right now to get social security and being allowed to be in university. But i would be able to get social security.
Officially universities throw you out after x years, but no one will bat an eye if you sit in a big lecture because there is plenty of space. But the documents/video recordings etc. is protected by some passwords for no particular reason.
Imagine were you could go to a campus for a few years and have enough for feeding yourself, paper, pen and books and basic oversight (not blocking the space for someone who would use it to learn while you only sit in your room gaming).
> for thousands of years, the human labor required to feed, clothe, and shelter a family wouldn't have allowed anyone to learn, preserve, and advance human knowledge without the labor of many being exploited one way or another by an elite few.
That's quite a claim; is there a basis for it? Is there data? Research? Did manual labor really leave no time for other things - I've heard otherwise too.
And why do all those people working need an elite few taking most of the capital for themselves, e.g., to build massive homes and to guild their castles and churches? That capital could have been invested in the population and greatly improved the standard of living, technology (reducing the need for labor), knowledge, etc.
The elite few spent a lot of that capital fighting each other over power and land, not only consuming capital but destroying it - destroying much of what that labor built. They also use it to oppress many who could have raised humanity to greater fredom, knowledge, and prosperity.
We reside in a living example of the far, far more successful alternative - no authoritarian country, now or in the past, comes close to the prosperity of free, advanced democracies.
The justications for authoritarianism are popular these days.
> I was quite clear that I'm not defending past or present inequality.
How is that reconciled with (from GGP):
> for thousands of years, the human labor required to feed, clothe, and shelter a family wouldn't have allowed anyone to learn, preserve, and advance human knowledge without the labor of many being exploited one way or another by an elite few.
That seems to advocate for or justify exploitation of the poor by the wealthy?
What a stunning thought. I always think about the sheer number of things that have to go right in order for a person to achieve scientific greatness. It is such a difficult, life long endeavor, and the path is so fraught with events that can derail.
Like even being born in the wrong country, one lacking in food or academic mobility, for example. Right off the bat, how many millions of gifted humans just died of starvation, malnutrition, in poverty, in isolation, violence, etc. All that potential just lost to time.
I'd argue that Ramanujan was taking much more of a moonshot mailing Hardy as an unknown clerk, than Bose who was already an established academic when he contacted Einstein.
Stephen Jay Gould was one of the writers I read as a teenager that changed my world view and way of thinking for the rest of the life. And I don't even like baseball, even now :) Such a clear thinker.
clear thinking; his deep ideas he returned to again and again - history of deep time, punctuated evolution, the implications of human evolution not being a climb towards some teleological end but of complexity gradually increasing with time. The incredible degree to which evolution and biology "take advantage" of contingent happenings.
> Can't help but wonder what our knowledge here in 2025 would be like had we, as a species, tapped into our full potential by empowering women and people of color (to name just a few categories) earlier.
Can't speak for women, but we did tap into the potential of people of color. White race(s) getting ahead is a story of only the last few centuries, and they did benefit quite a bit from the work of "colored" races of the past.
Also, keep in mind that in that time period, plenty of "colored" races were independent, and capable of many of those advances. That they didn't achieve it should give you a clue that justice and equality overall play a very tiny role in these advancements. There are just so many other (random) factors that go into creating an Einstein that have nothing to do with treating people fairly.
As a random data point - my ancestors came from a society that did not value science and the accumulation of knowledge. It's why they were colonized, and also why that society continues to fare poorly today (long after the colonists left). Even today, amongst my relatives who live there, your are somewhat of a social outcast if you want to get deep into engineering/science. You're "supposed" to get that engineering degree to earn an income, and if you try to take it further (e.g. hobby), then you are "immature".
The more I learn about Kepler the more I believe that he alone advanced humanity several decades or possibly centuries. His incredible drive to prove his own theory, and then his ability to put that theory down and to match one to the evidence, oh man. I've loved his story since the Carl Sagan Cosmos episode on him sniped me as a kid, but I get just as excited about it in videos like these (part one of this series explains how Kepler determined the orbits of the planets).
If you want to be deeply inspired, read about his life, his book Somnium, what happened to his mother. It's all so profoundly motivating.
What is particularly wild is that Kepler had to wait for Tycho Brahe to die to steal his data before Brahe's heirs got their hands on it. Not only that, but Kepler was very close to making epicycles work but he was not satisfied with the (relatively small) predictive errors. So, if not for Kepler's combination of...flexible morality and unsatified nature, physics as we know it would have been delayed or perhaps never discovered at all!
By the time Kepler published his work, Copernicus had already developed the heliocentric model, and Galileo was starting to gather significant observational evidence for heliocentrism (and had begun developing the principles of mechanics).
Kepler made a huge contribution to the development of physics, but "the new physics" was already in motion by the time he published his work, and I think it's an exaggeration to say progress of physics would have stopped without Kepler.
Kepler’s half-insight, half-inferential-leap that the orbits were ellipses and not just off-center circles (made possible by the fantastic quality of the data Brahe gathered—he didn’t even have a telescope, remember) was very important to Newton’s positing the law of universal gravitation. (The universal part is much more important here, as far as a naturalist’s worldview is concerned, than the gravitation one.) See Arnold’s writings regarding just how tiny the difference is between the two possibilities.
Would Kepler’s absence have stopped scientific progress? Probably not. But some very, very important parts of it would not have proceeded as they did.
It was an old idea that had been out of favor for two millennia.
> what Copernicus did was not that impresive since it was wrong
What a statement. Copernicus was more right than anyone else of his time. His model revolutionized astronomy and led to the development of modern physics.
The same thought occurred to me, but then I realized we still don't know if his discovery was beneficial. I don't think we'll know that until humanity spreads life beyond Earth and avoids killing the biosphere in a number of innovative ways (bathing it in nuclear fire being perhaps the most relevant to this discussion). It's only possible to excuse the millions of lives that ended in pain and death during the many wars we've had since industrialization, itself driven by scientific understanding, if there really is light at the end of the tunnel. Otherwise, I can't help but think we'd have been better off living in small, low-tech hamlets at the teetering edge of the natural world, filled with wrong but comforting ideas about the heavens.
Maybe even more importantly, he dropped his preferred theory of fitting the orbits of known planets (at the time) with Platonic solids. That requires iron commitment to science.
"Blind watchers of the sky" is one of the best presentations of Kepler's and Galileo's oeuvre I have ever read. (I am an astrophysicist, but this book can be read by non-specialists too.)
I’m an asteroseismologist and really pleased to see a link to the Kappa mechanism. I usually teach it as a heat engine concept, and it’s applicable to most stars in the classical instability strip.
Another class of variables that aren’t mentioned are the solar like oscillators, driven by convection on the surface of the star.
There is no scientifically imaginable form of life that could evolve or survive in or on stars. (So to be clear, this is all a flight of fancy)
Anthropic bias suggests that liquid water and carbon are essential to life.
BUT! I do think it's fun to imagine what assumptions a solarian biologist would make about the world. What would Solarian Bias look like?
What might be easier for a solarian physicist to understand? Would they have a different view of gravity?
They would start with a better understanding of astronomy than us, assuming they could make observations of the 'sky'; As the band Mogwai says "The Sun Smells Too Loud". All manner of EM observations would be more obscure (or rather their instruments would be dazzled). They would have to find some kind of Spot on the Sun where it's dark enough to see out. Maybe they could learn to ride the flares!
They would definitely start with a better version of the atom - there's no way to ignore fusion and fission if you live on the sun!
Or! What if it were possible to make observations of gravity from the surface of a neutron star. We have math and observations from here that make sense to us, but perhaps there's something that would just 'click' if you lived next to one.
The corrections in his blog post show you the level of precision mathematicians are used to.
A regular interviewer would have left the inaccuracies as they are because it’s too tedious to go over all of them when you have a casual conversation.
.xyz (alongside some others like .top, .biz?) in particular have a reputation for phishing/malware/etc., I think because they’re among the cheapest to register.
The funny thing is, the number 1 & 2 spam/phishing/malware domains that hit my company's mail server is gmail.com and outlook.com, followed by random .com domains.
My domain block list is approaching 1,000 domains and I don't think I have a single .xyz or .biz in there. There's a few .top. But the overwhelming majority is .com.
Note that the modern cosmic distance ladder has multiple partially independent paths using different techniques, making it more like a DAG. The wikipedia page has a nice diagram.
tbh I would love to see full length video walking through the work that Kepler did with actual numbers, to me that part remained bit unclear. Especially how to get some quantitative values out of the analysis, considering how the eccentricity of the orbits is not really something easily visually discernible.
> In principle, using the measurements to all the planets at once could allow for some multidimensional analysis that would be more accurate than analyzing each of the planets separately
(from the blog post)
I'd also love to see this idea expanded further. Intuitively it feels like adding Venus into the calculations should dramatically help constrain the orbit of Mars, but how exactly that would work out I'm not sure.
The cosmic distance ladder is fascinating. At university, we had an astrophysics professor who said his secret worry is that something was broken about the ladder. If you have a wrong assumption close to the bottom, then the error would compound the more you go to larger distances. And you would not just have quantitative errors, such as mismeasured distances, but qualitative errors. The objects you think you are looking at might be something completely different. It is unlikely because the picture we have is consistent. But it could be also wrong and still consistent. The big open questions such as dark matter / dark energy could be the only hints we have that something is wrong.
I'm an experimental particle physicist by training and know that feeling. We never see the particles directly, but reconstruct them in a complex chain. Hits in a detector become tracks, tracks are assigned to particles according to our expectation of how those particles behave. Bunches of tracks are interpreted as decaying heavier particle. Sometimes I wonder if we missed something important in the early days of quantum mechanics and particle physics, and some of the things we think we are investigating don't actually exist, or are subtly different than we think. But we look at the data though our lens, and see what we are expecting to see. My gut feeling says everything is consistent, and experiments match the theory so incredibly closely that it can't be a coincidence, but I don't think there is a mathematical proof. It could be that our theory is just so flexible that it lets us see Higgs particles and top quarks, even though the actual entities are something different. Like when people thought planets move in epicycles.
I know it is likely nonsense, but it is what motivated me every now and then to go back and revisit the basics of our field, like how is a particle state defined in QM, how does it interact with the experiment, how do we reconstruct larger objects, and so on.
Luckily, the bottom rung of the distance ladder, parallax, is only dependent on geometry, and is therefore completely solid. With the Gaia space telescope, there are now parallax measurements almost to the center of the Milky Way.
Having parallax measurements to that distance helps to build multiple versions of the next rung in the ladder (such as Cepheids and the tip of the red giant branch).
i think one of the things astronomers were pleasantly surprised to see was that the Gaia results have indicated that other low rungs of the distance ladder were pretty well calibrated. Most of these are based in some way on stellar evolution, and given that stars can be kind of messy there was always a bit of nervousness that maybe our systematic errors are larger than we think. But the models turned out to be pretty good.
parallax is only perfectly solid before GR. once you accept that space can bend it becomes a lot more complicated (especially given that we currently think ~75% of mass is dark matter which could be bending light without being visible
General Relativistic effects are taken into account by Gaia, but they're dominated by Solar System objects. Space is very close to flat, unless you're close to a very massive object.
Even mathematical proofs don't have mechanized, verifiable proofs, so physics has a ways to go. Once most mathematicians are using formal tools like theorem provers, maybe they will be usable and general enough to trickle down to physicists, and you'll have a more verifiable chain of reasoning from top to bottom for machines and observations. It probably will turn up a few minor issues, but I wouldn't expect anything drastic.
This is so good. It reminded me of the foreword to Simon Jenkins’ “A short history of England” when he says that breadth of knowledge should come before depth (ie knowing about the details of Henry VIII or Charles I beheading fits better after a solid grounding in the overall scope of English history)
Similarly I now have a much clearer idea of how (say) the main sequence of star formation and standard candle stars fit into the historical picture.
The gravitational wave based distance measurements are really awesome because they are the only way to verify red shift distances. You can calculate how strong the wave should be based on the difference in mass between the two objects before collision and the combined object after and then calculate how strong the wave should be when it reaches earth. Right now the precision of the distances are only 10% but in the future when something like the Cosmic Explorer with 40km arms is built they will get a lot more precise.
Fantastic video, the methods are explained super clearly.
Also highly recommend David Butler's "How far away is it" video series. He covers the same methods, and spends a good amount of time discussing phenomena along the way (star life cycles, magnetars, black holes, galaxy mergers, etc).
Anyone looking for additional recommendations : the popular "A short history of nearly everything" by Bill Bryson covers in a historical context how these planetary distances were calculated
It's been a while since I read his writing, but I skimmed and didn't see anything that sounded unlike him. He writes with a very neutral tone.
It did make me wonder though how effectively you could lean on AI to flesh out a list of questions, but I think in this case he has the expertise to write each response quickly and he'd be conscious that this is overall a piece of content doing properly.
Stephen Jay Gould said: "I am, somehow, less interested in the weight and convolutions of Einstein's brain than in the near certainty that people of equal talent have lived and died in cotton fields and sweatshops."
This quote really drives home the point that the overwhelmingly vast majority of scientific discovery and progress throughout history has come with humanity's entirely self-inflicted handicapping, like a V8 engine running on only 1 cylinder. Can't help but wonder what our knowledge here in 2025 would be like had we, as a species, tapped into our full potential by empowering women and people of color (to name just a few categories) earlier. You can almost see it in action with the people mentioned here as time went on.
Wonderful set of videos.
I believe that geniuses like Einstein are just the tip of the iceberg. We need them, but they are not the limiting factor, and producing more of them may not have that much of an influence on scientific progress.
What really drives progress, I think is production and technology. Like better telescopes. For the cosmic distance ladder, the clever mathematical tricks are nice, and necessary, but the real important part is the precise measurements. And for that, we need precise instruments. And precise instruments need good quality materials, skilled tradesmen, good tools, etc... The tools themselves need the same, and the tools to make the tools, etc... A lot of the measurements involve travel and long distance communication, which wasn't trivial either. Mounting an expedition to the other side of the world requires a ship, a crew, etc... Then we need to collect these data, and people have to write these books, we need librarians, archivists, etc... All that so that finally, one guy can look at the data and do the maths.
And all that is far from the whole story. Skilled craftsmen and sailors need food and shelter, and the raw materials to practice their craft of course. They need farmers, miners, lumberjacks, etc... Farmers, miners and lumberjacks need their tools too. Advancing in the cosmic distance ladder is the work of millions of people over several lifespans, and some of them worked in cotton fields. We could wish the guy in the cotton fields was treated better, but it doesn't change the fact that in order to advance science, we actually need more people in cotton fields than people doing maths.
With technological progress, we can afford to have more people doing maths and provide them with enough data to be useful, but that's a very recent development.
A better theory is that it is legal innovation. If the wealthiest and most powerful are threatened by progress ... there will be no progress. If the wealthiest and most powerful get more power and status from progress, there will be progress. Without insurance, for example, it isn't possible to run serious sea trade. Without the joint stock corporation, it isn't feasible for the British to organise and conquer India. It takes democracy to really align the political class with increasing prosperity for the median citizen; otherwise states tend towards tinpot dictatorships.
There isn't a shortage of smart people or opportunities to make technological progress. The handicap is powerful humans looking at new approaches and saying "No" with the firmness of a man who sees a threat to their position. Even today I have a list of things that from an engineering perspective would probably result in improved prosperity, it just isn't possible to get them through the political process (nuclear power springs to mind, but I'm sure there are less controversial examples - Uber v. the Taxi industry maybe).
I get your point about not being able to do everything in a vacuum, but I think there's also just a very limited set of geniuses that are of the Einstein/Newton level that might only exist once a century if you're lucky. We have millions in academia now and how many more physicists than the 1800s? There has certainly been progress, but it seems diminished.
There's a lot of discussion on this online and some folks speaking past each other. Yeah, there has been the invention of the internet, faster computers, the blue LED, sequencing the human genome...etc, but that is argued to mainly be engineering innovations on already understood physics. Where is the next discovery on the level of general relativity? Are we just at diminishing returns now where all the low hanging fruit has been found? How many physicists wasted away researching string theory? Were we just putting resources in the wrong place?
I do strongly think that modern research has become so beauracratic that it gets in the way of actual progress. The endless paperwork, presentations, teaching...etc isn't very conducive to discovery. Your average professor is more like a project manager than what Newton did.
The physics of the 1800s had a lot of low hanging fruit. Most undergrads in physics can show you a derivation of Maxwell's equations from first principles, and I think a fair few of them could have come up with it themselves if they were in Maxwell's shoes. The hard truth is that the physics/math of today is just much further afield, and much harder.
Very little of the stuff physicists came up with in the 19th century was obvious or low hanging at the time. And no your undergrads would likely have never came up with Maxwell's equations on their own.
Yeah, I agree with you on this one. It's kind of easy once you understand it, but it took Maxwell to figure it out. I might not have figured that out in ten centuries by myself lol.
I definitely think it takes a Maxwell to describe the physics behind displacement current (which I think was not around in Maxwell's initial drafts), but the derivations of the four classic Maxwell equations are fairly straightforward multivariable calculus problems that start with fairly simple assumptions. Multivariable calculus was relatively young in his era, but I think a motivated student from the current era could discover it given a summer of thought experimentation.
See for yourself: https://m.youtube.com/watch?v=AWI70HXrbG0
If you want some true genius, behold the shear terror of the near field of a dipole antenna. All shall view her and despair.
For those interested, see slide 4 of section 7: Hertzian dipoles
https://courses.grainger.illinois.edu/ece350/ece350lecture_n...
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That's a highly biased opinion. The Newtonian conception of physics is trivial for us, and we can say that most people could come up with the ideas by their own, but that's because our world conception is based on those ideas; it's already implicit in how we understand the world. That's why Newton was so important, there was a shift in the whole conceptualization of the physical world. With Maxwell's equations is similar. The interpretation as waves, the fact that the equations are Lorentz symmetric but no Newton symmetric, etc. All that is free for us, and it is not obvious at all.
Spend a trillion dollars building a bigger supercolider if you want more fundamentals. I think the application of these discoveries is much more important at this point. What do we actually use GR for? Corrections to gps, and ... it's not like it's gonna cure cancer. Technology will do that. We've exhausted all the fundamentals that we can access, that's what's happened. You want more fundamentals, you need more access. You want more access, Get ready to ride the exponential curve of costs
That is pretty contentious even in physics circles (from what I've heard in videos). The build me a bigger particle collider might not have any impact. We might not see any of the hypothetically proposed stuff.
That doesn't change the general issue:
You need a certain amount of motivation, grid, etc. If these skills would be broadly available and the situation also, we would have a lot more Einsteins today.
There is plenty of things which do not require global projects building multibillion devices.
Mathematic thinking for ML for example.
DeepSeek paper for example.
I'm not so sure. It seems these kinds of people are exceedingly rare that grasp a fundamental truth we've all missed. ChatGPT is really cool, but building a really really big neural network and training it off all the stuff on the internet certainly seems less impressive than discovering calculus. I mean ..LLMs are impressive and magical of course.
The the single best way to drive science and technology: teach everyone to format a json string share it via a URL.
The people on the bleeding edge of science and technology aren't just sitting in futuristic labs, surrounded by holograms and AI tech assistants, spouting one brilliant insight after another.
They are spending most of their days arranging various types of poorly formatted data, be it scientific metadata, purchase orders, journal proofs, grant proposals, interview schedules, their shopping list, or maybe (for a brief moment) actual scientific data. The real productive geniuses are the ones who figure out a way to ignore all this noise for along enough to get something done. It all comes down to logistics in the end.
A huge fraction of this work could conceivably be automated, or just trivial if people migrated to a better data structure. Maybe LLMs will help us bring order here, but that's only half the battle: part of learning to format data is thinking about the formal structure, what consumers will actually need, what parts are duplicated, etc.
20 years ago Tim Burners-Lee was advocating to clean this up via a better structured web [1], but, for various reasons, we haven't made much progress. I suspect a big reason is that the vast majority of people would struggle to understand the purpose of structured data: like basic literacy it's only useful if other people in your community use it.
[1]: https://en.wikipedia.org/wiki/Semantic_Web
> I believe that geniuses like Einstein are just the tip of the iceberg. We need them, but they are not the limiting factor
For the alternative viewpoint: https://slatestarcodex.com/2019/02/26/rule-genius-in-not-out...
I love Scott, but I think OP's meaning is not about verifying discoveries, but rather having the tools necessary to create discoveries in the first place. You can't invent an electric motor without electricity. Alternatively, think about how Da Vinci has many notebooks full of ideas- but lacked the resources to create them.
Scott's article is mostly on point here, but he dismisses the "respect" idea too quickly. As humans we are confronted with an overwhelming array of information and opinions from a huge number of sources. It's natural to apply a filtering based on our perceived reputation of said sources. And hearing that someone does not believe that HIV causes Aids despite extremely compelling evidence to the contrary is good cause for decreasing that reputation value.
My view of genius has changed quite a bit as I've gotten a bit older.
I think the word "genius" best describes a body of work, or an accomplishment that changes the world in a surprising way, that is, genius is not just intelligence, it is being in the right place at the right time, with the right people around you (Einstein's wife was reportedly brilliant as well), and then being driven to understand and describe the world back to people through new science or art. It means that a person has enough resources and few distractions that occupy their minds.
In other words, 'genius' to me describes a situation, not just the person.
> genius is not just intelligence, it is being in the right place at the right time, with the right people around you
Intelligence + circumstance is key, I agree, but I don't think you should devalue the intelligence part. Plenty of people face similar circumstances but don't move the world.
I liken intelligence to a catalyst in chemistry: nothing happens if the ingredients aren't there, but if they are, it's remarkable. Without the catalyst, the progress of a reaction that has all of the right ingredients might not even be perceptible.
If we're going to talk seriously about intelligence, I think we need to have a multi-factor understanding of intelligence. Too many people think that intelligence means doing well on tests (this was my view as I grew up).
In the SciFi book "Children of Memory", Tchaikovsky at least splits intelligence into reasoning and recall. People also talk about system size and working set.
Persistence is another thing I've come to view differently. The mind is willing to entertain a problem as long as progress feels possible. I wonder if that feeling of possible progress is trainable. Another view of 'possible progress' is rational faith (lower case f, sorry I don't have a less loaded term, after all, many consider faith to be irrational).
But mainly, I think we are still in the dark ages of psychology, brain function, and theory of the mind. Thus it is important to me to be humble about how I talk about what intelligence might mean.
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By the way, I love the Children of Time series, but I had to really defocus my mind and suspend my disbelief and scientific critique to try to imagine other intelligences.
> Tchaikovsky at least splits intelligence into reasoning and recall.
I'm not sure these are cleanly separable or observable. Reasoning is assisted by recall, and if there is some distinct reasoning ability then one can use it to make up for poorer recall by deriving knowledge.
In computational terms: you can gain speed up computation via memoization (trade off memory for more computation), but you can also trade off computation speed for memory with suitable compression. If you only had a black box, how would you distinguish these different internal mechanisms? I don't think you can, increasing either recall or reasoning ability will both improve performance on any conceivable intelligence metrics.
> In computational terms: ...
Agreed. I do not mean that these facets are completely separable, but that they can be evaluated as their own "thing"/schema/clade/subgens. After all, even though a von Neumann computer needs both memory and computation to function, you can benchmark them separately.
I really wish I had better ontology words. Ontolographs.
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Also, I'm doing the book a great disservice by simplifying it so much.
I wonder. I'm against wealth inequality, but for thousands of years, the human labor required to feed, clothe, and shelter a family wouldn't have allowed anyone to learn, preserve, and advance human knowledge without the labor of many being exploited one way or another by an elite few. That's not to justify anything or argue against egalitarianism today.
A great point! I beleive today the main problem is no longer the amount of human labor needed to feed or clothe, but to have access to those universities/labs/companies that have the necessary resources to enable meaningful research that humanity values. Costs of creating food and clothe have plummeted - this is good from any possible point of view, and clearly shows we do no longer "need" inequlity from these perspectives. However, access to human institutions does not follow the same democratization and pricefall. In several fields (space, medical and material sciences), advances we yearn for require lots of capital/military power. In many fields, innovations are tied to huge amounts of money to be spent (mostly accessible only in one particular capital market of the world). But even in "cheaper" fields (like mathematics, economics etc.) simply being heard requires working in prestiguous universities. And many of those have no choice but to select and hire people based on their previous work or their financial capabilities. Thus, reinforcing the same stratification as we've seen with food and clothing, and slowing the process of finding the right bright minds to do what they excel at in greater numbers. It's quite unlikely we will solve any major part of this social problem before 2086 (or any projected population peak)... People seem to be still stuck in celebrity culture in politics and everywhere.
It's hard to differentiate between transients and steady-state on a short time-line. The "research factory" model, I believe, is a transient, at least in physics, sustained by the low-hanging fruit left between industrialization and now. Progress is slowing down asymptotically approaching zero. And I think that's okay - consider that the progenitors of the current approach all had day jobs, all of them did this in addition because they HAD to do it. As long as society allows people to have sufficient free time, we'll still get progress in the foundations of physics. (Note that this argument does NOT apply to capital intensive experimentation, e.g. the LHC, space telescopes, or fusion research).
Journeyman physics isn't all bad, and in fact can be quite good. Not only do you not have to worry about the social, administrative, political and funding headaches of academia, you are also not suffused in the always reasonable-sounding groupthink that persistently tells you what can and cannot be done, what should and should not be questioned. I strongly believe that the next truly big shift in physics, if it ever comes, must come from an outsider. (And if that happens, ironically, we'll have another period of fruitful professional academic physics, and later another iteration of this same discussion).
I don't know where this viewpoint comes from where, even though a cursory look at history gives counter evidence. We have ample anthropological evidence of societies engaging in labor that is beyond eat, cloth and shelter.
The biggest such evidences are still there: The pyramids and other huge monuments, which took 100s of thousands or more of manhours to build. Many cultures had temples with ample evidence that people spent a lot of time engaging in religious activities there. Everywhere you evacuate, you see art pieces that had to be made by people spending time. The dead were often buried with weapons and food. There is plenty of evidence of people engaging in massive yearly festivals with lots of food, drinks and music.
How is all of this happening if humans were like cattle spending all their looking for food?
The pyramids is a perfect example of an elite few exploiting the labor of many. All that labor to build tombs for a small handful of people looking for an advantage in the after-life.
Sure, in some places and times there was enough slack to allow common people to celebrate festivals or partake in elaborate religious activities. But I think you underestimate how costly education was when every book had to be painstakingly copied by hand.
None of us is making cloth, working in fields or even baking.
We are so good, that we have an epidemic of people consuming too many calories.
There is no way for me right now to get social security and being allowed to be in university. But i would be able to get social security.
Officially universities throw you out after x years, but no one will bat an eye if you sit in a big lecture because there is plenty of space. But the documents/video recordings etc. is protected by some passwords for no particular reason.
Imagine were you could go to a campus for a few years and have enough for feeding yourself, paper, pen and books and basic oversight (not blocking the space for someone who would use it to learn while you only sit in your room gaming).
> for thousands of years, the human labor required to feed, clothe, and shelter a family wouldn't have allowed anyone to learn, preserve, and advance human knowledge without the labor of many being exploited one way or another by an elite few.
That's quite a claim; is there a basis for it? Is there data? Research? Did manual labor really leave no time for other things - I've heard otherwise too.
And why do all those people working need an elite few taking most of the capital for themselves, e.g., to build massive homes and to guild their castles and churches? That capital could have been invested in the population and greatly improved the standard of living, technology (reducing the need for labor), knowledge, etc.
The elite few spent a lot of that capital fighting each other over power and land, not only consuming capital but destroying it - destroying much of what that labor built. They also use it to oppress many who could have raised humanity to greater fredom, knowledge, and prosperity.
We reside in a living example of the far, far more successful alternative - no authoritarian country, now or in the past, comes close to the prosperity of free, advanced democracies.
The justications for authoritarianism are popular these days.
> That's not to justify anything or argue against egalitarianism today.
I was quite clear that I'm not defending past or present inequality. I said nothing to defend the lavish lifestyles of feudal lords.
I'm not a historian, but here's a description of the day-to-day life of a medieval peasant:
https://www.reddit.com/r/AskHistorians/comments/mcgog5/comme...
> I was quite clear that I'm not defending past or present inequality.
How is that reconciled with (from GGP):
> for thousands of years, the human labor required to feed, clothe, and shelter a family wouldn't have allowed anyone to learn, preserve, and advance human knowledge without the labor of many being exploited one way or another by an elite few.
That seems to advocate for or justify exploitation of the poor by the wealthy?
That doesn't have to mean exploitation. Labor can be done fairly (but not in capitalism, not really).
What a stunning thought. I always think about the sheer number of things that have to go right in order for a person to achieve scientific greatness. It is such a difficult, life long endeavor, and the path is so fraught with events that can derail.
Like even being born in the wrong country, one lacking in food or academic mobility, for example. Right off the bat, how many millions of gifted humans just died of starvation, malnutrition, in poverty, in isolation, violence, etc. All that potential just lost to time.
Makes Ramanujan’s journey all the more special.
Or Bose for that matter
I'd argue that Ramanujan was taking much more of a moonshot mailing Hardy as an unknown clerk, than Bose who was already an established academic when he contacted Einstein.
Stephen Jay Gould was one of the writers I read as a teenager that changed my world view and way of thinking for the rest of the life. And I don't even like baseball, even now :) Such a clear thinker.
He wrote his books as more or less first drafts. He had a lot of great ideas, but clear is not an adjective I would have attributed to his books.
clear thinking; his deep ideas he returned to again and again - history of deep time, punctuated evolution, the implications of human evolution not being a climb towards some teleological end but of complexity gradually increasing with time. The incredible degree to which evolution and biology "take advantage" of contingent happenings.
> Can't help but wonder what our knowledge here in 2025 would be like had we, as a species, tapped into our full potential by empowering women and people of color (to name just a few categories) earlier.
Can't speak for women, but we did tap into the potential of people of color. White race(s) getting ahead is a story of only the last few centuries, and they did benefit quite a bit from the work of "colored" races of the past.
Also, keep in mind that in that time period, plenty of "colored" races were independent, and capable of many of those advances. That they didn't achieve it should give you a clue that justice and equality overall play a very tiny role in these advancements. There are just so many other (random) factors that go into creating an Einstein that have nothing to do with treating people fairly.
As a random data point - my ancestors came from a society that did not value science and the accumulation of knowledge. It's why they were colonized, and also why that society continues to fare poorly today (long after the colonists left). Even today, amongst my relatives who live there, your are somewhat of a social outcast if you want to get deep into engineering/science. You're "supposed" to get that engineering degree to earn an income, and if you try to take it further (e.g. hobby), then you are "immature".
(Sorry for that tangent, but it's not a tangent).
Incredibly funny reply. If only the Sumerians "empowered people of color". The big "What If" of history.
Nice try but I'm not talking about Sumerians and I have a feeling you know that.
Are you talking about US race politics? Do you feel this has not been discussed enough yet?
I heard last week "Give It Away" by the Red Hot Chili Peppers and that lyric catched me:
"we have so much we need to share"
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"do not throw your pearls before pigs"
The more I learn about Kepler the more I believe that he alone advanced humanity several decades or possibly centuries. His incredible drive to prove his own theory, and then his ability to put that theory down and to match one to the evidence, oh man. I've loved his story since the Carl Sagan Cosmos episode on him sniped me as a kid, but I get just as excited about it in videos like these (part one of this series explains how Kepler determined the orbits of the planets).
If you want to be deeply inspired, read about his life, his book Somnium, what happened to his mother. It's all so profoundly motivating.
I agree, and if you want to learn more about him I highly recommend this two-part series: https://www.youtube.com/watch?v=Phscjl0u6TI
What is particularly wild is that Kepler had to wait for Tycho Brahe to die to steal his data before Brahe's heirs got their hands on it. Not only that, but Kepler was very close to making epicycles work but he was not satisfied with the (relatively small) predictive errors. So, if not for Kepler's combination of...flexible morality and unsatified nature, physics as we know it would have been delayed or perhaps never discovered at all!
By the time Kepler published his work, Copernicus had already developed the heliocentric model, and Galileo was starting to gather significant observational evidence for heliocentrism (and had begun developing the principles of mechanics).
Kepler made a huge contribution to the development of physics, but "the new physics" was already in motion by the time he published his work, and I think it's an exaggeration to say progress of physics would have stopped without Kepler.
Kepler’s half-insight, half-inferential-leap that the orbits were ellipses and not just off-center circles (made possible by the fantastic quality of the data Brahe gathered—he didn’t even have a telescope, remember) was very important to Newton’s positing the law of universal gravitation. (The universal part is much more important here, as far as a naturalist’s worldview is concerned, than the gravitation one.) See Arnold’s writings regarding just how tiny the difference is between the two possibilities.
Would Kepler’s absence have stopped scientific progress? Probably not. But some very, very important parts of it would not have proceeded as they did.
>By the time Kepler published his work, Copernicus had already developed the heliocentric model
The heliocentric model was an old idea anyway(Aristarchus), what Copernicus did was not that impresive since it was wrong.
It was an old idea that had been out of favor for two millennia.
> what Copernicus did was not that impresive since it was wrong
What a statement. Copernicus was more right than anyone else of his time. His model revolutionized astronomy and led to the development of modern physics.
The important thing is to be self aware enough to clearly differentiate between good and bad, even when doing bad stuff sometimes could be beneficial.
The same thought occurred to me, but then I realized we still don't know if his discovery was beneficial. I don't think we'll know that until humanity spreads life beyond Earth and avoids killing the biosphere in a number of innovative ways (bathing it in nuclear fire being perhaps the most relevant to this discussion). It's only possible to excuse the millions of lives that ended in pain and death during the many wars we've had since industrialization, itself driven by scientific understanding, if there really is light at the end of the tunnel. Otherwise, I can't help but think we'd have been better off living in small, low-tech hamlets at the teetering edge of the natural world, filled with wrong but comforting ideas about the heavens.
Maybe even more importantly, he dropped his preferred theory of fitting the orbits of known planets (at the time) with Platonic solids. That requires iron commitment to science.
Or listen to the opera about his mothers trial: https://en.wikipedia.org/wiki/Kepler_(opera)
Besides the Cosmos episode, do you have any recommendations on learning more?
"Blind watchers of the sky" is one of the best presentations of Kepler's and Galileo's oeuvre I have ever read. (I am an astrophysicist, but this book can be read by non-specialists too.)
They don't go into detail, but Cepheid stars are amazing
https://en.wikipedia.org/wiki/Cepheid_variable
Consensus mechanism for pulsation:
https://en.wikipedia.org/wiki/Kappa%E2%80%93mechanism
Basically the changes in ionization state, opacity, and temperature all influence each other, causing a cycle.
I’m an asteroseismologist and really pleased to see a link to the Kappa mechanism. I usually teach it as a heat engine concept, and it’s applicable to most stars in the classical instability strip.
Another class of variables that aren’t mentioned are the solar like oscillators, driven by convection on the surface of the star.
https://en.m.wikipedia.org/wiki/Solar-like_oscillations
Our sun is one such example and has a period of 5 minutes!
Neat!
There is no scientifically imaginable form of life that could evolve or survive in or on stars. (So to be clear, this is all a flight of fancy)
Anthropic bias suggests that liquid water and carbon are essential to life.
BUT! I do think it's fun to imagine what assumptions a solarian biologist would make about the world. What would Solarian Bias look like?
What might be easier for a solarian physicist to understand? Would they have a different view of gravity?
They would start with a better understanding of astronomy than us, assuming they could make observations of the 'sky'; As the band Mogwai says "The Sun Smells Too Loud". All manner of EM observations would be more obscure (or rather their instruments would be dazzled). They would have to find some kind of Spot on the Sun where it's dark enough to see out. Maybe they could learn to ride the flares!
They would definitely start with a better version of the atom - there's no way to ignore fusion and fission if you live on the sun!
Or! What if it were possible to make observations of gravity from the surface of a neutron star. We have math and observations from here that make sense to us, but perhaps there's something that would just 'click' if you lived next to one.
Anyway, thanks for coming to my TEDx talk.
The corrections in his blog post show you the level of precision mathematicians are used to.
A regular interviewer would have left the inaccuracies as they are because it’s too tedious to go over all of them when you have a casual conversation.
https://terrytao.wordpress.com/2025/02/13/cosmic-distance-la...
Note this blog post also has links to both parts of the video. (Our corporate firewall annoyingly blocks a bunch of new gTLDs, including xyz).
Direct link to video:
https://youtu.be/hFMaT9oRbs4
Announcement post on bsky: https://bsky.app/profile/3blue1brown.com/post/3liu3ybnowk2w
As a side question, what's the rationale for this? Is there a list of nsfw gTLDs?
.xyz (alongside some others like .top, .biz?) in particular have a reputation for phishing/malware/etc., I think because they’re among the cheapest to register.
The funny thing is, the number 1 & 2 spam/phishing/malware domains that hit my company's mail server is gmail.com and outlook.com, followed by random .com domains.
My domain block list is approaching 1,000 domains and I don't think I have a single .xyz or .biz in there. There's a few .top. But the overwhelming majority is .com.
I feel like .zip and .mov gTLDs are more understandable to have blocked
.top is definitely a shady spot. They’re inexpensive and not very responsive to abuse reports - https://www.icann.org/uploads/compliance_notice/attachment/1...
.xyz though I mostly associate with abc.xyz, the investor relations page for Alphabet.
Note that the modern cosmic distance ladder has multiple partially independent paths using different techniques, making it more like a DAG. The wikipedia page has a nice diagram.
https://en.wikipedia.org/wiki/Cosmic_distance_ladder
Cosmic distance scaffold?
tbh I would love to see full length video walking through the work that Kepler did with actual numbers, to me that part remained bit unclear. Especially how to get some quantitative values out of the analysis, considering how the eccentricity of the orbits is not really something easily visually discernible.
> In principle, using the measurements to all the planets at once could allow for some multidimensional analysis that would be more accurate than analyzing each of the planets separately
(from the blog post)
I'd also love to see this idea expanded further. Intuitively it feels like adding Venus into the calculations should dramatically help constrain the orbit of Mars, but how exactly that would work out I'm not sure.
There are videos by Welch labs that go into detail about what he did:
https://www.youtube.com/watch?v=Phscjl0u6TI https://www.youtube.com/watch?v=MprJN5teQxc
Related. Others?
Climbing the cosmic distance ladder: Terence Tao book announcement - https://news.ycombinator.com/item?id=24743177 - Oct 2020 (13 comments)
Terrence Tao: The Cosmic Distance Ladder - https://news.ycombinator.com/item?id=1782398 - Oct 2010 (6 comments)
The cosmic distance ladder is fascinating. At university, we had an astrophysics professor who said his secret worry is that something was broken about the ladder. If you have a wrong assumption close to the bottom, then the error would compound the more you go to larger distances. And you would not just have quantitative errors, such as mismeasured distances, but qualitative errors. The objects you think you are looking at might be something completely different. It is unlikely because the picture we have is consistent. But it could be also wrong and still consistent. The big open questions such as dark matter / dark energy could be the only hints we have that something is wrong.
I'm an experimental particle physicist by training and know that feeling. We never see the particles directly, but reconstruct them in a complex chain. Hits in a detector become tracks, tracks are assigned to particles according to our expectation of how those particles behave. Bunches of tracks are interpreted as decaying heavier particle. Sometimes I wonder if we missed something important in the early days of quantum mechanics and particle physics, and some of the things we think we are investigating don't actually exist, or are subtly different than we think. But we look at the data though our lens, and see what we are expecting to see. My gut feeling says everything is consistent, and experiments match the theory so incredibly closely that it can't be a coincidence, but I don't think there is a mathematical proof. It could be that our theory is just so flexible that it lets us see Higgs particles and top quarks, even though the actual entities are something different. Like when people thought planets move in epicycles.
I know it is likely nonsense, but it is what motivated me every now and then to go back and revisit the basics of our field, like how is a particle state defined in QM, how does it interact with the experiment, how do we reconstruct larger objects, and so on.
Luckily, the bottom rung of the distance ladder, parallax, is only dependent on geometry, and is therefore completely solid. With the Gaia space telescope, there are now parallax measurements almost to the center of the Milky Way.
Having parallax measurements to that distance helps to build multiple versions of the next rung in the ladder (such as Cepheids and the tip of the red giant branch).
i think one of the things astronomers were pleasantly surprised to see was that the Gaia results have indicated that other low rungs of the distance ladder were pretty well calibrated. Most of these are based in some way on stellar evolution, and given that stars can be kind of messy there was always a bit of nervousness that maybe our systematic errors are larger than we think. But the models turned out to be pretty good.
parallax is only perfectly solid before GR. once you accept that space can bend it becomes a lot more complicated (especially given that we currently think ~75% of mass is dark matter which could be bending light without being visible
General Relativistic effects are taken into account by Gaia, but they're dominated by Solar System objects. Space is very close to flat, unless you're close to a very massive object.
> I don't think there is a mathematical proof.
Even mathematical proofs don't have mechanized, verifiable proofs, so physics has a ways to go. Once most mathematicians are using formal tools like theorem provers, maybe they will be usable and general enough to trickle down to physicists, and you'll have a more verifiable chain of reasoning from top to bottom for machines and observations. It probably will turn up a few minor issues, but I wouldn't expect anything drastic.
This is so good. It reminded me of the foreword to Simon Jenkins’ “A short history of England” when he says that breadth of knowledge should come before depth (ie knowing about the details of Henry VIII or Charles I beheading fits better after a solid grounding in the overall scope of English history)
Similarly I now have a much clearer idea of how (say) the main sequence of star formation and standard candle stars fit into the historical picture.
The gravitational wave based distance measurements are really awesome because they are the only way to verify red shift distances. You can calculate how strong the wave should be based on the difference in mass between the two objects before collision and the combined object after and then calculate how strong the wave should be when it reaches earth. Right now the precision of the distances are only 10% but in the future when something like the Cosmic Explorer with 40km arms is built they will get a lot more precise.
Fantastic video, the methods are explained super clearly.
Also highly recommend David Butler's "How far away is it" video series. He covers the same methods, and spends a good amount of time discussing phenomena along the way (star life cycles, magnetars, black holes, galaxy mergers, etc).
https://www.youtube.com/watch?v=HgNJwg2GISs&list=PLpH1IDQEoE...
Anyone looking for additional recommendations : the popular "A short history of nearly everything" by Bill Bryson covers in a historical context how these planetary distances were calculated
This was very entertaining. I had a rough idea of the timeline before, but had never thought about it in this way (that is, a ladder).
The coolest YouTube videos I’ve seen in a while, even better cause I saw the eclipse last year
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I have a suspicion Tao's FAQ [1] is at least partially AI generated, based off the language used.
[1] https://terrytao.wordpress.com/2025/02/13/cosmic-distance-la...
Considering the author in question, it may be equally accurate to say that AI generated content has been fed a lot of his writing as training data.
Tao is so prolific LLMs have been trained on a LOT of his writings.
It's been a while since I read his writing, but I skimmed and didn't see anything that sounded unlike him. He writes with a very neutral tone.
It did make me wonder though how effectively you could lean on AI to flesh out a list of questions, but I think in this case he has the expertise to write each response quickly and he'd be conscious that this is overall a piece of content doing properly.
I read it and it sounded like 100% all natural organic intelligence generated.
Nothing jumps out at me.
Any specific parts?