[HN Gopher] Part two of Grant Sanderson's video with Terry Tao o...
___________________________________________________________________
Part two of Grant Sanderson's video with Terry Tao on the cosmic
distance ladder
Author : ColinWright
Score : 365 points
Date : 2025-02-23 18:51 UTC (3 days ago)
(HTM) web link (mathstodon.xyz)
(TXT) w3m dump (mathstodon.xyz)
| j7ake wrote:
| 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.
| maxnoe wrote:
| https://terrytao.wordpress.com/2025/02/13/cosmic-distance-la...
| pavon wrote:
| 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).
| hakaneskici wrote:
| As a side question, what's the rationale for this? Is there
| a list of nsfw gTLDs?
| pxeger1 wrote:
| .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.
| ziddoap wrote:
| 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.
| daedrdev wrote:
| I feel like .zip and .mov gTLDs are more understandable
| to have blocked
| mcpherrinm wrote:
| .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.
| ericjmorey wrote:
| Direct link to video:
|
| https://youtu.be/hFMaT9oRbs4
|
| Announcement post on bsky:
| https://bsky.app/profile/3blue1brown.com/post/3liu3ybnowk2w
| Gunax wrote:
| 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).
| dang wrote:
| 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)
| jessriedel wrote:
| 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
| csours wrote:
| Cosmic distance scaffold?
| zokier wrote:
| 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.
| asattarmd wrote:
| 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
| csours wrote:
| 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.
| mithrene wrote:
| 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!
| csours wrote:
| 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.
| throwawayk7h wrote:
| 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...
| dado3212 wrote:
| Any specific parts?
| Folcon wrote:
| 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.
| NotYourLawyer wrote:
| Nothing jumps out at me.
| UltraSane wrote:
| Tao is so prolific LLMs have been trained on a LOT of his
| writings.
| prawn wrote:
| 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.
| djmips wrote:
| I read it and it sounded like 100% all natural organic
| intelligence generated.
| erulabs wrote:
| 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.
| anamexis wrote:
| Besides the Cosmos episode, do you have any recommendations on
| learning more?
| ziotom78 wrote:
| "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.)
| simpaticoder wrote:
| 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!
| z3phyr wrote:
| 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.
| simpaticoder wrote:
| 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.
| DiogenesKynikos wrote:
| 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.
| rs_rs_rs_rs_rs wrote:
| >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.
| DiogenesKynikos wrote:
| 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.
| mananaysiempre wrote:
| 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.
| niemandhier wrote:
| Or listen to the opera about his mothers trial:
| https://en.wikipedia.org/wiki/Kepler_(opera)
| isolli wrote:
| 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.
| jayrot wrote:
| 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.
| istjohn wrote:
| 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.
| District5524 wrote:
| 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.
| simpaticoder wrote:
| 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).
| immibis wrote:
| That doesn't have to mean exploitation. Labor can be done
| fairly (but not in capitalism, not really).
| BLubliulu wrote:
| 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).
| mmooss wrote:
| > 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.
| istjohn wrote:
| > 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/comm
| e...
| abdullahkhalids wrote:
| 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?
| istjohn wrote:
| 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.
| lanstin wrote:
| 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.
| queuebert wrote:
| 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.
| dimator wrote:
| 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.
| xeonmc wrote:
| Makes Ramanujan's journey all the more special.
| Xmd5a wrote:
| Or Bose for that matter
| xeonmc wrote:
| 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.
| GuB-42 wrote:
| 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.
| jstanley wrote:
| > 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...
| jychang wrote:
| 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.
| n4r9 wrote:
| 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.
| roenxi wrote:
| 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).
| dguest wrote:
| 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
| 7thaccount wrote:
| 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.
| ijustlovemath wrote:
| 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.
| varjag wrote:
| 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.
| pepinator wrote:
| 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.
| BLubliulu wrote:
| 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.
| wholinator2 wrote:
| 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
| BLubliulu wrote:
| 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"
| piombisallow wrote:
| Incredibly funny reply. If only the Sumerians "empowered people
| of color". The big "What If" of history.
| jayrot wrote:
| Nice try but I'm not talking about Sumerians and I have a
| feeling you know that.
| csours wrote:
| 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.
| naasking wrote:
| > 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.
| csours wrote:
| 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.
|
| ---
|
| 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.
| naasking wrote:
| > 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.
| csours wrote:
| > 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.
|
| ---
|
| Also, I'm doing the book a great disservice by
| simplifying it so much.
| BeetleB wrote:
| > 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).
| UltraSane wrote:
| 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.
| EcommerceFlow wrote:
| The coolest YouTube videos I've seen in a while, even better
| cause I saw the eclipse last year
| merek wrote:
| 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...
| udkl wrote:
| 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
| captainmuon wrote:
| 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.
| DiogenesKynikos wrote:
| 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).
| adgjlsfhk1 wrote:
| 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
| DiogenesKynikos wrote:
| 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.
| antognini wrote:
| 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.
| naasking wrote:
| > 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.
| vmilner wrote:
| 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.
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