5 ms·

We still don't have a more precise value for "Big G"

82 points by rbanffy 7mo ago

https://www.nist.gov/news-events/news/2026/04/nist-weighs-mystery-gravitational-constant https://www.nist.gov/news-events/news/2026/04/nist-weighs-my...

gnabgib 6mo ago
Source: https://www.nist.gov/news-events/news/2026/04/nist-weighs-mystery-gravitational-constant https://www.nist.gov/news-events/news/2026/04/nist-weighs-my... (4 points, 12 days ago) https://news.ycombinator.com/item?id=47796892 https://news.ycombinator.com/item?id=47796892
aaron695 6mo ago
[dead]
vscode-rest 6mo ago
I appreciate the scientists’ honesty. When asked about big G and time invariance, he says he just takes it on faith that it has been the same forever. If more people would admit their leaps I think the theistic schism would be far more shallow.
- i_think_so 6mo ago
  It might also be nice if cosmologists stopped claiming their Big Bang "Theory" wasn't more accurately termed a mere Hypothesis. IIRC, 12 out of 13 predictions failing and necessitating "model" "tweaks" is not a fantastic track record for a Theory, which are supposed to robustly survive investigation.
  - dudisubekti 6mo ago
    We can literally observe cosmic microwave background and it fits our prediction that the universe was denser and hotter. It is a scientific theory. You might be confusing the established big bang with the more speculative cosmic inflation model. They're very closely related.
    - i_think_so 6mo ago
      > We can literally observe cosmic microwave background and it fits our prediction that the universe was denser and hotter. I can't observe that, because I don't have the gear. (Nor the time, budget, inclination nor training, for that matter. :-) But I am happy to admit the possibility that some of those observations, as reported in the literature, are correct. However, unlike a depressingly large percentage of my former scientific colleagues, I also appreciate just how much of what gets reported in the literature, from the conclusions all the way back to the raw data, is anything from sloppily wrong to flat out lies. Witness the decades-long fiasco in genetics that is only this past month being corrected: Before: https://www.nature.com/articles/437047a https://www.nature.com/articles/437047a After: https://www.nature.com/articles/s41586-025-08816 https://www.nature.com/articles/s41586-025-08816 TLDR: The original work by the CSAC reported only a fraction of the actually relevant data and hid the remainder where nobody was going to look. This was not the kind of Reproducibility Crisis mess, where an undergrad isn't paying attention when he grabs the electrophoresis gel off the shelf and then writes down the wrong brand name in his lab book. This was fraud. They intentionally misrepresented the data and hence the conclusions by an order of magnitude, which allowed them to delude the whole world for decades that "humans are 98.8% the same as chimps!" Many people had their entire worldview swayed by this pronouncement, myself included. I don't like being lied to. So yeah, you'll have to forgive me if I'm a bit skeptical when it comes to scientific observations and reportage that I'm a few $million shy for confirming myself. And I'll continue to think poorly of those who have been making lucrative careers out of doing "well-established" physics that "everybody" "accepts", only to have to quietly admit under scrutiny that their predictions didn't work out quite as nicely as the popular press has told us. Furthermore, > It is a scientific theory. It is a scientific hypothesis. It has not been subjected to repeated experimental trials or observations and found to be correct. A hypothesis does not become "well-established" simply because every college professor whose salary depends upon supporting the grant authority's narrative repeats it. I am fully aware that some people (present company excluded; I'm not placing any blame here) have watered down the definition of these terms. They are wrong. I do not consent to and will not be bullied into accepting changes to my language. Especially nothing as important as the language of science. > You might be confusing the established big bang with the more speculative cosmic inflation model. They're very closely related. Perhaps. I was never too terribly interested in things "smaller than an electron"[1] or larger than a whale. Lerner's arguments[2], particularly on relative elemental abundances, are persuasive to me. That may be because during my formative years I was a bit preoccupied with H vs D, because deuterated compounds for the NMR were too expensive for me to just play around with as I liked, so I had to tinker with spectroscopy/spectrophotometry instead. In any case, he's right. You can't have a cosmological constant be one value to account for the D and another value to account for the He3. As for the CMB, he addresses that as well, though once again I haven't done the work to confirm either side myself. Lerner has a whole basket full of other arguments as well, but I'm not a fan of lazy people posting Youtube links to hour long videos and saying "watch this!", so I shan't be a hypocrite. I believe that pdf should give a good flavor of it. It's been a while since I read it and I only skimmed it now, but I believe it a good representative sample of his other work. [1] PS: Yes, I know, I know. Stop being pedantic. This site is a hobby and I'm not about to cheat and get a chatbot to write me a 12 page essay every time I want to save a few words. I get to abuse quotation marks when I'm feeling lazy. [2] See sections II and IV in particular: https://web.archive.org/web/20260429053749/https://www.researchgate.net/profile/Eric-Lerner/publication/260864724_The_Case_Against_the_Big_Bang/links/592c695e0f7e9b9979b21d6d/The-Case-Against-the-Big-Bang.pdf https://web.archive.org/web/20260429053749/https://www.resea...
  - atoav 6mo ago
    The model failing is a question of how accurately you want it to model the world. Many laypersons have absolutely no conception of how accurate those "failing" models were. A good example is Newtonian physics. Strictly speaking it is a failing model, after all, under certain conditions and if you look very closely ot falls apart. Yet, every bridge you ever walked on and the most precise mechanical watches ever made were all only calculated using newtonian physics. It is still accurate enough for most tasks on earth. A model can still be useful despite its limitations, you just need to know those. People who are like "Ha! It is not accurate!" often have their own mental models of the world which are magnitudes worse, miss key bits or get other parts completely wrong (despite clear evidence to the opposite). As if a morbidly obese person for whom even walking presents a challenge made fun of an Olympic silver medalist for only getting second place. "Ha! You didn't get it 100% right so now my fringe theory that fails to even explain the most basic observations must be seen as equally valid!" So if you say it fails, consider how many digits after the comma it was accurate before it failed and how many digits your own theory would manage.
    - dingdongditchme 6mo ago
      This is what has always made it hard for me to go beyond the Newtonian physics. The only thing I know and use daily that relies on relativity is GPS and having looked into the equations on how it accounts for this it seemed to me that I could not discount that the equations account for some arbitrary consistent (or random) error, not relativity specifically. All experiments I have run never needed precision beyond Newtonian physics, but I am not at the end of my career yet so maybe relativity will become relevant some day. I will be looking forward to it if that is the case...
      - kergonath 6mo ago
        You could well live your whole life without needing anything more than Newtonian Physics. For most of us, relativity is a fun thought experiment. If you want to grapple with it, special relativity is the answer to "how can the speed of light be constant regardless of the speed of whoever is measuring it?" In his "vulgarisation" books, Einstein explains it with nothing more sophisticated than trains and stopwatches. General relativity is more complex and quickly goes in complicated mathematical weeds but is just as profound from a philosophical point of view, which is that things do not merely affect other things around them, but instead change space-time itself. You can see with a couple of clicks observations of phenomena predicted by it, like black holes and gravitational lenses. It’s interesting to think about even if you are not directly affected.
  - eesmith 6mo ago
    https://en.wikipedia.org/wiki/Big_Bang https://en.wikipedia.org/wiki/Big_Bang > The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. .. A wide range of empirical evidence strongly favors the Big Bang event, which is now widely accepted. ... > The Big Bang models offer a comprehensive explanation for a broad range of observed phenomena, including the abundances of the light elements, the cosmic microwave background, large-scale structure, and Hubble's law. > Precise modern models of the Big Bang appeal to various exotic physical phenomena that have not been observed in terrestrial laboratory experiments or incorporated into the Standard Model of particle physics. Of these features, dark matter is currently the subject of most active laboratory investigations. ... Viable, quantitative explanations for such phenomena are still being sought. These are unsolved problems in physics.
    - fc417fc802 6mo ago
      In reality it's just that the output of the procedural generation routines doesn't quite match that of the primary simulation loop. A classic worldbuilding inconsistency.
      - eesmith 6mo ago
        Even if your observation were 100% correct, it's also 100% irrelevant to the point. We still refer to Maxwell's theory of electromagnetism as a theory even though we know quantum electrodynamics is a more precise match to the primary simulation loop. I suppose a few might have decided to rename it Maxwell's hypothesis of electromagnetism, but I would consider them crackpots or dilettantes with little understanding of the meaning underlying those terms.
      - i_think_so 6mo ago
        +1 I got your joke and I appreciate the effort you put in to make it. :-)
  - mr_mitm 6mo ago
    What are the 13 predictions? Can you list them or provide a link to that list?
    - i_think_so 6mo ago
      Whew. This is work! :-) As I said in my effortpost above, the pdf I linked is a sample. There's more in his book, which I can't post here. And the videos he has put out are long, slow and some might find tedious, so I didn't bother to link them. (I didn't see your response while I was writing. Now I feel bad so I'm going to have to take a look and see what I can find that will post well.) A simple search for "big bang predictions" will find plenty of even mainstream press discussing them, albeit in a positive light, usually along the lines of "oh look, some scientists are talking about how they discovered something really interesting!" when what they really ought to be saying is "some scientists discovered that their hypotheses were wrong, their models failed to predict observable reality, and they were forced to make corrections that they shouldn't have to, if their hypotheses were actually a correct theory." As in so many different kinds of scientific endeavors, if your "theory" is based on a "model" and you have to keep correcting your "constants", they aren't constants, they are variables. And you don't have a theory.
    - i_think_so 6mo ago
      I didn't upload this and I haven't verified it. But it might be useful to reference. https://archive.org/download/the-big-bang-never-happened https://archive.org/download/the-big-bang-never-happened And this is briefer but more recent. https://web.archive.org/web/20260321014458/https://www.lppfusion.com/science/cosmic-connection/plasma-cosmology/the-growing-case-against-the-big-bang/ https://web.archive.org/web/20260321014458/https://www.lppfu... I trust anyone sufficiently interested can manage to google further without my help.
- deleted 6mo ago
  [deleted]
- mananaysiempre 6mo ago
  > If more people would admit their leaps I think the theistic schism would be far more shallow. There’s an important gap here between science as practiced and science communication. Working scientists will absolutely admit their ignorance, shaky foundations, etc. This is especially important in astronomy and cosmology, as the field is relatively young and experiments are impossible, outside of those that nature has already done for us. (Both evolutionary biology and linguistics have similar problems but cosmology has it especially hard.) This, however, is a losing strategy for communication. Most people equate confidence with credibility (and by high school we’ve beat children down enough that they do so as well), so if you do not sound confident people will not listen to you. (I could pontificate on how this is one of the greatest societal ills of our time, science or no science, but I won’t.) Even outside social situations, most people frankly cannot deal with holding a position and simultaneously not being confident in it, and absolutely cannot deal with holding an entire network of mutually-supporting positions and different degrees of confidence in each, while also having multiple alternatives with different degrees of plausibility for some of them. (This is somewhat more advanced than the programmer’s skill of relying on a deep stack of supporting services and debugging tools while keeping in mind that any given subset of them could be lying, which I’m sure you’re aware is also fairly difficult to communicate the experience of.) Then there’s the active (if not always successful) effort towards never ever reasoning backwards from things you would prefer to be true or that would make the world nicer for you. (The “History Plots” section[1] of the biennial Review of Particle Physics is there solely as an admonishment never to go with the herd. And that’s for things that have no implications for anybody’s worldview, morality, or livelihood!) It is very uncomfortable to genuinely not know where you are going and also not be able to aim anywhere in particular. (It might among other things imply that the entirety of your life’s work only serves to seal off a dead end and you might not even live long enough to learn that. And either way you’re consigning yourself to a very lonely sort of life if you veer away from the mainstream.) On the flip side from the vagueness, there’s the experience of doing everything you can to break something and failing, of your forefathers doing the same at their most imaginative and still failing. (The aforementioned RPP has pages and pages of tests for frickin’ energy conservation, without which most of physics and engineering just falls apart. And cosmologists can only dream of doing the same on the scales that are relevant to them, and indeed they do keep things like “modified Newtonian dynamics” around. Note that time invariance [as much as there is such a thing in general relativity] is energy conservation [ditto].) It is a sort of confidence that few others have justifiably had in their lives. (Few other things will infuriate a physicist more than offhand quoting a number with six significant digits. They know—in some cases from direct experience—that this sort of precision takes generations. And a well-established theory needs multiple times the effort.) So when, say, a cosmologist says that cosmic inflation is a bit of a speculative crapshoot but probably true, the Big Bang is likely true, general relativity they’re fairly sure is true but it sure would be nice to find some cracks, the Standard Model is true despite everybody doing their level best to break it because the foundational issues are quite serious, the mass of a free electron is nearly certain, and the inability to surpass the speed of light is pretty much absolute—this is a dynamic range of confidence that none of us can adequately feel. Now take one of those statements in isolation and try to make your listener understand what the apparent equivocation in it really means. (I do not believe the typical theist in a debate is on more than an advanced amateur level in all of this.) Then you get into the cursed philosophical issues, like the (weak) anthropic principle (a class of “why” questions don’t and can’t actually have much of a meaningful answer) or nonexceptionalism in cosmology (it is possible that everything we can or will ever be able to see around us is in fact wildly atypical as a great cosmic joke, but if so we couldn’t ever know enough to join in and any science we do would be completely meaningless, so we might as well proceed on the assumption that it is not, and happily enough it’s been working out thus far.) [1] https://pdg.lbl.gov/2025/reviews/rpp2025-rev-history-plots.pdf https://pdg.lbl.gov/2025/reviews/rpp2025-rev-history-plots.p...
- mattclarkdotnet 6mo ago
  The theistic schism? I had to look it up, and was not cleverer after. Nobody can ever know an ultimate why, for obvious and well established philosophical reasons. At least the scientists are trying to squeeze the knowledge gap down as small as possible instead of making up stories.
  - bowsamic 6mo ago
    > Nobody can ever know an ultimate why, for obvious and well established philosophical reasons Yes we can, you are just presupposing that philosophy is ultimately ineffective. For example Hegel gave a presuppositionless development of all metaphysics among other things. It’s not some kind of philosophical consensus that ultimate justification is impossible
    - mattclarkdotnet 6mo ago
      Philosophy can be perfectly effective as a tool of thought while still being unable to resolve self evidently unsolvable “ultimate questions”
      - bowsamic 6mo ago
        It can resolve them though
        mattclarkdotnet 6mo ago
        Only by embracing solipsism, in which case why are you here debating things, since your entire truth is derivable from your existence alone with no other observations or interactions required?
        bowsamic 6mo ago
        Solipsism is wrong.
    - kergonath 6mo ago
- kergonath 6mo ago
  > he says he just takes it on faith that it has been the same forever It’s not faith, it’s a working assumption. There are in facts Physicists working on figuring out what would change if some fundamental constants changed with time. Our best measurements and understanding right now is that they do not. If we show tomorrow that it’s wrong, then we’ll build better theories and move on. There is absolutely no faith involved.
  - vscode-rest 6mo ago
    Did you watch the video?
- deleted 6mo ago
  [deleted]
jocelyner 6mo ago
[flagged]
dooglius 6mo ago
Figure 1 in the paper helps contextualize the numbers better.
- nine_k 6mo ago
  The paper is https://iopscience.iop.org/article/10.1088/1681-7575/ae570f https://iopscience.iop.org/article/10.1088/1681-7575/ae570f
i_think_so 6mo ago
[flagged]
- contact9879 6mo ago
  how is this at all related to TFA
  - i_think_so 6mo ago
    Gravity experiments? Easier to do accurately in lower gravity environments, like away from the Earth? And we just so happen to have a nearly permanent laboratory in orbit, which was built and is maintained at tremendous taxpayer expense? I thought this would be obvious from TFA. I should have been more explicit.
    - rcxdude 6mo ago
      Are you confident this would be easier to do in space? It's not entirely obvious to me that the tradeoffs would be worth it.
    - contact9879 6mo ago
      our station in orbit still experiences ~0.9g. it’s not clear if gravity experiments would be at all easier on it
    - BigTTYGothGF 6mo ago
      > And we just so happen to have a nearly permanent laboratory in orbit, which was built and is maintained at tremendous taxpayer expense? Resources are finite, and even though they're not fungible, which current ISS experiment would you replace for this? Also: https://link.aps.org/accepted/10.1103/PhysRevD.100.062003 https://link.aps.org/accepted/10.1103/PhysRevD.100.062003 >>> LISA Pathfinder (LPF) [10] was a drag-free interfer- ometer located at the first Lagrange point in space be- tween the Earth and Sun. It measured the differential acceleration between two gold-platinum test masses sus- pended in drag free control. By the end of its lifetime, it had surpassed both its requirements and those of its full scale model LISA [11]. Given the success of the mission, and in coordination with other system tests, a handful of days near the end of the mission extension were allocated to performing a dedicated big G experiment for the first time in space. However, because Pathfinder was not de- signed to perform this sort of measurement, it was known that systematics such as absolute distances would limit the results to no better than 1 % relative uncertainty.
jiggawatts 6mo ago
[flagged]
- lordgrenville 6mo ago
  Are you sure these are actually issues, or are you just trusting that the AI criticism is correct?
- grey-area 6mo ago
  Apology not accepted.
- thrance 6mo ago
  There's a new-ish rule on HN: > Don't post generated comments or AI-edited comments. HN is for conversation between humans. No one cares about what ChatGPT had to say to you on TFA. What do you have to say about it?
- antiloper 6mo ago
  You must feel so smart.
alkonaut 6mo ago
> Cavendish painstakingly recorded those oscillations to measure the gravitational force of the larger spheres on the smaller ones, and from that he could infer Earth’s density. I can't wrap my head around this sentence. How is the force between two objects, none of which is the earth, related to any property of the earth (its mass or density)? Wouldn't Cavendish's experiment have worked - even better - in zero g and given the same result? There is something more to his setup beyond two big weights pulling on each other that I'm probably missing?
- ricksunny 6mo ago
  By ascertaining an approxiamte value of G , perhaps? After that, you know M_earth, and already knowing Earth’s geometry, one arrives at average density rho.
  - imrehg 6mo ago
    Yup, that's exactly it: - get the gravitational constant with these two known masses - then can deduct the mass of the unknown Earth by its interaction with other masses (say the "g" gravitational acceleration value) - then from the mass and the otherwise measured size of Earth the density pops out More details in good ol' Wikipedia: https://en.wikipedia.org/wiki/Cavendish_experiment#Derivation_of_G_and_the_Earth's_mass https://en.wikipedia.org/wiki/Cavendish_experiment#Derivatio...
    - UncleSlacky 6mo ago
      It's also a notoriously difficult experiment to perform. When I did it at university, the value of G I got was out by an order of magnitude - and that was considered a good result!
  - phh 6mo ago
    Laying out the math (assuming earth is an homogeneous sphere) just in case it's not clear: F_gravitational = G m1 m2 /r^2 g = G Mass_earth / r_earth^2 Mass_earth = r_earth^2 * g/G Density_earth = r_earth^2 * g/G / V_earth Density_earth = 3*g / (4*Pi*G*r_earth) Prior to Cavendish we already new g and r_earth, just missing G.
themafia 6mo ago
If you use a unit of length that is 1e33 plank lengths, and a unit of time that is 1e42 plank time, and a unit of mass that is 1e6 plank masses then big G is just 1e-9 length^3/mass*time and the speed of light is 1e9 length/time. Which would be convenient. Along with a unit of charge that is related to the elementary charge by the square root of the fine structure constant then the conductance quantum is 1/pi units of conductance and the inverse conductance quantum is pi units of resistance. Which is somewhat funny.

82 points by rbanffy 7mo ago

https://www.nist.gov/news-events/news/2026/04/nist-weighs-mystery-gravitational-constant https://www.nist.gov/news-events/news/2026/04/nist-weighs-my...

gnabgib 6mo ago

Source: https://www.nist.gov/news-events/news/2026/04/nist-weighs-mystery-gravitational-constant https://www.nist.gov/news-events/news/2026/04/nist-weighs-my... (4 points, 12 days ago) https://news.ycombinator.com/item?id=47796892 https://news.ycombinator.com/item?id=47796892

aaron695 6mo ago

[dead]

vscode-rest 6mo ago

I appreciate the scientists’ honesty. When asked about big G and time invariance, he says he just takes it on faith that it has been the same forever. If more people would admit their leaps I think the theistic schism would be far more shallow.

i_think_so 6mo ago
It might also be nice if cosmologists stopped claiming their Big Bang "Theory" wasn't more accurately termed a mere Hypothesis. IIRC, 12 out of 13 predictions failing and necessitating "model" "tweaks" is not a fantastic track record for a Theory, which are supposed to robustly survive investigation.
- dudisubekti 6mo ago
  We can literally observe cosmic microwave background and it fits our prediction that the universe was denser and hotter. It is a scientific theory. You might be confusing the established big bang with the more speculative cosmic inflation model. They're very closely related.
  - i_think_so 6mo ago
    > We can literally observe cosmic microwave background and it fits our prediction that the universe was denser and hotter. I can't observe that, because I don't have the gear. (Nor the time, budget, inclination nor training, for that matter. :-) But I am happy to admit the possibility that some of those observations, as reported in the literature, are correct. However, unlike a depressingly large percentage of my former scientific colleagues, I also appreciate just how much of what gets reported in the literature, from the conclusions all the way back to the raw data, is anything from sloppily wrong to flat out lies. Witness the decades-long fiasco in genetics that is only this past month being corrected: Before: https://www.nature.com/articles/437047a https://www.nature.com/articles/437047a After: https://www.nature.com/articles/s41586-025-08816 https://www.nature.com/articles/s41586-025-08816 TLDR: The original work by the CSAC reported only a fraction of the actually relevant data and hid the remainder where nobody was going to look. This was not the kind of Reproducibility Crisis mess, where an undergrad isn't paying attention when he grabs the electrophoresis gel off the shelf and then writes down the wrong brand name in his lab book. This was fraud. They intentionally misrepresented the data and hence the conclusions by an order of magnitude, which allowed them to delude the whole world for decades that "humans are 98.8% the same as chimps!" Many people had their entire worldview swayed by this pronouncement, myself included. I don't like being lied to. So yeah, you'll have to forgive me if I'm a bit skeptical when it comes to scientific observations and reportage that I'm a few $million shy for confirming myself. And I'll continue to think poorly of those who have been making lucrative careers out of doing "well-established" physics that "everybody" "accepts", only to have to quietly admit under scrutiny that their predictions didn't work out quite as nicely as the popular press has told us. Furthermore, > It is a scientific theory. It is a scientific hypothesis. It has not been subjected to repeated experimental trials or observations and found to be correct. A hypothesis does not become "well-established" simply because every college professor whose salary depends upon supporting the grant authority's narrative repeats it. I am fully aware that some people (present company excluded; I'm not placing any blame here) have watered down the definition of these terms. They are wrong. I do not consent to and will not be bullied into accepting changes to my language. Especially nothing as important as the language of science. > You might be confusing the established big bang with the more speculative cosmic inflation model. They're very closely related. Perhaps. I was never too terribly interested in things "smaller than an electron"[1] or larger than a whale. Lerner's arguments[2], particularly on relative elemental abundances, are persuasive to me. That may be because during my formative years I was a bit preoccupied with H vs D, because deuterated compounds for the NMR were too expensive for me to just play around with as I liked, so I had to tinker with spectroscopy/spectrophotometry instead. In any case, he's right. You can't have a cosmological constant be one value to account for the D and another value to account for the He3. As for the CMB, he addresses that as well, though once again I haven't done the work to confirm either side myself. Lerner has a whole basket full of other arguments as well, but I'm not a fan of lazy people posting Youtube links to hour long videos and saying "watch this!", so I shan't be a hypocrite. I believe that pdf should give a good flavor of it. It's been a while since I read it and I only skimmed it now, but I believe it a good representative sample of his other work. [1] PS: Yes, I know, I know. Stop being pedantic. This site is a hobby and I'm not about to cheat and get a chatbot to write me a 12 page essay every time I want to save a few words. I get to abuse quotation marks when I'm feeling lazy. [2] See sections II and IV in particular: https://web.archive.org/web/20260429053749/https://www.researchgate.net/profile/Eric-Lerner/publication/260864724_The_Case_Against_the_Big_Bang/links/592c695e0f7e9b9979b21d6d/The-Case-Against-the-Big-Bang.pdf https://web.archive.org/web/20260429053749/https://www.resea...
- atoav 6mo ago
  The model failing is a question of how accurately you want it to model the world. Many laypersons have absolutely no conception of how accurate those "failing" models were. A good example is Newtonian physics. Strictly speaking it is a failing model, after all, under certain conditions and if you look very closely ot falls apart. Yet, every bridge you ever walked on and the most precise mechanical watches ever made were all only calculated using newtonian physics. It is still accurate enough for most tasks on earth. A model can still be useful despite its limitations, you just need to know those. People who are like "Ha! It is not accurate!" often have their own mental models of the world which are magnitudes worse, miss key bits or get other parts completely wrong (despite clear evidence to the opposite). As if a morbidly obese person for whom even walking presents a challenge made fun of an Olympic silver medalist for only getting second place. "Ha! You didn't get it 100% right so now my fringe theory that fails to even explain the most basic observations must be seen as equally valid!" So if you say it fails, consider how many digits after the comma it was accurate before it failed and how many digits your own theory would manage.
  - dingdongditchme 6mo ago
    This is what has always made it hard for me to go beyond the Newtonian physics. The only thing I know and use daily that relies on relativity is GPS and having looked into the equations on how it accounts for this it seemed to me that I could not discount that the equations account for some arbitrary consistent (or random) error, not relativity specifically. All experiments I have run never needed precision beyond Newtonian physics, but I am not at the end of my career yet so maybe relativity will become relevant some day. I will be looking forward to it if that is the case...
    - kergonath 6mo ago
      You could well live your whole life without needing anything more than Newtonian Physics. For most of us, relativity is a fun thought experiment. If you want to grapple with it, special relativity is the answer to "how can the speed of light be constant regardless of the speed of whoever is measuring it?" In his "vulgarisation" books, Einstein explains it with nothing more sophisticated than trains and stopwatches. General relativity is more complex and quickly goes in complicated mathematical weeds but is just as profound from a philosophical point of view, which is that things do not merely affect other things around them, but instead change space-time itself. You can see with a couple of clicks observations of phenomena predicted by it, like black holes and gravitational lenses. It’s interesting to think about even if you are not directly affected.
- eesmith 6mo ago
  https://en.wikipedia.org/wiki/Big_Bang https://en.wikipedia.org/wiki/Big_Bang > The Big Bang is a physical theory that describes how the universe expanded from an initial state of high density and temperature. .. A wide range of empirical evidence strongly favors the Big Bang event, which is now widely accepted. ... > The Big Bang models offer a comprehensive explanation for a broad range of observed phenomena, including the abundances of the light elements, the cosmic microwave background, large-scale structure, and Hubble's law. > Precise modern models of the Big Bang appeal to various exotic physical phenomena that have not been observed in terrestrial laboratory experiments or incorporated into the Standard Model of particle physics. Of these features, dark matter is currently the subject of most active laboratory investigations. ... Viable, quantitative explanations for such phenomena are still being sought. These are unsolved problems in physics.
  - fc417fc802 6mo ago
    In reality it's just that the output of the procedural generation routines doesn't quite match that of the primary simulation loop. A classic worldbuilding inconsistency.
    - eesmith 6mo ago
      Even if your observation were 100% correct, it's also 100% irrelevant to the point. We still refer to Maxwell's theory of electromagnetism as a theory even though we know quantum electrodynamics is a more precise match to the primary simulation loop. I suppose a few might have decided to rename it Maxwell's hypothesis of electromagnetism, but I would consider them crackpots or dilettantes with little understanding of the meaning underlying those terms.
    - i_think_so 6mo ago
      +1 I got your joke and I appreciate the effort you put in to make it. :-)
- mr_mitm 6mo ago
  What are the 13 predictions? Can you list them or provide a link to that list?
  - i_think_so 6mo ago
    Whew. This is work! :-) As I said in my effortpost above, the pdf I linked is a sample. There's more in his book, which I can't post here. And the videos he has put out are long, slow and some might find tedious, so I didn't bother to link them. (I didn't see your response while I was writing. Now I feel bad so I'm going to have to take a look and see what I can find that will post well.) A simple search for "big bang predictions" will find plenty of even mainstream press discussing them, albeit in a positive light, usually along the lines of "oh look, some scientists are talking about how they discovered something really interesting!" when what they really ought to be saying is "some scientists discovered that their hypotheses were wrong, their models failed to predict observable reality, and they were forced to make corrections that they shouldn't have to, if their hypotheses were actually a correct theory." As in so many different kinds of scientific endeavors, if your "theory" is based on a "model" and you have to keep correcting your "constants", they aren't constants, they are variables. And you don't have a theory.
  - i_think_so 6mo ago
    I didn't upload this and I haven't verified it. But it might be useful to reference. https://archive.org/download/the-big-bang-never-happened https://archive.org/download/the-big-bang-never-happened And this is briefer but more recent. https://web.archive.org/web/20260321014458/https://www.lppfusion.com/science/cosmic-connection/plasma-cosmology/the-growing-case-against-the-big-bang/ https://web.archive.org/web/20260321014458/https://www.lppfu... I trust anyone sufficiently interested can manage to google further without my help.
deleted 6mo ago
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mananaysiempre 6mo ago
> If more people would admit their leaps I think the theistic schism would be far more shallow. There’s an important gap here between science as practiced and science communication. Working scientists will absolutely admit their ignorance, shaky foundations, etc. This is especially important in astronomy and cosmology, as the field is relatively young and experiments are impossible, outside of those that nature has already done for us. (Both evolutionary biology and linguistics have similar problems but cosmology has it especially hard.) This, however, is a losing strategy for communication. Most people equate confidence with credibility (and by high school we’ve beat children down enough that they do so as well), so if you do not sound confident people will not listen to you. (I could pontificate on how this is one of the greatest societal ills of our time, science or no science, but I won’t.) Even outside social situations, most people frankly cannot deal with holding a position and simultaneously not being confident in it, and absolutely cannot deal with holding an entire network of mutually-supporting positions and different degrees of confidence in each, while also having multiple alternatives with different degrees of plausibility for some of them. (This is somewhat more advanced than the programmer’s skill of relying on a deep stack of supporting services and debugging tools while keeping in mind that any given subset of them could be lying, which I’m sure you’re aware is also fairly difficult to communicate the experience of.) Then there’s the active (if not always successful) effort towards never ever reasoning backwards from things you would prefer to be true or that would make the world nicer for you. (The “History Plots” section[1] of the biennial Review of Particle Physics is there solely as an admonishment never to go with the herd. And that’s for things that have no implications for anybody’s worldview, morality, or livelihood!) It is very uncomfortable to genuinely not know where you are going and also not be able to aim anywhere in particular. (It might among other things imply that the entirety of your life’s work only serves to seal off a dead end and you might not even live long enough to learn that. And either way you’re consigning yourself to a very lonely sort of life if you veer away from the mainstream.) On the flip side from the vagueness, there’s the experience of doing everything you can to break something and failing, of your forefathers doing the same at their most imaginative and still failing. (The aforementioned RPP has pages and pages of tests for frickin’ energy conservation, without which most of physics and engineering just falls apart. And cosmologists can only dream of doing the same on the scales that are relevant to them, and indeed they do keep things like “modified Newtonian dynamics” around. Note that time invariance [as much as there is such a thing in general relativity] is energy conservation [ditto].) It is a sort of confidence that few others have justifiably had in their lives. (Few other things will infuriate a physicist more than offhand quoting a number with six significant digits. They know—in some cases from direct experience—that this sort of precision takes generations. And a well-established theory needs multiple times the effort.) So when, say, a cosmologist says that cosmic inflation is a bit of a speculative crapshoot but probably true, the Big Bang is likely true, general relativity they’re fairly sure is true but it sure would be nice to find some cracks, the Standard Model is true despite everybody doing their level best to break it because the foundational issues are quite serious, the mass of a free electron is nearly certain, and the inability to surpass the speed of light is pretty much absolute—this is a dynamic range of confidence that none of us can adequately feel. Now take one of those statements in isolation and try to make your listener understand what the apparent equivocation in it really means. (I do not believe the typical theist in a debate is on more than an advanced amateur level in all of this.) Then you get into the cursed philosophical issues, like the (weak) anthropic principle (a class of “why” questions don’t and can’t actually have much of a meaningful answer) or nonexceptionalism in cosmology (it is possible that everything we can or will ever be able to see around us is in fact wildly atypical as a great cosmic joke, but if so we couldn’t ever know enough to join in and any science we do would be completely meaningless, so we might as well proceed on the assumption that it is not, and happily enough it’s been working out thus far.) [1] https://pdg.lbl.gov/2025/reviews/rpp2025-rev-history-plots.pdf https://pdg.lbl.gov/2025/reviews/rpp2025-rev-history-plots.p...
mattclarkdotnet 6mo ago
The theistic schism? I had to look it up, and was not cleverer after. Nobody can ever know an ultimate why, for obvious and well established philosophical reasons. At least the scientists are trying to squeeze the knowledge gap down as small as possible instead of making up stories.
- bowsamic 6mo ago
  > Nobody can ever know an ultimate why, for obvious and well established philosophical reasons Yes we can, you are just presupposing that philosophy is ultimately ineffective. For example Hegel gave a presuppositionless development of all metaphysics among other things. It’s not some kind of philosophical consensus that ultimate justification is impossible
  - mattclarkdotnet 6mo ago
    Philosophy can be perfectly effective as a tool of thought while still being unable to resolve self evidently unsolvable “ultimate questions”
    - bowsamic 6mo ago
      It can resolve them though
      - mattclarkdotnet 6mo ago
        Only by embracing solipsism, in which case why are you here debating things, since your entire truth is derivable from your existence alone with no other observations or interactions required?
        bowsamic 6mo ago
        Solipsism is wrong.
  - kergonath 6mo ago
kergonath 6mo ago
> he says he just takes it on faith that it has been the same forever It’s not faith, it’s a working assumption. There are in facts Physicists working on figuring out what would change if some fundamental constants changed with time. Our best measurements and understanding right now is that they do not. If we show tomorrow that it’s wrong, then we’ll build better theories and move on. There is absolutely no faith involved.
- vscode-rest 6mo ago
  Did you watch the video?
deleted 6mo ago
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jocelyner 6mo ago

[flagged]

dooglius 6mo ago

Figure 1 in the paper helps contextualize the numbers better.

nine_k 6mo ago
The paper is https://iopscience.iop.org/article/10.1088/1681-7575/ae570f https://iopscience.iop.org/article/10.1088/1681-7575/ae570f

i_think_so 6mo ago

[flagged]

contact9879 6mo ago
how is this at all related to TFA
- i_think_so 6mo ago
  Gravity experiments? Easier to do accurately in lower gravity environments, like away from the Earth? And we just so happen to have a nearly permanent laboratory in orbit, which was built and is maintained at tremendous taxpayer expense? I thought this would be obvious from TFA. I should have been more explicit.
  - rcxdude 6mo ago
    Are you confident this would be easier to do in space? It's not entirely obvious to me that the tradeoffs would be worth it.
  - contact9879 6mo ago
    our station in orbit still experiences ~0.9g. it’s not clear if gravity experiments would be at all easier on it
  - BigTTYGothGF 6mo ago
    > And we just so happen to have a nearly permanent laboratory in orbit, which was built and is maintained at tremendous taxpayer expense? Resources are finite, and even though they're not fungible, which current ISS experiment would you replace for this? Also: https://link.aps.org/accepted/10.1103/PhysRevD.100.062003 https://link.aps.org/accepted/10.1103/PhysRevD.100.062003 >>> LISA Pathfinder (LPF) [10] was a drag-free interfer- ometer located at the first Lagrange point in space be- tween the Earth and Sun. It measured the differential acceleration between two gold-platinum test masses sus- pended in drag free control. By the end of its lifetime, it had surpassed both its requirements and those of its full scale model LISA [11]. Given the success of the mission, and in coordination with other system tests, a handful of days near the end of the mission extension were allocated to performing a dedicated big G experiment for the first time in space. However, because Pathfinder was not de- signed to perform this sort of measurement, it was known that systematics such as absolute distances would limit the results to no better than 1 % relative uncertainty.

jiggawatts 6mo ago

[flagged]

lordgrenville 6mo ago
Are you sure these are actually issues, or are you just trusting that the AI criticism is correct?
grey-area 6mo ago
Apology not accepted.
thrance 6mo ago
There's a new-ish rule on HN: > Don't post generated comments or AI-edited comments. HN is for conversation between humans. No one cares about what ChatGPT had to say to you on TFA. What do you have to say about it?
antiloper 6mo ago
You must feel so smart.

alkonaut 6mo ago

> Cavendish painstakingly recorded those oscillations to measure the gravitational force of the larger spheres on the smaller ones, and from that he could infer Earth’s density. I can't wrap my head around this sentence. How is the force between two objects, none of which is the earth, related to any property of the earth (its mass or density)? Wouldn't Cavendish's experiment have worked - even better - in zero g and given the same result? There is something more to his setup beyond two big weights pulling on each other that I'm probably missing?

ricksunny 6mo ago
By ascertaining an approxiamte value of G , perhaps? After that, you know M_earth, and already knowing Earth’s geometry, one arrives at average density rho.
- imrehg 6mo ago
  Yup, that's exactly it: - get the gravitational constant with these two known masses - then can deduct the mass of the unknown Earth by its interaction with other masses (say the "g" gravitational acceleration value) - then from the mass and the otherwise measured size of Earth the density pops out More details in good ol' Wikipedia: https://en.wikipedia.org/wiki/Cavendish_experiment#Derivation_of_G_and_the_Earth's_mass https://en.wikipedia.org/wiki/Cavendish_experiment#Derivatio...
  - UncleSlacky 6mo ago
    It's also a notoriously difficult experiment to perform. When I did it at university, the value of G I got was out by an order of magnitude - and that was considered a good result!
- phh 6mo ago
  Laying out the math (assuming earth is an homogeneous sphere) just in case it's not clear: F_gravitational = G m1 m2 /r^2 g = G Mass_earth / r_earth^2 Mass_earth = r_earth^2 * g/G Density_earth = r_earth^2 * g/G / V_earth Density_earth = 3*g / (4*Pi*G*r_earth) Prior to Cavendish we already new g and r_earth, just missing G.

themafia 6mo ago

If you use a unit of length that is 1e33 plank lengths, and a unit of time that is 1e42 plank time, and a unit of mass that is 1e6 plank masses then big G is just 1e-9 length^3/mass*time and the speed of light is 1e9 length/time. Which would be convenient. Along with a unit of charge that is related to the elementary charge by the square root of the fine structure constant then the conductance quantum is 1/pi units of conductance and the inverse conductance quantum is pi units of resistance. Which is somewhat funny.