exchemist

1 hour ago, jalaldn said:

If light had the property you think it has, this is exactly how it would behave.

This graph ends at 8; extend it to the right up to 100. No matter which number you pick between 4 and 100, the amount of time Jupiter blocks the light at that point will always be the same, because distance does not change the duration of the blocking.

But what Ole Rømer observed was different. He started counting time from the moment Io disappeared. When Earth was very close to Jupiter, it took 2 hours and 10 minutes for Io to disappear and reappear. Six months later, when he recorded it again (with Earth on the opposite side of the Sun, very far from Jupiter), it took Io 2 hours and 21 minutes to disappear and reappear. He subtracted the first measurement from the second and said the remaining 11 minutes was the delay.

Yes, that’s because the distance between Jupiter and the observer changed. So the light path got longer.Your diagram fails to show this basic point.

10 minutes ago, xenog123 said:

Yeah that incident was in 2005, he resigned from the presidency of Harvard in 2006. Uh the more recent stuff with Epstein is pretty disappointing though, yeah.

Are you referring to Watson's comments about race and IQ? The only specific comment I'm familiar with is that he said he was "gloomy" about improving life in Africa because one has to assume that their innate intelligence is equal to "ours" [Whites].

Regarding genetic markers in populations: as far as I know no conclusive studies have been done linking specific genes to intelligence, or identifying those genes in various populations, so you can't say anything conclusive about the genes in Asian or Black Brazilian populations. The hypothesis that measured differences in IQ have a hereditary basis is just that, an hypothesis.

There's got to be at least some meaningful hereditary component to IQ though. It seems pretty absurd a priori to admit that all other physical traits are subject to genetic influence but that your brain alone is this mysterious organ that's immune. So unless you're a hard-core mind-body dualist or something you have to admit that cognition is subject to laws of heredity as well. The main motive I think for this kind of denialism is that people in the West are loathe to let go of their feel-good egalitarianism and are (justifiably) afraid of sliding back into Nazi-style eugenics (which, interestingly enough, was adopted much earlier and practiced for much longer and more stringently in Britain, America and Canada than Nazi Germany).

I agree it seems more than likely that there is a hereditary component to intelligence. Intelligent parents tend to have intelligent offspring, though it is notoriously hard to disentangle heredity from upbringing and culture. But you are proposing something quite different: that there could be an innate level of intelligence that correlates with race.

While that can’t be wholly excluded, there are good reasons to be highly suspicious of it, given that “race” has such a superficial genetic significance. Culture, on the other hand, has a very great deal to do with the collection of characteristics that people have in mind when they assign someone to a race. And we know that culture and upbringing have quite an effect on how people perform in intelligence tests.

I’m not expert on this but my understanding is that the main genetic difference between people of largely European and those of largely African descent is that the European genome often has a small residual Neanderthal component, from interbreeding with Neanderthals in prehistoric times. Perhaps someone could select samples with and without this residue and attempt to correlate that with intelligence. I suspect however that the signal to noise ratio would be so poor that no conclusion could be drawn.

12 hours ago, Rudolf said:

I believe that each of us has a personal moment in time that we can call “now.” We experience reality from our own point of view, always with a slight delay—light needs a full second to travel 300,000 km, after all. Everyone carries their own internal clock, their own “now,” observing the world from a unique position in space and time.

When I take an action, no one can witness it in truly absolute real time. The distances between us are essentially small differences in space-time; we can never occupy exactly the same place at exactly the same moment. Fortunately, in everyday life this hardly causes any problems. 😉

The point I want to make is that what we perceive as reality is always a glimpse of the past. Our sense of “now” is, in a way, an illusion—an internal construction created and projected by the brain.

True, but does this matter? I'd have thought that if there are a few microseconds delay in our perceptions, this has no practical impact (aside perhaps from a few physics or neural experiments).

11 hours ago, xenog123 said:

The best possible hypothesis for racial hereditarianism that I know of would be something like the following: strictly speaking, discrete races do not exist, but different populations that evolved in isolation from one another for at least some time would have different frequencies of certain genes across the population, as well as seemingly trivial phenotypical traits that distinguish them from one another. So Sub-Saharan Africans differ from Northwestern Europeans in some superficial ways, but these surface-level differences are just correlates with underlying real genotypical differences that arose due to their adaptation to different environments. So there are no rigid natural delineations between these groups and they can intermix, but you'd still expect to see emergent average hereditary differences in behaviour (like cognitive ability).

Empirically you have to account for why it is that measured differences between racial groups are so consistent over time and across different societies; if skin color was just arbitrary why are these differences so stubborn.

OK if you can indicate what measured differences you have in mind, we could perhaps take a look at what might be responsible.

We would need to bear in mind @CharonY 's point that mixing of genes has some interesting results, e.g. that "black" Brazilians are more genetically similar to "white" Brazilians than they are to "black" Americans.

(We would of course also need to bear in mind the effects of culture when it comes to evaluating measured behavioural attributes.)

6 minutes ago, xenog123 said:

Yeah I mean the uncontroversial part is just the recording of the scores as such, the rest is more complicated. Personally I lean towards the concept of general intelligence and IQ testing to be well-founded but there are still a lot of issues (and in any case that's kind of beside the point of this discussion).

I do find it a bit unfortunate that we're so squeamish in the West about saying so many things though - Watson's controversial comments are tactless but I don't think ill-intentioned and not totally unreasonable to speculate on. It reminds me of the Larry Summers scandal back in 2005-ish; poor man was driven out of his job at Harvard just for suggesting that maybe sex-based differences it achievement and representation in prestigious STEM positions could be at least in part due to factors unrelated to systemic/societal discrimination, and suggested a few potential causes. Seemed unnecessary.

As I understand it, one of the objections to attempting to correlate "race" (i.e. skin colour) with IQ is that skin colour is no more fundamental to the human genome than say eye colour or the presence or absence of ear lobes. So it would be a bit like correlating cancer incidence with TV ownership.

2 hours ago, raphaelh42 said:

Thanks @KJW

@Rudolf I didn't really seen it like that ^^ But that makes me think about the fact we don't all see the colors looking exactly the same

Could you share some of the ideas you have in mind regarding reality?

I suspect most of us have moments in which we wonder, fleetingly, whether what we seem to be experiencing is real or just in our minds.

As far as science goes, we have a way round that issue by relying on reproducible observations of nature. That means others besides ourselves need to agree they see whatever it is too. So that gives us at least some reason to believe there is some kind of objective reality "out there", as it were. Of course we could be hallucinating what these supposed other people seem to be agreeing with us about, but going down that rabbit hole rapidly becomes paralysing, so there seems little point in pursuing that train of thought.

1 hour ago, CharonY said:

I disagree. Every scientist has pet theories in their field of study. Most of them will turn out to be wrong and some will happen to be right. The hard work is not coming up with them, but to provide evidence. Franklin looked at the data and proposed the various possibilities based on that. She specifically pointed out the high likelihood of a helical structure in the first paper. But as mentioned, the measurement accuracy did not allow for a fully resolved structure. Nowadays, you wouldn't be able to publish a paper on how you think the 3D structure is, without getting sufficient resolution. Rather, you would need to outline the possible variations, though you could discuss what you favor.

Again, reading Franklin's paper's and the Watson & Crick one side by side, one is to m e a proper crystallography paper, the other one is merely putting forward a hypothesis. Just because they pushed it harder doesn't make it better in my mind.

What you describe is essentially taking imaginary leaps based on incomplete data. It is fine for building hypotheses, but providing evidence is so much more important. There are folks, including scientists but also increasingly influencers who built careers from overselling their pet hypotheses based on incomplete data. The most obvious offenders are in the health sector which is full of grift and overselling health advice and products mostly based on overselling limited biological data. It is a non-zero chance that at least one of those folks happen to be correct, but we wouldn't (and shouldn't) just take their word for it. Rather we should continue to collect evidence until we can tell.

Eh, in his autobiography he severely downplayed Franklin's role. While he might have reconsidered his stance later on, I am not confident that he would have recognized her contributions around the time the Nobel came around.

Incidentally, the Nobel Price committee had another serious issue with sexism a while earlier with a true titan in natural sciences: Marie Curie. For her first Nobel, she wasn't even considered until her husband refused to accept one without her as an equal partner on it.

Yes that’s true but Marie Curie’s prize was about half a century earlier, back in 1903. Women’s emancipation had moved on a fair bit in the intervening years.

I do dimly recall a rather catty comment in a lecture, from an old-fashioned (gay/misogynist) don at Oxford in the 1970s when I was reading for my degree, to the effect that Franklin’s contribution was the sort of humdrum, painstaking fiddly work suitable for a woman, as opposed to the brilliant insight of Crick and Watson. A bit shocking; perhaps there was a rather broader attempt to belittle the work that actually provided the data!

2 hours ago, xenog123 said:

Well the reference is a page from the official Nobel prize website that states Watson said that in an interview.

Yes that reference says Watson made this remark in a recent interview with Scientific American. So it looks as if no one at the time thought to put Franklin’s name forward. Maybe this was an attempt by Watson to put things straight at the end of his life, long after the damage was done. It’s such a shame she died so young. If she had lived longer, she probably would have had her contribution recognised.

7 hours ago, TheVat said:

That's funny, I used the same phrase, mixed bag, on the SFC thread.

Watson basically stole a Nobel from her, imo. Then slandered her after she died. It's pretty reprehensible and goes way beyond poaching from grad students.

That's not the impression given by the Wiki article on Watson, however: https://en.wikipedia.org/wiki/Rosalind_Franklin.

According to that, Watson said she should have got the Nobel with Wilkins, but the prize could not be awarded posthumously (she died at 37, of ovarian cancer, apparently). But I don't know who wrote the Wiki piece of course.

17 minutes ago, xenog123 said:

Oh well that was supposed to be a joke, poking fun at the public/media's tendency to hyperbolize or simplify. Of course the reality is more complicated.

Haha, then.

1 hour ago, jalaldn said:

There's nothing wrong with using AI to confirm whether the event I'm telling you is false or not.

Yes there is. LLMs are programmed to tell you what you want to hear. You can get an initial idea from them but to confirm something you need to go behind the AI and get to the references it is relying on.

2 minutes ago, jalaldn said:

Ask an AI to confirm the truth.

That’s what an idiot would do.

29 minutes ago, xenog123 said:

This giant of biology has recently passed at the age of 97, leaving behind a coloured legacy. What's the verdict? Gifted pioneer of scientific inquiry or scheming, bigoted plagiarist? There is no middle ground.

https://www.irishtimes.com/science/2025/11/19/an-irish-perspective-james-watson-1928-2025-the-dna-titan-with-a-downside/

Why not both? Most people are a mixed bag.

Newton was by all accounts an unpleasant man, Einstein was sexually unfaithful, Mozart had a scatological sense of humour…..

This notion that famous people must be pigeonholed as either saints or devils seems very naïve to me.

28 minutes ago, jalaldn said:

It takes Io 1.77 Earth days (42 hours 29 minutes) or 2,548.8 minutes to complete one orbit around Jupiter.

We know where Io is in these 2,548.8 minutes, including being behind Jupiter. Those minutes that disappeared after coming out are lost and will never be get again.

Whut?

5 minutes ago, jalaldn said:

Io takes two hours to pass behind Jupiter. After that, all the remaining occulted times depend on the distance.

That is, when Jupiter and Earth are close together, Io will be hidden by Jupiter for two hours. After those two hours, when Io comes out, it will be occulted again for about ten minutes (when there is nothing between Io and Earth), depending on the distance.

Moreover, when Jupiter and Earth are very far apart, Io will be hidden by Jupiter for two hours, and additionally for about 20 minutes when there is nothing between Earth and Io.

If we were perhaps watching from Neptune, Io would be hidden by Jupiter for two hours, and the remaining 4 hours would be occulted depending on the distance.

What you leave out, though, is that we continue to see Io for about 10 minutes after it has actually been occulted, due to light already in transit after occultation starts.

26 minutes ago, jalaldn said:

It takes Io 1.77 Earth days (42 hours 29 minutes) or 2,548.8 minutes to complete one orbit around Jupiter.

If Earth is close to Jupiter, Io will be occulted for an average of 2 hours and 10 minutes.

If Earth is far from Jupiter, it will be occulted for up to 2 hours and 20 minutes.

When Jupiter and Neptune are on opposite sides of the Sun, Io will be occulted for 6 hours and 15 minutes when viewed from Neptune.

During those four hours and 10minuts, what happens to the sunlight that normally falls on Io?

Surely it is occulted for the same duration, regardless of the distance from Earth?

Where are you getting your information from?

It is the intervals between occultations that vary.

6 hours ago, jalaldn said:

I can guess what all of you haven’t understood. If it doesn’t click for you immediately, there’s no mistake—it’s the very same thing that nobody understood for 350 years.

If light had the properties you think it has, Ole Rømer would never have had any chance to measure its speed.

Let me give an example with balls: Imagine you’re inside a room, and right above your head there’s a hole through which balls fall into a basket via a pipe.

You’re inside the room. You tell your friend outside: “Throw a ball in every five minutes. The distance is up to you, but once you start throwing, don’t change your position.”

You, inside the room, will see a ball arrive exactly every five minutes. Just from that, can you tell how far away he was when he sent the balls?

Let’s look at it from another angle: You throw 10 balls toward me. If I tell you that the first four balls never reached me—they vanished on the way—how would that feel? That’s exactly what those eleven minutes are.

In this place, something about the nature of light is unable to reach us; something else has reached us instead. It is up to us to separate them.

If the thrower drops 2 balls 5 mins apart when he is next to the hole, then sure, you will time them as arriving 5minutes apart. But if he then moves 50 metres away to throw the next one, you will note that the 3rd ball arrives slightly more than 5 minutes after the previous one. And if he then returns to his position next to the hole before dropping the 4th one, you will note that the interval between arrival of the 3rd and 4th balls is slightly less than 5 minutes. The differences are caused by the time of flight of the ball when it is thrown from a distance.

What Rømer observed was the difference in timing of occultation of Io, depending on whether the Earth was at its closest to Jupiter or at its furthest away. He correctly attributed this difference to differences in the time of flight of the light, according to the variation in the distance it had to cover between Io and the Earth.

6 hours ago, jalaldn said:

Suppose we set up a flashlight on the io that blinks in a regular cycle: 30 minutes ON followed by 30 minutes OFF, repeating continuously.

If we observe this flashlight from Earth, we would see a strange pattern: it appears to stay OFF for 41 minutes, then ON for only 19 minutes, then OFF for 41 minutes again, and so on.

How would you explain this distorted timing using the concept of light-travel delay?

As others have also pointed out, that is not what we would see. Leaving aside the complication of what would happen when Io passed behind Jupiter, we would see the light on for 30mins and then off for 30 mins.

You have still not explained what you mean by real time.

4 minutes ago, jalaldn said:

I have not published anywhere in full what the form of light is, and I will not publish it now. I am only talking about those things which have evidence to explain the properties of light.

WHAT DO YOU MEAN BY REAL TIME?

4 minutes ago, jalaldn said:

Third possibility:

We are observing Io and Jupiter in real-time before Io hides. After Io hides, we see Jupiter without Io. When Io reappears, we still see Jupiter. However, Io's light doesn't arrive, but Io continues its journey without stopping. But when the light arrives, we see Io at the position it is at that time.

That means, instead of seeing Io at the position where it was when the light left, we are seeing Io at the position where it is now.

No, answer my questions, please, first of all, without adding further complications.

1) what do you mean by the “format” of light being “different”?

2) What do you mean by “real time”? Do you mean instantaneous, or something different and if so, what?

2 hours ago, jalaldn said:

What is real-time energy transfer?

Suppose there is a wall clock on Jupiter. When it shows 12 o'clock on Jupiter, even if we look at it from Earth and the light takes 10 minutes to reach us, we still see that same 12 o'clock. (real-time)

But you would think it would show 11:50, that's not the case, the format of the light is different.

Yes it would show the time 10minutes earlier, because that is the time it takes for the light signal to travel to us from Jupiter.

But now we get to it: you appear to have some notion that this conventional understanding is wrong, because “the format of the light is different”. What do you mean by that? Format of light?? Kindly explain.

Also, you still have not explained what you mean by “real time”. From the context it looks as if you mean “instantaneous”. Is that what you mean, or something else?

6 hours ago, jalaldn said:

Although Ole Rømer's discovery confirmed four things, as far as he was concerned, it only confirmed one thing: that light takes time to reach its destination (there is a delay). it had nothing to do with the speed of light c.

Everything we see happens in real time — whether Io disappears for one minute or for a whole year, it proves the same thing. The only question is whether it disappeared or not.

What Ole Rømer actually discovered through his observation was the time it takes light to travel the distance of Earth's diameter. The later confusion arose because subsequent scientists redefined that distance as 1 AU (astronomical unit). Rømer himself never wrote it that way in his original work. That is exactly why the original ~11-minute light delay later became ~22 minutes (diameter vs. radius of Earth's orbit).

https://da.wikisource.org/wiki/Om_Ole_R%C3%B8mers_Opdagelse_af_Lysets_T%C3%B8ven

I think you need to explain what exactly you mean by "real time". This is something you constantly refer to and you have not made clear what it means in the way you are using it.

19 minutes ago, pinball1970 said:

Never heard that, the only thing that colours my urine is Marrowfat peas.

When I was a tiny boy I loved beetroot and my parents did in fact once call the doctor because my urine went pink. Betanin:

A zwitterion, apparently, at least at some pH values.

P.S. Diagram seems to have an error, the O substituent on the ring joined to the sugar should be OH.

1 hour ago, TheVat said:

Also, avoid putting an unopened jar in the fridge; the metal lid will contract > the jar. This was so effective at further tightening that I had to run hot water on the top over a minute before it would yield. I had stupidly put peanut butter in the fridge directly from the grocery sack. @geordief 's stabbing trick might have helped for that, given that PB is pretty mold resistant.

This problem reminds me of the now iconic comedy sketch called White People Problems. My God, man, there are people in this world who would LOVE to struggle with foie gras jars! Related to this - in the US, foie gras started to be viewed as evil in the seventies, as there was all this publicity on how the geese were abused. Did that improve, or did everyone just stop caring? Sorry, a bit OT, perhaps I can do a separate thread if that's not too much of a _____ _______ _____.

Yeah definitely a 1st World problem, I grant you. But in France, everyone gets in foie gras at Christmastime. And so do my (half-French) son and I, for Réveillon on New Year's Eve, accompanied by Sauternes. (We also do boudins blancs with apples and a chenin blanc on Christmas Eve - though I can't drink much as I have to sing carols, Gregorian chant and a motet or two at Midnight Mass.) I'm now over 70, damn it, and these traditions are something I hang onto increasingly tenaciously. 😄

1 hour ago, TheVat said:

Interesting. Which is the more significant effect, coefficient of expansion of metal threads, or raising pressure in the airspace?

The hole method has a downside if it's a jam jar and your fridge is not the cleanest. Those wee spores find their way in there.

I'm sure it is the vacuum inside that is the chief issue. But then the difference in difficulty of apparently identically-sized jars must be due to differences in friction in the threads and seal.

By the way, as we are approaching that time of year, those rubber seals on foie gras jars from France are a bastard. Sometimes I have to resort to pliers to pull the rubber tag enough to break the seal.