Constellations are younger than continents(lesswrong.com)
lesswrong.com
Constellations are younger than continents
https://www.lesswrong.com/posts/YMakfmwZsoLdXAZhb/constellations-are-younger-than-continents
131 comments
Although I like the idea, there's no reason to posit the preservation of the myth of a lost star for tens of thousands of years. People can still see all Seven Sisters under the right conditions, and the right conditions were probably much more prevalent back before the insane degree of light and air pollution that exists today.
https://skyandtelescope.org/astronomy-news/many-pleiades-can...
https://skyandtelescope.org/astronomy-news/many-pleiades-can...
Would this have been true in a society without optics and therefore corrective lenses?
When I was young, I was told a story about how native tribes used the star as a vision test for warriors. Only people with excellent vision could discern the second star.
No idea if there's any truth in the story, but I wouldn't be surprised
No idea if there's any truth in the story, but I wouldn't be surprised
You're probably thinking of Mizar and Alcor, which are at the middle of the handle of the Big Dipper. This was used as a vision test in ancient times and in the middle ages.
A fun fact is that it is actually six stars. Alcor is a binary star system and Mizar is a quadruple star system.
A fun fact is that it is actually six stars. Alcor is a binary star system and Mizar is a quadruple star system.
That might be it. I was probably 10 at the time so I don't remember the details
Yes, nearsightedness is much worse in modern times. Many less people needed corrective lenses, even as they got older.
This is one of my favorite stories.
One of the best parts is the legend of the seven sisters in Australian aboriginal tradition.
Theory goes that the legend far, far predates first contact with Europeans, so it must have come with the first aboriginal settlers when they sailed from Africa. Which would make it one of (if not the) oldest stories in history.
One of the best parts is the legend of the seven sisters in Australian aboriginal tradition.
Theory goes that the legend far, far predates first contact with Europeans, so it must have come with the first aboriginal settlers when they sailed from Africa. Which would make it one of (if not the) oldest stories in history.
Sailed from Africa? I always thought they crossed the Torres Strait.
On a related note, something that has always intrigued me is why there is no historical record of Polynesian arrival on the east coast of Australia.
On a related note, something that has always intrigued me is why there is no historical record of Polynesian arrival on the east coast of Australia.
I admit I don't really know. The story I read suggested that settlers sailed from Africa directly. But I don't know what the actual scientific consensus is on this. Really I don't find it particularly interesting as it's mostly guesswork about something 65000 years ago
Genome sequencing of ancient human bones has revealed a ton of interesting evidence about ancient human migration patterns! See the book Who We Are and How We Got Here
Considering all Seven Sisters are visible to people with good vision in sufficiently remote areas of Australia today, I don't know how one can draw any conclusions about how old the story is.
Indeed, with sufficiently good conditions and good vision, you can see more than seven. The Seven Sisters are just the brightest of the Pleiades.
Indeed, with sufficiently good conditions and good vision, you can see more than seven. The Seven Sisters are just the brightest of the Pleiades.
Because it's the same seven sisters legend as found in many other places around the world.
Seven sisters chased into the sky by a hunter, and the seventh sister left the sky to marry the hunter.
The aboriginals were isolated from the rest of the world for tens of thousands of years. That their legend is nearly exactly the same as European legends is incredibly unlikely to be coincidence. More likely the legend of the seven sisters is a story that was first told before humans left Africa. All of the Pleiades legends must stem from that original story.
The interesting part isn't that they have a story about the Pleiades, but that it's the exact same story as everyone else. And they've been telling it for tens of thousands of years before ever encountering the Europeans.
Seven sisters chased into the sky by a hunter, and the seventh sister left the sky to marry the hunter.
The aboriginals were isolated from the rest of the world for tens of thousands of years. That their legend is nearly exactly the same as European legends is incredibly unlikely to be coincidence. More likely the legend of the seven sisters is a story that was first told before humans left Africa. All of the Pleiades legends must stem from that original story.
The interesting part isn't that they have a story about the Pleiades, but that it's the exact same story as everyone else. And they've been telling it for tens of thousands of years before ever encountering the Europeans.
I don't think the number 7 is a smoking gun: https://psychology.stackexchange.com/questions/25611/explain...
It's unremarkable that there are so many legends with 7 whatevers if humans choose it 45% of the time they're asked to guess a random number between 1 and 10. People just really like the number 7.
It's unremarkable that there are so many legends with 7 whatevers if humans choose it 45% of the time they're asked to guess a random number between 1 and 10. People just really like the number 7.
Isn't it just as likely that people have a social bias towards 7 in part because of the amount of legends with 7 whatevers?
But the stories are about either 6 or 7 stars, or 7 where and then 1 star disappeared after some time. So it's not only the number 7. And the legends are about the Pleiades specifically. So I see more correlation than coincidence.
But there are actually many more stories, which are not about sixes or sevens, and some which don't see them as a group at all. People are selecting only the stories that match.
I am the last person to promote historical criticism over oral and written traditions, but the case is much weaker than what people who repeat this suggest.
1. There's a lot of stars, and they were very important to most every ancient culture on Earth.
2. Our pattern-matching brains are inclined to see vaguely similar things, even across different times and cultures.
3. Even so, there is very little overlap between Aboriginal constellations and other cultures' constellations.
4. The aboriginal Australians do not in fact all recognize the Pleiades. Some don't see it as a group at all. Other aboriginal groups actually note differing numbers of sisters (5-7) and have different stories about them, although the motif of fleeing from different men represented by different astronomical objects is a more common one than not.
The case for this is nice to imagine but very weak. It is not the case that "they" have the "exact same story" at all.
1. There's a lot of stars, and they were very important to most every ancient culture on Earth.
2. Our pattern-matching brains are inclined to see vaguely similar things, even across different times and cultures.
3. Even so, there is very little overlap between Aboriginal constellations and other cultures' constellations.
4. The aboriginal Australians do not in fact all recognize the Pleiades. Some don't see it as a group at all. Other aboriginal groups actually note differing numbers of sisters (5-7) and have different stories about them, although the motif of fleeing from different men represented by different astronomical objects is a more common one than not.
The case for this is nice to imagine but very weak. It is not the case that "they" have the "exact same story" at all.
Can confirm: My neighbour said "Pleiades" is a word I made up, and insists the only constellation is the "Big Dipper"
Humans, given the same input (seeing stars), may have a null hypothesis of the same output (story) moreso than expecting the same story to be unlikely random chance or coincidence.
The less special and more similar we are, the more I expect isolated cultures to converge on identical stories.
The less special and more similar we are, the more I expect isolated cultures to converge on identical stories.
I think you need exceptionally good eye sight to distinguish more than 6 stars. And it's not surprising that folklore stories originate around what most people's experiences are.
You don’t. You just need dark skies. Careful observers with good eyes see much more than 7.
It's also worth mentioning that, as I alluded to in another comment, myopia is much more common than it was pre-industrially, and it's still rising to what opthamalogists say is "epidemic" proportions. Good eyesight was much more common then.
It's also worth mentioning that, as I alluded to in another comment, myopia is much more common than it was pre-industrially, and it's still rising to what opthamalogists say is "epidemic" proportions. Good eyesight was much more common then.
I don't know. When I look at Pleiades I can see how you could see 5 (the brightest ones) or 8-9 (the best brightest ones), but not 6 or 7.
Are you looking at pictures, or actually in the sky with naked eyes?
In the sky. I thought it was well known that whatever number of stars you can see in Pleiades it probably isn't 7. I can see 5 with my eyes and more like 10 with binoculars.
That's a cute idea, but it's extremely unlikely to be true. If nothing else, the human fascination with 7 is a much more likely explanation, especially since 6 is nowhere near as important a number in this way (1,2,3 and 7 are much more common in myths and fairytales).
Australian natives have stories than originate over 10000 years ago that have been proven to be factual.
That's still 90,000 years younger than the supposed story of the 7 Pleiades.
Also consider that no myths survived of much more interesting and recent astronomical phenomena, like the supernova that was visible for a few weeks even in full daylight [https://en.m.wikipedia.org/wiki/SN_1054].
Also consider that no myths survived of much more interesting and recent astronomical phenomena, like the supernova that was visible for a few weeks even in full daylight [https://en.m.wikipedia.org/wiki/SN_1054].
Humans have made stories about the stars for as long as there have been humans. Why do you think this is unreasonable?
It’s not unreasonable per se but seems a weak hypothesis without more supporting evidence.
Also: Polaris (the north star) is younger than sharks.
(This one is less interesting as an overall observation about timescales though. Polaris is just quite a young star and sharks are quite and old life form).
(This one is less interesting as an overall observation about timescales though. Polaris is just quite a young star and sharks are quite and old life form).
Polaris as the north star is younger than the Roman Empire!
Because of the precession of the Earth's axis, Polaris didn't become the north star until about 500 AD. To the ancient Egyptians, Thuban was the north star. When humans were first discovering agriculture 12,000 years ago, Vega was the north star.
Wikipedia has a great table showing the cycle of north stars: https://en.m.wikipedia.org/wiki/Pole_star#Precession_of_the_...
Because of the precession of the Earth's axis, Polaris didn't become the north star until about 500 AD. To the ancient Egyptians, Thuban was the north star. When humans were first discovering agriculture 12,000 years ago, Vega was the north star.
Wikipedia has a great table showing the cycle of north stars: https://en.m.wikipedia.org/wiki/Pole_star#Precession_of_the_...
So, that "I am as constant as the northern star" simile is a little mixed?
Constant for a few hundred years until they inevitably get knocked off track.
As the article implies, all the brightest stars in Orion are younger than hominids. Indeed they formed around the time when the last common ancestor of humans and chimpanzees lived.
Another fun fact: very early humans (Australopithecus) coexisted with megalodons, giant dinosaur sharks that could swallow a hairless ape whole.
I wonder what the probability was back then to die by shark and per prehistoric cow.
The rings of Saturn are also (probably) younger than sharks!
These kind of facts always blow my mind. For instance, the Sun orbits the milky way once every 212m years.
That means that if the sun existed from the big bang to now, it would have only done ~63 complete revolutions around Sagittarius A*. If you account for the Milky Way's creation, that number gets even lower. I'm no expert, so maybe this makes sense to someone who knows more about this, but it definitively feel weird to me.
That means that if the sun existed from the big bang to now, it would have only done ~63 complete revolutions around Sagittarius A*. If you account for the Milky Way's creation, that number gets even lower. I'm no expert, so maybe this makes sense to someone who knows more about this, but it definitively feel weird to me.
I wondered the same thing and I asked Sean Carroll about it [1]. He didn’t go into much detail, but here is his answer:
> I guess my only insight is, I'm not sure why you relate the number of revolutions that the Milky Way has made to its complex and symmetric structure. The spiral arms that you see in a galaxy like the Milky Way do not rigidly rotate with it, they are more like... This is complicated, but they are more like regions where star formation is going on, and therefore the galaxy is brighter rather than regions where there's more density or anything like that. So if you're worrying how the spiral structure forms. It can form pretty easily in one or two revolutions, I don't see why it would take even 68, much less, but need more than that.
[1] https://www.preposterousuniverse.com/podcast/2023/10/09/ama-...
> I guess my only insight is, I'm not sure why you relate the number of revolutions that the Milky Way has made to its complex and symmetric structure. The spiral arms that you see in a galaxy like the Milky Way do not rigidly rotate with it, they are more like... This is complicated, but they are more like regions where star formation is going on, and therefore the galaxy is brighter rather than regions where there's more density or anything like that. So if you're worrying how the spiral structure forms. It can form pretty easily in one or two revolutions, I don't see why it would take even 68, much less, but need more than that.
[1] https://www.preposterousuniverse.com/podcast/2023/10/09/ama-...
I think your story is about the spiral structure of the milky way, whereas the parent is about the amount of revolutions of our solar system around the milky way. So 2 different things I think. That might be the confusion here.
Regarding the spiral arms: the arms itself do not really move, but stars move through the arms. The arms contain a lot of gas and when stars move through them, they can collect more gas and result in supernovas creating new stars.
Regarding the spiral arms: the arms itself do not really move, but stars move through the arms. The arms contain a lot of gas and when stars move through them, they can collect more gas and result in supernovas creating new stars.
Fair enough, it's a bit of a tangent. Thanks for the extra insight! I kinda' assumed that stars wouldn't move across a galaxy, like from one arm to another. I'll have to look into that.
Yes, stars move through the arms, and circle around the center of the galaxy. The arms actually also "move", but not in the way you would maybe expect. They are actually density waves - areas of greater density of gas & dust, similar to a traffic jam on a highway. These waves also "move" along with the gas & dust. But this wave-movement is illusory, because they are formed by these traffic jams.
The stars move through these waves (traffic jams), and in these high density areas new star formation and supernovas happens mostly (because there is more stuff to collect). The stars move through the gas & dust faster than the gas & dust themselves, because the stars are more massive and need more velocity to stay in stable orbit. The illusory movement of the waves is also slower than the stars, because the illusory waves move as slow as the dust & gas that forms them, and the stars are faster.
Apart from that, you also have dark matter which influences the rotation speed of objects based on it's distance from the galaxy center. It causes objects at the end of the spiral arms of the galaxy to rotate at the same speed as the ones close to the center, or anywhere. That is a mysterious area, and actually caused the requirement of dark matter into the equation. Because in Einstein's relativity theory, objects with same mass that are farther away from the galaxy center, need to move slower to have a stable orbit, which is the case in our solar system and other solar systems we observe. But in galaxies the case seems to be different. That is why dark matter was introduced, and makes it more complicated.
The stars move through these waves (traffic jams), and in these high density areas new star formation and supernovas happens mostly (because there is more stuff to collect). The stars move through the gas & dust faster than the gas & dust themselves, because the stars are more massive and need more velocity to stay in stable orbit. The illusory movement of the waves is also slower than the stars, because the illusory waves move as slow as the dust & gas that forms them, and the stars are faster.
Apart from that, you also have dark matter which influences the rotation speed of objects based on it's distance from the galaxy center. It causes objects at the end of the spiral arms of the galaxy to rotate at the same speed as the ones close to the center, or anywhere. That is a mysterious area, and actually caused the requirement of dark matter into the equation. Because in Einstein's relativity theory, objects with same mass that are farther away from the galaxy center, need to move slower to have a stable orbit, which is the case in our solar system and other solar systems we observe. But in galaxies the case seems to be different. That is why dark matter was introduced, and makes it more complicated.
That's very interesting! Thank you again for the extra insight!
Thanks. This discussion also triggered me to research some more about this subject. This video also gives a good insight: https://www.youtube.com/watch?v=kBU9Luc4NuM
Nice find! That also gave me some more rabbit holes to dig through :)
Problem with Sean and most cosmologists is they are proliferate regurgitates with little independent thought.
I really don't understand how you can put forth a criticism like this and be so vague at the same time. It really undermines your credibility. Be specific or why bother.
They probably adhere to some crackpot theory. The focus on “independent thought” as opposed to facts point in that direction. Don’t bother.
I have no credibility.
Sean jumps on the hype train all day long. I'm skeptical. I don't think this illustrious dark matter or big bang mean anything. So it's like that telephone game where Sean is the last person and gets to tell you what the first person said and he's always very excited but baseless. Really do like his energy. I just don't think he's much of an independent thinker.
Sean jumps on the hype train all day long. I'm skeptical. I don't think this illustrious dark matter or big bang mean anything. So it's like that telephone game where Sean is the last person and gets to tell you what the first person said and he's always very excited but baseless. Really do like his energy. I just don't think he's much of an independent thinker.
Well, as someone with a shred of credibility, he really does have strong theoretical evidence for the things he's saying. The difficulty here is that theoretical physics is really fucking hard. Way too hard to distill down into a paragraph. I'm sure the man could do a lecture series on star formation in spiral galaxies to convince you but you're going to need a bachelor's at minimum to even start that.
I think he's easy to dismiss because much of his exposition deals in philosophical physics, it's really his specialty. There's levels of solidity. Experimental physics is reality. Theoretical physics is an explanation of reality, sometimes attempting to extend to predict the next experiment. Philosophical physics takes theoretical tools and expands them to explain everything in the Universe, including the Hard questions. I don't think it's a problem that they do it, someone should be thinking of this stuff. Do you have much experience with theoretical physics or cosmology. I have some and the math really helps make these things comprehensible and reasonable. Theoretical physics without math is indeed just continuous excited, but baseless assertions. The math fixes this
I think he's easy to dismiss because much of his exposition deals in philosophical physics, it's really his specialty. There's levels of solidity. Experimental physics is reality. Theoretical physics is an explanation of reality, sometimes attempting to extend to predict the next experiment. Philosophical physics takes theoretical tools and expands them to explain everything in the Universe, including the Hard questions. I don't think it's a problem that they do it, someone should be thinking of this stuff. Do you have much experience with theoretical physics or cosmology. I have some and the math really helps make these things comprehensible and reasonable. Theoretical physics without math is indeed just continuous excited, but baseless assertions. The math fixes this
I don't believe you.
I prefer alternative theories. Plasma physics. Electric universe models.
There's Gareth Samuel on YouTube, See The Pattern. He just explores various theories. Treats them as merely theories (instead of facts) and I like that approach. It's very historic and really fleshes out ideas. Then you got the Lerner himself, author of The Big Bang Never Happened, which I think has been overwhelmingly falsified so you mean you can take Sean and his amazing fantastic firework singularity that blew up from a dimensionless point and yeah blah blah blah blah blah inflation blah blah blah acceleration blah blah blah and it makes no fucking sense whatsoever.
I'm really good at math. At least compared to most people. I'm 38 and really only started questioning the big bang maybe in the last decade, and then I found Eric Lerner and well, now I can firmly say the big bang never happened.
I prefer alternative theories. Plasma physics. Electric universe models.
There's Gareth Samuel on YouTube, See The Pattern. He just explores various theories. Treats them as merely theories (instead of facts) and I like that approach. It's very historic and really fleshes out ideas. Then you got the Lerner himself, author of The Big Bang Never Happened, which I think has been overwhelmingly falsified so you mean you can take Sean and his amazing fantastic firework singularity that blew up from a dimensionless point and yeah blah blah blah blah blah inflation blah blah blah acceleration blah blah blah and it makes no fucking sense whatsoever.
I'm really good at math. At least compared to most people. I'm 38 and really only started questioning the big bang maybe in the last decade, and then I found Eric Lerner and well, now I can firmly say the big bang never happened.
> now I can firmly say the big bang never happened.
You really can't. And aren't. If you could, you would be, and people with credibility would be listening and taking you seriously. They would have to, because seriously composed arguments aren't ignorable by individuals who understand and care about the subject matter.
This is the purpose of mainstream scientific work: to take serious arguments seriously and to dispense with those that don't hold up.
Being a contrarian with crackpot theories is far easier, since the only people listening are people who don't know what they are talking about, and so all you get is false validation in response to any output.
In general, if a theory isn't endorsed by professionals in a field, it's because the theory is wrong.
You really can't. And aren't. If you could, you would be, and people with credibility would be listening and taking you seriously. They would have to, because seriously composed arguments aren't ignorable by individuals who understand and care about the subject matter.
This is the purpose of mainstream scientific work: to take serious arguments seriously and to dispense with those that don't hold up.
Being a contrarian with crackpot theories is far easier, since the only people listening are people who don't know what they are talking about, and so all you get is false validation in response to any output.
In general, if a theory isn't endorsed by professionals in a field, it's because the theory is wrong.
You might want to be careful with accepting alternative theories. They can sound very convincing when you don't understand the subject very well. Often people make illogical connections that sound nice but are either in conflict with other observations or theories, or are simply incorrect but just sound logical on the surface.
Professor Dave Explains has a lot of scientific debunking videos where he thoroughly discusses these kind of popular alternative theories. For example about the electric universe: https://www.youtube.com/watch?v=T9q-v4lBGuw&t=0s
Professor Dave Explains has a lot of scientific debunking videos where he thoroughly discusses these kind of popular alternative theories. For example about the electric universe: https://www.youtube.com/watch?v=T9q-v4lBGuw&t=0s
Btw, the big bang theory is not something personal from Sean Carroll. He might talk about it (a lot), but a lot of scientists talk about it, and it's a theory that has evolved over the last 100 years by thousands of scientists around the world. So in that sense it's not really "Sean" against another guy with an alternative theory. No it's 100 years of worldwide collaborative science research.
And yes it is an incomplete theory, like all the theories we currently have. But it is currently the theory that matches our observations in experiments the closest.
It could always be that we're on the wrong path, and that a completely other paradigm is necessary. And it is good to be open to such posibilities and to think about it. But as long as an alternative theory doesn't do a better job at predicting the observations we get in experiments, you can't dismiss the current theory.
And yes it is an incomplete theory, like all the theories we currently have. But it is currently the theory that matches our observations in experiments the closest.
It could always be that we're on the wrong path, and that a completely other paradigm is necessary. And it is good to be open to such posibilities and to think about it. But as long as an alternative theory doesn't do a better job at predicting the observations we get in experiments, you can't dismiss the current theory.
Even before LLMs were dismissed as "stochastic parrots" (and even more so since then), I find myself noticing when people dismiss the intellectual capacity of entire groups.
"Mickey Mouse degrees", https://xkcd.com/793/, the attitude displayed by the bully in "Zero for Conduct" and similar IRL dismissals of the entire ME area in the post 9/11 discourse, mid-Brexit politicians saying the country had had enough of experts, some of my fist girlfriends' anecdotes from her childhood, town v gown, …
"Mickey Mouse degrees", https://xkcd.com/793/, the attitude displayed by the bully in "Zero for Conduct" and similar IRL dismissals of the entire ME area in the post 9/11 discourse, mid-Brexit politicians saying the country had had enough of experts, some of my fist girlfriends' anecdotes from her childhood, town v gown, …
Another fun fact: there are more trees on Earth (3×10¹²) [1] than stars in the Milky Way (1-4×10¹¹).
[1] "Mapping tree density at a global scale" https://www.nature.com/articles/nature14967
[1] "Mapping tree density at a global scale" https://www.nature.com/articles/nature14967
Depends on your definition of "tree".
My follow-up fun fact is that even though "tree", like "fish", is a term of common parlance, there is no universally recognised and precise definition of the category, either botanically or in common language.
My follow-up fun fact is that even though "tree", like "fish", is a term of common parlance, there is no universally recognised and precise definition of the category, either botanically or in common language.
What's a tree?
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height.
In the words of Justice Potter Stewart: "I know it when I see it." (1964)
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are usable as lumber or plants above a specified height.
In the words of Justice Potter Stewart: "I know it when I see it." (1964)
That fact sounds like it will become fiction very very soon. :\
On the postive side, there's probably more microplastics in our oceans than there are stars in all of the galaxies summed together.
Ocean microplastics were probably overestimated. https://phys.org/news/2023-08-plastic-litter-oceans-overesti... Most plastic in the oceans is in larger chunks… so far anyway.
Maybe not. Deforestation rates peaked in the 80’s
https://ourworldindata.org/global-deforestation-peak
https://ourworldindata.org/global-deforestation-peak
Have another fact since we are talking about trees, wood is the rarest element in the universe, even more rare than diamonds, in fact, wood can only be found on earth!
A piece of me dies every time I see someone cutting a tree for useless reasons.
Yeah sorry to be kinda pedantic but wood is not an element, it's just a material. And if we're talking rarity of materials there are undoubtedly much much rarer materials, like LK99 for instance.
In fact, even if we're talking elements themselves, there are elements with halflives of picoseconds. I can't know for sure but i'd bet those elements are more rare than wood. And since I'm extending the analogy, how do we know wood is the rarest? We can't really get a good look at exoplanets yet, they're still just fuzzy balls to us like pluto used to be. Trees could be an evolutionary essential step.
Anyways, it's a nice thought but could probably be phrased in a way to defeat pedants like me. Merry Christmas <3
In fact, even if we're talking elements themselves, there are elements with halflives of picoseconds. I can't know for sure but i'd bet those elements are more rare than wood. And since I'm extending the analogy, how do we know wood is the rarest? We can't really get a good look at exoplanets yet, they're still just fuzzy balls to us like pluto used to be. Trees could be an evolutionary essential step.
Anyways, it's a nice thought but could probably be phrased in a way to defeat pedants like me. Merry Christmas <3
Wood isn't an element?
Do you think cutting a tree annihilates the wood?
Agreed. Another surprising one to me is that the earth itself has been around for about 1/3 the age of the universe. I always assumed that the timescale of the universe was vastly longer than the life of the earth.
Wow it’s amazing that we could somehow time the orbit period.
There is a nice simulation of constellations changing over time in one of the episodes of Sagan’s Cosmos, where he explains parallax and some of the other important phenomena.
H A Rey The Stars (1952) had a nice series of cartoons depicting a caveman, a grey-flannel-suit man, and a futuristic man all looking at their respective versions of the big dipper.
The Barbers' When They Severed Earth From Sky (2004) hypothesises that the various kingship changes in heaven of several ancient mythologies correspond to the precession of the solstices and equinoxes through the zodiac. Eg, for Greek mythology, they give:
According to this hypothesis, when the fall equinox moved into Virgo and Saturn and Jupiter came into conjunction with Pisces in 6 BC, many ancients took it as marking the advent of a new Kingdom of Heaven ruling a New Age, making them more susceptible to picking up new religions emanating from the middle east around that time, eg Mithraism.
Does Virgil, writing ca 40 BC, predict the New Age? [Fourth Eclogue 4-10]
> Now is come the last age of Cumaean song; the great line of the centuries begins anew. Now the Virgin returns, the reign of Saturn returns; now a new generation descends from heaven on high. Only do you, pure Lucina, smile on the birth of the child, under whom the iron brood shall at last cease and a golden race spring up throughout the world!
(but note that by this counting the "Age of Aquarius" wouldn't be due to start until ca 2160; rather far off in human lifetimes from the 1960s)
The Barbers' When They Severed Earth From Sky (2004) hypothesises that the various kingship changes in heaven of several ancient mythologies correspond to the precession of the solstices and equinoxes through the zodiac. Eg, for Greek mythology, they give:
Head God Summer Spring
CHAOS Libra Cancer
~6480 BC
OURANOS Virgo Gemini
~4320 BC
KRONOS Leo Taurus
~2160 BC
ZEUS Cancer Aries
According to this hypothesis, when the fall equinox moved into Virgo and Saturn and Jupiter came into conjunction with Pisces in 6 BC, many ancients took it as marking the advent of a new Kingdom of Heaven ruling a New Age, making them more susceptible to picking up new religions emanating from the middle east around that time, eg Mithraism.
Does Virgil, writing ca 40 BC, predict the New Age? [Fourth Eclogue 4-10]
> Now is come the last age of Cumaean song; the great line of the centuries begins anew. Now the Virgin returns, the reign of Saturn returns; now a new generation descends from heaven on high. Only do you, pure Lucina, smile on the birth of the child, under whom the iron brood shall at last cease and a golden race spring up throughout the world!
(but note that by this counting the "Age of Aquarius" wouldn't be due to start until ca 2160; rather far off in human lifetimes from the 1960s)
This is tremendous. One could write a book relating well documented history and mythology with the changing constellations.
I actually remember a couple of diagrams in a science book way back in elementary school, so we’re talking 70s here, showing the Big Dipper today and what it would look like in 50,000 years.
It was a kind of weird feeling as a young boy “seeing” change to something considered so static, and all the deeper considerations from that.
It was a kind of weird feeling as a young boy “seeing” change to something considered so static, and all the deeper considerations from that.
I've played with Celestia and had it draw the constellations, then zoomed around the galaxy and seen how they got distorted as I moved away from Earth and saw them from different angles. Really drove home that the constellations are three-dimensional arrangements, not flat.
I was surprised to learn that Pangaea is believed to have formed and broke up at least five times so far.
Pangaea is only the name of the most recent supercontinent. The past ones all have their own names. https://en.wikipedia.org/wiki/Supercontinent
Of the 10 on that list, multicellular life appears around #8 (Pannotia).
Tolkien himself was unsure if we were in the 6th or 7th age
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I doubt if there would have been much gain; and I hope the, evidently long but undefined, gap* in time between the Fall of Barad-dûr and our Days is sufficient for 'literary credibility', even for readers acquainted with what is known or surmised of 'pre-history'
I imagine the gap to be about 6000 years : that is we are now at the end of the Fifth Age, if the Ages were of about the same length as S.A. and T.A. But they have, I think, quickened; and I imagine we are actually at the end of the Sixth Age, or in the Seventh.
Source - The Letters of J.R.R. Tolkien, Letter 211
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I doubt if there would have been much gain; and I hope the, evidently long but undefined, gap* in time between the Fall of Barad-dûr and our Days is sufficient for 'literary credibility', even for readers acquainted with what is known or surmised of 'pre-history'
I imagine the gap to be about 6000 years : that is we are now at the end of the Fifth Age, if the Ages were of about the same length as S.A. and T.A. But they have, I think, quickened; and I imagine we are actually at the end of the Sixth Age, or in the Seventh.
Source - The Letters of J.R.R. Tolkien, Letter 211
We have basically had to conclude that Tolkien’s star Borgil[0] is Aldebaran, because Betelgeuse wasn’t a red star in the classical era[1], or before.
[0]: https://tolkiengateway.net/wiki/Borgil [1]: https://news.ycombinator.com/item?id=32478492
[0]: https://tolkiengateway.net/wiki/Borgil [1]: https://news.ycombinator.com/item?id=32478492
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Another one: dinosaurs existed on the other side of the galaxy.
The galaxy has revolved about half a revolution since then.
The galaxy has revolved about half a revolution since then.
The Milky Way is also moving through space. So they actually existed way out in intergalactic space (probably).
A UI can combine those two: Sun's galactic orbit as analog-clock selector, and MW motion (wrt CBR, towards Great Attractor) as a slider. Though IIRC, the range of a slider with a finger-tip sized MW is relatively limited. Yay implicit curriculum.
This article brought back memories of when I was playing around with astronomy simulation software like Redshift by Maris Multimedia.
I started searching for it, and as it usually goes with HN stories, I ended up on their new/modern version of it over at: https://redshiftsky.com
A brief history of their famous titles (check also aviation) is over at: http://archaic.maris.com/content/indexe5cc.html
Older versions of Redshift can be downloaded/found over at the Internet Archive:
https://archive.org/details/redshift_202204
https://archive.org/details/redshift2
https://archive.org/details/Redshift_3_Maris_Multimedia_1998
I started searching for it, and as it usually goes with HN stories, I ended up on their new/modern version of it over at: https://redshiftsky.com
A brief history of their famous titles (check also aviation) is over at: http://archaic.maris.com/content/indexe5cc.html
Older versions of Redshift can be downloaded/found over at the Internet Archive:
https://archive.org/details/redshift_202204
https://archive.org/details/redshift2
https://archive.org/details/Redshift_3_Maris_Multimedia_1998
There’s also the FLOSS Stellarium: http://stellarium.org/
How accurately could we predict when betelgeuse will go? What are the CIs?
Literally any moment in the next 10000 years. The probability distribution (afaict) is pretty flat, and either 1000, 10000, or 1000000 years long.
Part of the problem is that direct observations of supernovas is small and indirect. We have small numbers of recorded occurrences to judge from.
Also, we don’t have observations of the stars before supernova. Most are in other galaxies so don’t even see the star. Betelgeuse is first case where we can observe late stage star closely.
Animation from GAIA data: https://www.esa.int/ESA_Multimedia/Videos/2020/12/Gaia_s_ste...
Humanity might one day spread to all over the galaxy by hitchhiking passing stars.
Well, assuming we don't self-annihilate ourselves at some point. Or be destroyed by some cataclysm.
I guess we'd better spread to as many locations in the solar system as, err, humanly possible.
Well, assuming we don't self-annihilate ourselves at some point. Or be destroyed by some cataclysm.
I guess we'd better spread to as many locations in the solar system as, err, humanly possible.
Communication across interstellar space would be super slow, because the speed of light is so slow compared to the distances, like, at least several years for a single one-way message.
This makes it likely that if we ever do settle multiple stars, culture and language will diverge pretty strongly across the different settlements, potentially making other, distant humans our worst potential enemies.
This makes it likely that if we ever do settle multiple stars, culture and language will diverge pretty strongly across the different settlements, potentially making other, distant humans our worst potential enemies.
Humans might evolve tools to lower cultural drift or get it to zero even, which is also needed I think if you want to build galaxy spanning societies, for precisely the reason you state.
E.g. you could have many jobs in society be done by machines, have humans be raised by them, interact with them on a daily basis, etc. If you want to prevent language drift, you could have these machines speak only one specific kind of language. That way, all the cultural works of the ancestors are still directly accessible to everyone without translation.
E.g. you could have many jobs in society be done by machines, have humans be raised by them, interact with them on a daily basis, etc. If you want to prevent language drift, you could have these machines speak only one specific kind of language. That way, all the cultural works of the ancestors are still directly accessible to everyone without translation.
Luckily those same distances ensure that interactions between those worst enemies are practically zero.
I think the constellations through the ages chart make it clear that orion has been recognisable long enough to see continents change and will be recognisable for a long time to come.
The article goes on to say these stars are very young at ~10My, which is about the smallest time scale at which you might notice some change on continents'aspect. So you're probably technically right, but by a very thin margin.
Did you read the article? The stars in Orion are only between 6 and 12 million years old, and the continents already looked almost the same as today in that time frame. Furthermore, they are types of stars that won't live very long, at most 20 million more years. Betelgeuse will go supernova within just the next 100,000 years. The Orion stars will see a little bit of continental movement over their lifetime, but not "rise and fall".
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Life in West Virginia is younger than the mountains but older than the trees
Isn’t life everywhere older than the trees?
If you take it as "life on land", it's accurate on both counts. Those are some old mountains.
https://twitter.com/bookishseawitch/status/15727512783669493...
“the appalachian mountains are older than saturn’s rings. the appalachian mountains are older than dinosaurs. the appalachian mountains are older than trees. the appalachian mountains are literally older than BONES. the appalachian mountains should be regarded with pure terror.”
“the appalachian mountains are older than saturn’s rings. the appalachian mountains are older than dinosaurs. the appalachian mountains are older than trees. the appalachian mountains are literally older than BONES. the appalachian mountains should be regarded with pure terror.”
I believe it’s a reference to a John Denver song.
Oh, ha, thanks for pointing that out :)
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Here's a yule-flavored reminder that Denver's talking about Western Virginia, since that's where the Blue Ridge mountains are.
He'd also never been here, so he might have just been wrong.
He'd also never been here, so he might have just been wrong.
Oh I dont know the history, but I think I could throw a baseball from the 7 and hit west virginia, and if you are on the country roads trying to get around the traffic headed up bluemount you could probably find yourself in west virginia pretty easy.
Speaking of never been there, I'm always amused by what you get when Dutch attempt to interpret the Denver lyrics: https://www.youtube.com/watch?v=ZVz_IJoyO6Y
(or for that matter the German notion of western: https://www.youtube.com/watch?v=DZrXWdLxtfM )
(or for that matter the German notion of western: https://www.youtube.com/watch?v=DZrXWdLxtfM )
The first one sent me into fits. The point is that we're old here, not the wild West. Hilariously, I live in one of the most German areas of Appalachia, so the people look more or less like my neighbors.
The second one would fit in at the CMAs.
The second one would fit in at the CMAs.
This is probably why West Virginia is never going to let go of Harper’s Ferry now
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Also, not to mention that constellations are a human made construct. It is like how day night cycles are natural, and have existed before us, but calling every seventh cycle “monday” is not.
The stars and their appearance on the sky is natural like the day-night cycles, while how they are grouped together and what they are called is human made. (And different civilisations had wildly differing opinions on how this should be done.)
The stars and their appearance on the sky is natural like the day-night cycles, while how they are grouped together and what they are called is human made. (And different civilisations had wildly differing opinions on how this should be done.)
No matter how one would choose to group stars in the sky, the point is that their relative angular closeness varies faster than that of continents on our planet.
I wonder when we started telling stories about them though. There’s not much to do once the sun sets, prior to the invention of the oil lamp.
Unfortunately Orion is still older than most hominids. I can imagine a new constellation triggering the “need” for new stories, but only after language developed.
And while I strongly believe we will continue to push back the beginnings of Man, and of civilization, we are probably past the inflection point. I suspect we aren’t likely to quadruple the origin dates for our species. Which is what you’d need to have a plausible story about oral traditions affected by Orion sprouting a new star.
Unfortunately Orion is still older than most hominids. I can imagine a new constellation triggering the “need” for new stories, but only after language developed.
And while I strongly believe we will continue to push back the beginnings of Man, and of civilization, we are probably past the inflection point. I suspect we aren’t likely to quadruple the origin dates for our species. Which is what you’d need to have a plausible story about oral traditions affected by Orion sprouting a new star.
Wouldn’t Saturday be the seventh cycle, given it is the end of the week?
'Every' modifies the meaning. It's just as sensible and correct to say 'every second number is even' and 'every second number is odd'.
> Wouldn’t Saturday be the seventh cycle, given it is the end of the week?
Every 7th cycle would be the start of the week; the 6th cycle would be the end. (Think, for example, if you had a 2-day week; the 1st cycle would take you to the 2nd day.) But when the week starts is not universally agreed—I believe USians usually start it on Sunday, and Europeans usually start it on Monday.
Every 7th cycle would be the start of the week; the 6th cycle would be the end. (Think, for example, if you had a 2-day week; the 1st cycle would take you to the 2nd day.) But when the week starts is not universally agreed—I believe USians usually start it on Sunday, and Europeans usually start it on Monday.
There are seven day weeks, the 1st to 7th. The 8th day is the start of the next week. The 1st cycle is the 1st day.
I would argue that as a result of circadian rhythms, the Lunar calendar atleast makes more sense than the Gregorian one.
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Around 2/3 of cultures have a story in which there are seven things (seven sisters, seven boys, seven chickens, and so forth.). The other 1/3 of cultures have a story in which there are six things. And a surprising number of them have a story in which there were originally seven, but one got lost (like in the Greek myth of Electra).
The interesting thing is that two of the stars in the cluster are quite close together and can't be distinguished by eye. A pair of astronomers looked at the proper motions of the stars in the cluster and figured out that tens of thousands of years ago these two stars were far enough apart that they could have been distinguished by eye. So it seems that early humans recognized the Pleiades as having seven stars and this persisted in the myths of most cultures for tens of thousands of years, even when the seventh star was no longer visible.
[1]: https://arxiv.org/abs/2101.09170