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[rotting bones]

Blast from the past: There's a new version of Ithkuil, the maximalist conlang with an eye towards concision.

[rotting bones]

Since the new interpretation of the constitution gives a carte blanche to religion, I bought a tarot deck called Hermetic Tarot.

According to my first reading, I will fail in my endeavors because of excessive attention to detail (IIRC Eight of Swords: Lord of Shortened Force. Jurisdiction of the angels Vemibael VMBAL and Yehohel YHHAL).

I like this. If I'm going to fail, that's what I want the reason to be.

It's also sadly accurate. I probably suffer from hypergraphia. My compulsive list making may well be the death of me.

[Raphael]

1) Earlier today, for what It think was the first time in my life, I had to check an "I'm not a robot" box in order to visit the official website of a city. This is getting out of hands.

2) Unrelated, and inspired by a recent post by WeepingElf in the Languages forum: Can you give me one good reason why I shouldn't believe that dark matter and dark energy will eventually go the way of the luminous ether? (I recently saw a social media post where someone pointed out that the social sciences routinely get criticized because they often can't make precise predictions, and even accused of not being proper sciences on that ground, but astrophysicists get to posit that the reason why their equations don't work out is some mysterious phenomenon called "dark energy", and people go along with that.)

[rotting bones]

There's a physics YouTuber called Sabine Hossenfelder who's similarly skeptical. Recently, she pointed out (again) that "dark energy" doesn't sound mysterious if you call it "vacuum space curvature", i.e. random quantum fluctuations. She has said similar things about dark matter before, but I forgot what it was.

I found her through a link on Paul Cockshott's YouTube channel.

[zompist]

Can you give me one good reason why I shouldn't believe that dark matter and dark energy will eventually go the way of the luminous ether?

There's a physics YouTuber called Sabine Hossenfelder who's similarly skeptical. Recently, she pointed out (again) that "dark energy" doesn't sound mysterious if you call it "vacuum space curvature", i.e. random quantum fluctuations. She has said similar things about dark matter before, but I forgot what it was.

I found her through a link on Paul Cockshott's YouTube channel.

This must be a trending topic or something... I just read a book on dark matter, and also recently discovered Hossenfelder.

Here's Hossenfelder on dark matter. It's a good backgrounder: she gives the evidence for dark matter, also some things particle theories don't explain.

On one level, Raphael's question could be answered that dark matter, unlike the ether, has been observed. That is, we find that there's far more mass in galaxies than can be accounted for by visible matter, gas, and black holes. "Dark matter" is just a cover term for this mass that we can't identify with known particles. (It's "dark" because it doesn't interact with electromagnetism.)

No particles that fit the bill have been discovered, and people have been looking for fifty years. That's frustrating, and you can get mad at particle theories if you like, but you can't throw out the actual evidence (galaxy rotations, cosmic clumping, gravitational lensing, etc.).

The major alternative people have come up with is modifying the laws of gravity. As Hossenfelder says, this solves many problems but not all.

I'd also point out that though we threw out "ether" per se... we replaced it with concepts like "fields" and "spacetime." We could easily have called those things "ether" just as both Newton and Einstein referred to something called "gravity", and both Democritus and Heisenberg called things "atoms." That is, "dark matter" is just a name for a problem (excess mass). It won't go away in the sense of the underlying observations going away. It may go away in the sense that the problem will be satisfactorily explained and replaced with new terminology.

[bradrn]

This must be a trending topic or something... I just read a book on dark matter, and also recently discovered Hossenfelder.

Yep, I’ve also seen a lot of her recently. She’s a contrarian, but good at explaining stuff to a popular audience.

Here's Hossenfelder on dark matter. It's a good backgrounder: she gives the evidence for dark matter, also some things particle theories don't explain.

On one level, Raphael's question could be answered that dark matter, unlike the ether, has been observed. That is, we find that there's far more mass in galaxies than can be accounted for by visible matter, gas, and black holes. "Dark matter" is just a cover term for this mass that we can't identify with known particles. (It's "dark" because it doesn't interact with electromagnetism.)

No particles that fit the bill have been discovered, and people have been looking for fifty years. That's frustrating, and you can get mad at particle theories if you like, but you can't throw out the actual evidence (galaxy rotations, cosmic clumping, gravitational lensing, etc.).

The major alternative people have come up with is modifying the laws of gravity. As Hossenfelder says, this solves many problems but not all.

… "dark matter" is just a name for a problem (excess mass). It won't go away in the sense of the underlying observations going away. It may go away in the sense that the problem will be satisfactorily explained and replaced with new terminology.

This agrees with what I’ve seen.

I'd also point out that though we threw out "ether" per se... we replaced it with concepts like "fields" and "spacetime." We could easily have called those things "ether" just as both Newton and Einstein referred to something called "gravity", and both Democritus and Heisenberg called things "atoms."

Not sure I agree with this, though. Einstein’s ‘gravity’ is founded on somewhat different concepts to Newton’s, but the former gives a very very good approximation of the latter under the conditions Newton could observe. Similarly, Democritus’s ‘atoms’ were simply ‘the smallest possible particles’, which is indeed how modern ‘atoms’ were defined — at least until the discovery of the electron, and even now it’s reasonable to consider atoms the smallest possible particles in many contexts (e.g. much of chemistry).

By contrast, ‘fields’ and ‘spacetime’ are both fundamentally different concepts to the ‘luminiferous aether’ of the 19th century. The latter was considered to be a genuine physical substance which permeated the whole universe. This is why Michaelson and Morley constructed their famous experiment to find the aether the way they did — they assumed that it was a physical substance, which meant they could measure how fast we’re moving with respect to it. And, when they couldn’t measure anything, that was considered a proof that the aether as commonly defined did not exist. By contrast, ‘spacetime’ is merely a coordinate system, and a ‘field’ is just a wavefunction defined over spacetime. Neither has any of the properties usually assigned to the aether.

(Of course, if it had been linguists doing this, both spacetime and all kinds of fields would certainly have been called ‘aether’, and they would have spent half their time looking for non-existent similarities between the concepts. The physics way may result in a proliferation of terms, but it does actually let you talk about stuff unambiguously.)

[zompist]

By contrast, ‘spacetime’ is merely a coordinate system,

No, this isn't the case! Spacetime is deformed by gravity— it has physical characteristics. And "empty space" is not empty— it is a froth of quantum events, and it has mass— at least, that's one interpretation of dark energy.

By contrast, the Cartesian plane is merely a coordinate system— it has no mass, it doesn't deform, it doesn't reflect gravity, precisely because it is an abstraction and not a physical thing.

and a ‘field’ is just a wavefunction defined over spacetime.

And ether was just a medium that supported waves. We happen to have thrown out the term, but it could easily have been re-used.

And sure, the M-M experiment demonstrated that there was no medium that behaved like water and could slow down light. That has nothing to do whether we should talk about "ether" or "fields". We still don't have language that gives us the right assumptions for relativity and quantum mechanics, and it still gives us problems. (E.g. we did re-use "particle" and "wave" and neither is a very great model.)

[bradrn]

By contrast, ‘spacetime’ is merely a coordinate system,

No, this isn't the case! Spacetime is deformed by gravity— it has physical characteristics.

OK, maybe ‘merely’ was poor word choice. Still, it is a coordinate system — a curved one with non-intuitive geodesics, which is where gravity comes from, but a coordinate system nonetheless, on par with Cartesian coordinates (though not as simple).

And "empty space" is not empty— it is a froth of quantum events, and it has mass— at least, that's one interpretation of dark energy.

We don’t know this. We think it might have mass, but ah, that’s when the maths blows up, so we can’t quite be certain of anything yet.

By contrast, the Cartesian plane is merely a coordinate system— it has no mass, it doesn't deform, it doesn't reflect gravity, precisely because it is an abstraction and not a physical thing.

It doesn’t reflect gravity because it has curvature 0 and straight geodesics! Or, to put it another way, you’ve defined the coordinate system so that it has no gravity. Cartesian coordinates work perfectly well for a universe without any masses.

and a ‘field’ is just a wavefunction defined over spacetime.

And ether was just a medium that supported waves. We happen to have thrown out the term, but it could easily have been re-used.

Sure, but you wouldn’t have been re-using it for the same thing, was my point. This was the point of my parenthetical at the end: physicists like keeping their terms as consistent and well-defined as possible.

And sure, the M-M experiment demonstrated that there was no medium that behaved like water and could slow down light.

Not at all. In fact, some responses trying to save the aether after M-M postulated an aether that was more water-like than previously thought, in that the Earth could ‘drag’ it along as it rotated. But it soon became apparent that no theory which postulated an aether could explain how our universe works.

That has nothing to do whether we should talk about "ether" or "fields". We still don't have language that gives us the right assumptions for relativity and quantum mechanics, and it still gives us problems. (E.g. we did re-use "particle" and "wave" and neither is a very great model.)

I think you’ll find that no-one uses the term ‘wave’ in quantum-mechanical: they’re always referred to as either ‘wave-like behaviour’ or ‘wavefunctions’ (both of which mean different things to each other, by the way). Same with ‘particle’, although when the traditional meaning of ‘particle’ gives a sufficiently close approximation to the actual behaviour we’re happy to use it.

[zompist]

By contrast, ‘spacetime’ is merely a coordinate system,

No, this isn't the case! Spacetime is deformed by gravity— it has physical characteristics.

OK, maybe ‘merely’ was poor word choice. Still, it is a coordinate system — a curved one with non-intuitive geodesics, which is where gravity comes from, but a coordinate system nonetheless, on par with Cartesian coordinates (though not as simple).

I'm not sure what you mean by "non-intuitive geodesics, which is where gravity comes from"-- that's a non sequitur. Of course coordinate systems can be curved, non-linear, non-intuitive, etc. They're mathematical abstractions and don't exist. You can create any wacky coordinate system you want, and it won't respond to gravity, or create gravity, because mathematical abstractions are not physical things.

No one understands why gravity can affect spacetime itself, but the fact that it does makes it something physical. This is kind of philosophical, but really, do you think that the number two is affected by gravity? Math is not physics.

And "empty space" is not empty— it is a froth of quantum events, and it has mass— at least, that's one interpretation of dark energy.

We don’t know this. We think it might have mass, but ah, that’s when the maths blows up, so we can’t quite be certain of anything yet.

We know even less about dark energy than we know about dark matter. And given all this stuff, and the long-term inability to get a quantum theory of gravity, we don't understand gravity very well.

Sure, but you wouldn’t have been re-using it for the same thing, was my point. This was the point of my parenthetical at the end: physicists like keeping their terms as consistent and well-defined as possible.

Yes, except when they totally change their definitions. Any my point is that they are completely free to do so, because that's how language works.

FWIW, this bit from Wikipedia makes exactly the point I was making-- some physicists find that "ether" and "spacetime" are not so different concepts as they are usually described.

[Ares Land]

I'm hereby stealing the idea of reusing 'ether' for 'spacetime' for conlanging purposes.

[keenir]

and even accused of not being proper sciences on that ground, but astrophysicists get to posit that the reason why their equations don't work out is some mysterious phenomenon called "dark energy", and people go along with that.)

I can remember when I first heard of "dark energy"...astronomers were puzzled by the rotation rates of the inner and outer sections of galaxies, and they couldn't work out why it was acting like that...so "dark matter" was suggested.

...And now we also need "dark energy" to make the "dark matter" work?

(also, i am irked that I can't always remember the meaning of a linguistic term, yet i can always recall how i heard of that)

Since the new interpretation of the constitution gives a carte blanche to religion,

?
In the USA?

When did that happen?

(i swear, i take my eyes off the news for three weeks, and everything happens...) *sigh*

It's also sadly accurate. I probably suffer from hypergraphia. My compulsive list making may well be the death of me.

Only the lists are made into books which then fall - but I believe you'll be more careful than to let that happen.

[bradrn]

I'm not sure what you mean by "non-intuitive geodesics, which is where gravity comes from"

To simplify: a ‘geodesic’ is the shortest path between two points. On the Cartesian plane, these are straight lines. But they don’t have to be: on the surface of a sphere, the geodesics are great circles. (And to be perfectly clear, the surface of a sphere is a 2D coordinate system! The geodesics may look straight when you embed that surface in 3D, but not when you e.g. look at a map projection onto a 2D Cartesian plane.)

Now, general relativity states that spacetime is a curved manifold. In particular, it is a manifold where the motion of an object under the influence of gravity alone traces out a geodesic. That is to say, what we interpret as gravity is merely the fact that spacetime is a coordinate system with nonzero curvature, and so objects trace out those curved geodesics in the absence of external forces.

[Coordinate systems are] mathematical abstractions and don't exist. You can create any wacky coordinate system you want, and it won't respond to gravity, or create gravity, because mathematical abstractions are not physical things.

Now we’re getting into philosophical territory. Are mathematical abstractions physical things? I tend to reject such questions entirely as being category errors — that pesky word ‘are’ causes trouble when we’re trying to be precise. I prefer to say that ‘mathematical abstractions describe physical things’, and leave it at that.

No one understands why gravity can affect spacetime itself …

Another category error. Gravity does not ‘affect’ spacetime — gravity is spacetime! (Or at least, part of spacetime.)

Math is not physics.

True, but physics is maths. Specifically, physics is merely the mathematics which describes physical phenomena (plus associated experiments, of course). If you want some proof of this, feel free to ask me about the research I’m doing right now. Or perhaps just have a look at the resource I’ve been using: https://oceanopticsbook.info/. (Which, incidentally, I can recommend as surprisingly excellent, even in the less mathematical sections!)

And "empty space" is not empty— it is a froth of quantum events, and it has mass— at least, that's one interpretation of dark energy.

We don’t know this. We think it might have mass, but ah, that’s when the maths blows up, so we can’t quite be certain of anything yet.

We know even less about dark energy than we know about dark matter. And given all this stuff, and the long-term inability to get a quantum theory of gravity, we don't understand gravity very well.

Indeed; I never disagreed with this.

Sure, but you wouldn’t have been re-using it for the same thing, was my point. This was the point of my parenthetical at the end: physicists like keeping their terms as consistent and well-defined as possible.

Yes, except when they totally change their definitions. Any my point is that they are completely free to do so, because that's how language works.

The only consistent rule about how language works is that it’s determined by its speakers. And physicists conventionally keep terms unambiguous, or at least reasonably close to previous usages. This is helped by the fact that terms tend to have precise and formal definitions in terms of mathematics, so this is more feasible than it would be in a field like linguistics.

This is actually a really important point, because it allows us to talk about falsification. I could never say that, for instance, ‘serial verb clauses do not exist’, because ‘serial verb clause’ never referred to any one specific thing in the first place. The most I could say is that ‘the term “serial verb clause” is not a helpful or a coherent concept’. By contrast, we can easily say that ‘the aether does not exist’, because ‘the aether’ has always referred to a specific thing, the existence of which we disproved.

(Of course, laypeople can and do change the meaning of words and phrases — just look at what happened to the ‘quantum jump’! — but we’re talking physics here, not anything else. And the usage of language in the field of physics is determined by the linguistic conventions which are accepted amongst physicists.)

FWIW, this bit from Wikipedia makes exactly the point I was making-- some physicists find that "ether" and "spacetime" are not so different concepts as they are usually described.

For Einstein, I feel that https://doi.org/10.1088/2058-7058/14/6/33 summarises it well:

Largely to please his revered father-figure, Hendrik Lorentz, who was passionately attached to the ether concept, Einstein agreed that the word could be used to describe the space-time structures, so long as it was understood that the new ether lacked a key property of the old: the concepts of rest and motion are quite inapplicable to the new, relativistic ether … Einstein's "new ether" is just space-time endowed with the physically distinctive properties ascribed to it by general relativity [namely the stress–energy tensor]

That is, Einstein’s ‘new ether’ becomes just another word for ‘spacetime plus the energy within it which causes its curvature’. In other words, it was crucially different to the previous notion of the aether (which I’d summarise as ‘a substance at rest which acts as a medium for electromagnetic waves’), because it had nothing to do with electromagnetic waves, and was barely even a ‘substance’ — insofar as that last term means anything anyway. I find it telling that no other physicist adopted this terminology, even though it was proposed by Einstein itself and came not long after the heyday of aether theories. (And the suggested use of ‘aether’ for the vacuum state runs into all the same issues.)

...And now we also need "dark energy" to make the "dark matter" work?

No; the two are different things.

[Raphael]

Since the new interpretation of the constitution gives a carte blanche to religion,

?
In the USA?

When did that happen?

(i swear, i take my eyes off the news for three weeks, and everything happens...) *sigh*

See the latest discussions in the "What are you reading, watching, and listening to" thread, starting with my post here:

https://www.verduria.org/viewtopic.php?p=67477#p67477

For a short overview, you might check out the first part of the document I link to there.

[alice]

I'm hereby stealing the idea of reusing 'ether' for 'spacetime' for conlanging purposes.

There are also plenty of interesting potential analogical chemical uses, too.

[Raphael]

I'm hereby stealing the idea of reusing 'ether' for 'spacetime' for conlanging purposes.

There are also plenty of interesting potential analogical chemical uses, too.

19th-century physicists should have figured out that there were flaws in their theories by simply observing that we do not constantly drop to the floor after losing consciousness as a result of all the ether around us.

[keenir]

...And now we also need "dark energy" to make the "dark matter" work?

No; the two are different things.

That was kinda my point: we invented "dark matter" to make a few of the equations with galaxies' rotations work, and now to make the "dark matter" equations work, brought about the invention of "dark energy".
(two totally different things...that we have no idea what either of them are; thats not worrying in the slightest)

[zompist]

I'm not sure what you mean by "non-intuitive geodesics, which is where gravity comes from"

To simplify: a ‘geodesic’ is the shortest path between two points. On the Cartesian plane, these are straight lines. But they don’t have to be: on the surface of a sphere, the geodesics are great circles. (And to be perfectly clear, the surface of a sphere is a 2D coordinate system! The geodesics may look straight when you embed that surface in 3D, but not when you e.g. look at a map projection onto a 2D Cartesian plane.)

Yes, Brad, I've been reading physics books for fifty years. That's why I mentioned that coordinate systems can be curved.

[Coordinate systems are] mathematical abstractions and don't exist. You can create any wacky coordinate system you want, and it won't respond to gravity, or create gravity, because mathematical abstractions are not physical things.

Now we’re getting into philosophical territory. Are mathematical abstractions physical things? I tend to reject such questions entirely as being category errors — that pesky word ‘are’ causes trouble when we’re trying to be precise. I prefer to say that ‘mathematical abstractions describe physical things’, and leave it at that.

Honestly if you're going to nitpick the word "is", you're simply looking to attack, not to converse. Yes, I could have put in all sorts of nuances about what "existing" means. Nothing you've said acknowledges what I was saying, which is that gravity does not affect mathematical objects. Nothing about the number two changes if it's "near" a large mass... it can't be near anything except another number. That is not how spacetime works.

No one understands why gravity can affect spacetime itself …

Another category error. Gravity does not ‘affect’ spacetime — gravity is spacetime! (Or at least, part of spacetime.)

That's one way of looking at it, but a) it doesn't deal with why spacetime is deformed by mass, and b) as you agreed, we don't really understand gravity, so saying "what it is" is overblown.

Analogies can be misleading, but let's try: if you were a sailor you'd see the ocean as a curved 2-D surface, and the shortest path to your destination is a curve. For purposes of surface navigation, you never need to wonder why all paths are curved— you make your spherical model and you're done. But we can ask why you can't actually go in a straight line, and provide an answer (there's a planet in the way). On another level, we can explain why planets have the shape they do.

Math is not physics.

True, but physics is maths. Specifically, physics is merely the mathematics which describes physical phenomena (plus associated experiments, of course).

I understand what you mean, but I hope you realize that math is not philosophy, and when scientists try to do philosophy of science, they're as able to tie themselves in knots as anyone else. E.g. look at the last hundred years of argument over measurement and QM. And you do know that physics is not just math, because you later talk about falsification, which is humanistic procedure, and ultimately ethical.

As I said, I've read physics, so I totally get the feeling that we should forget the words and just grok the underlying equations. But I'm sorry, it's a feeling, not even a philosophical stance. Once you start saying that the equations "are" anything, you're deep in ontology.

And just to be clear, gazing at the equations can keep you out of some trouble— that was one of Feynman's points. If you start reifying Ψ, you end up confusing probabilities with actual particles and may end up believing Everett. (Apologies if you're an Everettian— but if you are, many-worlds is not math, it's philosophy.) But, you know, Feynman was also very good at using words, at relating the math to actual things in the world (something students memorizing the equations don't always grasp), and for that matter invented what he called a "dippy process" to make QED actually calculable. (Renormalization is more difficult for your "physics is math" position than Ψ, because the whole point is that there is a whole series of possible renormalizations, depending on what you use as a lower bound on distance— and if you try to extrapolate to infinitesimals, the whole things blows up. Which renormalization process is "real"?)

This is actually a really important point, because it allows us to talk about falsification. I could never say that, for instance, ‘serial verb clauses do not exist’, because ‘serial verb clause’ never referred to any one specific thing in the first place.

You should really know more about linguistics by this point! Linguists also talk, possibly way too much, about philosophy of science. Now, it's highly questionable to try to treat all science as if it's physics— see Ernst Mayr, a biologist, on this. But yes, linguistics can make predictions, and those can be verified or not. And if you think the problem is that terms are not defined, you obviously haven't read Chomsky. I mean, that's probably a good life choice, but on the plus side Chomskyans usually do have definitions of their terms, expressed in structural terms.

That is, Einstein’s ‘new ether’ becomes just another word for ‘spacetime plus the energy within it which causes its curvature’. In other words, it was crucially different to the previous notion of the aether (which I’d summarise as ‘a substance at rest which acts as a medium for electromagnetic waves’), because it had nothing to do with electromagnetic waves, and was barely even a ‘substance’ — insofar as that last term means anything anyway. I find it telling that no other physicist adopted this terminology, even though it was proposed by Einstein itself and came not long after the heyday of aether theories. (And the suggested use of ‘aether’ for the vacuum state runs into all the same issues.)

Thank you for showing my point so exactly. Physicists could have adopted Einstein's redefinition; if they did, all your books would talk about ether rather than (or in addition to) spacetime, and they'd say that Einstein redefined how the ether was understood, and all the underlying math would be the same. The world would not be worse, and perhaps better, in that people would be a little less tempted to dismiss Einstein's achievements as just "proving that ether doesn't exist."

[alice]

I'm hereby stealing the idea of reusing 'ether' for 'spacetime' for conlanging purposes.

There are also plenty of interesting potential analogical chemical uses, too.

19th-century physicists should have figured out that there were flaws in their theories by simply observing that we do not constantly drop to the floor after losing consciousness as a result of all the ether around us.

Although referring to it by its correct name "ethoxyethane" is a bit less catchy, admittedly.

[zompist]

19th-century physicists should have figured out that there were flaws in their theories by simply observing that we do not constantly drop to the floor after losing consciousness as a result of all the ether around us.

This is almost the plot of one of Arthur Conan Doyle's Prof. Challenger series, which is deservedly less well known than Sherlock Holmes. The story: the Earth goes through a spot of poisonous ether and everyone is knocked out, except for Challenger and his friends who are provided with oxygen tanks. They are all sad that everybody else died, but in the end it turns out the rest of the world recovered. Recounting this I don't know how he dragged this idea out to book length.

[Ares Land]

19th-century physicists should have figured out that there were flaws in their theories by simply observing that we do not constantly drop to the floor after losing consciousness as a result of all the ether around us.

This is almost the plot of one of Arthur Conan Doyle's Prof. Challenger series, which is deservedly less well known than Sherlock Holmes. The story: the Earth goes through a spot of poisonous ether and everyone is knocked out, except for Challenger and his friends who are provided with oxygen tanks. They are all sad that everybody else died, but in the end it turns out the rest of the world recovered. Recounting this I don't know how he dragged this idea out to book length.

I remember the Lost World as an okay-ish book; I didn't know there were sequels. From what you describe it's probably for the best that they were forgotten