Researching a cosmic mystery like dark matter has its downsides. On the one hand, it's exciting to be on the road to what might be a profound scientific discovery. On the other hand, it's hard to convince people it's worth studying something that's invisible, untouchable, and apparently made of something entirely unknown.
While the vast majority of physicists find the evidence for dark matter's existence convincing, some continue to examine alternatives, and the views in the press and the public are significantly more divided. The most common response I get when I talk about dark matter is: "isn't this just something physicists made up to make the math work out?"
The answer to that might surprise you: yes! In fact, everything in physics is made up to make the math work out.
[...] This level of abstraction is especially apparent in particle physics, because the existence or non-existence of a single particle on a subatomic scale is a rather fuzzy notion. The equations describing the motion of an electron through space don't actually include a particle at all, but rather an abstract mathematical object called a wavefunction that can spread out and interfere with itself.
Is it ever true, then, to say that an electron is 'real' when it's in motion? If we believe that electrons are real things, have we just made up the wavefunction to make the math work out? Absolutely – that was, in fact, the whole point. We couldn't get the equations to work if the electron was a solid, isolated particle, so we made up something that wasn't, and then the numbers started making sense.
It may be that in the future, we find some solution that we prefer to a wavefunction and we abandon that concept altogether. But if we do, it will be because the math stopped working out: we'll have some experimental or observational result that doesn't add up when we put the data into our current equations. Then, if we're doing our jobs right, we'll find a new set of equations that better describe the electron's behaviour, and we'll give those equations names and conceptual analogies and textbooks will be written saying "this is what's really happening."
[...] While the way we observe something determines what kind of data points we can use, in the end, everything we do is to make the math work out. We certainly hope that all this calculating brings us a better description of reality, but the mind of God is best left to the philosophers; we don't have an equation for that.
(Score: 4, Interesting) by DannyB on Monday March 06, @04:49PM (10 children)
I am reminded of Luminiferous aether. [wikipedia.org]
But on a more serious note:
It isn't just that the numbers start making sense. It is that reality makes sense in practical ways. The Edison Effect [wikipedia.org] showed some practical things about electrons. The glass diode bulb with a filament had practical (and patented) applications.
As I understand it, semiconductors are the result of an understanding of quantum behavior of electrons [soylentnews.org] (and "holes") in the doped semiconductor materials.
Quantum Cryptography is based on the understanding about the polarization behavior of individual single photons.
The two slit experiment becomes more interesting when done with single individual photons or electrons.
Even relativity is unintuitive to us in an everyday sense of how things work. Yet GPS must be compensated for relativity in order to work.
So bottom line: WHY is it so difficult to convince people it's worth studying something that's invisible, untouchable, and apparently made of something entirely unknown?
Europe's "Apollo Project" was the LHC. They spent a good deal of money on that to study things are are invisible, untouchable and apparently made of something entirely unknown (to most people).
Chat GPT, I would like to introduce you to the LHC.
How often should I have my memory checked? I used to know but...
(Score: 0) by Anonymous Coward on Monday March 06, @05:16PM (4 children)
The difference with the aether is that observations were made to try to confirm something that the mathematics says must be there (based on the "common sense" assumption that some medium has to be carrying the wave disturbances), while with dark matter we're looking for the mathematics to explain what the observations are showing us.
(Score: 2) by PiMuNu on Monday March 06, @05:23PM (3 children)
I disagree - a medium for light to propagate is needed to explain superposition, which is an experimental phenomenon (i.e. if you cross two coherent light waves, the waves add up in the "peaks" and subtract in the "troughs" so you end up with a diffraction pattern).
(Score: 2) by Immerman on Tuesday March 07, @03:10AM (2 children)
No it's not. In fact the existence of the aether was pretty thoroughly disproven a long time ago, and conflicts with relativity since a medium has an innate velocity, a preferred reference frame.
That's based on the idea that a wave can only propagate in a medium. Which is intuitively obvious, but it the last couple of centuries of science have taught us anything, it's that our intuition is *really* bad at understanding the fundamental nature of reality. Intuition is based on an understanding of how the world works at the scale we operate at - maybe micrometers to kilometers. Get far outside that range though and we'll guess wrong more often than that. The rules that dominate the universe at those scales and energies just don't bear any real resemblance to the ones that dominate the world we operate in.
A medium for light hasn't been needed since the existence of radio waves was confirmed (initially as a theoretical curiosity with no possible practical value, just to verify a weird corner case of Maxwell's equations) . They are the same thing as light, and are not a wave *in* anything, but are a wave *of* electromagnetism. A self-propagating assembly of perpendicular electric and magnetic fields traveling through space. Kind of like a far more elegant Minecraft missile.
Quantum wavefunctions are the same - just because a wave exists, doesn't imply that the wave is *in* something. As far as we can tell it just *is*, there's no evidence of any medium.
(Score: 2) by PiMuNu on Tuesday March 07, @10:56AM (1 child)
I don't really see how the LA is anything but a field theory. A medium that one cannot see or feel within which light waves can propagate. To put it another way, there is no experimental way to distinguish between LA and a classical field theory. One can say that LA "just is", same as a field.
I realise that LA is in contradiction with both special relativity and general relativity (but not Galilean relativity, I don't think). I realise that quantum theory has quantisation as a thing, which LA does not. That was the whole point of the thread.
(Score: 2) by Immerman on Tuesday March 07, @03:54PM
Fields don't impose a preferred reference frame, mediums do. A medium is by definition made of "stuff", and stuff has a velocity that will affect anything traveling through it.
(Score: 5, Insightful) by PiMuNu on Monday March 06, @05:20PM (4 children)
Your example of Luminiferous Aether (LA) is exactly the point; the concept of light passing through some medium makes sense. A modern analogue for LA might be exactly the (non-relativistic) wave function. This is essentially an LA.
LA only gets dumped when someone (Michelson and Morley) made a measurement that showed that light propagates at the same speed regardless of the speed of the earth relative to the proposed LA. Therefore the equations no longer describe correctly the measurements and we dump the equations. 10 years later Einstein came along with a mathematics that fits the Michelson Morley experiment.
This is how physics work. We choose a model that best fits the measurement, until someone more clever comes along with a better model or the experimentalists nail a measurement that shows it is very wrong (and then we need a clever maths guy to fix the model).
The Dark Matter sceptics are happy to complain about the model, but no one (MOND proponents included) have a better model. Meanwhile, for a particle physicist the model seems quite natural and it fits with lots of experimental data.
(Score: 2) by DannyB on Monday March 06, @05:37PM (3 children)
And THAT is why it is worth studying things that are invisible, untouchable, and apparently made of something entirely unknown.
That's why I picked Luminiferous Aether because it seemed like a good idea for a while. So do Newton's laws until you realize they are an approximation for relativity at low velocities.
There are enough examples with practical applications that it seems strange today that there would even be an argument that these invisible things are worth studying.
"Why should we subsidize intellectual curiosity?" -Ronald Reagan
How often should I have my memory checked? I used to know but...
(Score: 2) by PiMuNu on Monday March 06, @06:15PM (2 children)
Thanks - I misunderstood the direction of your comment. Yes, absolutely we should study this stuff. It is apparently* a completely unknown form of stable matter in the universe. It is imperative that we find out what it is made of.
*modulo TFA, that we don't really know what it is.
(Score: 2) by DannyB on Monday March 06, @06:49PM (1 child)
Quantum Mechanics was inspired by how banks work.
Your money only appears to be in the bank's safe when you look at it.
Otherwise, when unobserved, it is not actually there but lent out to someone else.
How often should I have my memory checked? I used to know but...
(Score: 0) by Anonymous Coward on Tuesday March 07, @03:13AM
Not only simpler, iteration is also faster for short (few hundred elements) lists (how much depends on the hash function and data, obviously). Trees often outperform hashes if inserts are rare and can be vastly superior in memory demands. Hashes are like linked lists: loved by CS professors, but not the best solution for most real-world problems.
(Score: 2, Informative) by Isia on Monday March 06, @06:03PM (5 children)
What's Going Wrong in Particle Physics?
Well, people doing things wrong.
Very good video from Ms. Hossenfelder about the topic: https://www.youtube.com/watch?v=lu4mH3Hmw2o [youtube.com]
(Score: 4, Interesting) by aafcac on Monday March 06, @06:39PM (3 children)
If you think that's bad, just look at string theory. It's been around for decades, and I don't think they've come up with a single testable hypothesis. (If I'm wrong, then it's still such a small number as to be countable on one hand without using all my fingers)
There is some benefit to the fancy math in that it can be applied to other things, but it's not science to make predictions and then hand wave them away as being in a different dimension or not really what you're talking about.
(Score: 2) by PiMuNu on Monday March 06, @07:05PM (2 children)
Yes, but no reasonable physicist believes in string theory.
(Score: 2) by aafcac on Monday March 06, @07:14PM (1 child)
True, but it does suck up research dollars that could be used for actual science. I'm not sure why we don't have an applied astrology department if we don't need to get results ever.
(Score: 2) by PiMuNu on Tuesday March 07, @11:01AM
Theorists are cheap compared to hardware people, and they might produce some maths which is useful elsewhere; or train some graduates who do some useful banking when they get their PhD.
(Score: 3, Insightful) by PiMuNu on Monday March 06, @07:02PM
It's an interesting video, but she is quite skewed in her view. Funding and effort has, historically, pursued those places where the standard model does not fit the data or some prediction is not observed. She conflates theorists with experimentalists. These are two quite different groups.
The LHC discovered the Higgs boson. The tevatron discovered the top quark. LEP measured W/Z boson (for example confirming three neutrinos). SLAC measured CP violation. She doesn't point this stuff out. Sure theorists write papers on random wacky particles; but the investment in theorists is small (one LHC buys about 10,000 theorist-years of effort).
Top level funding continues to follow the holes in the standard model. For example neutrino oscillations do not fit the standard model and this is where the next round of funding is going (DUNE and T2HK for example). Dark matter is another example where we have an observation and no theory, so we can push (although there is not currently big money in dark matter, because the parameter space is too big for a directed search).
Second tier funding pushes at the standard model to look for holes. In her "graph", they are trying to put some data points on the standard model graph on the right hand side, to inform the theorists. Examples are g-2, where we see a "4 sigma" deviation from the standard model. Probably there will be a top tier funding in the "next but one" round to study the Higgs boson in detail.
I guess it's the second tier funding that she is complaining about. This is where the theorists invent a wacky particle, or look heuristically and say "this is an interesting parameter to study because" and then the experimentalists build an experiment to measure the parameter in more detail than was done previously. I think that is a reasonable approach, but she doesn't seem to like it. She carefully avoids proposing a better approach, I notice.
(Score: 2) by mcgrew on Monday March 06, @06:04PM (2 children)
People don't believe what they can't understand. Good luck describing the color red to a man born without eyes.
Carbon, The only element in the known universe to ever gain sentience
(Score: 2) by DannyB on Monday March 06, @06:53PM
Yet THOSE people will believe all kinds of outlandish things if they hear it from the right people. Good luck describing how vaccines protect against an invisible virus or bacteria.
How often should I have my memory checked? I used to know but...
(Score: 0) by Anonymous Coward on Tuesday March 07, @05:59AM
One of the great embarrassments of physics is the pride taken in the incomprehensibility of quantum mechanics. It's like a cancer - if you don't need to understand it then why bother trying to understand the next thing or the next thing. Then you end up with pompous charlatans in bowties debating creationists, and waistcoated professors doing talk shows. Yes Bill Nye "the science guy" (as scientists call him) and Neil de Grasse Tyson I am looking at you....
(Score: 3, Interesting) by aafcac on Monday March 06, @06:36PM (5 children)
That's not really how it works. We had to abandon epicycles because that's not what was happening with the motion of the planets. The planets are revolving in an elliptical orbit around the sun and the mathematical formula isn't what forced us to abandon the previous belief. We abandoned it because the earth isn't the center of the universe and it's also not the center of the solar system. No amount of math would ever adequately explain the motion of the planets relative to the Earth without going to extreme lengths and using really weird reference frames where basically everything except the earth is moving in weird ways.
In other words, it's not because the math didn't work out that the view changed, the math not working out was a hint that we might not be looking at things correctly and that a different model was likely needed. As much as I like math, the fact of the matter is that it allows all sorts of things that logically don't make any sense and it requires people to look at it and recognize that. We then either set limitations on the domain for the formula or we look for one that better represents what is being observed.
Compare that with the work that's currently being done entirely based on math without the ability to evaluate the accuracy of the predictions any time soon. By the time that we know if some of the fancy math is applicable to the real world, we might all have died of old age and most of us will certainly have retired. If it comes out to be reliable, then great, but if not then we've created a multigenerational house of cards that could come crashing down at any time, requiring that anything that relies on the wrong bits be reevaluated and possibly redone. Not exactly the most scientific way of handling science.
Ultimately, the goal of the math is always to model what we get from experimental evidence. Sure, it might be a bit off at times, but with time it's supposed to be getting closer to making reliable predictions. The slight difference between classical mechanics and what relativity gives you when you're calculating somebody's velocity while walking on a train isn't likely relevant in most cases. But, if you really need the extra precision, there's nothing stopping you from using relativity to make the calculations. You'd just likely run into issues of being able to make measurements with suffiicent precision and accuracy to see the difference.
(Score: 2) by PiMuNu on Monday March 06, @07:07PM (1 child)
If you are referring to string theory (as per your comment above) - don't damn the whole of particle physics based on a niche theory that no one believes.
(Score: 2) by aafcac on Monday March 06, @07:18PM
I don't think that physics in general is that bad. My point is that it's only been within the last couple decades where the engineering was developed to be able to test some of the work that Einstein had done, and he's been dead since 1955. I do think that the work probably will pan out, or at least be close enough to not require major revisions, but without the ability to conduct the necessary experiments, there is always going to be a risk that everybody missed something. I mean, it took how long before Euclid's fifth postulate was finally set aside? Prior to that a lot of work was done that was close enough, but wouldn't have allowed for much of what's been done in the years since. Fortunately, for the things that we were doing the simpler models were sufficient.
(Score: 1) by shrewdsheep on Tuesday March 07, @11:08AM (2 children)
Every physicist will tell you, it is just a matter of choosing your coordinate system. BTW, how do you define universe?
(Score: 3, Interesting) by aafcac on Tuesday March 07, @12:48PM (1 child)
Yes, and I did mention that we could have defined things with respect to the earth and had math that was effectively impossible to work with using 17th century tools for performing calculations or at least ones so complicated that nothing would ever get done.
If that's the standard, then pretty much all of this is moot.
As far as the universe goes, you don't need that to define a center. The logical place to put it is the place where things are moving away from. I'm well aware that the observable universe isn't necessarily the entire universe and that it's kind of strange that things are expanding more rapidly over time.
(Score: 0) by Anonymous Coward on Thursday March 09, @01:08AM
Based on science I'm the center of the observable universe (that's observable to me). 😉
(Score: 2) by Mojibake Tengu on Monday March 06, @08:48PM (3 children)
Both Mathematics and Physics are just a kind of Symbolatry.
Yes, that's a real word:
https://en.wiktionary.org/wiki/symbolatry [wiktionary.org]
https://www.definitions.net/definition/symbolatry [definitions.net]
Some 50000+ years forward, no matter if it survive current petty political clashes or not, our civilization may be denoted as The Cult of Lagrangian symbols, and mocked for only a weak understanding of reality.
Faction of Physics is just a sect of this cult.
The edge of 太玄 cannot be defined, for it is beyond every aspect of design
(Score: 2, Redundant) by PiMuNu on Tuesday March 07, @11:03AM
No they aren't.
(Score: 2) by Freeman on Tuesday March 07, @02:46PM
E=MC² has a meaning. Most (maybe not all) people aren't worshiping the symbols we use to denote mathematical equations or the like. There's certainly the possibility that some do, but the symbols were created to convey information and that information wasn't "and the holy speed of light shall be called C neither shalt it be called E nor M, lest it be naughty in thy sight". Yes, that was a very bad take on Monty Python and maybe a little sacrilegious, but the point is made.
Joshua 1:9 "Be strong and of a good courage; be not afraid, neither be thou dismayed: for the Lord thy God is with thee"
(Score: 2) by aafcac on Tuesday March 07, @06:19PM
Mathematics has a language component, but if we're going down this rabbit hole, it's arguably more accurate to describe it as applied logic. Mathematics is essentially a language for the creation and generalization of models. The symbols are just much more concise.
(Score: 4, Interesting) by Beryllium Sphere (r) on Monday March 06, @09:56PM (4 children)
Someone was talking with him, and he refused to say that electrons exist. What he said boiled down to, they are the story we tell to explain experiments with oil drops and evacuated tubes, and we'll have to throw out that story if another works better.
(Score: 3, Funny) by maxwell demon on Tuesday March 07, @05:08AM (3 children)
I haven't ever seen anyone who's posting here (with the exception of myself, of course), only their posts. Thus I can't say anyone here actually exists. I mean, sure, it is the currently best explanation I have, but in the end, AI might be much further than I think, and this whole site may be a big AI experiment, with me as only human participating. Well, assuming that I actually am a human, and not an AI that merely thinks it is a human. After all, how do I know my body and the environment it's in isn't some fancy computer simulation made to make me think I'm human?
The Tao of math: The numbers you can count are not the real numbers.
(Score: 0) by Anonymous Coward on Tuesday March 07, @06:02AM
Descartes figured this all out 400 years ago... or perhaps it was just a dream...
(Score: 2) by Freeman on Tuesday March 07, @02:56PM (1 child)
One can only assume that programs can't be sentient and thus, you're not a computer simulation. In the event that a computer program could be sentient, all bets are off. As one could be constrained by the bounds of the program and never know it. Still, you can use your experience and existence as basis of a "I think therefore I am" kind of realization. Also, you could weigh the probabilities, but it ultimately boils down to, you can't know.
Joshua 1:9 "Be strong and of a good courage; be not afraid, neither be thou dismayed: for the Lord thy God is with thee"
(Score: 0) by Anonymous Coward on Wednesday March 08, @09:11AM
I know I experience consciousness. and that's actually the only thing that I can be 100% sure of, everything else could be an illusion. I don't know about the rest of you. Maybe you all don't actually experience it. I've had responses from some commenters that make me doubt that they experience the same thing that I do - they might have some sort of self-awareness but they don't seem to experience the same thing - to me you'd know it if you do.