Comment by fabatka
7 years ago
> and it could break physics as we know it.
Stopped reading there. I hate that a lot of pop-science articles suggest that the foundations of natural sciences are so shaky that a new finding can turn them upside-down. I've lived together with 50-60 social scientists in a small community during my student years, and I found that they don't have the slightest idea about how thoroughly e.g. special and general relativity have been tested in controlled experiments and every day when they use gps in their smartphones. For them these theories may be true, but who knows? I find it really sad that media that are supposed to bring sciences closer to non-scientists fail this way.
EDIT: added last sentence
> a lot of pop-science articles suggest that the foundations of natural sciences are so shaky that a new finding can turn them upside-down
Dark matter, Dark energy, The cosmological constant problem [1], Quantum entanglement, Quantum gravity...
[1] https://en.wikipedia.org/wiki/Cosmological_constant_problem
The foundations are shaky. Of course it's an easy rhetoric tool to use by journalists, but often they are not wrong, if those claims turn out to be true.
That's not so much a crack in the foundation as it is a patch of dirt next to the foundation.
To get an idea of what happens to old physics when new physics is discovered, realize that Newton's laws are still correct, and can be derived from QM. That's what you get when you do a good job of actually checking the truth with experiments. All theories have implicit tolerances embedded within the known precision of the experiments used to confirm them, and with these tolerances you can say "Newton's laws are right" without denying other, finer details. Similarly, scientists 1000 years from now will agree with everything we presently know about the Standard Model, because all of our beliefs are tempered by how closely we know our experiments are looking.
>Quantum entanglement
I should add that entanglement isn't "shaky" at all, it was predicted from the start and has been observed in countless experiments to date.
Borrowing from an a old comment of mine:
On one hand, on some scales, Newtonian mechanics is correct "enough" to give results that work, and so in that sense it is just incomplete in that its domain is restricted. On the other, relativity and QM change everything. These new theories may reduce to Newtonian mechanics given certain assumptions, but Newtonian physics assumes things about the structure of spacetime that are fundamentally incorrect (e.g. velocity is not additive). In this sense, one can fairly say that Newton's mechanics are not just incomplete or missing some fine details, but wrong.
I think there is more to the foundations than just the best numbers we can come up with for a given experiment. Our numbers for the gravitational constant, for example, are pretty similar (if more precise) to the numbers in 1891, but the setting in which that number is completely changed. There is no aether, no absolute space, velocities don't add (even though it's "mostly" right on most scales we experience and measure, it is false), space and time get mixed up, etc. Those were all pretty foundational ideas just over a hundred years ago.
4 replies →
The standard model is anything but shaky at the moment.
It's very successful, but It's known to be incomplete, so this is why this article is interesting because it can point to a new theory that alter or event replace the standard model. Also, I linked to the cosmological constant problem, which to me looks like a gaping hole in the theory.
It's amazing that all this math can describe the world we live in and help build us all the modern gadgets we see:
https://www.symmetrymagazine.org/article/the-deconstructed-s...
But on the other hand it looks like spaghetti code written in APL and needs some refactoring :)
2 replies →
There are no more 'revolutions' left for physics? And I'm not talking about tomorrow but imagine a 1000 years from now. It seems a bit arrogant to assume that.
I also dislike the pseudo pop-science, but the visceral close mindedness is just another side of that coin imo.
"overhauled" is not the same as "broken". It's bit arrogant to assume that all those GPS measurements that pinpoint our location will one day be proven wildly incorrect. They clearly aren't. They might be refined, but are not all that wrong. Even Newtonian physics is under many circumstances a close approximation of reality.
Further reading from Dr Asimov: https://chem.tufts.edu/answersinscience/relativityofwrong.ht...
> living in a mental world of absolute rights and wrongs, may be imagining that because all theories are wrong, the earth may be thought spherical now, but cubical next century, and a hollow icosahedron the next, and a doughnut shape the one after.
> What actually happens is that once scientists get hold of a good concept they gradually refine and extend it with greater and greater subtlety as their instruments of measurement improve. Theories are not so much wrong as incomplete.
> Even when a new theory seems to represent a revolution, it usually arises out of small refinements. If something more than a small refinement were needed, then the old theory would never have endured.
The point isn't that you get a few more significant figures of accuracy on a slightly larger set of problems, but that you use completely new tools, techniques, and ideas to tackle completely new classes of problems.
Heliocentrism isn't a "refinement" of geocentrism. It's a completely new way of understanding the universe. The fact that you can make geocentrism work if you make your epicycles complicated enough doesn't change the fact that it's conceptually incorrect, and not a useful way to think about the solar system.
Likewise GR isn't a "refinement" of Newton. It drives a tank through the middle of the Newtonian world view and burns it to the ground. Then it says "New physics, this way" and off it goes, thinking about phenomena that are literally inconceivable in a Newtonian universe.
You can consider GR a more accurate refinement for certain problems only. There's a limited set of problems - large in everyday human terms, but extremely limited in cosmological terms - where Newton gives you all the accuracy you want.
But if your understanding stops there, you're missing the point of these revolutions. They're not about improved accuracy, they're about new world views that give access to entirely new problem classes.
You literally cannot imagine these problems if you consider Newton as a mostly correct foundation and GR as a kind of philosophical epicycle added to it later.
And that means you cannot do useful new physics.
5 replies →
It’s quite possible to have an understanding of something that works in some situations but does not explain every situation. I would say that we have mathematics models of fairly large portions of physics but they are limited because they can’t explain how gravitation works. We can describe how we see it working but not explain how and why it works. I think there will always be new more complete models that encompass more and more of what we cannot explain.
1 reply →
>They might be refined, but are not all that wrong. Even Newtonian physics is under many circumstances a close approximation of reality.
They might become wrong; we assume that the laws of physics are fixed and immutable, that they have operated unchanged for all time so far and will continue to operate unchanged for the rest of time. Some physics acknowledges that that they may change at the edges of time, but it may also be the case that they are subject to sudden radical shifts.
2 replies →
> There are no more 'revolutions' left for physics?
Sounds like how people were talking around the turn of the last century. Then came special and general relativity and quantum physics in about 20 years' time. Not to mention similar revolutions in math.
this writeup by cozzyd just below https://news.ycombinator.com/item?id=18082370 is much better and is exactly why I start reading HN links comments first :)
Physicists would love for some observation to end up breaking physics as we know it.
They know that 99,999/100,000 times something strange is observed, it turns out to be no big deal.
The day something breaks the Standard Model, physicists will cheer and begin a beautiful renaissance... and another... and another.
But can intelligent creatures in a simulation ever understand the scope and rules on which their simulation is based? Or can they only get closer and closer to the substrate, with a hard limit on ever modeling the details?
The answer is no. Gödel's incompleteness theorem is interesting here as it states that within a given axiomatic system, there are facts that are true but not provable within that same axiomatic system.
Another way to think about it is that if we are part of a set of fundamental rules that make up a simulation, it's impossible for us to prove everything about that system.
Is there a loophole?
If the creatures within a simulation can make contact with the creatures (or physics) outside it, then perhaps they can look in from the outside, to get all the information necessary for any proof?
Well, maybe you shouldn't have stopped reading. A particle that is not described by the standard model DOES "break physics as we know it." That phrasing is typical of science journalism hyperbole, but it is accurate in this case.
Perhaps my exact point didn't get through well. I find that exactly this kind of phrasing is what's bad, because I fear that it isn't interpreted as "new physics" or "overhalued physics" as in cozzyd's or SideburnsOfDoom's comments, but rather "look, scientists from Newton through Einstein were proved wrong". And the big issue is when this is followed by the thought "How can we know scientists aren't wrong about [insert issue here]?"
Its like when you open the screen door in summer and a whole swarm of uninvited guests come flying in
There are like dozens of hypothesized particles outside of the standard model. The standard model is not the be all and end all of physics as we know it.
I agree. It is frustrating. These journalists have an incentive to make their articles as sensational as possible.
Doesnt general relativity only predict the right thing if you allow for 90% of the universe to be made of dark matter/energy that is only detectable as deviations from from the predictions of GR?
No. (No, it predicts right things locally; no, dark energy is not in conflict with GR; and probably no on the scale of galaxies, with some assumptions).
We can (and do) test General Relativity to exquisite precision in the solar system.
Those tests constrain the local density of any sort of effectively undetectable matter which includes among other things the (thermal) cosmic neutrino background, lots and lots of relativistic neutrinos, and a fair amount of ultrarelativistic neutrinos (like those that ANITA studies).
Effective undetectability is a function of current technology versus the goodness of estimate of (high) flux of the particles; we can spot small numbers of GZK-interaction neutrinos (with various observatories, including ANITA), we can spot small numbers of Super-KK neutrinos (mostly because we know the path they follow), we can spot small numbers of solar neutrinos (there are A LOT of them and we also know what direction they're coming from), but we have no real hope right now of spotting relic neutrinos (since as we take the momentum to zero, we lose the ability to spot recoil interactions; the emitted photons get drowned out by the CMB; the cosmic neutrinos are also travelling in random directions, like the cosmic photons).
If we take the local density of any of these neutrinos way up, their gravitational effects in the solar system (and indeed in similar systems we can study with various different telescopes) will be pronounced, and straightforward to study with General Relativity.
We do see pronounced gravitational effects at the scale of galaxies; one way to explain them is to add a thin dust of slow-moving mass where the dust motes remain on extremely stable orbits (implying no heating from (photon) radiation, no cooling by emitting (dark? photon? whatever) radiation, and no collisions with ordinary matter dust).
Dark matter is extremely sparse at the scale of star systems -- but then star systems are extremely sparse at the scale of large galaxies! (Likewise, the interstellar medium is extremely sparse, but there's a lot of space among the stars!) Low-interaction is easy enough; Earth is highly opaque to ultrarelativistic neutrinos, but as you take the momentum of the neutrinos down, Earth becomes highly transparent to them (so do telescopes and other instruments, alas, which is why they are hard to observe). (Standard-model) neutrinos are too light to stay in the places where the gravitational effects are observed -- gravitational interactions with the ordinary mass of the galaxy would kick them away. So something else is needed. The question is what, microscopically, it is. However, wishing the gravitational effects away doesn't work, and neither does modifying General Relativity (at least not so far).
In the standard cosmology, Dark Energy is precisely a component of the Einstein Field Equations of General Relativity (it's literally \Lambda, the cosmological constant). So it is entirely the opposite of being in conflict with General Relativity. The research question is mainly why it takes on the value it does, and whether it does so in any sort of spacetime-position-dependent way.
Nothing to take away from your point, but the harsh fact about much of physics especially the modern kind is built on 'Models'. Most of it still remains true in that Model, even if a new Model shows totally different set of truths.
Albert Einstein himself said this about Entropy:
A theory is the more impressive the greater the simplicity of its premises, the more different kinds of things it relates, and the more extended its area of applicability. Therefore the deep impression that classical thermodynamics made upon me. It is the only physical theory of universal content which I am convinced will never be overthrown, within the framework of applicability of its basic concepts.
https://en.wikiquote.org/wiki/Thermodynamics#Second_Law_of_T...
It's just a case of provocative phrasing to hook the reader.
The rest of the article is interesting, does NOT make out-sized claims and even references source material in arxiv for those who are interested.
You're expecting too much from a popular science article!
Michelson-Morley experiment was did with precision of up to 1E-17(!) and found nothing. Distance to Alpha-Centaur is just 4E16 meters. But then LIGO performed roughly the same experiment with precision of 1E-18 and found waves.
One of the reasons that many 'pop-science articles' get things wrong is that they're seldom written by scientists. Scientists who venture into popular writing can be looked down on as 'glory-hounds' by their colleagues. (E.g., George Gamow.)
So it's not entirely the journalist's fault if they don't have the credentials to simplify things adequately without distorting something.
It's just evidence for the existence of hell. Dante's Inferno is a physics treatise.
Hey now, not that long ago, we assumed that the universe had C, P, and T symmetry, but after looking closely at the weak force, have found that our universe only maybe has CPT symmetry. We could still find out that CPT symmetry is bunk.
I agree, this is annoying, but this looks like an editor addition. The title should say 'contradict supersymmetry theory'.