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Physicists finally nail the proton’s size, eliminating an anomaly

quantamagazine.org

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Re: Physicists finally nail the proton’s size, eliminating an anomaly

#41

Post by brummm »

Bostonian wrote: post #4

I think in some areas of physics, such as high-energy physics, there is not much left to discover. The Standard Model works. What branches of physics are likely to see progress?

There are lots of unexplained things that we already know about that are outside of the standard model. For example:

- The standard model doesn't explain any of the rest masses of the fundamental particles nor any of the coupling constants and a bunch of mixing angles. I think in total there are more than 30 input parameters that are completely unexplained

- Neutrino oscillation/masses are NOT part of the standard model as it predicts them to be massless

- Gravity is just not part of the standard model and currently cannot be combined properly with the other fundamental interactions

Re: Physicists finally nail the proton’s size, eliminating an anomaly

#42

Post by cthalupa »

Sharlin wrote: post #20
certifiedloud wrote: post #9

Earlier quoted context omitted.

Einstein's theory hasn't yet been reconciled with quantum theory. That's a good place to watch for progress.

Not really sure about that. Physicists are getting really frustrated by the fact that the LHC has found exactly the missing piece that the SM predicted (the Higgs) and zero evidence of any physics beyond that, anything that would get us closer to quantum gravity. No strings, no supersymmetry, not even any hints as to the nature of dark matter. All it has done is give new lower bounds to the energy scales at which som…

>For all we know, we might need a solar system size collider to attain the required energies.

We just need to observe the collisions happening at these energies - we don't necessarily need to produce them ourselves.

Some physicists are starting to think about how we might be able to observe naturally occurring collisions at these energy levels rather than producing them ourselves.

Re: Physicists finally nail the proton’s size, eliminating an anomaly

#43

Post by auntienomen »

Bostonian wrote: post #4

I think in some areas of physics, such as high-energy physics, there is not much left to discover. The Standard Model works. What branches of physics are likely to see progress?

The Standard Model works with two significant asterisks. It is almost certainly not mathematically consistent, due to the presence of Landau poles in the hypercharge and in the Higgs self-coupling. It also does not include gravity. Neither of these caveats is a problem at experimentally accessible energies, but they do indicate that there's something left to discover. It's a bit irritating: We know we're missing something. We just don't know what.

Re: Physicists finally nail the proton’s size, eliminating an anomaly

#44

Post by jarfil »

qws wrote: post #10
Bostonian wrote: post #4

I think in some areas of physics, such as high-energy physics, there is not much left to discover. The Standard Model works. What branches of physics are likely to see progress?

Someone please help correct my intuition here: the harder it is to find flaws in the Standard Model, the harder it would be to use such new physics in engineering. Basically I'm curious whether continuing failures to find new physics can be taken as evidence that, if and when we find the new physics, it will be very difficult to apply. I'm not against science for its own sake, however. Just more of an engineer than a…

Depends on the kind of difficulty. If it's quantitative, as in requiring orders of magnitude more energy, mass or time, then yes.

But it might be just more difficult qualitatively, like some different and non-intuitive way of interpreting everything, which might only require switching a few equations and changing some procedures.

Re: Physicists finally nail the proton’s size, eliminating an anomaly

#45

Post by WhitneyLand »

ur-whale wrote: post #21

I wish a physicist could explain here how the very notion of "diameter" has any meaning for an object whose size (IIUC) belong entirely to the quantum realm. Is the hydrogen atom two hard little balls of matter orbiting one another, as we were taught in primary school, or are they a probabilistic soup with various, vaguely localized extrema? If the latter, how do you even define the notion of diameter?

It may be simpler to start our not thinking of particles as matter, but instead thinking of them as little energy fields. Like a magnetic field, a particle has properties and interacts with some things and not others. This is why it's a "field theory".

Say you had ten different light bulbs. Could it make sense to talk about their differing light output as "diameters"? It wouldn't be defined in terms of a physically measured length of the bulbs, rather a diameter could be defined to be about properties of a light bulb.

Remember all these words are in some ways arbitrarily chosen by people. If you replaced the word diameter everywhere with "fat content" would all the math still work?

The math would still work fine. The problem would be it's even less understandable than diameter, and it makes it less efficient as an abstraction that you can grok and reason about.

Re: Physicists finally nail the proton’s size, eliminating an anomaly

#46

Post by RandomTisk »

cthalupa wrote: post #38
RandomTisk wrote: post #18

Earlier quoted context omitted.

Worse are the "best explanations" that get adopted as if they were real observations with militant fervor, something we're seeing with Dark Matter and Energy today. It's gotta be difficult to make progress sometimes when most of your field insists that their best theory must be the correct one.

Please. Millions of dollars are spent every year researching alternative theories and modifications to GR that eliminate the need for Dark Matter and Dark Energy. The problem is, and has always been, that these alternative theories are never as accurate or precise as GR and their observational evidence is never as good as what we have for DM and DE. It's not a conspiracy that scientific consensus is that they both ex…

It's not a conspiracy per se, but it fits into a realm where virtually every single documentary about space these days are making overt or not-so-overt claims that it's absolutely real and we're not even considering other possibilities. Of course we are, but that's not how it gets presented by the vast majority of "television physicists" and I find most documentaries about space completely unwatchable these days. Usually it's presented with unwavering faith that dark matter and energy exist, if only we could detect it. The more humble approach would be "95% of the universe is Dark Matter and Energy, unless one of our assumptions is wrong and we just don't know which one yet". That's honesty you just don't find much in media for public consumption, and if it's wrong (I'm not saying it is), then millions of bright minds are being led down the wrong path. I'm just hoping for more honesty about what we actually observe or what we desperately want to observe in popular (scientific) culture.

Re: Physicists finally nail the proton’s size, eliminating an anomaly

#47

Post by analog31 »

adrusi wrote: post #26
analog31 wrote: post #14

Earlier quoted context omitted.

There's still physics in every successive new digit of the physical constants. The gravitational constant is only known to roughly 5 digits. Get to work!

While it is never safe to affirm that the future of Physical Science has no marvels in store even more astonishing than those of the past, it seems probable that most of the grand underlying principles have been firmly established and that further advances are to be sought chiefly in the rigorous application of these principles to all the phenomena which come under our notice. It is here that the science of measureme…

One thing that's always interested me is that the recent history of breakthroughs doesn't tell you when the next one will arrive. For instance reconciling quantum mechanics and gravity, we don't know if we're within 11 years, 110 years, or even 1100 years!

Re: Physicists finally nail the proton’s size, eliminating an anomaly

#48

Post by cpsempek »

chrisamiller wrote: post #34
vectorEQ wrote: post #3

so, a failure in measurement sparked a mystery which went on for decades. i wonder how often that happens in science ;P

All the time! People propose hypotheses, supported by some preliminary data, and then they need to be tested. Some problems are easy, some take years or decades to be overturned. It's messy sometimes, but that's how science is supposed to work!

I think the parent was being sarcastic, hence the ;P emoji at the end of the post.

However, I wanted to commend your reply. It seeks to educate without judgement. Cheers.

Re: Physicists finally nail the proton’s size, eliminating an anomaly

#49

Post by earthboundkid »

cthalupa wrote: post #38
RandomTisk wrote: post #18

Earlier quoted context omitted.

Worse are the "best explanations" that get adopted as if they were real observations with militant fervor, something we're seeing with Dark Matter and Energy today. It's gotta be difficult to make progress sometimes when most of your field insists that their best theory must be the correct one.

Please. Millions of dollars are spent every year researching alternative theories and modifications to GR that eliminate the need for Dark Matter and Dark Energy. The problem is, and has always been, that these alternative theories are never as accurate or precise as GR and their observational evidence is never as good as what we have for DM and DE. It's not a conspiracy that scientific consensus is that they both ex…

DM and DE matching observational data is like a ML model match its training data. Okay sure, that's necessary, but it's not sufficient to actually believing they're a good model.

Re: Physicists finally nail the proton’s size, eliminating an anomaly

#50

Post by WhitneyLand »

conistonwater wrote: post #11

> If the discrepancy was real, meaning protons really shrink in the presence of muons, this would imply unknown physical interactions between protons and muons — a fundamental discovery. Hundreds of papers speculating about the possibility have been written in the near-decade since. This reminds me of a joke. An experimental physicist walks into a theoretical physicist's office with a really cool experimental result,…

The clever thing about these kinds of jokes as when it happens in politics is, they manage to mock two groups of people such that each group reads the joke and tends to laugh because they infer it as poking fun at the other group.
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