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Is particle physics dead, dying, or just hard?

quantamagazine.org

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Re: Is particle physics dead, dying, or just hard?

#231

Post by albatross79 »

drdeca wrote: post #111
albatross79 wrote: post #97

Why are we even trying to look deeper? To fit our mathematical curves better? Abstract spacetime, fields, virtual particles, wave function collapse, quantized energy, wave particle duality, etc. This is all BS. And I'm not disputing the theories or the experimental results. These concepts are unintelligible. They are self contradictory. They are not even abstractions, they are mutually exclusive paradigms forced toge…

The universe is not obligated to appeal to your aesthetic tastes in its innermost functioning. Maybe you aren’t going to be satisfied with the sort of complicated mathematics which appears to be correct (or, on the right track). If you have complaints about the aesthetics of how the universe works, take it up with God. Personally, I think there is a lot of beauty to be found in it. I’ll admit that there are a few par…

It's not a matter of taste. This is like going to a restaurant, expecting a delicious meal, and being brought a dish with a fancy name made out of the actual menu itself. Would anyone go back there to eat?

Re: Is particle physics dead, dying, or just hard?

#232

Post by empath75 »

andyferris wrote: post #114
tasty_freeze wrote: post #15

Here is one fact that seems, to me, pretty convincing that there is another layer underneath what we know. The charge of electrons is -1 and protons +1. It has been experimentally measured out to 12 digits or so to be the same magnitude, just opposite charge. However, there are no theories why this is -- they are simply measured and that is it. It beggars belief that these just happen to be exactly (as far as we can…

The hint from quantum field theory (and things like lattice gauge theory) is that charge emerges from interesting topological states/defects of the underlying field (by "interesting topological shapes" I mean - imagine a vortex in the shape of a ring/doughnut). It's kind of a topological property of a state of the photonic field, if you will - something like a winding number (which has to be an integer). Electric cha…

> something like a winding number (which has to be an integer). Electric charge is a kind of "defect" or "kink" in the photonic field, while color charge (quarks) are defects in the strong-force field, etc.

Quark's don't have integer charge

Re: Is particle physics dead, dying, or just hard?

#233

Post by davrosthedalek »

adrian_b wrote: post #228
jhrmnn wrote: post #205

Earlier quoted context omitted.

This depends very much on what "practical purposes" are. For almost all conceivable technology, relativistic quantum mechanics for electrons and light, ie QED, is sufficient fundamental theory. This is unlike before quantum mechanics, when we basically didn't have fundamental laws for chemistry and solid-state physics.

The vast majority of useful things cannot be computed with QED from fundamental principles. You cannot compute even simple atomic energy spectra. The fundamental laws of chemistry have not been changed much by quantum physics, they just became better understood and less mysterious. Quantum mechanics has explained various cases of unusual chemical bonds that appeared to contradict the simpler rules that were believed…

What are you talking about? The spectra of hydrogen is very well understood and a text book example for students to calculate.

We use spectra to test QED calculations to something like 14 digits.

Re: Is particle physics dead, dying, or just hard?

#234

Post by bryanrasmussen »

hugh-avherald wrote: post #218
brazzy wrote: post #193

Earlier quoted context omitted.

Just as funny as armchair science enthusiasts not being able to fathom that research budgets are limited and it makes sense to redirect them into other, more promising fields when a particular avenue of research is both extremely expensive and has shown diminishing returns for decades.

Does targeting research towards 'more promising' fields actually produce greater economic returns?

The field of Elon Musk has been promising shit for years, what do you think?

Re: Is particle physics dead, dying, or just hard?

#235

Post by bryanrasmussen »

brazzy wrote: post #176
sigmoid10 wrote: post #167

Earlier quoted context omitted.

This kind of slow, incremental improvement that costs tens of billions of dollars and takes decades gave us the microchips that ultimately enabled you to type this comment on your phone/computer. The return on that investment is obvious. But it is not just about making money: The entire field of radiation therapy for cancer exists and continues to improve because people figured out ways to control particle beams with…

> This kind of slow, incremental improvement that costs tens of billions of dollars and takes decades gave us the microchips that ultimately enabled you to type this comment on your phone/computer. No. These two cases are absurdly different, and you're even completely misunderstanding (or misrepresenting) the meaning of the "tens of billions of dollars" figure. Microchips were an incremental improvement where the ind…

>Absolutely not.

A statement that certain needs some backing.

You might say that the statement you were replying to also needs some backing, but they did give some, although you believe it was incorrect.

It just seems that "absolutely not" goes against the conventional wisdom that knowledge for knowledge sake will lead to some greater return than was expended on getting that knowledge somewhere down the road which really is one of the main underlying ideas of Western Civilization since before Newton.

Absolutely not means future society will not be better off! That seems to be a big weird absurdly pompous and conceited statement to make unless you have a time machine, or at least a big mess of statistics that can show that scientific advances in physics for a significant amount of time has failed to provide a return value on existence, although I would think that does not rise to the promise of "absolutely not".

Re: Is particle physics dead, dying, or just hard?

#236

Post by alt227 »

pjmlp wrote: post #159

As CERN Alumni, this isn't easy, the data is endless, processing it takes take, usually everything is new technology, and also needs to be validated before being put into use. Thousands of people have worked on bringing LHC up during a few decades before, Higgs came to be, across all engineering branches. This stuff is hard, and there is no roadmap on how to get there.

> Higgs came to be

Did it? I thought the whole point was that the data that came from LHC showed that it was inconclusive and needed a bigger more powerful machine to prove it. Happy to be proved wrong.

Re: Is particle physics dead, dying, or just hard?

#237

Post by toast0 »

sashank_1509 wrote: post #158
mattlangston wrote: post #71

Experimental particle physicist here. It's just hard. I measured the electron's vector coupling to the Z boson at SLAC in the late 1990s, and the answer from that measurement is: we don't know yet - and that's the point. Thirty years later, the discrepancy between my experiment and LEP's hasn't been resolved. It might be nothing. It might be the first whisper of dark matter or a new force. And the only way to find ou…

What would the cost of the “next machine” be? Is it going to be tens of billions or can we make progress with lesser money. If it is going to be tens of billions, then maybe we need to invest in engineering to reduce this cost, because it’s not sustainable to suspend thirty years, tens of billions for every incremental improvement.

Spending tens of billions every thirty years is pretty sustainable actually.

"Fundamental Research" may or may not pan out, but the things that happen along the way are often valuable... I don't think there's any practical applications related to generating Higgs Bosons, but it's interesting (at least for particle physicists) and there's a bunch of practical stuff you have to figure out to confirm them.

That practical work can often generate or motivate industrial progress that's generally useful. For example, LHC generates tons of data and advances the state of the art in data processing, transmission, and storage; that's useful even if you don't care about the particle work.

Re: Is particle physics dead, dying, or just hard?

#238

Post by adrian_b »

jhanschoo wrote: post #184
adrianN wrote: post #172

Earlier quoted context omitted.

The experiments that lead to the invention of quantum theory are relatively simple and involve objects you can touch with your bare hands without damaging them. Some are done in high school, eg the photoelectric effect.

Whereas I did hedge my point regarding macroscopic quantum phenomena, I think that the quantum nature of the photoelectric effect would have been harder to discern without modern access to pure wavelength lighting. But you could still rely on precise optics to purify mixed light I suppose. But without even optics it should be even harder.

All the 19th century experiments that desired monochromatic light, including those that have characterized the photoelectric effect, used dispersive prisms, which separated the light from the Sun or from a candle into its monochromatic components. These are simple components, easily available.

This allowed experiments where the frequency of light was varied continuously, by rotating the prism.

Moreover, already during the first half of the 19th century, it became known that using gas-discharge lamps with various gases or by heating certain substances in a flame you can obtain monochromatic light corresponding to certain spectral lines specific to each substance. This allowed experiments where the wavelength of the light used in them was known with high accuracy.

Already in 1827, Jacques Babinet proposed the replacement of the platinum meter standard with the wavelength of some spectral line, as the base for the unit of length. This proposal has been developed and refined later by Maxwell, in 1870, who proposed to use both the wavelength and the period of some spectral line for the units of length and time. The proposal of Babinet has been adopted in SI in 1960, 133 years later, while the proposal of Maxwell has been adopted in SI in 1983, 113 years later.

So there were no serious difficulties in the 19th century for using monochromatic light. The most important difficulty was that their sources of monochromatic light had very low intensities, in comparison with the lasers that are available today. The low intensity problem was aggravated when coherent light was needed, as that could be obtained only by splitting the already weak light beam that was available. Lasers also provide coherent light, not only light with high intensity, thus they greatly simplify experiments.

Re: Is particle physics dead, dying, or just hard?

#239

Post by Yossarrian22 »

T-A wrote: post #213
TheOtherHobbes wrote: post #208

Earlier quoted context omitted.

It's trivial to add a matrix to account for neutrino masses, but that doesn't explain their origin. That is not a trivial problem at all. It certainly has not been solved, and it's possible experiments will say "Both the current ideas are wrong."

> It's trivial to add a matrix to account for neutrino masses The matrix you are thinking of is presumably the PMNS matrix [1]. It's equivalent to the CKM matrix for quarks [2]. The purpose of both is to parametrize the mismatch between flavor [3] and mass eigenstates, not "to account for neutrino masses" or "explain their origin". As far as the standard model is concerned, neutrino masses and quark masses all origin…

Thanks Lord Kelvin

Re: Is particle physics dead, dying, or just hard?

#240

Post by davrosthedalek »

KolibriFly wrote: post #220

This feels less like a story about particle physics "failing" and more like a story about a field running out of easy leverage

Exactly. The field has been a tik-tok between times of discovery and times of precision. We are now just swinging back from a discovery period. The next machine will be first a precision machine and then upgraded to be a discovery machine again.
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