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Is particle physics dead, dying, or just hard?

quantamagazine.org

191–200 of 408 posts

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

#191
post #24

It's basically the opposite situation from 150 years ago. Back then, we thought our theory was more or less complete while having experimental data which disproved it (Michelson-Morley experiment, Mercury perihelion, I am sure there are others). Right now, we know our theories are incomplete (since GR and QFT are incompatible) while having no experimental data which contradicts them.

Doesn't that imply our theories are "good enough" for all practical purposes? If they're impossible to empirically disprove?

The existing theories are extremely far from being good enough for practical purposes.

There exists a huge number of fundamental quantities that should be calculated from the parameters of the "standard model", but we cannot compute them, we can only measure them experimentally.

For instance, the masses and magnetic moments of the proton, of the neutron and of all other hadrons, the masses and magnetic moments of the nuclei, the energy spectra of nuclei, of atoms, of ions, of molecules, and so on.

The "standard model" can compute only things of negligible practical importance, like the statistical properties of the particle collisions that are performed at LHC.

It cannot compute anything of value for practical engineering. All semiconductor devices, lasers and any other devices where quantum physics matters are not designed using any consistent theory of quantum physics, but they are designed using models based on a great number of empirical parameters determined by measurement, for which quantum physics is only an inspiration for how the model should look like and not a base from which the model can be derived rigorously.

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

#192
post #140

Earlier quoted context omitted.

Personally—and this is where I expect to lose the materialists that I imagine predominate HN—I think we are already in a nightmare scenario with regard to another area: the science of consciousness. The following seem likely to me: (1) Consciousness exists, and is not an illusion that doesn't need explaining (a la Daniel Dennett), nor does it drop out of some magical part of physical theory we've somehow overlooked u…

I don't think any of this is particularly nightmarish. Just because we don't yet know how this complex system arises from another lower level one doesn't make it new physics. There's no evidence of it being new or orthogonal physics. Imagine trying to figure out what is happening on someone's computer screen with only physical access to their hardware minus the screen, and an MRI scanner. And that's a system we built…

Knowing how to build a brain is different from knowing whether that brain has consciousness in the sense that you or I do. The question of consciousness appears to demand new/orthogonal physics because according to our existing physics, there's no sense in which you or should "feel" any differently than a rock does, or a computer does, or Searle's room does, or a Chinese brain does, or the universe as a whole does, etc.

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

#193
post #176

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. 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 Engineers not being able to fathom that by building this huge-ass and complicated machines to answer questions about the fundamentals of nature, other problems are solved or new things are invented that improve and change our life will never not be funny to me

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.

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

#194
post #176

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. 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. I'd not be so sure about that. Doing this research will probably allow us to answer "it works but we don't know exactly why" cases in things we use everyday (i.e. li-ion batteries). Plus, while the machines are getting bigger, the understood tech is getting smaller as the laws of physics allows. If we are going to insist on "Absolutely not" path, we should start with proof-of-work crypto farms and A…

That "probably" is really more of a "maybe" given the experience with the current big accelerators, and really needs to be weighed against the extreme costs - and other, more promising avenues of research.

> If we are going to insist on "Absolutely not" path, we should start with proof-of-work crypto farms and AI datacenters which consume county or state equivalents of electricity and water resources for low quality slop.

Who exactly is the "we" that is able to make this decision? The allocation of research budgets is completely unrelated to the funding of AI datacenters or crypto farms. There is no organization on this planet that controls both.

And if you're gonna propose that the whole of human efforts should somehow be organized differently so that these things can be prioritized against each other properly, then I'm afraid that is a much, MUCH harder problem than any fundamental physics.

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

#195
It is obviously not dead but it should be dead: Almost all of the technical and economic progress made in the last century was achieved with macroscopic quantum effects. Particle physics spends a lot of energy and material resources to measure microscopic effects. The priorities are esentially inverted. At this point it is not even about discovery. Experiments are relegated to precision measurements. What practical use will it be if we know the mass/charge distribution/polarizability of some particles more precicely by a few percent? About nothing.

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

#196

Earlier quoted context omitted.

If you imagine the universe is made of random real fundamental constants rather than random integer fundamental constants, then indeed there's no reason to expect such collisions. But if our universe starts from discrete foundations, then there may be no more satisfying explanation to this than there is to the question of, say, why the survival threshold and the reproduction threshold in Conway's Game of Life both in…

Why do you assume the two have to be small integers? There is nothing currently in physics which would disallow the electron to be -1 and the proton to be +1234567891011213141516171819. The fact they are both of magnitude 1 is a huge coincidence.

If they were, I'd assume that there wouldn't be anyone in the universe to observe that.

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

#197
post #189
post #185

Earlier quoted context omitted.

> The latest ones cost billions and have confirmed a few things we already thought to be true. Yes, but we had hopes that it would lead to more. And had lead to more, something only known to be false in hindsight, who knows where that would have ended us up? What if it upended the standard model instead of reinforcing it? > Absolutely not. What are we supposed to do then? As humans, I mean. No one knows why we're her…

>I'm not arguing for mindlessly building bigger accelerators, and I don't think anyone is But you are and they are. Just by the comments here its clear that even suggesting not to use untold billions on maybe pushing theoretical physics a little forward is meet with scorn. The value proposition either, in knowledge or technology, is just not well argued anymore besides hand waving.

No, I'm not and neither is anyone else. It's common sense that we should explore options that require less effort, just as one would in any project. I'm saying that we can't discredit huge particle accelerators due to, in the grandest scheme of things, a small economic cost and past results of a different experiment.

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

#198
post #181
post #176

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. 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…

I'm torn between "yes, these experinets are way too expensive and the knowlage is too niche to be really usefull" and "We said this about A LOT and we found utility in surprising ways so it could be a gamble worth taking" That's the problem with cutting edge reaserch....you don't even know if you will ever needed it or if a trilion dollar industry is waiting for just a number to be born

Yes, we don't really know. But at some point the gamble is just too big.

Because the costs aren't just numbers. They represent hundreds or thousands of person-years of effort. You're proposing that a large number of people should spend their entire lives supporting this (either directly as scientists, or indirectly through funding it) - and maybe end up with nothing to show for it.

And there's the opportunity costs. You could fund hundreds of smaller, yet still substantial scientific efforts in many different fields for the cost of just one particle accelerator of the size we think is sufficient to yield some new observations.

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

#199
post #190
post #185

Earlier quoted context omitted.

> The latest ones cost billions and have confirmed a few things we already thought to be true. Yes, but we had hopes that it would lead to more. And had lead to more, something only known to be false in hindsight, who knows where that would have ended us up? What if it upended the standard model instead of reinforcing it? > Absolutely not. What are we supposed to do then? As humans, I mean. No one knows why we're her…

> Yes, but we had hopes that it would lead to more. And had lead to more, something only known to be false in hindsight, who knows where that would have ended us up? What if it upended the standard model instead of reinforcing it? Sure, but it didn't. Which is knowledge that really should factor into the decision to build the next, bigger one. > What are we supposed to do then? As humans, I mean. Invest the money and…

> Which is knowledge that really should factor into the decision to build the next, bigger one.

It was always factored in, and of course it would be in any next iteration.

> Invest the money and effort elsewhere, for now. There are many other fields of scientific exploration that are very likely to yield greater return (in knowledge and utility) for less. You could fund a hundred smaller but still substantial intiatives instead of one big accelerator. And be virtually guaranteed to have an exciting breakthrough in a few of them.

I agree with this to a large extent. I'm just not against particle accelerators as a venue for scientific advancement and in the best of worlds we could do both.

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

#200
post #140

Earlier quoted context omitted.

I don't think any of this is particularly nightmarish. Just because we don't yet know how this complex system arises from another lower level one doesn't make it new physics. There's no evidence of it being new or orthogonal physics. Imagine trying to figure out what is happening on someone's computer screen with only physical access to their hardware minus the screen, and an MRI scanner. And that's a system we built…

Knowing how to build a brain is different from knowing whether that brain has consciousness in the sense that you or I do. The question of consciousness appears to demand new/orthogonal physics because according to our existing physics, there's no sense in which you or should "feel" any differently than a rock does, or a computer does, or Searle's room does, or a Chinese brain does, or the universe as a whole does, e…

> The question of consciousness appears to demand new/orthogonal physics because according to our existing physics, there's no sense in which you or should "feel" any differently than a rock does,

deepak chopra may interest you

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