Finding new physics will require a new particle collider • Hacker News Board

Re: Finding new physics will require a new particle collider

#191

Post by eigenspace » Sun, May 10, 2020, 8:00 PM UTC

jjdredd wrote: post #170

hpcjoe wrote: post #108

As a (non-practicing) physicist, I've always disliked the penchant of some in the HEP community to say what this article says. They (the HEP community) tends to equate physics with HEP physics. It's not. When this is pointed out to the people espousing this odd viewpoint, they usually respond with some passive aggressive comment. I've seen/experienced much of this during my time in research. New physics not requiring…

SM/beyond SM is the only field in fundamental physics though. Everything else is either a consequence of those models or applied physics.

I'm a big fan of Phil Anderson's article, More is Different[1] where he argues why he things this reductionist view (the view that the physics most worthy of understanding is the physics of the smallest things) is flawed. The fact of the matter is that at all sorts of scales regularities in the laws of nature emerge, and understanding the smaller and smaller building blocks is only one interesting path for physics research.

Condensed matter physics is, in my opinion, a far more interesting and varied field of study than high energy physics. Not only does it contribute to society in a way high energy physics no longer does, but in many senses it takes on a fundamental character like HEP. Every material in the long wavelength limit acts like its own little universe with its own set of fundamental particles and quantum fields.

The universes Condensed matter physics studies have supersymmetry, Majorana fermions, magnetic monopoles, dualities and any other genuinely interesting physical phenomenon you could want.

What's more is that by understanding the physics of these phenomena, we can create new technologies that really matter.

[1] https://www.tkm.kit.edu/downloads/TKM1_2011_more_is_differen...

Re: Finding new physics will require a new particle collider

#192

Post by eigenspace » Sun, May 10, 2020, 8:05 PM UTC

baq wrote: post #186

eigenspace wrote: post #151

Earlier quoted context omitted.

The problem is that the effects they're looking at are confined to such high energy and small length scales that they're utterly invisible to things even on the scale of a single proton. It's very difficult to imagine how (or even why) one would ever build a device that takes advantage of a TeV scale effect to do something useful, given that these effects are meaningless to the sorts of matter we care about and inter…

I agree with your point but it skips over a different equally important thing completely: technology built to create and observe events at these energies are not without value, similarly to NASA going to the Moon and inventing Velcro while at it (yes, not true, but you get the idea).

Actually I don't think I skipped over that. I explicitly mentioned "spinoff technologies" and in my analogy to digging a hole in your back yard I said

> Arguing that it'd have good effects like increasing your fitness and "who knows, you might strike gold!" isn't really a convincing argument for me to dig up my yard.

What I mean by this is that I don't think that the spin off technologies or discoveries from high energy particle physics research (i.e. the fitness you might gain by digging up your yard) are a valid justification for doing it.

Spin off technologies and discoveries will be found in almost any research endeavour, including other particle physics experiments that aren't just "build another collider, but bigger", they're not a justification for the research, they're a bonus.

Re: Finding new physics will require a new particle collider

#193

Post by at_a_remove » Sun, May 10, 2020, 8:24 PM UTC

jcims wrote: post #169

Complete physics moron here, is there no way to use particle/anti-particle annihilation to drive collision energy up? Also, i think if we invested the money for a new collider into an effort to develop what we've learned so far into a useful technology that inspires the general public, the funding for the next collider would take care of itself.

I'll drastically oversimplify here, but in a collider, the particles being collided are highly regimented. First, you have a very specific type of particle you want to move around, like a proton (and you had best hope you picked a charged particle so you and move it easily with an EM field). Second, you have a very specific direction for that particle so you can smash it against something else. Third, the energy the particle is at at the time of smashing is well-known and very high. It's all very specific.

Annihilation is too uncontrolled to help, often in terms of direction.

Accelerators are all about trying to add just a tiny bit more velocity to something already moving at 99.99% of the speed of light, in the exact direction that particle is already going in. So it is both precision and vanishing results.

It's a tricky situation.

Re: Finding new physics will require a new particle collider

#194

Post by djaque » Sun, May 10, 2020, 8:27 PM UTC

SiempreViernes wrote: post #155

djaque wrote: post #70

My personal opinion (and I might be biased since I'm not a collider guy) is that it's time to take a break from the energy frontier and put our efforts into other kinds of physics. There's a whole world out there besides "fixing" the standard model. I'm having a hard time finding it, but there's a quote from a famous physicist along the lines of "we already have a theory of everything we encounter in daily life, it's…

The field of x-ray light sources seems to be pretty well developed, lightsource.org lists 30 of them world wide, so adding one more doesn't look like it's going to critically impact anything except maybe the local community getting the extra jobs. There was at one point truly a fight about the relative importance of the various fields, but the condensed matter people won that. Just look at lightsources.org again, tha…

> The field of x-ray light sources seems to be pretty well developed, lightsource.org lists 30 of them world wide, so adding one more doesn't look like it's going to critically impact anything except maybe the local community getting the extra jobs.

And that's based on what? The number of lightsources in the world? There's dozens of research groups studying quantum computing. I guess they should just pack up and move on to less developed fields.

In reality, there are huge open problems with synchrotron light sources that people are spending their careers on (and I don't think they're jealous of HEP). What I'm more interested in, however, are university scale sources of xrays and matter for atomic scale physics. Even though there are a few dozen facilities around the world, all of them are oversubscribed. Many times if you apply for time on a synchrotron you'll be denied because there just isn't space for you. Even companies that pay for time (and yes these machines don't just impact local job counts) don't always get a slot. It would be transformative to take some of these techniques (and more advanced ones) to a wider audience.

Re: Finding new physics will require a new particle collider

#195

Post by fao_ » Sun, May 10, 2020, 8:48 PM UTC

eigenspace wrote: post #142

djaque wrote: post #110

Earlier quoted context omitted.

Well said. Whenever I bring up that point on physics subreddits I also get tons of passive aggressive comments. It's super toxic. The HEP people in my own department also seem to believe that anything other than beyond the standard model physics isn't fundamental or isn't pure enough to care about.

I think a lot of it comes from the fact that they used to be the golden child of science, but the influence and prestige of HEP has been a victim of it's own success. HEP just doesn't hold the same importance it used to, and that stings for the people who dedicated their lives to it. As they pushed to higher and higher energies and events with lower and lower cross sections, they're solving problems that matter less…

> but without a promise of practical applications, or at least a convincing argument that they'll find something interesting with this new collider, I find it really hard to justify the price tag.

I mean, you can say that about people going to the moon, right? What data are they going to get? Something about rocks and the consistency of the moon dust, right? The technologies developed in going to the moon got us so many things we didn't see from the goal.

This is the same for a lot of things around the frontiers of science! More experimental data is beneficial to all levels of science. Look at how many papers have been written in obscure and 'irrelevant' fields of higher mathematics only to -- 40 or 200 years later -- be found extremely relevant and useful?

The point is we don't know. It's not like we can't afford it. If the United States, for example, distributed the defense budget into social care and the sciences, we wouldn't be having a conversation about monetary distribution. It's not inherently mutually exclusive, and it doesn't have to be at the moment, either.

> Would knowing what physics does at 100TeV be any more valuable to us than a great work of literature? I'm not sure.

Those things aren't mutually exclusive.

Re: Finding new physics will require a new particle collider

#196

Post by jameslevy » Sun, May 10, 2020, 8:51 PM UTC

hpcjoe wrote: post #108

As a (non-practicing) physicist, I've always disliked the penchant of some in the HEP community to say what this article says. They (the HEP community) tends to equate physics with HEP physics. It's not. When this is pointed out to the people espousing this odd viewpoint, they usually respond with some passive aggressive comment. I've seen/experienced much of this during my time in research. New physics not requiring…

> the pseudo-quantum stuff of adiabatically cooled circuits

Where is the innovation/research in this area happening? This is one of those topics that I find very interesting but any attempt to serious inquiry into it tends to result in ridicule from people I know with some expertise in physics and thermodynamics, as though it was just obviously nonsense.

Re: Finding new physics will require a new particle collider

#197

Post by konschubert » Sun, May 10, 2020, 9:02 PM UTC

hpcjoe wrote: post #108

As a (non-practicing) physicist, I've always disliked the penchant of some in the HEP community to say what this article says. They (the HEP community) tends to equate physics with HEP physics. It's not. When this is pointed out to the people espousing this odd viewpoint, they usually respond with some passive aggressive comment. I've seen/experienced much of this during my time in research. New physics not requiring…

HEP stands for High Energy Physics, which is what is done with an accelerator.

Re: Finding new physics will require a new particle collider

#198

Post by konschubert » Sun, May 10, 2020, 9:07 PM UTC

jjdredd wrote: post #170

hpcjoe wrote: post #108

As a (non-practicing) physicist, I've always disliked the penchant of some in the HEP community to say what this article says. They (the HEP community) tends to equate physics with HEP physics. It's not. When this is pointed out to the people espousing this odd viewpoint, they usually respond with some passive aggressive comment. I've seen/experienced much of this during my time in research. New physics not requiring…

SM/beyond SM is the only field in fundamental physics though. Everything else is either a consequence of those models or applied physics.

we haven’t really understood quantum theory yet on a theoretical level.

Everybody seems to agree with that, yet it seems most Physicists immediately refuse to spend any further thought on it and go back to modeling what happens if you double the number of particles and then crash them at 100 TeV

Re: Finding new physics will require a new particle collider

#199

Post by hpcjoe » Sun, May 10, 2020, 9:23 PM UTC

fsflover wrote: post #175

eigenspace wrote: post #151

Earlier quoted context omitted.

The problem is that the effects they're looking at are confined to such high energy and small length scales that they're utterly invisible to things even on the scale of a single proton. It's very difficult to imagine how (or even why) one would ever build a device that takes advantage of a TeV scale effect to do something useful, given that these effects are meaningless to the sorts of matter we care about and inter…

You could say the same during invention of quantum mechanics: "They are looking at the effects on the scale of single atom/electron, hardly ever useful in our everyday life." Or about going to the space. You can never know what new discoveries bring.

Non-sequitur.

Quantum mechanics didn't require $10B (or whatever the equivalent would be in 1930-ish currency) to create. The "inventors" of QM were trying to explain measurements that were already made, quite inexpensively, that did not fit the model of nature that we had at that time.

Basically, the experiments were done, measurements made. Now the theorists were trying to understand what they needed in order to be able to provide a model that fit these results. This required a number of specific mental leaps of faith. Some of these are controversial even today. But they fit the experiments, so the issue for us is one of a mental model.

But ... and this is critical, not all of physics is quantum mechanical. Orbital calculations don't (normally) require QM. Steam engines, heat engines, etc. don't normally require QM.

The objections some of us have with classifying "all of physics being HEP" is that it is not, and the reality is that most physics do not require accelerators. Most new physics won't require accelerators.

A great example from earlier this year is the first sighting of a Majorana fermion[1]. Though this article also makes the mistake of "In particle physics, fermions are a class of elementary particles". Its not in particle (HEP) physics. Its in physics.

[1] https://news.mit.edu/2020/first-majorana-fermion-metal-quant...

Re: Finding new physics will require a new particle collider

#200

Post by magv » Sun, May 10, 2020, 9:29 PM UTC

jcims wrote: post #169

Complete physics moron here, is there no way to use particle/anti-particle annihilation to drive collision energy up? Also, i think if we invested the money for a new collider into an effort to develop what we've learned so far into a useful technology that inspires the general public, the funding for the next collider would take care of itself.

LEP was annihilating electrons with positrons; LHC does not, as it only accelerates protons. FCC will have the option to do both: the plan includes two separate pipes in the same tunnel, one for protons, one for electrons.

This however does not increase the collision energy significantly: a single electron-positron pair has the (rest) energy of ~1MeV -- this is what is released during the annihilation, but the energies we want to go to at the next collider go up to 10TeV, so 10^7 times larger.