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Finding new physics will require a new particle collider

economist.com

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Re: Finding new physics will require a new particle collider

#111

Post by hpcjoe »

Deukhoofd wrote: post #10
_fizz_buzz_ wrote: post #8

A counter point by Sabine Hossenfelder: https://www.nytimes.com/2019/01/23/opinion/particle-physics-...

> I still believe that slamming particles into one another is the most promising route to understanding what matter is made of and how it holds together. But $10 billion is a hefty price tag. And I’m not sure it’s worth it. When is it worth it? They tested many theories, and many of them were proven wrong, and some were proven right. What price can you attach to having this knowledge? Is there a maximum price tag for…

The issue is, quite literally, what is the opportunity cost of this expenditure. If that money could help create a pandemic mitigation framework that would enable us to collectively respond faster and better to outbreaks, which is better to fund? If the money can help us build faster/more computers that enable us to better model many processes: weather, disease, materials, etc. is that a better expenditure?

I don't see anyone arguing that science is not a good investment.

I do see people asking the salient question of, is this the right science to fund right now, given all of societies needs.

The answer to that question should be obvious, we have other priorities at the moment.

Re: Finding new physics will require a new particle collider

#112

Post by djaque »

MiroF wrote: post #89
djaque wrote: post #82

Earlier quoted context omitted.

Oh, that's right. I wasn't really placing the electron ion collider (EIC) under the energy frontier umbrella, because they're moving in a different direction. I'm actually sort of involved with them too, but from a distance. I'm pretty sure it will happen, it's just a question of which of two proposals will succeed (more of a political question to be honest). My own interest isn't in colliders at all, but in building…

like cheap RHEED?

Not quite... the two main technologies I'm talking about are free electron lasers (FELs) and ultrafast electron diffraction. New technologies that only exist at national labs right now. If we could bring access to them to the university scale, then I think it would be a revolution similar to what the wide access to electron microscopy provided.

There's so much unexplored physics in chemistry and biology happening at atomic time and length scales. Electron diffraction and FELs are right now the only good ways to study that, but right now they're locked away behind long waiting lists because they're too expensive to have a lot of them.

Re: Finding new physics will require a new particle collider

#113

Post by marcosdumay »

achillesheels wrote: post #86
achillesheels wrote: post #72

Earlier quoted context omitted.

Can you please elaborate on QM being necessary for the transistor? Was it necessary for its invention in Bell Labs?

I found a Physics Stackexchange thread addressing this.[1] The science of quantum mechanics was not necessary for its invention. I’m still uncertain of its direct application other than “at [1] https://physics.stackexchange.com/questions/112615/why-is-it...

Hum... That thread goes a long way about diodes, but I couldn't find any such claim about transistors.

Yeah, somebody would probably invent them at some point. Somebody would probably even invent FETs, even if it took many decades more. MOSFETs are a completely different matter, I don't think anybody would invent them without understanding how they work.

What everybody seems to forget is modern chemistry, material engineering and medicine. The world would be a completely different place without quantum mechanics. Electronics is just a tiny part of the change.

Re: Finding new physics will require a new particle collider

#114

Post by djaque »

eigenspace wrote: post #97
MiroF wrote: post #81

Earlier quoted context omitted.

> we still have no idea how unconventional superconductors work. Of course, they're completely described by plain old quantum mechanics without even using field theory News to me - I thought that study of non-conventional superconductors relied heavily on effective field theories. Also, I think this is a bit of a strawman - there's a ton of money and effort going into condensed matter physics right now.

> News to me - I thought that study of non-conventional superconductors relied heavily on effective field theories. What they meant is that understanding the microscopic degrees of freedom, the electrons and ions in a superconductor, does not require field theory. The plain old particle based Schrodinger equations for N electrons interacting with N ions should be absolutely fine. The problem is that we can't actually…

Exactly, I was talking about the full many body Hamiltonian being unsolvable.

Re: Finding new physics will require a new particle collider

#115

Post by wbl »

eigenspace wrote: post #97
MiroF wrote: post #81

Earlier quoted context omitted.

> we still have no idea how unconventional superconductors work. Of course, they're completely described by plain old quantum mechanics without even using field theory News to me - I thought that study of non-conventional superconductors relied heavily on effective field theories. Also, I think this is a bit of a strawman - there's a ton of money and effort going into condensed matter physics right now.

> News to me - I thought that study of non-conventional superconductors relied heavily on effective field theories. What they meant is that understanding the microscopic degrees of freedom, the electrons and ions in a superconductor, does not require field theory. The plain old particle based Schrodinger equations for N electrons interacting with N ions should be absolutely fine. The problem is that we can't actually…

If the muon lifetime was just a bit longer life would be fantastic.

Re: Finding new physics will require a new particle collider

#116

Post by djaque »

embwbam wrote: post #101
djaque wrote: post #82

Earlier quoted context omitted.

Oh, that's right. I wasn't really placing the electron ion collider (EIC) under the energy frontier umbrella, because they're moving in a different direction. I'm actually sort of involved with them too, but from a distance. I'm pretty sure it will happen, it's just a question of which of two proposals will succeed (more of a political question to be honest). My own interest isn't in colliders at all, but in building…

Huge segue, I'm a semi-retired web / data engineer just dipping my toes into research data software. I'm collaborating on a psychology paper, but I love physics. Can I ask you some questions? My email is in my profile.

Sure, I don't see your email though. I'm also only a grad student in one specialized field (accelerator physics) so not sure how much I can help with HEP questions.

Re: Finding new physics will require a new particle collider

#117

Post by marcosdumay »

tsimionescu wrote: post #42
roenxi wrote: post #34

Earlier quoted context omitted.

Something that really sunk in for me while arguing with people on HN is that the entire Nuclear power industry is ~60 years old and provides around ~10% of humanity's electricity [0]. Even after the effective moratorium from 1985. It seems very unlikely that we've really run up against the limits of what physics can do for us. That is an enormous change and it isn't even a lifetime ago. One more development like that…

> If I really wanted to start a fight I'll argue that diverting all welfare spending to scientific research would probably result in a greater net good over two generations. Why welfare spending? Why not corporate subsidies? Or just forcefully seize the entire assets of some number of non-scientists, chosen at random? Cutting out welfare as a whole seems to be the single spending cut most likely to kill the largest n…

> Cutting out welfare as a whole seems to be the single spending cut most likely to kill the largest number of people.

Yes. I think the GP's point was that even on the worst case it would still pay off.

Personally, I doubt it. Increasing social risks would move things the other way around and decrease the speed of science advances, even with high investment.

Re: Finding new physics will require a new particle collider

#118

Post by willis936 »

MiroF wrote: post #94
willis936 wrote: post #90

Earlier quoted context omitted.

Then it should be easy to demonstrate with smaller scale projects. Where are those demonstrations?

https://en.wikipedia.org/wiki/Five-hundred-meter_Aperture_Sp... If you mean smaller accelerators, it's unclear what the value in that would be.

Actual design and building of physics experiments is a lot more complicated than “just doing it”. There are thousands of places that one small oversight will cause the entire project to fail. You will never successfully make a city size particle accelerator if you cannot demonstrate the ability to design and build a tabletop version, let alone a room scale, let alone a building scale, let alone a city block scale. It is cheap to demonstrate at a small scale. It is expensive to fail at a large scale.

With respect, I have no idea what your link has to do with anything. Making a giant dish is absolutely trivial compared to a particle accelerator.

My point is that Chinese medium-scale magnetic confinement fusion research devices have not learned from 60 years of painful lessons that the fusion research community have learned and published. Magnetic confinement fusion research machines share a lot of similarities to particle accelerators. Is there any indication that China would succeed in making a particle accelerator other than “they are good at STEM” and have made a giant parabola? It’s not very convincing.

Re: Finding new physics will require a new particle collider

#119

Post by TheOtherHobbes »

kochthesecond wrote: post #95
Koshkin wrote: post #51

Earlier quoted context omitted.

Difference is, the discovery of quantum mechanics did not require billion-dollar investment in equipment and manpower (not until work began on nuclear weapon, anyway). Besides, current research in high-energy physics, while being expensive, only brings scientific value and not much at all in the way of practical application (except, perhaps, as a side-effect of building more and more sophisticated equipment - but tha…

I think its too dismissive to claim it will have 0 practical applications. Often this type of fundamental research take decades to result in something useful in an unexpected way. We can only go where the roads lead us, who are we to dismiss the roads not taken.

You're dismissing other roads not taken.

What is more likely to revolutionise physics - spending $20bn on an incremental increase in collider energies, on spending $20bn funding a new generation of PhDs and postdocs exploring quantum gravity fundamentals?

At this point practical HEP shows every signs of being a boondoggle. There are plenty of hard theoretical questions that haven't been answered, but with a few exceptions they're outside of the mainstream. Research into them has been actively discouraged, except at a few locations.

Physics doesn't need more hardware, it needs more ideas - more intellectual diversity, and more creativity.

Re: Finding new physics will require a new particle collider

#120

Post by canjobear »

djaque wrote: post #57
_fizz_buzz_ wrote: post #8

A counter point by Sabine Hossenfelder: https://www.nytimes.com/2019/01/23/opinion/particle-physics-...

I post this every time someone links to Hossenfelder, but please take her opinions with a grain of salt. She seems more interested in attacking the "physics establishment" than in giving people a picture of the reality of our situation. Take a look at her articles on LIGO [1] for instance where she makes conspiracy theory level claims saying that the group is lying about their data and that "big physics" is in on it.…

For what it's worth, I usually find Sabine Hossenfelder to be insufferably critical and self-promoting, but I found that LIGO article fairly disturbing. As someone who has worked with complex analyses of large datasets, I know how easy it can be to fool yourself.
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