3 ms·

> which ultimately could allow us to unravel any number of established mysteries. These include the nature of the invisible dark matter that fills the universe,

> which ultimately could allow us to unravel any number of established mysteries. These include the nature of the invisible dark matter that fills the universe, or the nature of the Higgs boson. It could even help theorists unify the fundamental particles and forces... To this non-physicist, it's not clear at all how this potential discovery might do any of that. From here, it looks like a mininally consequential addendum to the standard model, almost like a single epicycle to a geocentric cosmology. The effect only shifts by a few percent the chance of some obscure and rare interaction. Is it really plausible that it could have such grand implications?

ISL 6y ago
To continue the epicycle analogy: The problem in modern physics is that the epicycles work too well. There are some big obvious mysteries and an incredibly-successful epicycle-based theory. Essentially everyone expects that the epicycles are not the truly fundamental theory of things. So, physicists keep comparing the predictions of the "epicycle-theory" with reality in new ways, ways where a deviation from the prediction would be an unambiguous signpost pointing a direction toward which one might be able to address a big mystery. As those tests become established, they are then performed with higher and higher precision. The signal potentially seen with LHCb is, if it persists, important. In a nutshell, electrons are, in this particular way, predicted to act exactly like muons. No ifs, ands, or buts. What they see is that electrons and muons might be acting slightly differently. If so, some new physics (or a major error in our understanding of the epicycles -- I'm looking at you, loops) must be at work. If this result persists, it is guaranteed that we will learn something. Too convoluted? Here is a different analogy: You're pretty sure someone is embezzling from your company. You look at your bank account, and you have ~95% less money than you thought you should. Really. Oh, no. You check the summary budgets, they're balanced. So you do this for all the company's divisions. Yep. Still balanced. You get paranoid. You do this for decades -- the books balance, but at the end of the day? 5%. Then an employee runs up to you and says, "Shmageggy! We're not sure yet, but it looks like one of our most-trusted partners, whom the firm has worked with since 1936, transferred thirty-seven cents to an account in the Cayman Islands!" Until we find the embezzler, that's what every one of these precision physics tests that makes the news is all about.
- timelincoln 6y ago
  love this!
  - timelincoln 6y ago
    office space for the universe
- shmageggy 6y ago
  Thanks for the well thought out reply. So IIUC it's (probably) not that this result is the One True Answer in itself, but rather a potential chink in the armor that tells us where to pry.
  - ISL 6y ago
    Yes. There are well-known places where we think the armor might be weak and we're trying all of them roughly equally. The moment someone finds an actual hole in the armor, a lot of people will jump in and hammer on that one in particular. The key properties of the weak points are: a) We have to be able to hit it there in a meaningful way b) Anywhere that we expend millions of dollars and oodles of people-years of work to look for holes, we have to be capable of verifying that a possible-hole is an actual-hole. This particular anomaly scores pretty well on b). If they have a clean signal there, then it is a pretty big deal.
omgwtfbbq 6y ago
The implication is that there is something beyond the Standard Model which has been essentially completely bulletproof for the last 50 years. Nothing outside truly unknown phenomena, dark matter, dark energy, etc. has ever invalidated it. We know theoretically there has to be more physics but have had no experimental inkling that was really the case.

ISL 6y ago

To continue the epicycle analogy: The problem in modern physics is that the epicycles work too well. There are some big obvious mysteries and an incredibly-successful epicycle-based theory. Essentially everyone expects that the epicycles are not the truly fundamental theory of things. So, physicists keep comparing the predictions of the "epicycle-theory" with reality in new ways, ways where a deviation from the prediction would be an unambiguous signpost pointing a direction toward which one might be able to address a big mystery. As those tests become established, they are then performed with higher and higher precision. The signal potentially seen with LHCb is, if it persists, important. In a nutshell, electrons are, in this particular way, predicted to act exactly like muons. No ifs, ands, or buts. What they see is that electrons and muons might be acting slightly differently. If so, some new physics (or a major error in our understanding of the epicycles -- I'm looking at you, loops) must be at work. If this result persists, it is guaranteed that we will learn something. Too convoluted? Here is a different analogy: You're pretty sure someone is embezzling from your company. You look at your bank account, and you have ~95% less money than you thought you should. Really. Oh, no. You check the summary budgets, they're balanced. So you do this for all the company's divisions. Yep. Still balanced. You get paranoid. You do this for decades -- the books balance, but at the end of the day? 5%. Then an employee runs up to you and says, "Shmageggy! We're not sure yet, but it looks like one of our most-trusted partners, whom the firm has worked with since 1936, transferred thirty-seven cents to an account in the Cayman Islands!" Until we find the embezzler, that's what every one of these precision physics tests that makes the news is all about.

timelincoln 6y ago
love this!
- timelincoln 6y ago
  office space for the universe
shmageggy 6y ago
Thanks for the well thought out reply. So IIUC it's (probably) not that this result is the One True Answer in itself, but rather a potential chink in the armor that tells us where to pry.
- ISL 6y ago
  Yes. There are well-known places where we think the armor might be weak and we're trying all of them roughly equally. The moment someone finds an actual hole in the armor, a lot of people will jump in and hammer on that one in particular. The key properties of the weak points are: a) We have to be able to hit it there in a meaningful way b) Anywhere that we expend millions of dollars and oodles of people-years of work to look for holes, we have to be capable of verifying that a possible-hole is an actual-hole. This particular anomaly scores pretty well on b). If they have a clean signal there, then it is a pretty big deal.

omgwtfbbq 6y ago

The implication is that there is something beyond the Standard Model which has been essentially completely bulletproof for the last 50 years. Nothing outside truly unknown phenomena, dark matter, dark energy, etc. has ever invalidated it. We know theoretically there has to be more physics but have had no experimental inkling that was really the case.