5 ms·

The crisis that Hossenfelder is addressing is that there has been no significant progress that's been experimentally verified in fundamental physics since the b

by Zanni 8y ago

The crisis that Hossenfelder is addressing is that there has been no significant progress that's been experimentally verified in fundamental physics since the birth of string theory in the 1980s. Yes, there are a lot of big open problems, but they remain open. Yes, we have recently found experimental evidence for things like the Higgs boson, but that was first predicted in the 1960s. Yes, we can rule out some versions of string theory thanks to LHC results, but there are a vast multitude of string theories, and that's not a lot to show for nearly 40 years.

gus_massa 8y ago
Some results that I remember just now: * There is a recent 4.5+4.8 sigma excess in neutrinos oscillation that hints a new neutrino https://arstechnica.com/science/2018/06/weird-neutrino-excess-wont-go-away-hints-at-new-physics/ https://arstechnica.com/science/2018/06/weird-neutrino-exces... [technical note, you can't add sigmas naively, 4.5+4.8=6.1] * The value of the magnetic moment of the muon (g) is too high. IIRC this result has only a 2.5 or 3 sigma, so it's far from confirmed. * There are some experiment to prove that the neutrino is a majorana particle and that the neutrino and the anti-neutrino is the same particle. I don't remember any good announcement, so I think that the experiments have still too early results or the results are not interesting. [I don't like this theory, but many people that knows more than me like it.]
- noobermin 8y ago
  Do you have a link for the majorana bit?
  - gus_massa 8y ago
    https://www.symmetrymagazine.org/article/august-2013/neutrinoless-double-beta-decay https://www.symmetrymagazine.org/article/august-2013/neutrin... https://en.wikipedia.org/wiki/Double_beta_decay#Neutrinoless_double_beta_decay https://en.wikipedia.org/wiki/Double_beta_decay#Neutrinoless...
- jerf 8y ago
  That kind of emphasizes the point rather than disproves it, though. Nearly 40 years of physics to pull your examples from, and you pull something from last month, something not confirmed (there's been tons of 2.5-3 sigma results over the past 40 years, but there's a reason physicists have learned to wait for more sigma), and something that is unannounced and may be uninteresting. I believe there are some other things in that time frame. I believe the discovery that the universe is accelerating in its rate of separation fits in that time frame, and that's pretty big. We don't know how to fit it in with anything, but it's big. And I'd still say confirming Higgs is big. But... yeah... it is a pretty short list compared to preceding decades.
- ravar 8y ago
  When I spoke to an exo collaborator he told me that exo put a really tight limit on the rate of neutrino-less double beta decay. If I was a betting man I would put it in the same category as proton decay, another theoretical physics favorite.
- mcnamaratw 8y ago
  Sorry to nitpick but if we're adding variances, 4.5^2 + 4.8^2 = 6.6^2
  - gus_massa 8y ago
    Essentially yes (unless you are nearby an tactician or a journal referee). I just copied the number from the article, I guess there is some rounding. Also, the 6.2 or 6.1 is "unofficial" because it's difficult to mix results from different experiments.
dodobirdlord 8y ago
There's the outstanding issue of the proton size.

by Zanni 8y ago

gus_massa 8y ago

Some results that I remember just now: * There is a recent 4.5+4.8 sigma excess in neutrinos oscillation that hints a new neutrino https://arstechnica.com/science/2018/06/weird-neutrino-excess-wont-go-away-hints-at-new-physics/ https://arstechnica.com/science/2018/06/weird-neutrino-exces... [technical note, you can't add sigmas naively, 4.5+4.8=6.1] * The value of the magnetic moment of the muon (g) is too high. IIRC this result has only a 2.5 or 3 sigma, so it's far from confirmed. * There are some experiment to prove that the neutrino is a majorana particle and that the neutrino and the anti-neutrino is the same particle. I don't remember any good announcement, so I think that the experiments have still too early results or the results are not interesting. [I don't like this theory, but many people that knows more than me like it.]

noobermin 8y ago
Do you have a link for the majorana bit?
- gus_massa 8y ago
  https://www.symmetrymagazine.org/article/august-2013/neutrinoless-double-beta-decay https://www.symmetrymagazine.org/article/august-2013/neutrin... https://en.wikipedia.org/wiki/Double_beta_decay#Neutrinoless_double_beta_decay https://en.wikipedia.org/wiki/Double_beta_decay#Neutrinoless...
jerf 8y ago
That kind of emphasizes the point rather than disproves it, though. Nearly 40 years of physics to pull your examples from, and you pull something from last month, something not confirmed (there's been tons of 2.5-3 sigma results over the past 40 years, but there's a reason physicists have learned to wait for more sigma), and something that is unannounced and may be uninteresting. I believe there are some other things in that time frame. I believe the discovery that the universe is accelerating in its rate of separation fits in that time frame, and that's pretty big. We don't know how to fit it in with anything, but it's big. And I'd still say confirming Higgs is big. But... yeah... it is a pretty short list compared to preceding decades.
ravar 8y ago
When I spoke to an exo collaborator he told me that exo put a really tight limit on the rate of neutrino-less double beta decay. If I was a betting man I would put it in the same category as proton decay, another theoretical physics favorite.
mcnamaratw 8y ago
Sorry to nitpick but if we're adding variances, 4.5^2 + 4.8^2 = 6.6^2
- gus_massa 8y ago
  Essentially yes (unless you are nearby an tactician or a journal referee). I just copied the number from the article, I guess there is some rounding. Also, the 6.2 or 6.1 is "unofficial" because it's difficult to mix results from different experiments.

dodobirdlord 8y ago

There's the outstanding issue of the proton size.