# Back from Break

Clouds cleared about 15 minutes too late at Torshavn in the Faroe Islands, so totality was behind a cloud, but still an impressive sight. And the Faroe Islands are quite a remarkable place to visit. Some recent news:

• The plan has been to inject a beam into the LHC this week, leading to a news item in the UK Daily Express about how Scientists at Large Hadron Collider hope to make contact with PARALLEL UNIVERSE in days. This nonsense comes to us courtesy of this paper published in Physics Letters B.
• Unfortunately the machine checkout going on at the LHC has identified a problem that may delay contact with the PARALLEL UNIVERSE for a little while. Looks like no beam this week, for details see this from CERN. Some news is put out here, details of discussions of the problem here.
• Also on the parallel universe front, Quanta magazine has an interview with Weinberg. About the multiverse, he repeats some of the arguments for it, but also says:

I am not a proponent of the idea that our Big Bang universe is just part of a larger multiverse.

About string theory, the LHC and SUSY, the exchange went:

If the LHC finds no evidence for supersymmetry, what happens to string theory?
Damned if I know!

Weinberg went on to respond to the issue of the testability of string theory by discussing the possible measurement of primordial B-modes, without mentioning that string theory makes no predictions at all about this.

• Quanta magazine keeps putting out some of the best coverage of math and physics available. See for instance Natalie Wolchover on penguins (although also read Tommaso Dorigo and Adam Falkowski) and Erica Klarreich on moonshine.
• Jess Riedel has a wonderful blog posting about the subtleties of the classical limit in quantum mechanics. Textbooks like to claim this is explained by just taking the hbar goes to zero limit of a path integral, but that doesn’t really provide an explanation, for reasons clearly laid out by Riedel.
• Nominations are open for this year’s Breakthrough Prizes, see here. There will be $3 million prizes in physics and mathematics, as well as$100,000 “New Horizons Prize” for younger researchers, up to 3 each in both math and physics. For more, see here.

Update
: Sabine Hossenfelder performs the public service of reading the “PARALLEL UNIVERSES” paper and explaining what is going on here.

Update: This year’s Abel Prize went to John Nash and Louis Nirenberg. Nature News has a story here. The award to Nash was for his work on PDEs and the Nash embedding theorem. He already has an Economics Nobel, for his work on game theory. This surely makes him the first person to win not-quite-Nobels in two completely different fields.

Update: Also at Nature, news about the LHC problem.

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### 33 Responses to Back from Break

1. Justin says:

You beat me to posting about the moonshine Quanta article. I was going to link it to you as soon as you got back, as I knew it would be in line with your interests. Are you as excited about this research as I am?

2. The arXiv version of the Phys. Lett. B paper is here

3. Bee says:

Hi Peter,

I just posted a rant about the parallel nonsense: http://backreaction.blogspot.com/2015/03/no-lhc-will-not-make-contact-with.html

Best,

Sabine

4. momerathe says:

I wouldn’t get too wound up about the Daily Express – it’s not really considered a serious source of news; more a soapbox for whatever the proprietor’s latest racist or paranoid conspiracy theory is.

5. Anna says:

The parallel universe hype has been all over the media here in the UK – not just the Daily Express, even reaching the Metro. Another example of ‘Churnalism’ (the article appears to originate with physics.org) and poor scientific reporting. Unfortunately, it is being reported as being CERN’s primary objective – with the inevitable reaction from the public (‘money wasted by those delusional boffins’).

6. piscator says:

The comments on the Quanta magazine article are depressing, as people take turns to explain how Weinberg doesn’t know what science is.

7. Peter Woit says:

Justin,

In my case, the right word is more “intrigued”. This is one topic I wish I knew more about, once I catch up on other things, hope to learn some more about it.

8. SteveB says:

Is it just me or does everyone see that Tommaso Dorrigo’s articles and everyone else’s articles on Science 2.0 are newly blocked? Firefox tells me “Access denied”. The site appears to want me to login as if I were an author of a blog — which I am not. I have enjoyed Tommaso’s articles for some years now and would miss them.

9. Pingback: Papers I want to write - foreXiv

10. Peter Lund says:

This surely makes him the first person to win not-quite-Nobels in two completely different fields.

http://en.wikipedia.org/wiki/Herbert_A._Simon

11. Peter Shor says:

Peter Lund: Awfully close, but doesn’t a not-quite-Nobel prize have to be awarded in a Scandinavian country?

This nonsense comes to us courtesy of this paper published in Physics Letters B.

As a brief aside from the substantive comments, I can’t help but be dismayed that – at this late date – Elsevier is completely incompetent at generating HTML from such material, even though they’re obviously throwing an algorithm at it, which appears to specialize in hopelessly breaking things (e.g., Eq. [1]; the rendering of the $\sim 10^{19}$ GeV” in the original in the introduction is something to behold, as someone or something had to explicitly change the font of the “GeV,” which was missed in Table 1).

I generally have to go to campus to snarf papers (this one is OA), so I’m used to the amateurish typesetting in the PDFs (Eqs. [25] and [28] are in close competition), but this takes the cake. And PDF is so Not Mobilly Enough.

Gah. I hope the rant won’t be received too poorly; I’m back to reading, where I belong.

Linus Pauling won two unrelated quite-Nobel prizes, chemistry and peace.

14. MB says:

“The mass of this remnant is found to be greater than the energy scale at which experiments were performed at the LHC. We propose this as a possible explanation for the absence of black holes at the LHC.”

Hmm let me see here…

P(BH | not seen at LHC) = P(not seen at LHC | BH) P(BH prior) / (P(not seen at LHC | BH) P(BH prior) + P(not seen at LHC | no BH) P(no BH prior))
~ 1.0 * P(BH prior) / (1.0 * P(BH prior) + 1.0 * P(no BH prior))
= P(BH prior).

Yep, completely useless.

15. Geoff says:

In the Freeman Dyson spirit of “It’s better to be wrong than vague”, I’ve read seemingly serious proposals from supposedly sober physicists that quantum computations would be done in parallel universes. Perhaps it is best that alleged parallel universes are discovered at the LHC. I don’t think The Onion is creative enough to come up with a headline reading “Parallel Universes Discovered at NSA”.

Re: the earlier GR100 post—

If it should happen that, even with more sensitive detectors, no gravitational waves are observed, would some sort of graviton extinction occurring in interstellar space be a possible explanation—or is it basically a given that nothing could plausibly scatter gravitational waves at classical length scales enough to cause a null result?

To Adw (and please pitch in folk who know better than I):
(a) do not confuse graviton detection with gravitational wave detection, and
(b) unless said energy is beam-like, scattering is not extinction.

18. Nathalie says:

There is no Nobel Prize in economy. If someone says that there is, you should tell him or her: sorry, you can’t reverse time – Nobel died already in 1896 and the “Bank of Sweden Prize” in economy was created around 1969! Scientists should make accurate statements and not get carried away by incorrect statements in the press.

19. imho says:

Hmmm…

What are the ramifications of this article that claims to rule out extensions to the standard model that require significant interation between dark matter particles. Isn’t this contrary to the whole “dark matter particles are supersymmetric partners” idea?

20. Shantanu says:

Peter, check out Cliff Burgess recent talk
https://cds.cern.ch/record/2002541?ln=en

21. Dom says:

On the subject of the LHC, I hope that this isn’t something that has been linked many times before LHC Configurable Monitors

22. M says:

The End (of string theory) is Near:
http://arxiv.org/pdf/1503.08130.pdf

23. Peter Woit says:

M,
Quite the opposite, that paper shows that string theory research should be the highest priority for mankind, crucial for the survival of the species (as long as possible…).

24. bugannoyer says:

From Dr Sen’s paper, the solution to the vacuum-instability apocalypse is to send spaceships out to 10^10 light years, where they will be carried out of causal connection with the nucleating vacuum:

“In our universe the horizon size is of the order of 1010 light years. This means that by sending out space-ships we can reach and establish civilizations on dierent worlds situated within a radius of about 10^10 light years from us today”

And:

“The cost of this endeavour is clearly going to be high”

And concludes that we need to research the vacuum parameters to best allocate resources:

“In the context of string theory this means that we need to identify the correct minimum of the potential that describes the phase in which we live and then compute the probability of decay of this phase by standard techniques.”

Perhaps he could help us get a start on funding by donating a modest portion of the Milner prize? Or is it too much to hope that this is just all an early start on Wednesday?

Wilczek has an article about physics in the next 100 years, http://arxiv.org/abs/1503.07735 , much of which could have probably been written 30 years ago. But he still has 70 to go.

Radioactive, it was written 14 years ago:
http://arxiv.org/abs/hep-ph/0101187

“5.5.Produce the New Particles!
Of course, the ultimate test for low-energy supersymmetry will be to produce some of the predicted new R-odd particles. Even in the focus point scenario, there must be several accessible to the LHC.”

– From Wilczek’s future summary above.

Well in that he says “I expect that in ten to fifteen years we will know a lot more”, and now’s he’s revising his estimate from O(10) to O(100) years. As far as parameter tuning BSM papers I’ve seen a lot worse 😉

29. CU Phil says:

Peter,

Thought you might be interested in this special issue of Philosophia Mathematica on “Mathematical Depth.” It came out of a conference on the topic involving mathematicians, philosophers & historians of mathematics, and a physicist or two. Links to videos of the talks are here: https://www.youtube.com/playlist?list=PLQw7KTnzkpXfGo93vo3kQk7_jA_HgwbnC

and the foreword to the special issue itself here: http://philmat.oxfordjournals.org/content/early/2015/02/27/philmat.nkv003.full

30. Peter Woit says:

CUPhil,

Thanks! That is very interesting. It’s very hard to figure out exactly what “Mathematical Depth” is, but I think it’s a very real and important characteristic of some ideas.

31. Chris W. says:

On that Weinberg interview, some might find it interesting to compare his responses with his essay (book chapter) “Against Philosophy” in Dreams of a Final Theory (1993). I found this PDF online.

Also see this review of his new book, To Explain the World.

32. Socrates says:

There has been so much interest in the lay press regarding Fuwa, Wiseman et. al’s papers regarding nonlocal wavefunction collapse and EPR steering, but very little discussion in the online physics community.

Off-topic, but interesting?

Thanks

33. Yatima says:

Off-topic, but interesting?

As I see it, yes: “QM works exactly as expected.”