I mean, there's a slight chance that my papers will get buried by volcanic ash and become dug up by future archeologists (like the scrolls in the Pompei library), while there's pretty much no hope of any server surviving such a treatment, but that's too unlikely to be considered a valid argument for using wood paper.
Today we write about LHC, SSC, and Nielsen and Ninomiya's crazy proposal in 2008 about why LHC shut itself down. Then it digresses to a depressing thought about the ends of scientific and mathematical fields.
Start with Sean Caroll's review, which gives a good overview of the paper. It's crazy.
Basically, the LHC shut down on 2008-09-19 in a quench accident, delaying its operation by 14 months. The SSC got cancelled halfway through construction (started in 1991, cancelled in 1993). What's with those expensive "accidents"? Could they have been not accidents after all??
The proposal by Nielsen and Ninomiya (2007), Search for Effect of Influence from Future
in Large Hadron Collider, is that those are not accidental. Basically, the universe "abhors" large collections of Higgs bosons and if such collections do happen, it would have backward-cause the past to change so that this collection does not happen.
The abstract really does not mince words:
In action-formulation of physics, a system is described by a Lagrangian $L$, and each history of the system corresponds to a time-integral of the Lagrangian which gives a number $$S = \int_{\text{history of the world}} L$$ called the "action" of the history. Classically, only the least action history is the true history. Quantum mechanically, all histories could be true, but the probability-amplitude is $\exp(i\hbar S)$, and some analysis later (use the method of stationary phase), it's shown that classical physics is recovered as $\hbar\to 0$.
In the Nielsen and Ninomiya paper, if the action were a complex number, then the imaginary part would make certain histories of the world highly unlikely to happen, even if those trajectories stationize the real action, but in a way that appears "nonlocal in spacetime", making weird things like backward causation appear.
Then, it remains to design a complex action that allows Higgs boson to do backward causation, and the authors did design one, even if it's kind of ad hoc. The end result is that, if this complex action is actually true in our world, any history in which large numbers of Higgs bosons are produced is very unlikely, compared to similar histories where there are not that many Higgs bosons.
In story-form, it's like there is some fate in this universe: the Higgs bosons are cursed by fate, doomed are those who seek its forbidden creation, as everything would turn against them.
Or in many-worlds language: you might think that you are in a universe with a future with LHC intact and creating lots and lots of Higgs bosons, but most likely, the universe you are in is heading towards a future with LHC not intact, a war breaks out between France and Switzerland forcing a shutdown, etc. A future with a war between France and Switzerland is extremely unlikely, but it's still more likely than a future with a ball of Higgs bosons!
The authors are quite concerned about this, and it's a bit justified:
The authors then proposed "an economical or ethical attempt to rescue LHC from even worse fates", a game of cards! Basically, to rescue us from worse fates, it's important to know if the theory is true or not. If true, stop LHC, else, go ahead. To test the theory, shuffle a deck with, say, 2 million cards, with one card saying "stop LHC" and all others saying "go ahead". The reason is that, if we do the experiment and got "stop LHC", there's a high chance that the fault is not in us, but in the stars. That is, we didn't just get randomly unlucky with our attempts to create Higgs bosons, the laws of physics are really against us.
They even did a cost-analysis of this experiment. If we run the experiment with 0.2 million cards, and were genuine about our experiment, and really stop the LHC upon taking the card, then the expectation of loss from the experiment is
The proposal by Nielsen and Ninomiya (2007), Search for Effect of Influence from Future
in Large Hadron Collider, is that those are not accidental. Basically, the universe "abhors" large collections of Higgs bosons and if such collections do happen, it would have backward-cause the past to change so that this collection does not happen.
The abstract really does not mince words:
We propose an experiment which consists of drawing a card and using it to decide restrictions on the running of Large Hadron Collider... There may potentially occur total shut down. The purpose of such an experiment is to search for influence from the future, that is, backward causation.Sean Caroll summarized the technical details. I'll regurgitate my understanding too.
In action-formulation of physics, a system is described by a Lagrangian $L$, and each history of the system corresponds to a time-integral of the Lagrangian which gives a number $$S = \int_{\text{history of the world}} L$$ called the "action" of the history. Classically, only the least action history is the true history. Quantum mechanically, all histories could be true, but the probability-amplitude is $\exp(i\hbar S)$, and some analysis later (use the method of stationary phase), it's shown that classical physics is recovered as $\hbar\to 0$.
In the Nielsen and Ninomiya paper, if the action were a complex number, then the imaginary part would make certain histories of the world highly unlikely to happen, even if those trajectories stationize the real action, but in a way that appears "nonlocal in spacetime", making weird things like backward causation appear.
Then, it remains to design a complex action that allows Higgs boson to do backward causation, and the authors did design one, even if it's kind of ad hoc. The end result is that, if this complex action is actually true in our world, any history in which large numbers of Higgs bosons are produced is very unlikely, compared to similar histories where there are not that many Higgs bosons.
In story-form, it's like there is some fate in this universe: the Higgs bosons are cursed by fate, doomed are those who seek its forbidden creation, as everything would turn against them.
Or in many-worlds language: you might think that you are in a universe with a future with LHC intact and creating lots and lots of Higgs bosons, but most likely, the universe you are in is heading towards a future with LHC not intact, a war breaks out between France and Switzerland forcing a shutdown, etc. A future with a war between France and Switzerland is extremely unlikely, but it's still more likely than a future with a ball of Higgs bosons!
The authors are quite concerned about this, and it's a bit justified:
Nevertheless we might believe our model in that case upon witnessing a natural accidental stopping of LHC.The paper was written in 2007, and the quench accident happened in 2008. And if the theory were true, something more sinister could be on the horizon, as the universe turns to increasingly desperate attempts to stop humans from creating Higgs bosons.
The authors then proposed "an economical or ethical attempt to rescue LHC from even worse fates", a game of cards! Basically, to rescue us from worse fates, it's important to know if the theory is true or not. If true, stop LHC, else, go ahead. To test the theory, shuffle a deck with, say, 2 million cards, with one card saying "stop LHC" and all others saying "go ahead". The reason is that, if we do the experiment and got "stop LHC", there's a high chance that the fault is not in us, but in the stars. That is, we didn't just get randomly unlucky with our attempts to create Higgs bosons, the laws of physics are really against us.
Crudely speaking, a superficially “normal” accident would already be strong support for our model. However, it would be even more valid numerically if LHC were stopped by a card play... One could say “oh, it is an accident of bad diplomacy”. Drawing a single specific card from among 2 million cards could only be achieved either by a card magician or by a model like ours.Give them a Nobel Peace Prize for trying to stop the Higgs boson from starting the French-Switzerland war!
They even did a cost-analysis of this experiment. If we run the experiment with 0.2 million cards, and were genuine about our experiment, and really stop the LHC upon taking the card, then the expectation of loss from the experiment is
(1/ 0.2 million) * (3.3 billion dollars, the cost of LHC) = 17000 dollars.An okay price to pay to avoid
a natural stoppage due to explosion or bankruptcy of CERN or other similar things caused by the effect of $S_I$ [the imaginary part of the complex action] in the case that our theory were valid.By the way, Nielsen and Ninomiya have produced a no-go theorem back in 1981, which seems to be actually their most cited work.
Also, LHC has been on for just over 10 years recently ("first light" on 2008-09-10), and it produced some review articles about it, like this one. In general, one kind feels disappointed by the lack of excitement in particle physics while the other tries to look on the bright side and new excitement, such as by looking for deviations from the Standard Model (none so far), and "multi-messenger particle physics" (in analogy to the ""multi-messenger astronomy").
It seems that there's a feeling of less excitement in particle physics, just as in fields I'm better at: classical analysis, abstract algebra, topology. They are mature fields with not a lot to do, it feels, most of the easy or important results are gone and only the hard or less important ones remain. Law of diminishing returns, for sure.
It seems that there's a feeling of less excitement in particle physics, just as in fields I'm better at: classical analysis, abstract algebra, topology. They are mature fields with not a lot to do, it feels, most of the easy or important results are gone and only the hard or less important ones remain. Law of diminishing returns, for sure.
I remember a joke from somewhere that says
Mathematical analysts don't publish papers anymore, they publish treatises.
Well, treatises for sure! The book series Treatise on Analysis by Jean Dieudonné is 9-volumes long and a quick look tells me that the contents of the first two volumes follows pretty much what I studied in the 3-course undergraduate analysis sequence. I dread to think how much time it would take to work through the other 7 volumes if by some twist of fate I must become a classy analyst.
Also note that volumes 6 and 7 contains the first and second halves of chapter 13. Funny. Volumes are supposed to contain whole chapters!
Someone followed up the joke by saying
Well, it's not quite a problem yet, if the proof takes a whole book. Now, if the statement of the theorem takes a whole book, you have a problem.
It is as discussed in ω: with a whimper: messy fields.
A common “end” of a field is for it to degenerate into details; I believe that this is the usual way fields and subfields of science end. You might call it the “heat death” of a field.... wait, the joke is from the paper! Serendipity!
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