Sidney Coleman Is My Interpretation-of-Quantum-Mechanics Guru; Plus BRIEFLY NOTED: for 2021-03-17 We
The talk that made me a many-worlds Everettian; plus things that went whizzing by that I want to remember...
First:
I have long loved Sidney Coleman’s 1994 Quantum Mechanics in Your Face lecture. Now it has been published, for real, with well-drawn versions of the slides:
Sidney Coleman: Quantum Mechanics in Your Face: Transcript and slides edited by Martin Greiter: ’This is a write-up of Sidney Coleman’s classic lecture first given as a Dirac Lecture at Cambridge University and later recorded when repeated at the New England sectional meeting of the American Physical Society (April 9, 1994). My sources have been this recording and a copy of the slides Sidney send to me after he gave the lecture as a Physics Colloquium at Stanford University some time between 1995 and 1998. To preserve both the scientific content and most of the charm, I have kept the editing to a minimum, but did add a bibliography containing the references Sidney mentioned.—MG…
LINK: <https://arxiv.org/pdf/2011.12671.pdf>
And, of course, there still is the video: Sidney Coleman (1994): Quantum Mechanics in Your Face <https://www.youtube.com/watch?v=EtyNMlXN-sw>:
Plus there is the essential reading:
N. David Mermin: What’s Wrong with These Elements of Reality?<https://pdfs.semanticscholar.org/3d27/ad8d1cee3a12b35b4e424b9c36ec424ecc6e.pdf>
N. David Mermin: Is the Moon There When Nobody Looks?: Reality & the Quantum Theory <https://physics.csuchico.edu/kagan/435B/problems/Mermin.pdf>
N. David Mermin (1990): Quantum Mysteries Revisited <http://www.physics.smu.edu/scalise/P5382fa15/Mermin1990a.pdf>
Daniel M. Greenberger, Michael A. Horne, & Anton Zeilinger: Going Beyond Bell’s Theorem <https://arxiv.org/pdf/0712.0921.pdf>
Wojciech H. Zurek: Decoherence & the Transition from Quantum to Classical—Revisited <https://arxiv.org/pdf/quant-ph/0306072.pdf>
You know, i used to think that I would—someday—understand electron spin.
I used to think that I would—someday—understand why Stern-Gerlach magnets arranged along the x-axis would knock an electron that was in the <↑| state in the z-basis into the z-basis <↓| . And I used to think I would—someday—understand why if we rotated the magnets into the y-direction the little square-root-of-minus-one i’s would start appearing in the math…
Now I know that it is hopeless.
And, similarly, it is hopeless to ask why the triple measurement σ(1x)σ(2y)σ(3z) applied to the three electrons 1, 2, and 3 that are in Coleman’s entangled (<↑↑↑| - <↓↓↓|) state always produce the answer +1.
It is the Pauli matrices that are the underlying reality—or, at least, are our only through-a-glass-darkly shadowy and illusory simulacrum of understanding. They are not the things that can be explained in terms of more fundamental principles. They are, rather, our feeble monkey-brain grasp of what the fundamental data are.
All of which is to say that Sydney Coleman’s Quantum Mechanics in Your Face lecture—the title of which, I am told in good authority, is incomprehensible to Britishers, save that they suspect and fear that it is in some way obscene—is the best thing on the interpretation of quantum mechanics I have seen.
And if it does not convince you to be a root-and-branch Everettian many-worlder—well, then I think that, back in The Day, there would have been nothing to convince you to be a non-Ptolemaic Copernican either. The Copernican points would have whizzed by: In the Copernican model there is no unmotivated sharp division between the behavior of the inferior and the superior planets as there is in the Ptolemaic model? You would have shrugged. The peculiar coincidence in the Ptolemaic model that all of the planets have at least one epicycle that is the same as the main cycle of the sun, which lacks an epicycle? You would have stared blank-eyed.
If Coleman doesn’t convince you now. Copernicus would not have convinced you then…
Very Briefly Noted:
Arun Venkatesan: The Iconic Watches That Inspired Apple Watch Faces <https://www.arun.is/blog/apple-watch-faces/>
Econ 135: 4.3.3., 4.4.3., & 4.5.3. Zoom Session: Globalization, Convergence, & Underdevelopment :: Slides <https://www.bradford-delong.com/2021/03/econ-135-433-443-453-zoom-session-globalization-convergence-underdevelopment-slides.html>
Six Paragraphs:
Steve M.: We’re Living in a Post-Trump World, & Republicans Are Still Awful: ‘If you’ve been waiting for the moment when Republicans will start acting abashed, or begin examining their own behavior over the past several years, or acknowledge that their critics have a point about… well, anything, you’re going to have a long wait, because that moment will never come. It might come if Democrats beat Republicans mercilessly in several consecutive election cycles—but Democrats trounced Republicans in 2006 and 2008 and the GOP only got worse. Trumpism hasn’t supplanted old-school Republicanism. Trumpism has simply been added to all the other toxic strains of Republicanism. And we’re getting them all again, full strength…
LINK: <https://nomoremister.blogspot.com/2021/03/were-living-in-post-trump-world-and.html>
David Atkins: Could Democrats Finally Be Taking on the Filibuster?: ‘Most crucial at this inflection point in history, the Republican Party has set itself in fierce opposition to democracy itself. All across America, Republicans are pushing state-based legislation that would dramatically suppress voting rights and limit the ability of marginalized communities to have a voice in government. Republicans know they cannot persuade majorities with their current platform, so they plan instead to legally cheat their way into permanent minority power, reinstituting a new era of Jim Crow and apartheid at the ballot box. Given the current hyperconservative composition of the Supreme Court, The only way to stop it is by a federal act of Congress. But Congressional action will not take place as long as the filibuster remains standing in its current form. Everything, then, comes back to the filibuster…. Even Joe Manchin, the most famous holdout in favor of the filibuster in the Senate Democratic caucus, seems open to a talking filibuster reform…. My Washington Monthly colleague Bill Sher has been taking a contrary stand on this, hoping for compromise legislation between reasonable legislators in both parties and a de-escalation of partisan tensions. But it’s deeply unlikely that the authoritarian white supremacist fever on the right will be broken without destroying the possibility of their taking power through minority rule. Mitt Romney is not going to win the battle for the soul of the GOP–at least, not until the GOP is forced to acknowledge that their only path to legitimate power lies in persuading actual majorities of voters…
LINK: <https://washingtonmonthly.com/2021/03/13/could-democrats-finally-be-taking-on-the-filibuster/>
David Atkins: How Facebook Is Killing Journalism and Democracy | Washington Monthly: ‘It’s high time the federal government do something about It: At the heart of much of this bedlam are the deliberate actions of social media companies in general, which have broadly destroyed the revenue model for journalism–often through deliberate lies–and created engagement algorithms that incentivize hateful polarization and outright disinformation. And no social media has been more guilty of both than Facebook. Two big stories dropped this week highlighting Facebook’s ongoing role in sabotaging both journalism and democracy in the pursuit of profit. The first is a devastating story by Karen Hao at the MIT Technology Review on how Facebook’s artificial intelligence unit learned how to efficiently drive engagement on the platform by recommending increasingly inciteful and extremist content and groups. Then, when the teams involved in creating this monster began to realize what they had unleashed and took steps to curtail it, the company (largely at the direction of Mark Zuckerberg himself) refused to do anything significant about it–choosing instead to deflect the problem toward issues of bias rather than polarization and disinformation…. Worse, Facebook’s efforts at controlling bias were manipulated by Trump and the conservative media’s endless factory treadmill of self-pitying victimhood into specially privileging the very conservative disinformation that was the biggest offender for asymmetric polarization…. Facebook is not, of course, the only social media organization that has contributed to this. Youtube (now a subsidiary of Google’s parent company Alphabet) in particular is famous for leading users down a primrose path to radicalization, guiding the unsuspecting down a pipeline from videos on anything from Star Wars to fitness to economics, straight to Jordan Peterson, Prager University or Ben Shapiro in just minutes. But Facebook’s algorithms have been particularly aggressive, and its consequences especially devastating…. As if that were not bad enough, Facebook has also been responsible for lying to journalists about what would provide more of the paltry revenue they were still allowed to keep. Most striking was the “pivot to video” era, in which Facebook allegedly dramatically overstated the potential for revenue from video content…
David Atkins: Facebook’s Vaccine Disinformation Study Shows the Problem with Facebook: ‘Facebook can’t do anything about the fact that there are large pockets of angry, low-trust conspiracy theorists online. But Facebook could do something about the fact that those pockets have disproportionate impact on a larger universe, because Facebook tailors its engagement algorithms to promote the most controversial voices. It is no surprise at all that a small number of obnoxious people on Facebook are impacting the opinions of much larger groups on Facebook…
Financial Times Editorial Board: The Unhappy Consequences of Lula’s Return: ‘Latin America’s most famous politician has made a triumphant return to centre stage after a supreme court judge unexpectedly quashed his convictions for corruption. No matter that the ruling favouring former Brazilian president Luiz Inácio Lula da Silva was based on a mere technicality; his supporters hailed the decision as a vindication of their long-held belief that Lula was the victim of a politically motivated vendetta. The consequences of the ruling, assuming that it is upheld by the full court, are immense. At a stroke, it redraws the electoral map for next year’s presidential election by allowing Lula to run again. Hard-right President Jair Bolsonaro had been in a strong position to win re-election against a divided opposition; now he is likely to face a strong challenge from the left. Bolsonaro has a woeful record in power, which has included repeatedly praising dictatorship, allowing Amazon deforestation to surge to 12-year highs and dangerously mismanaging the pandemic, while disappointing investor hopes for big economic reforms. That might invite the conclusion that a ruling allowing Lula’s return can only be good for Brazil. Yet the judge’s decision has unhappy consequences. It strikes a heavy blow against the credibility of Latin America’s biggest and most successful corruption investigation. It raises disturbing questions about Brazil’s justice system. And it increases the chances that the country’s notoriously venal politicians can get back to business as usual…. In their zeal to bring the powerful to book, prosecutors made serious mistakes. Leaked messages between a judge trying the cases, Sergio Moro, and prosecutors discussing what evidence to use against Lula suggested corners were being cut to secure convictions. Moro’s subsequent decision to accept a cabinet post in Bolsonaro’s government only fuelled accusations of political bias…. Brazil now faces the ominous prospect of impunity for the corrupt: the “Lava Jato” investigation was quietly wound up last month after seven years. Almost as unappealing is the promise of a polarised election next year between candidates of the hard right and the old-fashioned left… LINK: <https://www.ft.com/content/90556eda-a658-4849-be51-fff7c0a99a23>
Noah Smith: Checking in on the Global South: ‘To some, the idea of a Global South means that history is destiny—that the dead hand of colonialism, or the living hand of neocolonialism, is holding down the developing world. To others, it’s an expression of the idea that poor countries just don’t have what it takes to get rich. Either way, it’s a form of implicit defeatism—a belief that historical and/or cultural forces are stronger than economic forces. Southeast Asia hasn’t yet broken these ideas on the wheel of hard data, but it might not take much longer to do so. Bangladesh’s similar performance, meanwhile, suggests that South Asia might not be far behind…
LINK: <https://noahpinion.substack.com/p/checking-in-on-the-global-south>
Kieran Healy: America’s Ur-Choropleths: ‘Maps of the U.S. for whatever variable in effect show population density more than anything else…. The other big variable… is Percent Black. Between the two of them, population density and percent black will do a lot to obliterate many a suggestively-patterned map of the United States… LINK: <https://kieranhealy.org/blog/archives/2015/06/12/americas-ur-choropleths/>
Kieran Healy references the indefatigable xkcd, and that reminded me that voting maps in the U.S. also show the shoreline of North America in the Cretaceous. Which is a different point.