tag:blogger.com,1999:blog-22973357.post8263610946455870866..comments2020-07-02T02:25:07.952-04:00Comments on Sabine Hossenfelder: Backreaction: Physicists still lost in mathSabine Hossenfelderhttp://www.blogger.com/profile/06151209308084588985noreply@blogger.comBlogger177125tag:blogger.com,1999:blog-22973357.post-76571778186815827112020-06-25T10:41:47.575-04:002020-06-25T10:41:47.575-04:00PhysicistDave,
“Andrei, I took QM and Intro to El...PhysicistDave,<br /><br />“Andrei, I took QM and Intro to Elementary Particle Physics from Dick Feynman.”<br /><br />OK, tell me if you agree or not with the formula 21.1 here:<br /><br />https://www.feynmanlectures.caltech.edu/II_21.html<br /><br />“You have no idea what you are talking about because, as you admitted, you cannot handle the math.”<br /><br />This is irrelevant. It’s not necessaryAndreihttps://www.blogger.com/profile/05519448415253342448noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-12655787935370955282020-06-25T01:39:38.192-04:002020-06-25T01:39:38.192-04:00Andrei wrote to me:
>Feynman says that there is...Andrei wrote to me:<br />>Feynman says that there is a clear mathematical correlation between the fields originating from a charge and that charge. He presents those equations in his lectures. Dave believes otherwise. Who is the better "brain surgeon" here? <br /><br />Andrei, I took QM and Intro to Elementary Particle Physics from Dick Feynman. The Feynman Lectures were the PhysicistDavehttps://www.blogger.com/profile/11111405959451703182noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-32728895579813502892020-06-22T23:16:14.155-04:002020-06-22T23:16:14.155-04:00Mozibur10:28 AM, June 22, 2020
I was being sarky....Mozibur10:28 AM, June 22, 2020<br /><br />I was being sarky. It's not going to take anybody 300 years to learn some new algebra and geometry. NCG is already used in theoretical physics.Steven Evanshttps://www.blogger.com/profile/13898046706669437332noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-72752966889602713742020-06-22T10:31:48.353-04:002020-06-22T10:31:48.353-04:00@ari:
'Everything is reduced to physics'....@ari:<br /><br />'Everything is reduced to physics'. I don't think the best physicists think like that. It's a simple-minded joke that keeps cropping up that's not really even worth a laugh. Moziburhttps://www.blogger.com/profile/11836761141351221660noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-81875450740564043792020-06-22T10:28:18.313-04:002020-06-22T10:28:18.313-04:00@Steve Evans:
I don't understand you. That se...@Steve Evans:<br /><br />I don't understand you. That seems like a really superficial way to understand the relationship between creativity and pedagogy. Moziburhttps://www.blogger.com/profile/11836761141351221660noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-2708600179446547562020-06-22T10:23:13.485-04:002020-06-22T10:23:13.485-04:00@Prof Edwards:
I had a quick glance at your '...@Prof Edwards:<br /><br />I had a quick glance at your 'paper'. It looks entertaining. Have you had it published in a peer reviewed journal yet?<br /><br />LQG is a continuation of Wheelers geometro-dynamics. And last time I looked, that programme is alive and kicking. <br /><br />When Maxwell came up with his equations it was mostly ignored. It took a couple of decades for the Physics Moziburhttps://www.blogger.com/profile/11836761141351221660noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-63617617835107192102020-06-22T06:38:09.173-04:002020-06-22T06:38:09.173-04:00Sabine,
I have only got as far as Chapter 7 so fa...Sabine,<br /><br />I have only got as far as Chapter 7 so far - yours is not a book to be rushed because it is full of insights!<br /><br />A notable example, was your observation that people didn't cling to the Earth-centred view of the cosmos just for religious reasons - naturalness played its part too - if we orbited the sun, there would be parallax effects visible by observing the sky David Baileyhttps://www.blogger.com/profile/06172248428321078417noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-87202069194252502302020-06-22T05:19:32.227-04:002020-06-22T05:19:32.227-04:00PhysicistDave,
"Andrei, you are not telling ...PhysicistDave,<br /><br />"Andrei, you are not telling the truth."<br /><br />Of course I am. Just another typical false accusation from your part.<br /><br />"You just think no one will bother to check out the fact that you are lying."<br /><br />Au contraire my dear Dave! I hope that everybody here will take the time to check and see for themselves that the link you providedAndreihttps://www.blogger.com/profile/05519448415253342448noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-80531672647141302462020-06-20T02:12:16.793-04:002020-06-20T02:12:16.793-04:00Werner wrote to me:
>This is true only if you t...Werner wrote to me:<br />>This is true only if you think of the wave function as describing an individual system. But it has been known for a long time that it should be thought of as representing an ensemble of identically prepared systems. Hasn't Schrödinger's cat demonstrated that long ago?<br /><br />>The "measurement problem" is the result of misunderstanding the rolePhysicistDavehttps://www.blogger.com/profile/11111405959451703182noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-17128957147969363092020-06-19T23:24:05.226-04:002020-06-19T23:24:05.226-04:00Andrei wrote to me:
>I feel no joy in respondin...Andrei wrote to me:<br />>I feel no joy in responding to this, but this statement is such a complete distortion of the truth that I need to defend myself.<br /><br />>PhysicistDave repeatedly failed to address my argument: <br /><br /><b>Andrei, you are not telling the truth.</b> You just think no one will bother to check out the fact that you are lying.<br /><br />On <a href="http://PhysicistDavehttps://www.blogger.com/profile/11111405959451703182noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-7821589065065394162020-06-19T13:04:02.508-04:002020-06-19T13:04:02.508-04:001. Everything is reduced physics. So they could cl...1. Everything is reduced physics. So they could claim the credit to everything. To get basics right doesn’t mean you get credit to everything. To think that person who invented piano or violin can think himself above Chopin or Vivaldi is just silly.<br /><br />2. <br />"So the transistor was invented by physicists, but those physicists were only inventors and not physicists, so it's not Arihttps://www.blogger.com/profile/05827770764242875617noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-63055349596704549072020-06-19T11:34:41.991-04:002020-06-19T11:34:41.991-04:00Dear Sabine,
I don't believe the "progre...Dear Sabine,<br /><br />I don't believe the "progress of the society" depends much on foundations of physics anymore. I'm sure it used to do. Perhaps better understanding QE will help with superconductivity but I'm skeptical. Can you elaborate on that? How much uptick in GDP or some other measure we can expect? Describe something more concrete or measurable. Even relativity Arihttps://www.blogger.com/profile/05827770764242875617noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-43538719930162586572020-06-19T09:01:55.834-04:002020-06-19T09:01:55.834-04:00" the average physicist/mathematician may exp..." the average physicist/mathematician may expect to understand what Connes is doing in 300 years time after the novelties of his work has been digested by the two communities. "<br /><br />That's right. It takes so much longer to read and understand a mathematical idea than to come up with it. Steven Evanshttps://www.blogger.com/profile/13898046706669437332noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-31902459625901988592020-06-19T07:10:44.271-04:002020-06-19T07:10:44.271-04:00I am rather constrained on time today, so I may no...I am rather constrained on time today, so I may not respond in full. Sixte's comments are in line, and the discussion on measurement is similar to the sort of undecidability of all possible outcomes on hidden variables. This is why I say superdeterminism is about nonlocal hidden variables. Conversely I disagree with Andrei. Attempts to work around the epistemological barrier or horizon of QM Lawrence Crowellhttps://www.blogger.com/profile/12090839464038445335noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-68658665051881904302020-06-19T05:37:26.163-04:002020-06-19T05:37:26.163-04:00@ Mozibur,
There are no sociological barriers to ...@ Mozibur,<br /><br />There are no sociological barriers to overcome; one 'merely' needs to know a great deal of modern mathematics. Connes' work is so great that it deserves a place on Sagan's Disk!!Prof. David Edwardshttps://www.blogger.com/profile/16079658994584920395noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-92188230055458924302020-06-19T05:34:13.575-04:002020-06-19T05:34:13.575-04:00@ Mozibur,
Wheeler gave up on his geometrodynamic...@ Mozibur,<br /><br />Wheeler gave up on his geometrodynamics program in the 70s because he couldn't geometricize Fermi-fields. One can now do that using Connes' noncommutative geometry. See my lecture notes "Einstein's Dream" on my webpage for a description of this revised program.Prof. David Edwardshttps://www.blogger.com/profile/16079658994584920395noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-5146380368611397882020-06-19T03:31:14.397-04:002020-06-19T03:31:14.397-04:00Lawrence Crowell,
Let me be more precise about th...Lawrence Crowell,<br /><br />Let me be more precise about the FR argument. From the FR paper we read:<br /><br />"The other observer, agent W, has no direct access to the outcome z observed by his friend F"<br /><br />It is not possible to isolate a lab in such a way so that someone outside cannot observe the outcome of a measurement. The only limit, for both the inside and outside Andreihttps://www.blogger.com/profile/05519448415253342448noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-72987551832765211792020-06-19T03:26:41.000-04:002020-06-19T03:26:41.000-04:00Lawrence Crowell,
"I see superdeterminism as...Lawrence Crowell,<br /><br />"I see superdeterminism as a sort of hidden variable theory."<br /><br />Yes, it is a deterministic HVT where the statistical independence assumption (SI) does not hold.<br /><br />"This has the implicaton superdeterminism is a formalism for a nonlocal hidden variable."<br /><br />Not true. If SI cannot be shown to hold for a specific theory, Bell&Andreihttps://www.blogger.com/profile/05519448415253342448noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-6320930624483098392020-06-19T03:07:26.223-04:002020-06-19T03:07:26.223-04:00@NickW:
I vaguely knew that Wolfram had come up w...@NickW:<br /><br />I vaguely knew that Wolfram had come up with some magnum opus on the foundations of physics but I'd dismissed it - I do this with anything that mentions computation in relation to physics. To me, it seems like the flavour of the era rather than something truly fundamental. <br /><br />Anyway, I just looked up his work now and it seems his work is akin to causal networks (Moziburhttps://www.blogger.com/profile/11836761141351221660noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-63504168222849702532020-06-19T02:48:07.526-04:002020-06-19T02:48:07.526-04:00I'd also mention LQG, they have actually made ...I'd also mention LQG, they have actually made some sense of the Wheeler-de Witt equation and moreover found solutions.<br /><br />Did you come across Connes work on the standard model? His spectral action principle outputs the entire SM including neutrino mixing - all hundred plus terms or so! <br /><br />I find that marvellous. I don't know why we weren't told this in our physics Moziburhttps://www.blogger.com/profile/11836761141351221660noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-59548679924364973882020-06-19T02:15:02.727-04:002020-06-19T02:15:02.727-04:00@Jean-Paul:
It's interesting to see Poppers m...@Jean-Paul:<br /><br />It's interesting to see Poppers motion of propensity turn up in this discussion. I managed to track down Poppers short work on propensity a few months ago where he dismisses the usual frequentist explanation of probability in favour of his notion of propensity as a quantitative measure, as you point out, of a potentiality of change.<br /><br />In fact, when I was Moziburhttps://www.blogger.com/profile/11836761141351221660noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-32595454648666994432020-06-19T02:04:49.072-04:002020-06-19T02:04:49.072-04:00@piotr:
To say that the light-bulb and transistor...@piotr:<br /><br />To say that the light-bulb and transistor is not fruit of physics, is rather like saying that the novel is not the fruit of writing.<br /><br />It's just silly. <br /><br />You might want to note that Bardeen won the Nobel prize for physics, not just once, but twice. <br /><br />I'd like to point out here that Shockley was a scientific racist - he was into the Moziburhttps://www.blogger.com/profile/11836761141351221660noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-30067744199637015372020-06-19T01:51:19.260-04:002020-06-19T01:51:19.260-04:00It's part of a certain mythical tradition of t...It's part of a certain mythical tradition of thought that says science requires 'iconoclasm'. I'd say that this is in the scientific realm what individualism amounts to in the social and political realm. <br /><br />But I don't think this is quite true. The great physicists were actually conservatives. They were, instead, forced to their new and novel conclusions by exhaustingMoziburhttps://www.blogger.com/profile/11836761141351221660noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-51407867837997975972020-06-19T00:54:33.401-04:002020-06-19T00:54:33.401-04:00It's not only physicists that can get lost in ...It's not only physicists that can get lost in maths, mathematicians can get lost in it too!<br /><br />Sometime ago I got excited about Connie's non-commutative Geometry. It sounded like an excellent idea. If Einstein can be said to have geometrised gravity, then geometrising quantum theory may turn out to yield new insights. And of course since quantum mechanics is famously Moziburhttps://www.blogger.com/profile/11836761141351221660noreply@blogger.comtag:blogger.com,1999:blog-22973357.post-37376295188482093492020-06-18T13:07:14.272-04:002020-06-18T13:07:14.272-04:00Lawrence This has the implicaton superdeterminism...Lawrence <i> This has the implicaton superdeterminism is a formalism for a nonlocal hidden variable.</i><br /><br />Exactly. In this regard, it is not less "nonlocal" than the De Broglie-Bohm theory. But I avoid the (problematic) word "nonlocal", because some people could get afraid of it. I prefer "spatially distributed support". <br /><br /><i>The solution to the Sixtehttps://www.blogger.com/profile/11403777924261665599noreply@blogger.com