The h Bar

user54412

12:44 AM

@PhysicsMeta You can even delete your own posts? You clever AI!

ACuriousMind

@ChrisWhite Could also have been a moderator.

user54412

Perhaps, but that's less fun.

user54412

@JamalS So how do you know about Mark Wise giving out money to students?

Kyle Kanos

4:22 AM

Anyone else notice something new on the Review Queue page?

JamalS

8:07 AM

@ChrisWhite Oh, I see you studied at Caltech. Did you have him for a course then?

I found out about it because there are some online lecture videos of him.

Sofia

12:00 PM

@dmckee are you in Internet? I would like to add an article to be permanently available for people interested in the 2slit experiment. But how to do so? It is an article that my Teacher in QM, Prof. A. Ron, gave me. How and where can I upload it?

@dmckee I think I did the upload. But what to do for preserving this upload, to be available to all the users?

alarge

@Sofia Is that not basically the standard derivation that's a part of most physics 101 books? Anyway, what do you mean that you want to make it permanently available? If you want to use SE, I suppose you could write a question and then answer it (that said, homework-type questions are usually discouraged, so you might end up with those minus votes).

Sofia

12:17 PM

@alarge yes, it is. But it is so clear, that it's worthy to be available to students. There is a young one that made many mistakes, and instead of explaining him, let him have this treatment.

@alarge I have no idea whether a newcomer has access to the h bar room. How can I make the article available to him? Have you any idea?

alarge

I'm not exactly sure who you want to help. Just send them the link to the image?

Sofia

@alarge I suppose that he doesn't have access to the hbar room. Yes, how can I send him a link to the image of the article? Do you know?

@alarge the fellow is a new user with reputation 1 - no privileges.

alarge

The URL is i.stack.imgur.com/5QFve.png, right?

Sofia

@alarge Yesss! So, shall I indicate this address?

@alarge you are a good fellow! Many thanks!

Sofia

3:10 PM

@KyleKanos I hope that you'd get my message. Where are you? Well, I am not sure what he talks about. For describing a sine wave there are two parameters. A sine wave is not described by a single sequence of numbers. He seems not to be aware of that. But I am afraid that his question is of too low level for our site.

Kyle Kanos

3:23 PM

@Sofia: I know what OPs problem is, but I don't see how it's a physics concept issue here, it is entirely a computational issue.

He needs to learn about cumulative distribution functions (probability) and how to sample random numbers (computer science)

There is zero physics content in that question

vzn

3:36 PM

sofia, blogs are good for that kind of archived stuff. might be willing to put it on mine. also running a longrunning discussion on neoclassical models (among other things) in toy models of qm. there is a similar analysis in the great book "quantum challenge" by greenstein/ zajonc.

it is a bit )( strange that feynman listed the 2slit experiment as one of the great/ core mysteries of physics/ light given that derivation... did he ever comment on that derivation? from his statement, its almost as if he wasnt aware of it.

oops ~~neoclassical~~ semiclassical

Sofia

@KyleKanos anyway I flagged the question as being of too low level for our site.

@vzn what is a blog ? I hear this word many times but I have no idea what it means.

vzn

?!? are you serious?

just click on the link

Sofia

@vzn Aye! I half-answered you in Romanian, and the utility began to quarrel with me.

@vzn Uuuuuh, you told me something that I understand nothing "running a longrunning discussion on neoclassical models (among other things) in toy models of qm. Ce mai e si asta?

vzn

there are even a bunch of stackexchange blogs. one of em has its own chat room, mathematics

?!? sof you understand highlighted links (blue) in the chat room right? click on them with your mouse?

actually all you physics geeks/ aficionados should seriously consider starting a physics blog here on stackexchange, its not too hard, & you have so much engagement/ energy here.... & sof virtually already has the 1st post already....

Sofia

3:57 PM

@vzn yes, I pressed and I saw all sort of things, e.g. "an interview with Paulo Cereda". Thank you a lot, I am not interesting in interviews.

vzn

"blogs" are part of the interweb

re this

23 hours ago, by Chris White

Gravitational Lensing by Spinning Black Holes in Astrophysics, and in the Movie Interstellar

a few cool/ fun articles on interstellar movie physics on wired. eg

metaphysics of interstellar, conversation with kip thorne/ christopher nolan wired

how building a black hole for interstellar led to an amazing scientific discovery / wired

alarge

4:19 PM

@vzn I don't really see the utility in a community blog (nor in a personal one, especially about physics, but this is a separate issue). It appears that most of the community blogs are half-dead and I doubt anyone reads them.

vzn

4:30 PM

hi alarge there are many excellent/ lively/ colorful blogs in the world, incl by top physicists, have you not encountered/ read any? cited eg aaronson earlier.

dmckee

@Sofia Document hosting is not part of what Stack Exchange does. There are many other sites around the internet that do, however.

vzn

yes the se blogs are a bit dilapidated in some cases (not in others) but that can also be taken as a more revealing metric/ barometer of "community involvement" that se mgt is always espousing.

se has not made hit statistics public, that annoys me a bit too, but someone could easily hook up a stats counter to a page to get a rough sample idea. anyway wrt low traffic & inactive blogs, it is difficult to disentangle cause & effect there.

vzn

4:51 PM

Luboš Motl, Czech Republic

109k 7 156 313

(argh hit the delete button by accident) ... lubos motl is another prolific/ engaging physics blogger that comes to mind, apparently highly read. his blogs sometimes get quite copious feedback/ dialog/ discussion in the comments.

his blog was cited several times in the recent bohmian mechanics discussion.

alarge

The little I've read of Lubos' blog, I don't think "physics blog" is a fair characterization. It's basically a collection of rants about some theories of physics, often misguided views of economics, with quite a bit of politics in the mix. No thanks, I can live without the rants (but I imagine they do contain interesting information for those working on string theory) and for the rest of the topics, I can find more credible sources.

What I am saying is basically that while some individual posts on some physics blogs may be interesting, I've yet to find a single one I'd like to follow.

I didn't mean to single out Motl or to critique him personally, but you brought him up as an example of a popular blog.

Sofia

5:24 PM

@dmckee I don't have the right to put on Internet that article. But, in the same way, it may be better that the article not be preserved, as I am not the author and not exactly free to do with it whatever I want.

@vzn Oooooo! Is Lubos a Bohmian? Aaaa! I didn't know. But I never see him around. Is he active in the site?

alarge

@Sofia You have to have the proper licence for anything you put on SE, because everything here is under CC BY-SA. This is to say that anyone can take your text from your answer, for example, and (with attribution), do whatever they want with it. For example I think I could make a textbook out of them and sell it for personal profit.

This also means, as I understand it but you should really consult someone more knowledgeable, that you cannot upload on SE anything that you do not give away (in the sense of CC BY-SA). As a result, if something is not yours to give away (you don't own the rights), you're not supposed to put it on here (for example, you shouldn't upload large sections of text books word by word as an answer)

(As for Motl, I think he was strongly against Bohmian mechanics; I also believe he is still quite active on SE)

Sofia

5:50 PM

@alarge , Aaaa, yes? Then I'd better delete that article.

@alarge have you any idea how can one delete an item from i.stack.imgur.com/ ?

alarge

@Sofia I don't know how to delete the images themselves, but if you take the link down, nobody is ever going to find it. The stuff you posted, though, is basically contained in every textbook of physics, so I don't think the author would mind even if his derivations were found online.

So it's not like it's a "secret" preprint of a new result that shouldn't leak or otherwise Nature might not publish it.

Sofia

@alarge aha! Thanks!

vzn

6:18 PM

sof, lubos seems to be a strong critic of bohmian mechanics but sometimes to critique something highly effectively one "must become one with it ('the enemy')" :)

Kyle Kanos

@alarge ...often misguided views of economics... I don't think his views on economics are misguided. Heck, it seems to me (and many others) that the prevailing wisdom in economics is what got us into the mess that the world sees (for the most part).

vzn

ie hes clearly highly well informed on bohmian mechanics & summarizes its deficiencies quite effectively.

re alarge assertion that semiclassical derivation of 2slit experiment "basically contained in every physics textbook".... lol... think it is a key derivation missing from many.

Kyle Kanos

@vzn: There's actually a professor at my university who focuses on early inflationary cosmology & quantum gravity via Bohmian mechanics. I'm tempted to ask him about Lubos' criticisms.

vzn

afaik, it is new/ novel, possibly entirely so, to link bohmian mechanics & cosmology (& universe creation). hence all the commotion over the recent paper.

Kyle Kanos

It's not that new, this guy got his PhD doing it in 1992

Thomas Klimpel

6:31 PM

> It's fair to say that the claim by quantum mechanics that the wave function is not an objectively real wave or field that can be in principle measured is something that we have proven by direct experiments. Attempts to pretend that the wave function is a classical wave are just attempts to mask the truth.

> I am confident that every Bohmist must ultimately realize it is so and he must be dishonest if he claims that his efforts are more justifiable than the efforts of creationists who are trying to obscure the explicit evidence in favor of evolution: they are exactly equally unjustifiable.

These are the words of Luboš Motl in motls.blogspot.de/2013/07/…

Even so they contain much physical truth, they also contain much unjustified rant.

Kyle Kanos

My understanding of Bohmian mechanics is not that they believe the wave function is real, but the modulus is real

They evolve $\rho$ over time, where $\psi=\sqrt{\rho}\exp\left[i S/\hbar\right]$

And $\rho$ is real/measurable.

I could be wrong, however.

Thomas Klimpel

And it also ignores the history, that David Bohm wanted to motivate deeper study of these questions, and the work of John S. Bell can be taken as proof that David Bohm succeeded and was right in a certain sense.

Kyle Kanos

That's just how I've come to understand it

Thomas Klimpel

> Because the wave function has a probabilistic interpretation in proper quantum mechanics (...), it doesn't matter that it spreads. The spreading of the wave function doesn't make the world more fuzzy. It only makes our knowledge about the world more uncertain.

The Bohmians believe that something which contains an unspeakable amount of information is real. This is similar to many-worlds, only that many-worlds is more honest about this point.

And I think Luboš Motl is spot on in this respect. But his ranting, the invented history and accusations of people's motivations are neither spot on, nor helpful.

But David Bohm already included decoherence in his articles, as a way to avoid the separation between classical physics and quantum physics so typical of the QM interpretations in the 30th.

Our physics books today no longer teach that we need classical physics for describing the measurement devises and quantum physics to describe the microscopic world.

They just state that classical physics emerges out of quantum physics, and quantum physics is the only valid description of our world. This is different from Bohr's initial interpretation, only people no longer remember this today.

Aharonov–Bohm effect

The Aharonov–Bohm effect, sometimes called the Ehrenberg–Siday–Aharonov–Bohm effect, is a quantum mechanical phenomenon in which an electrically charged particle is affected by an electromagnetic field (E, B), despite being confined to a region in which both the magnetic field B and electric field E are zero. The underlying mechanism is the coupling of the electromagnetic potential with the complex phase of a charged particle's wavefunction, and the Aharonov–Bohm effect is accordingly illustrated by interference experiments. The most commonly described case, sometimes called the Aharonov–Bo...

Thomas Klimpel

7:39 PM

Funny that Bohm wasn't the first to describe this effect named after him, just like he wasn't the first to describe the pilot wave theory named after him... He seems to have some things in common with Einstein!

Kyle Kanos

I often see it short-handed to dBB theory for de Broglie-Bohm, though I think more people are familiar with it as Bohmian mechanics.

Thomas Klimpel

7:59 PM

In Germany, Karl-Theodor zu Guttenberg committed serious plagiarism. Following this case, many people were accused of plagiarism and sometimes even convicted, even so they were at most a bit sloppy, but certainly didn't intentionally hide their sources.

Annette Schavan

Annette Schavan (born 10 June 1955) is a German politician (CDU). She was the Federal Minister of Education and Research from 2005 to 2013, when she resigned following the revocation of her doctorate due to plagiarism. She currently serves as the German ambassador to the Holy See. == Early life == Schavan was born in Jüchen on 10 June 1955. == Career == From 1995-2005, Schavan served as the minister of culture, youth, and sports for the German state of Baden-Württemberg. During this time, she oversaw school education in Baden-Württemberg. One controversy that erupted during this time was when...

I don't like Annette Schavan politically, but the the fact that she was convicted for plagiarism has worried me more about the state of the German universities than anything that happened to myself...

David Bohm (and Einstein) certainly were sloppy when they published more than once theories which had already been published before. But they were rewarded for their sloppiness. And I also have seen PhD thesis which were badly sloppy with respect to their sources and how they cited them.

In this light, randomly prosecuting people about things more than 30 years in the past is a strong violation of legal procedures to treat everybody on equal footing.

alarge

Related: Stigler's law

I am not very familiar with Schavan's case. Wikipedia says: "Investigators found paraphrasing of secondary literature without naming the source in over 60 cases in the dissertation" which makes it sound like she actively decided not to cite the sources she copypasted text from.

Which, one might argue, is not sloppiness but intentional.

Thomas Klimpel

8:26 PM

I had a look at VroniPlag at the time, and couldn't spot a single case of intentional obscuration in the found passages. There were passages like "according to XYZ such and such is the case", without a proper footnote and no entry about XYZ in the bibliography. Also note that VroniPlag itself decided against publication.

I cannot exclude the possibility that the investigators of the university found more serious cases of plagiarism independently, but in this cases what I could see with my own eyes also has a strong influence on my opinion. And even in case they found something, this still doesn't justify investigating something which is more than 30 years in the past from a random person for no good reason.

Kyle Kanos

I'd call that oversight

ACuriousMind

@ThomasKlimpel I think being a public person claiming to be qualified to oversee the ministry for science and education is different from being a random person

alarge

@ACuriousMind On that note, this is not at all an isolated case: Recently several politicians (of different countries) have had to resign over academic misdeeds.

ACuriousMind

@alarge And I see nothing wrong with that, really. If they indeed committed such misdeeds - however common they may be - they have to take the responsibility for that.

alarge

And on the topic of academic misdeeds, retractions are up. I think Nature had a personal "best" last year (if we don't count the physics papers from 10 years ago, of course)

ACuriousMind

8:35 PM

It's another question if it is always a severe enough thing to resign over, but at least if your qualification for your position derives (partially) from you holding a certain degree, it is.

Thomas Klimpel

@ACuriousMind This is a good reason for stepping down from that position, which she did immediately. This is not a good reason for invalidating her academic degree.

ACuriousMind

@ThomasKlimpel Since I really can't tell what theologian's degrees are awarded for, I also can't really tell whether or not what she did is "fraud" so severe that she should not have gotten her degree. I'm really not sure whether or not that decision was academically justified, or just the result of external pressure.

Thomas Klimpel

@ACuriousMind You serve your time at the university, you write enough relevant academic publications, and you get granted your degree in return. Her supervisors 30 years ago were probably more qualified to judge whether she earned that degree or not than a university committee today trying to judge this in retrospect.

But as I said before, my opinion is influenced by the fact that I read her work and the alleged passages of plagiarism on VroniPlag (and also in some online newspapers), and couldn't find a single case which I would have judged as intentional obscuration.

user54412

9:24 PM

@ThomasKlimpel A somewhat analogous thing happened a while back with Michelle Obama's senior thesis. There was no accusation of wrongdoing, but once her husband was running for President the media took an... unhealthy... interest in things she wrote as just a college student.

user54412

Where this story diverges is that Princeton decided to restrict access to the thesis

user54412

I'm not sure which is more worrying: having committees look into revoking degrees at the request of anonymous internet commentators (worrisome for the individual), or having universities bury published works (worrisome for the public)

user54412

@JamalS Indeed. He taught 3 out of the 4 terms of QM I had. He was quite fun, and I have a ton of anecdotes from that class. And yes, he did give out money, mostly for answering random American/Canadian geography trivia in the middle of class.

user54412

I didn't realize there were online lectures given by him

ACuriousMind

10:33 PM

So, I'll just leave this mathy valentine here: (I'd have thought someone else would have posted it by now :P)

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