tag:blogger.com,1999:blog-13869903.post9042337754194616053..comments2024-03-15T21:47:07.684-05:00Comments on nanoscale views: Ask me something.Douglas Natelsonhttp://www.blogger.com/profile/13340091255404229559noreply@blogger.comBlogger43125tag:blogger.com,1999:blog-13869903.post-37856533306312101802020-06-01T04:25:24.183-05:002020-06-01T04:25:24.183-05:00This comment has been removed by a blog administrator.Arhumhttps://www.blogger.com/profile/12824128421129731724noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-59539111864170675772015-04-14T06:48:21.924-05:002015-04-14T06:48:21.924-05:00This blog is one of a kind! Showing tips on how ar...This blog is one of a kind! Showing tips on how artists do their artwork is very useful to other artist also.High School Diploma Onlinehttp://www.stanleyhighschool.com/counselor/why-high-school-diploma-should-be-your-first-priority-or-preference.htmlnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-66783107443477413152015-03-26T01:08:41.442-05:002015-03-26T01:08:41.442-05:00You completed certain reliable points there. I did...You completed certain reliable points there. I did a search on the subject and found nearly all persons will agree with your blog. <br /><br />Accreditation GED Onlinehttp://accreditedgedonline.weebly.com/noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-54623371831397086392014-09-01T14:38:01.968-05:002014-09-01T14:38:01.968-05:00Want to Make Website or Software...? Any Type of W...Want to Make Website or Software...? Any Type of Website and Software and Desktop and Web Based Applications.<br />Want to Make Now, Just Contact us at Skype<br />Skype : Jobz.CornerAnonymoushttps://www.blogger.com/profile/11121184677516882155noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-67552976740899498002013-06-10T23:01:04.802-05:002013-06-10T23:01:04.802-05:00http://en.wikipedia.org/wiki/Quantum_biology
The ...http://en.wikipedia.org/wiki/Quantum_biology<br /><br />The physics department should get funds for this?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-23621145367967065312013-06-10T16:15:01.892-05:002013-06-10T16:15:01.892-05:00You have addressed molecular electronics so I will...You have addressed molecular electronics so I will ask 'what is the state of superconductors?'Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-64049774608631556962013-06-08T10:02:55.294-05:002013-06-08T10:02:55.294-05:00Anon@3:24, well, the last revisions to Landau and...Anon@3:24, well, the last revisions to Landau and Lifschitz are about fifty years in the past as far as I know. That means that it omits many things that have become very useful in modern experimental biology. That being said, LL is a tremendous set of books, and if you've really mastered it, you should be in great shape for a quantitative approach to many disciplines.Douglas Natelsonhttps://www.blogger.com/profile/13340091255404229559noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-86254935108133642082013-06-04T15:24:57.843-05:002013-06-04T15:24:57.843-05:00Cynical question, lets say i'm an amateur who ...Cynical question, lets say i'm an amateur who has studied all the volumes of the Course of Theoretical Physics:<br /><br />http://en.wikipedia.org/wiki/Course_of_Theoretical_Physics<br /><br />and wish to study Cell Biology. am i actually missing in regards to a proper grounding in physics due to recent research?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-74860926161540403472013-05-29T13:29:59.701-05:002013-05-29T13:29:59.701-05:00Anon@4:40 - Perhaps that's a better question t...Anon@4:40 - Perhaps that's a better question to ask a theorist. I think there are plenty of problems out there (e.g., general mechanism of high-Tc; computationally better ways to deal w/ exchange/correlations in DFT; strong coupling problems; quantum systems out of equilibrium).<br /><br />Anon@12:58, I don't know of a book that really takes the experimental perspective like that. There are a couple of very nice books about low temperature experiments (Pobell; Richardson and Smith), but if there's a meso/nano one, I don't know it. I have a colleague yesterday who was bemoaning even the lack of a really definitive work about the experimental details of scanning tunneling spectroscopy.<br /><br />Curious, MoS2 and other related dichalcogenides are very interesting. Spin orbit physics, correlation effects like charge density waves, the ability to intercalate things between the layers - all of these make these materials exciting. As for large scale use, I've said before there is an enormous economic inertia behind silicon. Given that growth of high quality, large-area MoS2 and the technology for making complementary devices on it are both rather immature, it seems unlikely that it will be a major player in conventional electronics applications for a long, long time. Still, it's early days yet.Douglas Natelsonhttps://www.blogger.com/profile/13340091255404229559noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-82645361350151039462013-05-28T23:51:01.310-05:002013-05-28T23:51:01.310-05:00Dear Prof. Natelson,
Could you please comment on ...Dear Prof. Natelson,<br /><br />Could you please comment on those recent experiments on MoS2 films? I read that MoS2 may be better than graphene for electronics applications because it has a large bandgap, while graphene does not.<br /><br />Does MoS2 have drawbacks that might make its large-scale use problematic? Do you think one could achieve current densities in planar MoS2 that could compete with Si FinFETs? <br /><br />And, lastly, is it an interesting material from the physicist's point of view?<br /><br />Best regards,<br />Curiousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-81930500161612056632013-05-28T00:44:06.819-05:002013-05-28T00:44:06.819-05:00Doug- Thanks for your response to my question abou...Doug- Thanks for your response to my question about D-wave. Knowing how fragile these nanoscale circuits can be, I wonder what will happen when one of the Josephson junctions of their fancy computer fails, and the $10M machine stops "annealing". I hope they have a good warranty!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-65255511041273967292013-05-27T12:58:42.735-05:002013-05-27T12:58:42.735-05:00Is there any in depth books on the subtle issues o...Is there any in depth books on the subtle issues of experimentation at the microscopic and mesoscopic scalesAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-73750158618153943342013-05-25T04:40:30.309-05:002013-05-25T04:40:30.309-05:00Do you have a personal list of the top 10 outstand...Do you have a personal list of the top 10 outstanding theoretical problems to consider in condensed matter?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-83844239849711938762013-05-24T17:17:04.559-05:002013-05-24T17:17:04.559-05:00Anon 9:01 - Be careful. Science is pretty sloppy ...Anon 9:01 - Be careful. Science is pretty sloppy with the word "Law". When I teach freshman physics, I call Ohm's Law "Ohm's observation that was approximately true for materials of interest in 1827". Ohm also has a law of acoustics that is widely held to be untrue.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-84187203236621578502013-05-24T09:21:23.305-05:002013-05-24T09:21:23.305-05:00Anon 8:57-9:13:
1) No, I don't think there'...Anon 8:57-9:13:<br />1) No, I don't think there's a deep connection between the Gibbs phase rule and geometric solids, though I'm prepared to learn if there is something deep there.<br />2) Don't know what you're asking here. The "laws" you mention (except Newton) are all related to linear-order solutions to transport-like equations. I suppose you could say that a "rigid body" is a super-tranporter of momentum, but I don't see how that's a useful way to think about things.<br />3) Magnetic units are awful, but if you properly treat magnetic work self-consistently you can find appropriate thermodynamic relations. See here: http://cdn.intechopen.com/pdfs/33437/InTech-Thermodynamics_of_electric_and_magnetic_systems.pdf<br />Yes, Pitzer was president at Rice, before my time.<br />4) Wikipedia is your friend: http://en.wikipedia.org/wiki/Pyrite<br />5) Again, not sure what you're asking, though this comment sounds like Uncle Al a bit.Douglas Natelsonhttps://www.blogger.com/profile/13340091255404229559noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-3018560786229748822013-05-24T09:11:50.327-05:002013-05-24T09:11:50.327-05:00Anon re: Dwave - sorry - somehow blogger ate my or...Anon re: Dwave - sorry - somehow blogger ate my original response to you and I didn't notice. Short version: I basically agree w/ Scott Aaronson on most things. Dwave's approach to publicity doesn't sit terribly well with me, though I understand it. Just because Google and LMCO spend money on something doesn't automatically make it correct, and both companies are willing to look at long-shot investment as a form of insurance.<br /><br />Anon@4:25pm - There is a natural symbiosis between theorists and experimentalists. The best experimentalists understand a lot of theory, and know when to worry about quantitative precision vs. qualitative scaling; the best theorists understand quite a bit about relevant experiments.Douglas Natelsonhttps://www.blogger.com/profile/13340091255404229559noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-77423524692198052982013-05-24T08:02:50.432-05:002013-05-24T08:02:50.432-05:00@Doug replying to Grumpy & David Brown: I hope...@Doug replying to Grumpy & David Brown: I hope Kurzweil is wrong, but I am not sure his prediction is nothing to worry about. My definition of the full onset of the Singularity is when (and if) the net AI IQ exceeds the sum of all the human IQs by a factor of at least one billion. The human brain might have about 100 billion neurons and 100 trillion synapses. The nervous system of the nematode C. elegans might have about 300 neurons. Thus my definition is roughly when (and if) the net AI IQ makes the net human IQ seem like a nematode level. (Bad news if it happens)<br />http://www.singularityweblog.com/17-definitions-of-the-technological-singularity/<br />http://en.wikipedia.org/wiki/Google_driverless_car<br />http://www.ted.com/talks/sebastian_thrun_google_s_driverless_car.html According to Wikipedia, Nevada, Florida, and California have already licensed the testing of Google's driverless automobiles on public streets. One such car has driven across the Golden Gate Bridge in ordinary traffic.David Brownhttps://www.blogger.com/profile/10537922851243581921noreply@blogger.comtag:blogger.com,1999:blog-13869903.post-19500070066813345602013-05-24T02:28:03.069-05:002013-05-24T02:28:03.069-05:00Hi Doug,
I think I found the answer to my previou...Hi Doug,<br /><br />I think I found the answer to my previous question about the D-wave news... Scott Aaronson has a very informative post about the "quantum annealer":<br /><br />http://www.scottaaronson.com/blog/?p=1400<br /><br />Vive l'internet!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-62894105038472819122013-05-23T21:13:01.282-05:002013-05-23T21:13:01.282-05:00With some pain, in high-school chemistry we all le...With some pain, in high-school chemistry we all learned to balance oxidation-reduction equations. Up for discussion is the rumor that anyone with a program that solves simultaneous linear equations can balance a redox reaction. It’s built into the TI-84 pocket calculator. <br /><br />For an example, try balancing the equation for a mixture of ammonium nitrate and nitromethane (CH3NO2). You want to end up with only nitrogen gas, water vapor, and carbon dioxide. It’s not very nice, but that was the recipe for the Oklahoma City bomb. <br /><br />Sincerely,<br />Born in Oklahoma City<br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-23162435657075765822013-05-23T21:10:36.584-05:002013-05-23T21:10:36.584-05:00Here’s one from condensed matter:
The mineral pyr...Here’s one from condensed matter:<br /><br />The mineral pyrite, fool’s gold, has the formula FeS2. Pyrite recently turned up in primary lithium batteries. What are the valences of iron and sulfur in pyrite?<br /><br />Enjoy,<br />Rox for Jacques<br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-65076563866267445282013-05-23T21:07:39.038-05:002013-05-23T21:07:39.038-05:00The second edition of Pitzer and Brewer’s rewrite ...The second edition of Pitzer and Brewer’s rewrite of Lewis and Randall’s Thermodynamics lists on page 513 eight pairs of intensive and extensive properties. For each pair, the product of intensive times extensive has the units of energy. (Their list can be extended, how about E = mc2)<br /><br />However, right after their list, Pitzer and Brewer had to punt. They don’t list magnetic properties; the intensive-extensive pair does not have the units of energy. The intensive SI Tesla seems OK. But the conventional extensive side of the pair has units of ampere meter. Their product is not energy. On the other hand, magnetic moment has the units of ampere (turns) times the area of the coil. That’s much more intuitive than ampere-meter and the product has the units of energy. <br /><br />Would “Killer E&M” need to have its textbook rewritten?<br /><br />Wasn’t Ken Pitzer the President of Rice?<br />BEE & AITCHAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-55209039226582873232013-05-23T21:01:42.963-05:002013-05-23T21:01:42.963-05:00There are at least five linear transport laws, nam...There are at least five linear transport laws, named after Ohm, Fick, Fourier, Darcy, and Newton. Newton’s Law is not F = ma, it is the transport of momentum across a velocity gradient. The laws have much in common. All of them go nonlinear if you try to go too fast. At low temperatures, Ohm’s Law and Darcy’s Law become supertransporters: something moves without a potential gradient. <br /><br />In the old Engineering Library at Princeton, I read a speculation that cooled materials become supertransporters of Newtonian momentum, and for some materials super transport extends above room temperature. Consider the legs of your desk; they shrinketh not but they transporteth momentum. Gravity distorts telescope lenses less than a quarter wavelength of light during 100 years.<br /><br />Later, I went back to the E-Quad library and couldn’t find the original reference.<br /><br />Regards,<br />Que es, Dee<br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-71897099328445687402013-05-23T20:57:33.989-05:002013-05-23T20:57:33.989-05:00F + P = C + 2 Gibbs
F + V = E + 2 Euler
...F + P = C + 2 Gibbs<br />F + V = E + 2 Euler<br /><br />Are these two equations the same thing? Is Gibbs’ degrees of Freedom, number of Phases, and Components related to Euler’s Faces, Vertices, and Edges? <br /><br />Love,<br />Deeth Keynes-Neff<br />Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-55297611324840519052013-05-23T16:25:41.206-05:002013-05-23T16:25:41.206-05:00I would like your opinion on the relationship betw...I would like your opinion on the relationship between theorists and experimentalists in condensed matter.<br />It seems there exists a substantial divide.<br /><br />http://condensedconcepts.blogspot.ca/2013/05/listen-to-experimentalists-sometimes.html#comment-formAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-13869903.post-29928041545395972392013-05-23T09:37:29.027-05:002013-05-23T09:37:29.027-05:00Grumpy, my best guess is, for mainstream computing...Grumpy, my best guess is, for mainstream computing applications over the next couple of decades, silicon all the way down (to a few nm critical feature size), followed by 3d integration and architecture advances to allow cooling in such geometries. Longer term, probably some kind of quantum computation in niche applications. A rise in optical interconnect technology, but right now I don't see nanoscale photonic logic happening any time soon.<br /><br />David Brown, while I respect Kurzweil's contributions in computing (e.g., optical character recognition), on this topic frankly I think he's a bit around the bend. I'm a bit sci-fi fan, but the Singularity as envisioned by some just isn't something I worry about. I think the probability that the Singularity (I'd be curious for your precise definition - strong AI, mind uploading, ubiquitous molecular nanofab or at least 3d printing, a post-scarcity societ?) happens for a significant part of the world's population by 2045 is very very small. Less than 1%. Regarding driverless cars, at most one state (California), though I think you are going to see some serious irrationality about risk from the general public on this one. Wait until the first accident where a driverless car has a failure or design glitch and kills a pedestrian. It won't matter what the ordinary per-mile-driven accident rates are - there will be big-dollar lawsuits and a backlash. I do think driverless cars will happen eventually, but five years is way to fast.Douglas Natelsonhttps://www.blogger.com/profile/13340091255404229559noreply@blogger.com