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Gerard ’t Hooft, Theoretical Physics as a Challenge

Gerard ’t Hooft, Theoretical Physics as a Challenge
by Gerard 't Hooft Note: This web site will soon be removed from its present address. An updated and renewed version is available at: This is a web site for young students - and anyone else - who are (like me) thrilled by the challenges posed by real science, and who are - like me - determined to use their brains to discover new things about the physical world that we are living in. It so often happens that I receive mail - well-intended but totally useless - by amateur physicists who believe to have solved the world. It should be possible, these days, to collect all knowledge you need from the internet. I can tell you of my own experiences. Theoretical Physics is like a sky scraper. Note that this site NOT meant to be very pedagogical. Languages:English is a prerequisite. French, German, Spanish and Italian may be useful too, but they are not at all necessary. Return to List Now, first things first : Algebraic equations. Related:  Quantum Mechanics

Physics of Collective Consciousness by Attila Grandpierre Attila Grandpierre, Ph.D. Konkoly Observatory of the Hungarian Academy of Sciences H-1525 Budapest P. O. Box 67., Hungary February 6, 1996 From: ABSTRACT: It is pointed out that the organisation of an organism necessarily involves fields which are the only means to make an approximately simultaneous tuning of the different subsystems of the organism-as-a-whole. 1. It is generally accepted that consciousness evolved parallel to the biological and social complexity of the living systems. 2. It is widely believed, that the way evolution manifest is from parts to the whole, from the inorganic matter through the unicellular organism towards the multicellular ones until the appearance of consciousness. This chain of thought places collective phenomena into the centre of evolution and the generation of consciousness. 3. Experiments show that collective biological fields may dominate the individual field (Popp, 1994). 4.

[nanocursus] De EPR-Paradox, het experiment van Bell en waarom het heelal waarschijnlijk niet gedetermineerd is - Cursussen en FAQ's - Wetenschapsforum De EPR-Paradox, het experiment van Bell en waarom het heelal waarschijnlijk niet gedetermineerd isDe EPR-paradoxDe EPR-paradox komt eigenlijk neer op de vraag of er toeval is in het heelal. Volgens de kwantumtheorie wel, daar gebeuren dingen die enkel van het toeval afhangen. 3 wetenschappers waren het daar echter niet mee eens: Einstein, Podolsky en Rosen. Daarom bedachten ze een paradox die aantoonde dat het heelal echt niet van het toeval kon afhangen. "Als het heelal echt toevallig is", zo zeiden ze, "dan komen wij de EPR-paradox uit. Om de EPR-paradox helemaal uit te leggen is echter moeilijk, ik snap het zelf niet helemaal, denk ik. Het experiment van Bell Het experiment kan op 2 manieren uitgelegd worden:1) Je kunt het volledige experiment begrijpen zonder iets van kwantummechanica af te weten. Verborgen inhoud uitleg met kwantumtheorie dicht laten.OF2) Je kunt meteen erbij lezen waarom de kwantumtheorie de metingen wel verklaart! open klikken. Stelling 1) De wet van Malus zegt dat

Pythagorean cup Cross section Cross section of a Pythagorean cup. A Pythagorean cup (also known as a Pythagoras cup, a Greedy Cup or a Tantalus cup) is a form of drinking cup that forces its user to imbibe only in moderation. Credited to Pythagoras of Samos, it allows the user to fill the cup with wine up to a certain level. If he fills the cup only to that level, the imbiber may enjoy a drink in peace. Form and function[edit] A Pythagorean cup looks like a normal drinking cup, except that the bowl has a central column in it – giving it a shape like a Bundt pan in the center of the cup. When the cup is filled, liquid rises through the second pipe up to the chamber at the top of the central column, following Pascal's principle of communicating vessels. Common occurrences[edit] A Pythagorean cup sold in Crete A Pythagorean cup sold in Samos Hero of Alexandria (c. 10–70 AD) used Pythagorean cups as hydraulic components in his robotic systems. See also[edit] References[edit] External links[edit] WHY DID THE CHICKEN CROSS THE ROAD? Plato: For the greater good. Karl Marx: It was a historical inevitability. Luming Duan' PERSONAL HOMEPAGE Group members Research and publications Teaching Links Welcome to the webpage for theoretical quantum optics and quantum information group at the University of Michigan. Group members Faculty Luming Duan E. Tel: ++1 734 763-3179 Fax: ++1 626 764-5153 Email: Web: List of publications Graduate students and postdocs: Tanvi Gujarati Zhengyu Zhang Yukai Wu Ceren Burcak Dag Former group members: Shengtao Wang, Yong Yu, Zhen Zhang, Dong-Ling Deng, Chao Shen, Zhe-Xuan Gong, Yang-Hao Chan, Wei Yi, Shi-Liang-Zhu, Khan Mahmud, Timothy Bodiya, Bin Wang, Xiong Jin, Zhaohui Wei, Zhangqi Yin, Wei Zhang, Tim Goodman, Jason Kestner, Guin-Dar Lin, Yong-Jian Han, Yue Wu Research Research Overview Quantum Information Science Our research focuses on theory and implementation of quantum information science. Physics of ultracold atoms Publications Teaching Service Links

Astronomy Interactives This site provides ranking tasks for teaching introductory astronomy. Pencil-and-paper versions as well as computer-based versions are available grouped by topic. New materials will be added as the computer-based versions are completed. Paper Based Ranking Tasks Online Ranking & Sorting Tasks Kepler's Laws The materials above are collectively the work of David Hudgins (Rockhurst University), Kevin Lee (University of Nebraska), and Edward Prather (University of Arizona). A Double Slit Quantum Eraser Experiment A Double-Slit Quantum Eraser Experiment This web-page was created as an assignment for PHY 566, taught by Prof. Luis Orozco at Stony Brook University in the fall semester of 2002. The following describes work done by S. This experiment uses the phenomena of interference, produced by light incident on a double slit, to investigate the quantum mechanical principle of complementarity between the wave and particle characteristics of light. A Peculiarity about Quantum Mechanics Interference Any wave in nature is capable of producing interference. Interference and photons Quantum mechanics governs all phenomena on the atomic scale. Mathematically the quantum description is not any different from the classical wave interference description. A single photon cannot of course make a whole interference pattern on a screen by itself. Formation of the interference pattern. Which Way? It is difficult at this point to not be tempted to ask, which way does the photon really go? Experimental Investigation

Personal and Historical Perspectives of Hans Bethe Why Nikola Tesla was the greatest geek who ever lived Additional notes from the author: If you want to learn more about Tesla, I highly recommend reading Tesla: Man Out of Time Also, this Badass of the week by Ben Thompson is what originally inspired me to write a comic about Tesla. Ben's also got a book out which is packed full of awesome. There's an old movie from the 80s on Netflix Instant Queue right now about Tesla: The Secret of Nikola Tesla. It's corny and full of bad acting, but it paints a fairly accurate depiction of his life.

Calling Bullshit — Syllabus Logistics Course: INFO 270 / BIOL 270. University of Washington Next offered: Autumn Quarter 2019 Credit: 3 credits, graded Enrollment: To be determined Instructors: Carl T. Learning Objectives Our learning objectives are straightforward. Remain vigilant for bullshit contaminating your information diet. We will be astonished if these skills do not turn out to be among the most useful and most broadly applicable of those that you acquire during the course of your college education. Schedule and readings Each of the week-long modules will explore one specific facet of bullshit. Modules Week 1. Harry Frankfurt (1986) On Bullshit. Supplementary readings Week 2. Week 3. Gordon Pennycook et al. (2015) On the reception and detection of pseudo-profound bullshit. Week 4. Supplementary reading Karl Pearson (1897) On a Form of Spurious Correlation which may arise when Indices are used in the Measurement of Organs. Week 5. Week 6. Week 7. Cathy O'Neil (2016) Weapons of Math Destruction Crown Press.

8 shocking things we learned from Stephen Hawking's book From the idea that our universe is one among many, to the revelation that mathematician Pythagoras didn't actually invent the Pythagorean theorem, here are eight shocking things we learned from reading physicist Stephen Hawking's new book, "The Grand Design," written with fellow physicist Leonard Mlodinow of Caltech. The book, covering major questions about the nature and origin of the universe, was released Sept. 7 by its publisher, Bantam. 1. The past is possibility According to Hawking and Mlodinow, one consequence of the theory of quantum mechanics is that events in the past that were not directly observed did not happen in a definite way. Instead they happened in all possible ways. This is related to the probabilistic nature of matter and energy revealed by quantum mechanics: Unless forced to choose a particular state by direct interference from an outside observation, things will hover in a state of uncertainty. Yeah, we're still trying to wrap our brains around this. 2. 3. 4. 5. 6.

quantum mechanics - Interference and which-path information So, to be clear, my understanding of your setup is that you are doing SPDC in a noncollinear geometry, so you get photons entangled in transverse momentum, and you basically want to get the momentum of one photon from the other, by studying the wall. To get interference, the momentum change must be indistinguishable in principle, not just practically. How could this happen? Well, the wall itself is also a quantum object, so if its two possible momenta from the photon are both within the uncertainty of its total momentum, it is not possible to distinguish the two cases. In the case of this setup, really what you are suggesting is a quantum eraser experiment, in a way. To compare this with a typical quantum eraser experiment, look here for example. (edit: this analysis is incorrect; see comments) edit2: from the comments: There is no inconsistency between what I am saying and what they are, but I have to be very careful to be clear about what I mean by 'decoherence,' and by 'environment.'

News - Magnetic bacteria may help build future bio-computers 7 May 2012Last updated at 09:40 GMT Tiny magnets form inside magnetic bacteria Magnet-making bacteria may be building biological computers of the future, researchers have said. A team from the UK's University of Leeds and Japan's Tokyo University of Agriculture and Technology have used microbes that eat iron. As they ingest the iron, the microbes create tiny magnets inside themselves, similar to those in PC hard drives. The research may lead to the creation of much faster hard drives, the team of scientists say. The study appears in the journal Small. As technology progresses and computer components get smaller and smaller, it becomes harder to produce electronics on a nano-scale. So researchers are now turning to nature - and getting microbes involved. Magnetic bacteria In the current study, the scientists used the bacterium Magnetospirilllum magneticum. These naturally magnetic microorganisms usually live in aquatic environments such as ponds and lakes, below the surface where oxygen is scarce.

The Feynman Lectures on Physics

Related:  Physics