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. If he exhibits gluttony, however, the cup spills its entire contents out of the bottom (onto the lap of the immodest drinker).[1] 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 See also[edit] References[edit] 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.
In short, it is for all those who decided to study theoretical physics, in their own time. It so often happens that I receive mail - well-intended but totally useless - by amateur physicists who believe to have solved the world. They believe this, only because they understand totally nothing about the real way problems are solved in Modern Physics. 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. Return to List Infinitesimals. Personal and Historical Perspectives of Hans Bethe.
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. Can hot water freeze faster than cold water? [Physics FAQ] - [Copyright] Written Nov, 1998 by Monwhea Jeng (Momo), Department of Physics, University of California Yes — a general explanation History of the Mpemba Effect More-detailed explanations References Yes — a general explanation Hot water can in fact freeze faster than cold water for a wide range of experimental conditions.
The phenomenon that hot water may freeze faster than cold is often called the Mpemba effect. This seems impossible, right? What's wrong with this proof is that it implicitly assumes that the water is characterized solely by a single number — its average temperature. It is still not known exactly why this happens. Why hasn't modern science answered this seemingly simple question about cooling water? So with the limited number of experiments done, often under very different conditions, none of the proposed mechanisms can be confidently proclaimed as "the" mechanism. Finally, supercooling may be important to the effect. History of the Mpemba Effect Evaporation. Atomic-scale magnetic memory. The world's smallest bit Scientists from IBM Research have been investigating and controlling matter on an atomic scale for decades. So, naturally, their latest quest would involve greatly decreasing the storage capacity needed for one bit of data, which on today's computers stands at about 1 million atoms.
They set out to develop the ultimate memory chips of the future. Starting at the very beginning of density—single atoms—they created the world’s smallest magnetic memory bit and answered the question of how many atoms it takes to reliably store one bit of magnetic information at a low temperature: 12. By studying the behavior of atoms, researchers can identify crucial factors for building smaller, faster and more energy-efficient devices for business and consumers. A history of innovation As one of the last remaining industrial labs, IBM continues to emphasize fundamental science and investment in R&D.
Weierstrass functions. Weierstrass functions are famous for being continuous everywhere, but differentiable "nowhere". Here is an example of one: It is not hard to show that this series converges for all x. In fact, it is absolutely convergent. It is also an example of a fourier series, a very important and fun type of series. It can be shown that the function is continuous everywhere, yet is differentiable at no values of x. Here's a graph of the function. You can see it's pretty bumpy. Below is an animation, zooming into the graph at x=1. Wikipedia and MathWorld both have informative entries on Weierstrass functions. back to Dr.