Mathematics & Logic
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Three Lectures by Hans Bethe IN 1999, legendary theoretical physicist Hans Bethe delivered three lectures on quantum theory to his neighbors at the Kendal of Ithaca retirement community (near Cornell University). Given by Professor Bethe at age 93, the lectures are presented here as QuickTime videos synchronized with slides of his talking points and archival material.
Personal and Historical Perspectives of Hans Bethe
Pandigital Approximations
The first formula, found by B. Ziv in 2004, produces the first 10 digits of pi. The second, astonishingly, reproduces e to 18,457,734,525,360,901,453,873,570 decimal places. It was discovered by Richard Sabey, also in 2004.
Pick a number at random from the universe. Not just from inside your head. Open a page of the financial times or look up the size of a planet; convert you height to cubits or measure the weight of your favourite book.
Benford's Law
Fractals
LiveMath™ Software Products
Thanks to James B.! LiveMath™ is a computer algebra and graphing system designed for the mathematician (or mathematics student or scientist) who is not necessarily a programmer. Many of the computer algebra products available today are based upon writing a strict syntax language of programming commands and structures.
An Intuitive Explanation of Fourier Theory
slehar@cns.bu.edu Fourier theory is pretty complicated mathematically. But there are some beautifully simple holistic concepts behind Fourier theory which are relatively easy to explain intuitively. There are other sites on the web that can give you the mathematical formulation of the Fourier transform. I will present only the basic intuitive insights here, as applied to spatial imagery.
fast and usable calculator
SpeedCrunch is a fast, high precision and powerful desktop calculator. Available for Linux , Microsoft Windows , and Apple Mac OS X .
Octave
GNU Octave is a high-level interpreted language, primarily intended for numerical computations. It provides capabilities for the numerical solution of linear and nonlinear problems, and for performing other numerical experiments. It also provides extensive graphics capabilities for data visualization and manipulation.
Math can be terrifying for many people. This list will hopefully improve your general knowledge of mathematical tricks and your speed when you need to do math in your head. To multiply by 25 you multiply by 100 (just add two 0’s to the end of the number) then divide by 4, since 100 = 25×4. Note: to divide by 4 your can just divide by 2 twice, since 2×2 = 4.
9 Mental Math Tricks
Impress your friends with mental Math tricks » Fun Math Blog
Being able to perform arithmetic quickly and mentally can greatly boost your self-esteem, especially if you don't consider yourself to be very good at Math. And, getting comfortable with arithmetic might just motivate you to dive deeper into other things mathematical. This article presents nine ideas that will hopefully get you to look at arithmetic as a game, one in which you can see patterns among numbers and pick then apply the right trick to quickly doing the calculation. The tricks in this article all involve multiplication. Don't be discouraged if the tricks seem difficult at first.December 2009 Think drug-induced hallucinations, and the whirly, spirally, tunnel-vision-like patterns of psychedelic imagery immediately spring to mind. But it's not just hallucinogenic drugs like LSD, cannabis or mescaline that conjure up these geometric structures. People have reported seeing them in near-death experiences, as a result of disorders like epilepsy and schizophrenia, following sensory deprivation, or even just after applying pressure to the eyeballs. So common are these geometric hallucinations, that in the last century scientists began asking themselves if they couldn't tell us something fundamental about how our brains are wired up.
Uncoiling the spiral: Maths and hallucinations