Bloxes: Modular Cardboard Adult-Sized Building Blocks How To Be A Little Gauss Return to my mathematics pages Go to my home page © Copyright 1997, Jim Loy [Imagine that you are in the audience at this lecture] There is a story about Carl Friedrich Gauss. Supposedly, when he was a little boy, his teacher asked the class to add up the numbers one through a hundred (1+2+3 etc., all the way up to 100). The teacher wanted to get some work done, or get some sleep, or whatever. Some people find that story hard to believe, even impossible. I think that you people can duplicate little Gauss's [2 feet tall] trick [doubt in the audience] . Nobody use your calculators, or even paper and pencil for a while. Here's the problem: We want to find X. What if we start at the other end: Do we get the same answer? That was your first hint, "Associative Law." Let's see, 100+99=199, +98=297, +. What if we add up the even numbers (that's 49 additions), then add up the odd numbers (that's 49 additions), and then add up the two totals? How about: Does that help? [There is general agreement] .
Dark matter Dark matter is invisible. Based on the effect of gravitational lensing, a ring of dark matter has been detected in this image of a galaxy cluster (CL0024+17) and has been represented in blue.[1] Dark matter is a hypothetical kind of matter that cannot be seen with telescopes but accounts for most of the matter in the universe. The existence and properties of dark matter are inferred from its gravitational effects on visible matter, radiation, and the large-scale structure of the universe. Other than neutrinos, a form of hot dark matter, it has not been detected directly, making it one of the greatest mysteries in modern astrophysics. Astrophysicists hypothesized dark matter because of discrepancies between the mass of large astronomical objects determined from their gravitational effects and the mass calculated from the observable matter (stars, gas, and dust) that they can be seen to contain. Overview[edit] Baryonic and nonbaryonic dark matter[edit] Observational evidence[edit]
Human-powered aircraft MIT Light Eagle human-powered aircraft, predecessor to the MIT Daedalus aircraft Early attempts at human-powered flight were unsuccessful because of the difficulty of achieving the high power-to-weight ratio. Prototypes often used ornithopter principles which were not only too heavy to meet this requirement but aerodynamically unsatisfactory. As of 2008, human-powered aircraft have been successfully flown over considerable distances. However, they are primarily constructed as engineering challenges rather than for any kind of recreational or utilitarian purpose. The Royal Aeronautical Society Human Powered Flight Group[edit] The Royal Aeronautical Society's "Man Powered Aircraft Group" was formed in 1959 by the members of the Man Powered Group of the College of Aeronautics at Cranfield when they were invited to join the Society. First attempts[edit] An early human-powered aircraft was the Gerhardt Cycleplane, developed by W. First flights[edit] Passenger aircraft[edit] Recent activity[edit]
Webstock: Aza Raskin, Design is the Beauty of Turning Constraints Into Advantages | danielbachhuber This week I’m at Webstock, a lovely conference in New Zealand. I’m doing my best to write little blog posts about the amazing presentations. Please forgive any typos, etc. If you’re here too, come write a haiku at Automattic’s booth. For the last couple of years, Aza Raskin (@aza) has been working on helping bring design to solving health challenges. In 1959, Henry Kramer had a dream that people should be able to fly under their own power. Paul Maccready in 1977 said that most participants were trying to solve the wrong problem. “Science is in the business of embracing failure because it’s only through failure that we learn.” It’s not about thinking outside the box, because that means there are no constraints. The origin of the 140 character limit for text messages is also one of constraints. Creativity comes from constraint, and asking the right question is the most important part of design.