Came across it, thought it was interesting...
- What It Was Like Being Criticized by Feynman
Unlike any other physics textbook that I have ever encountered, The Feynman Lectures on Physics never bothers to explain how to solve any problems, which made trying to complete the daunting homework assignments challenging and time-consuming. What the essays did provide, however, was something much more valuable—deep insights into Feynman’s original way of thinking about science. Generations have benefited from the Feynman Lectures. For me, the experience was an absolute revelation.
After a few weeks, I felt like my skull had been pried open and my brain rewired. I began to think like a physicist, and loved it. Like many other scientists of my generation, I was proud to adopt Feynman as my hero. I scuttled my original academic plans about biology and mathematics and decided to pursue physics with a vengeance.
- What Happened to the 100,000-Hour LED Bulbs?
There’s more to an LED bulb than just the LEDs. Outlets in our homes are actually fairly dirty sources of AC power. LEDs want clean, constant-current DC sources, so circuits inside the bulbs must rectify and filter the incoming AC, then limit current to the LED packages.
Since the LED bulbs contain a number of parts, it’s natural to ask which ones might be responsible for failures. The US Department of Energy (DoE)’s solid-state lighting program supports research and development of LED technologies, and their website contains volumes of data on LED lighting systems. Their Lifetime and Reliability Fact Sheet contains data on the failure rate of 5,400 outdoor lamps over 34 million hours of operation. Interestingly, the LEDs themselves account for only 10% of the failures; driver circuitry, on the other hand, was responsible almost 60% of the time. The remainder of failures were due to housing problems, which may not be as applicable for bulbs in indoor use. This data shows that at least for catastrophic failures (where the lamp ceases to emit light), extending lifetime means improving the power supplies.
Certainly moving away from incandescent bulbs to more efficient lighting makes sense, but maybe we never really needed 100,000 hour bulbs in the first place. The lifetime of even 7,500-hour bulbs is long compared to the rapid pace of advance in lighting technology. Does it makes sense to buy expensive long-lived bulbs today, when better, cheaper, more efficient ones may be available in the near future?
- Where Do I Start? A Very Gentle Introduction to Computer Graphics Programming
If you are here, it's probably because you want to learn computer graphics. Each reader may have a different reason for being here, but we are all driven by the same desire: understand how it works! Scratchapixel was created to answer this particular question. Here you will learn how it works and learn techniques used to created CGI, from the simplest and most important methods, to the more complicated and less common ones. Maybe you like video games, and you would like to know how it works, how they are made. Maybe you have seen a film a Pixar film and wonder what's the magic behind it. Whether you are at school, university, already working in the industry (or retired), it is never a bad time to be interested in these topics, to learn or improve your knowledge and we always need a resource like Scratchapixel to find answers to these questions. That's why we are here.
- The 26,000-Year Astronomical Monument Hidden in Plain Sight
On the western flank of the Hoover Dam stands a little-understood monument, commissioned by the US Bureau of Reclamation when construction of the dam began in 01931. The most noticeable parts of this corner of the dam, now known as Monument Plaza, are the massive winged bronze sculptures and central flagpole which are often photographed by visitors. The most amazing feature of this plaza, however, is under their feet as they take those pictures.
The plaza’s terrazzo floor is actually a celestial map that marks the time of the dam’s creation based on the 25,772-year axial precession of the earth.
- All the Bad Things About Uber and Lyft In One Simple List
Here’s the latest evidence that Uber and Lyft are destroying our world: Students at the University of California Los Angeles are taking an astonishing 11,000 app-based taxi trips every week that begin and end within the boundaries of the campus.
The report in the Daily Bruin revealed anew that Uber, Lyft, Via and the like are massively increasing car trips in many of the most walkable and transit friendly places in U.S.
It comes after a raft of recent studies have found negative effects from Uber and Lyft, such as increased congestion, higher traffic fatalities, huge declines in transit ridership and other negative impacts. It’s becoming more and more clear that Uber and Lyft having some pretty pernicious effects on public health and the environment, especially in some of the country’s largest cities.
We decided to compile it all into a comprehensive list, and well, you judge for yourself.
- Diagnosing 'art acne' in Georgia O'Keeffe's paintings
Even Georgia O'Keeffe noticed the pin-sized blisters bubbling on the surface of her paintings. For decades, conservationists and scholars assumed these tiny protrusions were grains of sand, kicked up from the New Mexico desert where O'Keeffe lived and worked. But as the protrusions began to grow, spread and eventually flake off, people shifted from curious to concerned.
A multidisciplinary team from Northwestern University and the Georgia O'Keeffe Museum in Santa Fe, New Mexico has now diagnosed the strange paint disease: The micron-sized protrusions are metal soaps, resulting from a chemical reaction between the metal ions and fatty acids commonly used as binder in paints.
Inspired by the research, the team developed a novel, hand-held tool that can easily and effortlessly map and monitor works of art. The tool enables researchers to carefully watch the protrusions in order to better understand what conditions make the protrusions grow, shrink or erupt.