Very nice webcast (of an old 1930’s filmstrip by GM) explaining how a differential gear works.
Related: how things work – A Journey Into the Human Eye – Science Explained: What The Heck is a Virus? – Magenta is a Color
Very nice webcast (of an old 1930’s filmstrip by GM) explaining how a differential gear works.
Related: how things work – A Journey Into the Human Eye – Science Explained: What The Heck is a Virus? – Magenta is a Color
This is a fantastic Do-It_Yourself (DIY) engineering story. Very interesting, definitely go read the whole article: Build Your Own Multitouch Surface Computer
As it turns out, most cameras are able to sense infrared light. If you want to see first-hand proof that this is the case, try this simple experiment: First, find a cheap digital camera. Most cell phone cameras are perfect for this. Next, point it at the front of your TV’s remote control. Then, while watching the camera’s display, press the buttons on the remote. You’ll see a bluish-white light that is invisible to the naked eye. That’s the infrared light used by the remote to control the TV.
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Like the computer, the projector we used for the build was something we scavenged up. The major concern for a projector to use in this kind of system is throw distance—the ratio between projection distance and image size. Short-throw projectors, which are sold by all the major projector brands, work the best for this kind of project, because they can be set up at the bottom of the cabinet and aimed directly at the surface. Unfortunately, they also tend to be more expensive.
Ever thrifty, we went with a projector we could use for free: an older home-theater projector borrowed from a friend. Because of the longer throw distance on this model, we had to mount the projector near the top of the cabinet, facing down, and use a mirror to reflect the image up onto the screen. For this we ordered a front-side mirror (a mirror with the reflective surface on the front of the glass, rather than behind it) to eliminate any potential “ghosting” problems, caused by dual reflections from the front and back of the glass in an ordinary mirror.
Related: Home Engineering: Gaping Hole Costume – Very Cool Wearable Computing Gadget from MIT – ‘DIY’ kidney machine saves girl – Holographic Television on the Way – Automatic Cat Feeder – Video Goggles
Genetic Algorithms: Cool Name and Damn Simple is a very nice explanation with python code of genetic algorithms.
We’ll also randomly select some lesser performing individuals to be parents, because we want to promote genetic diversity. Abandoning the metaphor, one of the dangers of optimization algorithms is getting stuck at a local maximum and consequently being unable to find the real maximum. By including some individuals who are not performing as well, we decrease our likelihood of getting stuck.
Related: DNA Seen Through the Eyes of a Coder – Evolutionary Design – Algorithmic Self-Assembly – The Chip That Designs Itself
More posts on how things work: Why do We Sleep? – Why is it Colder at Higher Elevations? – What Are Flowers For?
Related: How Bleach Kills Bacteria – Bacteria Survive On All Antibiotic Diet – Soil Could Shed Light on Antibiotic Resistance – Antibiotics Too Often Prescribed for Sinus Woes
In making a repair to my toilet last week I found this useful resource: Replace The Toilet Fill Valve, Flush Valve Or Flapper
The site does a great job of explaining what needs to be done and provides excellent graphics. It is also interesting to take a look at how things we use actually work.
The Soap-free Green Laundry Revolution by Tania Rabesandratana:
Right. Let’s go back to washing basics. Our machine works by combining three actions. First comes chemical action. Here, detergents act as surfactants: they lower the water’s surface tension, making it more likely to mix with oil, so that yucky grease and grime can be removed during rinsing. Second comes the mechanical action from the spinning of the washing machine drum. And finally, there is heat action, which consists of dunking your laundry in hot water.
The eco balls mostly increase the mechanical action so that you can do without the chemical action, thereby saving money and avoiding the use of evil pollutants. The increase of mechanical action also does away with the need for heat action, which in turn conserves electricity and water, which is good for your wallet and your planet.
Pretty cool, if they actually work. I think I might have to try these out. For the next stage of the process, DryerMax Dryer Balls claim to cut the drying time by 25% and soften the fabric. Some other cool gadgets and gizmos.
Related: Eco-balls – the big “wash off” – Ventless Clothes Dryers – Sarah, aged 3, Learns About Soap
Compounding is the Most Powerful Force in the Universe
Posted on December 8, 2008 Comments (3)
A talking head with some valuable info. I remember my father (a statistics professor) getting me to understand this as a small child (about 6 years old). The concept of growth and mathematical compounding is an important idea to understand as you think and learn about the world. It also is helpful so you understand that statistics don’t lie but ignorant people can draw false conclusions from limited data.
It is unclear if Einstein really said this but he is often quoted as saying “compounding is the most powerful force in the universe.” Whether he did or not, understanding this simple concept is a critical component of numeracy (literacy with numbers). Also quoted at times as: “Compound interest is the eighth wonder of the world.” My guess is that people just find the concept of compounding amazing and then attribute quotes about it to Einstein.
I strongly encourage you to watch at least the first 2 segments (a total of 15 minutes). And then take some time and think. Take some time to think about compounding in ways to help you internalize the concepts. You can also read his book: The Essential Exponential For the Future of Our Planet by Albert Bartlett.
Related: Playing Dice and Children’s Numeracy – Saving for Retirement (compound interest) – Bigger Impact: 15 to 18 mpg or 50 to 100 mpg? – Sexy Math – The Economic Benefits of Math
Categories: Economics, Math, quote, Science, Students
Tags: commentary, data, how things work, Math, quote, science facts, scientific literacy, systems thinking, think, webcasts