July 10, 2010
by Ted Beyer
One of my favorite authors, Arthur C. Clark, once said, “Any sufficiently advanced technology is indistinguishable from magic.” This has been quoted, misquoted and reused for years. Of course, it’s perfectly true, and magicians have been using science as part of their acts for centuries. Things that we take for granted today were once bleeding edge technology. I remember in high school reading that sometime ‘soon’ (this was more than 30 years ago) there would be TVs that would be so thin that they would hang on the wall like pictures – impossible! A generation before, the concept of television itself was astonishing, and a generation before that, moving pictures of any kind were magical.
As I started to think about this, I suddenly realized that there are many products that we sell here at Educational Innovations that are used – currently – by magicians as ‘tricks’ in their act. Let’s take a look…. Read the rest of this entry »
July 9, 2010
by: Martin Sagendorf
On a Bright Day:
A great deal of energy falls on the Earth’s surface – roughly 1 kW per square meter. This is about 0.6 Watt per square inch. This doesn’t sound like much energy, but suppose we collect and concentrate 63 square inches of this sunlight? These 63 square inches would collect about 38 Watts of energy. This doesn’t sound like much, but…
Suppose We Could Then:
Concentrate these 38 Watts into an area of only 1/8 of a square inch? This is exactly what we can do with an inexpensive plastic Fresnel lens. We’ll focus the sunlight into an area 3/8” in diameter – this is the equivalent of 300 Watts per square inch! With this energy level, we can easily ignite a piece of wood, boil some water, and even melt a penny.
A Suitable Device:
Is described in the book, Physics Demonstration Apparatus and in the blog The Sun’s Energy.
Now we’re going to describe how to build a much simpler version that works just as well – one that uses a very inexpensive Fresnel lens and is very easy to construct. Read the rest of this entry »