Select a Catagory:
Breaking News
This area does not yet contain any content.

Entries in optics (2)


Solar Oven

According to

Solar cooking is the simplest, safest, most convenient way to cook food without consuming fuels or heating up the kitchen. Many people choose to solar cook for  these reasons. But for hundreds of millions of people around the world who cook over fires fueled by wood or dung, and who walk for miles to collect wood or spend much of their meager incomes on fuel, solar cooking is more than a choice — it is a blessing. For millions of people who lack access to safe drinking water and become sick or die each year from preventable waterborne illnesses, solar water pasteurization is a life-saving skill. The World Health Organization reports that in 23 countries 10% of deaths are due to just two environmental risk factors: unsafe water, including poor sanitation and hygiene; and indoor air pollution due to solid fuel use for cooking.

Plans <> I like the solar funnel which is really easy to build.

My design is different than any of these and relies on the availabilty of satellite television dishes. In San Francisco, I often see Direct TV and Primestar parabolic dishes being thrown away -- not the receiver mind you -- just the metal dish. I then rubber cement aluminized mylar to the dish. These are amazing. They can get a pint of water to 160 degrees F in about 20 minutes and boil a like amount of water in about 30 minutes.


Teaching Optics at Down to a Science

Down to a Science is a science cafe in San Francisco where the host Kishore plays a more active role than in most science cafes. In February 2009 he had a presentation on new directions in science education, and I was there to talk about high school science. He posted a video on YouTube. My part begins at about the 30 minute mark.

Click on the video to get a larger image.