Pinhole Cameras
Pinhole cameras are so simple that people sometimes don't believe they will work. But ...
The microwave is a common kitchen appliance, but did you know that it was only recently invented? In the 1940s Percy Spencer was building magnetrons for radar sets. While he was doing this, he noticed that a candy bar in his pocket melted. He wasn't the first person to ever take note of this phenomenon, but he was the first person to do something with it. Percy, and the company for which he worked, started to develop the first microwave oven. They called the first one a Radarange. It weighed 750 pounds, and it stood over 6 feet tall. It was cooled by water. It produced over three times the power that common microwave ovens produce today. Eventually, they made microwaves smaller and smaller. As technology increased, they made microwaves more affordable too.
Pinhole cameras are so simple that people sometimes don't believe they will work. But ...
Thunder rattles the windows. Lightning brightens the sky. Winds howl through the trees. Th...
Composting means making soil from decayed leaves, grass, and kitchen scraps. Composting is...