Carbon dioxide (CO2) is heavier than most other molecules and elements in the air. In the same way that Helium rises (think of party balloons), CO2 sinks. With a very large bowl or container and lots and lots of vinegar and baking soda, you can make a little “puddle” of CO2. When soap bubbles – [...]
Glowing Glass. These glass squares look plain and unremarkable. But under ultraviolet light, they become brilliantly colored: red, orange, yellow, green, blue, and purple. Each square is doped with a chemical that fluoresces under UV light, producing a vibrant rainbow. That is, the glass absorbs energy from incoming UV light and reemits that energy as [...]
Get four popsicle sticks, preferrably after eating four popsicles. (Use normal thin ones, not thick ones from a craft store.) Assemble them as shown in the photos. Weaving in the last piece is just a little tricky. You’ll have to bend the sticks a bit. If you need a closer look, click on an image. [...]