Posted October 25, 2010
In honor of Halloween, let's look at the fun the Periodic Table of Videos folks had last year:
A theme across all three pumpkin demos is the generation of light. These reactions show how the color of light produced depends on the elements involved. As electrons return to their "ground state" from a higher energy level, they give off photons, and the amount of energy determines the wavelength and therefore color of the light.
Posted October 18, 2010
A real Mount Doom:
This footage shows a boiling caldera of lava on an island in the South Pacific. As dangerous as this is, molten lava eruptions like this are generally less hazardous than the violent explosions of large stratovolcanoes like Pinatubo in 1991 or St. Helens in 1980.
Posted October 11, 2010
Objects float when the buoyant force up on them is equal to the force of gravity pulling down. Sulphur hexafluoride is more dense than air, so it will sit in a tub, and an aluminum foil boat can be made to float on this invisible gas. Pouring the gas into the boat makes the boat heavier, and sends it to the bottom.
Posted October 4, 2010
There is a large pitcher plant savanna near my home in southern Mississippi. Here's how they catch their insect lunch:
A common misunderstanding of carnivorous plants is that they get their energy from the insects they eat. Actually, since they have green leaves, most of their energy comes from the Sun, and the insects provide nutrients (like nitrogen) that they cannot get from the soil.
Jacob Clark Blickenstaff is Assistant Professor of Physics and Assistant Director of the Center for Science and Mathematics Education at the University of Southern Mississippi.