Thursday, 9 February, 2012

Why is the sky blue? Half Dome (in California’s Yosemite National Park) under a bright blue sky. To understand why the sky is blue, we need to understand a little about light. Light is a form of electromagnetic energy, which can propagate through empty space. We describe this energy by wavelength – the distance between [...]

The external color does not significantly affect how much the inside of a car heats up in the sun, says Sanford Klein, director of the UW-Madison Solar Energy Laboratory and professor of mechanical engineering. Cars warm up in the sun due to the greenhouse effect: Sunlight passing through the windows into the car is mostly [...]