Bending Light Around a Corner

Most recent answer: 10/22/2007

Q:
Does light travel around corners??
- Jennifer (age 15)
arkansas
A:
Actually, light does travel around corners a little. To be honest, you don’t see this very much with our eyes, but with special instruments, you can measure it. This effect is called diffraction. Diffraction happens whenever you try to force light through an opening.

Light has this property called a wavelength. The size of the wavelength determines the color of the light. When the wavelength of light is comparable to the size of a hole or an object that it is going past, the light will tend to spread out as it passes the object. Light with a wavelength of around 630 nanometers or 6.3*10^-7 meters is red light. That’s so tiny compared to a 10 meter tall building that the light doesn’t bend much as it passes the building. On the other hand, radio stations send out light that has about a 3 meter wavelength. This is far to long for our eyes to be able to see (i.e. it is not visible light) however since the wavelength is similar in size to a building, these light waves will "bend" (i.e diffract) a lot more as they pass.

Adam

(published on 10/22/2007)