Friday Fact 24 April 2009

Yay, it's Friday!

Did you know that the smallest measurable unit of length is called the Planck length?

Here's some geek speak courtesy of Wikipedia:

In physics, the Planck length, denoted , is unit of length, equal to about 1.616 252 × 10^-35 meters. It is a base unit in the system of Planck units. The Planck length can be defined from three fundamental physical constants: the speed of light in a vacuum, Planck's constant, and the gravitational constant. Current theory suggests that 1 Planck length is the smallest distance or size about which anything can be known.

...and an interesting bit of information from New Scientist about measuring anything smaller than the Planck length:

Physicists have set a limit on the smallest length that can ever be measured - and any device that tries to beat the limit will be crushed into a black hole of its own making.

The finding is based on an analysis of interferometry, a technique that uses interference of waves to measure small lengths. Quantum theory says that the more accurate the measurement you want, the more massive the interferometer you need.

But Xavier Calmet, Michael Graesser and Stephen Hsu of the California Institute of Technology in Pasadena point out that any very massive interferometer would have to be spread over an extremely large region of space. Otherwise, the large mass concentrated in a small area would produce strong enough gravity to form a black hole, sucking in the interferometer.

Us riff raffs really only need one unit of measurement in real life, though (click for bigger):

Disclaimer: all images belong to their respective copyright holders.

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