Lorentz contraction facts for kids

Length contraction: Three blue rods are at rest in S, and three red rods in S'. At the instant when the left ends of A and D attain the same position on the axis of x, the lengths of the rods shall be compared. In S the simultaneous positions of the left side of A and the right side of C are more distant than those of D and F. While in S' the simultaneous positions of the left side of D and the right side of F are more distant than those of A and C

The Lorentz contraction is also called the Fitzgerald contraction or the Lorenz-Fitzgerald contraction. It is caused by relativistic effects seen between observers moving toward or away from one another. The size of one object as seen by someone moving toward or away from it it is decreased along their line of movement by an amount mathematically related to their speed and the speed of light.

In his book, One, Two, Three...Infinity, physicist George Gamow quoted a limerick (a kind of poem) that is said by some to have been changed from a more naughty poem. There are several other cleaned up versions:

There once was a young man named Fisk,
Whose fencing was extremely brisk,
So fast was his action,
The Lorentz contraction,
Foreshortened his foil to a disk.

Images for kids

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  Wheels which travel at 9/10 the speed of light. The speed of the top of a wheel is 0.994 c while the speed of the bottom is always zero. This is why the top is contracted relative to the bottom.

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  Formula on a wall in Leiden, Netherlands. Lorentz was chair of theoretical physics at the University of Leiden 1877-1910

See also

In Spanish: Contracción de Lorentz para niños