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# Meet the Measurement League

## Monsieur Kilogram

SI Unit of mass
Symbol: kg

Monsieur Kilogram is the master of mass.

Known to maneuver immense objects with ease, he also astonishes foes with the ability to precisely control nano objects.

Working with mass is a piece of cake.

## Professor Second

SI unit of time
Symbol: s

By broadcasting a precise stream of invisible microwaves, Professor Second has the power to fix any clock.

A second is the time it takes for 9,192,631,770 "wiggles" to hit the cesium atoms around her.

## Meter Man

SI unit of length
Symbol: m

With his sharp eyes and stretchy ruler arms, no distance is too big or too small for Meter Man to measure.

A meter is the distance light travels in a tiny fraction of a second.

## Ms. Ampere

SI unit of electric current
Symbol: A

Ms. Ampere has a shocking amount of power over the flow of electrons—electrical current.

An ampere is the measure of the flow of electrons past a point—about 6 quintillion electrons (that's a 6 followed by 18 zeros!) per second.

## Dr. Kelvin

SI unit of temperature
Symbol: K

With the ability to speed up or slow down particles, Dr. Kelvin can create and measure any temperature.

The kelvin temperature scale begins at absolute zero, the coldest possible temperature and the point at which even atoms would stand almost perfectly still. Water freezes at 273 K and boils at 373 K.

## Candela

SI unit of brightness
Symbol: cd

Don't let her small size fool you. Candela's power over light helps to brighten the world.

A candela is about equal to the light given off by a single candle.

## The Mole

SI unit of substance
Symbol: mol

Able to sniff out and count the atoms of every element, the Mole is the king of chemistry.

Equal to about 600 sextilion (that's a 6 followed by 23 zeros!), a mole is a shorthand way to talk about huge numbers, especially of tiny things.

## Major Uncertainty

Symbol: ?

An alien invader from parts unknown, Major Uncertainty uses his less-than-trustworthy monkey wrench to generate a dreadful "chaos beam," which causes us to doubt the accuracy and precision of our measurements.

Major Uncertainty feeds on this doubt, which makes him bigger, stronger, and less pleasant to be around.

Created August 9, 2016, Updated December 6, 2021