Over time, the field of physics has discovered many new phenomena that defy easy description or naming. What do you call something that has never been seen before?
As the industrial revolution began, power, pressure and force were analyzed. The newton, the unit of force, is named after Isaac Newton. The unit of power is the watt, named after James Watt who helped develop the steam engine. The unit of pressure is the pascal, named after the French mathematician Blaise Pascal, who tinkered with barometers (and created one of the first mechanical computers among other achievements). The joule, the unit of energy, is named after the English physicist James Prescott Joule.
The discoverers of electricity and magnetism are also honored. The volt, the unit of electromotive force, is named after the Italian physicist Alessandro Volta. The unit of electric charge, the coulomb, is named after French physicist Charles-Augustin de Coulomb. The unit of electric resistance, the ohm, is named after German physicist Georg Ohm. For awhile the unit of electrical conductance was the mho, since this conductance is the opposite of resistance. For better or worse, this unit was later renamed the seimens, after German inventor Ernst Werner von Seimens. Electrical current is measured in amperes, or amps, named after French physicist André-Marie Ampère. The English natural philosopher Michael Faraday was honored with the unit of electric capacitance, the farad. Magnetic flux is measured in webers, after German physicist Wilhelm Eduard Weber. Magnetic flux density is measured in teslas, after the enigmatic inventor Nikola Tesla who was responsible for alternating current, wireless communication, and remote power transmission.
Units of measurement are usually accompanied by prefixes denoting the scale of the measurement. Mega is Greek for great, kilo is Greek for a thousand, hecto was adapted from the Greek word hekaton, and means a hundred. Deca is Greek for ten, while deci derived from the Latin decimus, which means tenth. Centi is derived from the Latin centum for a hundred and is used to mean a hundredth. Milli is from the Latin mille, which is thousand and means a thousandth. Micro is Greek and simply means small.
Early on, mega to micro was sufficient, but later had to be expanded as our ability to measure things increased. On the large side, giga is Greek for giant, and tera is greek for monster. Peta is derived from the Greek penta, five, as a penta represents 1000 to the fifth power. In the same manner, exa is Greek for six, zetta is related to the Latin septum or seven, and yotta is Greek for eight. On the small side, nano is Greek for dwarf, femto is Old Norse for fifteen (10 to the negative 15), atto is derived from the Danish word atten, or eighteen (10 to the negative 18). Zepto is derived from the Latin septum, or seven, and represents 1000 to the negative seventh power, while yocto is Greek for eight (1000 to the negative eighth power).
