The laws list
G
 26Lw7 Laws

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
G.
G
See universal constant of gravitation.
Gaia hypothesis (J. Lovelock, 1969)
The idea that the Earth as a whole should be regarded as a living organism and that biological processes stabilize the environment.
Gauss' law (K.F. Gauss)
The electric flux through a closed surface is proportional to the algebraic sum of electric charges contained within that closed surface; in differential form,
div E = rho,
where rho is the charge density.
Gauss' law for magnetic fields (K.F. Gauss)
The magnetic flux through a closed surface is zero; no magnetic charges exist; in differential form,
div B = 0.
geometrized units
A system of units whereby certain fundamental constants (G, c, k, and h) are set to unity. This makes calculations in certain theories, such as general relativity, much easier to deal with, since these constants appear frequently.

As a result of converting to geometrized units, all quantities are expressed in terms of a unit of distance, traditionally the cm.

A paradox proposed to discount time travel and show why it violates causality. Say that your grandfather builds a time machine. In the present, you use his time machine to go back in time a few decades to a point before he married his wife (your grandmother). You meet him to talk about things, and an argument ensues (presumably he doesn't believe that you're his grandson/granddaughter), and you accidentally kill him.

If he died before he met your grandmother and never had children, then your parents could certainly never have met (one of them didn't exist!) and could never have given birth to you. In addition, if he didn't live to build his time machine, what are you doing here in the past alive and with a time machine, if you were never born and it was never built?

gray; Gy (after L.H. Gray, 1905-1965)
The derived SI unit of absorbed dose, defined as the absorbed dose in which the energy per unit mass imparted to the matter by ionizing radiation is 1 J/kg; it thus has units of J/kg.
See event horizon.
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