field
A field describes how a physical quantity is distributed in space and time. For instance, the area where electric forces act on a test particle is subject to an electric field. Or the gravitational forces which act on the mass of a test body define a ...
fermion
"Fermion" refers to quantum particles with half odd integer spin, such as spin 1/2, 3/2 or 5/2. Fermions include elementary particles, for example electrons or quarks, but also composite particles such as protons. In more vivid terms, Fermions are ...
false colour
Only a small part of astronomical observations is concerned with visible light, in other words: with electromagnetic radiation visible to the human eye. In order to visualize obervations made at invisible wave-length, such as infra-red ...
Fahrenheit scale
Usual temperature scale in the US. Temperatures are given in degrees Fahrenheit (°F); the scale is defined historically, by using as its zero point the lowest temperature measured in winter 1708/1709 in Danzig (today Gdansk, Poland, Daniel Gabriel ...
extra dimension
According to some of the candidate models for a theory of quantum gravity, notably in string theory, our world should have extra dimensions - space dimensions in addition to the three we know from everday life. More information about extra dimensions, ...
exponential
A quantity whose rate of growth is proportional to how large it already is is said to show exponential growth. For instance, exponential growth is a model for population growth on a planet with infinite resources: The larger the population, the more ...
exponential notation
In physics, very large and very small numbers are written with the help of powers of the number ten. For large numbers, 10n with n a non-negative integer is a 1 with n trailing zeros: 100 = 1 = one 101 = 10 = ten 102 = 100 = a hundred 103 = 1000 = a ...
