Algebra

Astronomy

The observational and theoretical study of celestial bodies, of the intervening regions of space, and of the Universe as a whole.  One of the oldest sciences, it progressed in steps with advances in instrumentation and other technology and advances in Physics, Chemistry, and Mathematics.

Biology

Chemistry

Cosmology

The study of the origin, evolution, and large-scale structure of the Universe.

Electricity

Energy

A measure of the capacity of a body or system for doing work, for changing the state of another body or system.  There are various form of energy.  Mass is also regarded as a form of energy.

Environment

Everything

Geometry

Gravity

The ability of all material bodies to attract each other.  This mutual attraction, gravity, is the most familiar force in Nature, and was first expressed in mathematical form by Isaac Newton.

History of Science

Life

Magnetism

Mathematics

Matter

Physics

Psychology

Quantum Mechanics

The theory put forward by German physicist Max Planck in 1900.  Whereas Classical physics regarded all changes in a system as continuous, Quantum mechanics allows changes to physical quantities, such as energy and angular momentum, only by discrete amounts or ‘quanta’.

Relativity

The theory put forward by Albert Einstein in 1915.  It describes how the relationship between space and time, as developed in the special relativity, is affected by the gravitational effects of matter.

Space

Time

Universe

The sum total of potentially knowable objects.  The study of the large-scale structure of the Universe is called Cosmology.

Waves