Cosma / Communication / Knowledge / Realm / Physical

There are some oddities in the perspective with which we see the world. The fact that we live at the bottom of a deep gravity well, on the surface of a gas covered planet going around a nuclear fireball 90 million miles away and think this to be normal is obviously some indication of how skewed our perspective tends to be, but we have done various things over intellectual history to slowly correct some of our misapprehensions. — Douglas Adams



Physics (Free Animated Education, YouTube Playlist)
Free Animated Education (Facebook)


Physical : (a) of or relating to physics (b) characterized or produced by the forces and operations of physics (c) having material existence : perceptible especially through the senses and subject to the laws of nature — Webster   See also OneLook

Realm : kingdom, sphere, domain — Webster   See also OneLook

Physical Realm : kingdom, sphere, or domain of things that have material existence and are perceptible, especially those things perceptible through the senses and subject to the laws of nature — M.E.Hopper


Physical universe or “material universe” is terminology used to distinguish the physical matter of the universe from a spiritual or supernatural essence. — Wikipedia



In our time, there has been unloosed a cataclysm which has swept away space, time, and matter hitherto regarded as the firmest pillars of natural science, but only to make place for a view of things of wider scope, and entailing a deeper vision. — Hermann Weyl, Space, Time, Matter


Physics is the science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. Physics is one of the most fundamental scientific disciplines, with its goal being to understand how the universe behaves. — Wikipedia

Physics (Encyclopædia Britannica)
Physics Portal (Encyclopædia Britannica)

Outline of Physical Science (Wikipedia)
Outline of Physics (Wikipedia)

Eric Weisstein’s World of Physics (ScienceWorld, Wolfram Research)
Physical Effects (Wolfram Alpha)

Classical physics is a group of theories that predate more modern and complete theories. Classical physical concepts are often used when modern theories are unnecessarily complex for a particular situation. Most often classical physics refers to pre-1900 physics, while modern physics refers to post-1900 physics which incorporates elements of quantum mechanics and relativity. Classical physics is typically concerned with everyday conditions: speeds are much lower than the speed of light, sizes are much greater than that of atoms, and energies are relatively small. — Wikipedia

The matter which we suppose to be the main constituent of the universe is built out of small self-contained building-blocks, the chemical atoms. It cannot be repeated too often that the word “atom” is nowadays detached from any of the old philosophical speculations: we know precisely that the atoms with which we are dealing are in no sense the simplest conceivable components of the universe. On the contrary, a number of phenomena, especially in the area of spectroscopy, lead to the conclusion that atoms are very complicated structures. So far as modern science is concerned, we have to abandon completely the idea that by going into the realm of the small we shall reach the ultimate foundation of the universe. I believe we can abandon this idea without any regret. The universe is infinite in all directions, not only above us in the large but also below us in the small. If we start from our human scale of existence and explore the content of the universe further and further, we finally arrive, both in the large and in the small, at misty distances where first our senses and then even our concepts fail us. — Emil Wiechert

Modern physics is concerned with extreme conditions, such as high velocities that are comparable to the speed of light (special relativity), small distances comparable to the atomic radius (quantum mechanics), and very high energies (relativity). Quantum and relativistic effects are believed to exist across all scales, although these effects may be very small at human scale. Quantum mechanical effects tend to appear when dealing with “lows” (low temperatures, small distances), while relativistic effects tend to appear when dealing with “highs” (high velocities, large distances), the “middles” being classical behavior.
Very often, it is possible to find – or “retrieve” – the classical behavior from the modern description by analyzing the modern description at low speeds and large distances (by taking a limit, or by making an approximation). When doing so, the result is called the classical limit. — Wikipedia

Modern Physics (Eric Weisstein’s World of Physics, Wolfram Research)



Physics Campaigns (Kickstarter)
Physics Campaigns (Indiegogo)


Physics Gifts (Zazzle)




Center for History of Physics (American Institute of Physics)


Melvil Decimal System # 53 Physics (Library Thing)
Library of Congress Subject Heading: Physics (Library Thing)

Library of Congress # QC Physics (UPenn Online Books)

WorldCat, Library of Congress, UPenn Online Books, Open Library




Contemporary Physics Project
PHET Interactive Simulations (University of Colorado)

American Association of Physics Teachers
Engineering Physics and Physics (American Society for Engineering Education)

MERLOT: Multimedia Educational Resource for Learning and Online Teaching
OER Commons: Open Educational Resources


Einstein, Oppenheimer, Feynman: Physics in the 20th Century (MIT Opencourseware)

Physics Courses (MIT Open Learning Library)
Physics Courses (MIT OpenCourseWare)
Physics Courses (edX)



Physicists (CareerOneStop, U.S. Department of Labor, Employment and Training Administration)
Careers in Physical Sciences (Physics World)


American Physical Society (APS)
European Physical Society (EPS)
American Institute of Physics (AIP)


arXiv (Cornell University)
Physics (AAAS EurekaAlert)
Nature Physics
Physics World
Physics (
Physics (Science News)
Physics (NPR Archives)


Physics (ISBNdb)



Physics (



Here are links to pages about closely related subjects.

Knowledge Realm


Law (Constant) Relativity
Force Gravity, Electromagnetism (Light, Color)
Matter (Microscope) Molecule, Atom (Periodic Table), Particle

Universe (Astronomical Instrument)
Galaxy Milky Way, Andromeda
Planetary System Star, Brown Dwarf, Planet, Moon

Our Neighborhood
Solar System Sun
Terrestrial Planet Mercury, Venus, Earth (Moon), Mars
Asteroid Belt Ceres, Vesta
Jovian Planet Jupiter, Saturn, Uranus, Neptune
Trans-Neptunian Object
Kuiper Belt Pluto, Haumea, Makemake
Scattered Disc Eris, Sedna, Planet X
Oort Cloud Etc. Scholz’s Star
Small Body Comet, Centaur, Asteroid


1.   The resources on this page are are organized by a classification scheme developed exclusively for Cosma.