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Physical Realm
Physical Laws (Constants) Relativity
Matter Molecule, Atom (Periodic Table), Particle
Force Gravity, Electromagnetism (Light, Color)


These are organized by a classification scheme developed exclusively for Cosma. More…



relativity : a theory which is based on the two postulates (1) that the speed of light in a vacuum is constant and independent of the source or observer and (2) that the mathematical forms of the laws of physics are invariant in all inertial systems and which leads to the assertion of the equivalence of mass and energy and of change in mass, dimension, and time with increased velocity — called also special relativity, special theory of relativity — Webster

OneLook, Free Dictionary, Wiktionary, Urban Dictionary


Roget’s II (, Merriam-Webster Thesaurus, Visuwords


Relativity, generally refers to the theory of relativity usually encompasses two interrelated theories by Albert Einstein: special relativity and general relativity.

Special relativity applies to elementary particles and their interactions, describing all their physical phenomena except gravity.

General relativity explains the law of gravitation and its relation to other forces of nature. It applies to the cosmological and astrophysical realm, including astronomy.

The theory transformed theoretical physics and astronomy during the 20th century, superseding a 200-year-old theory of mechanics created primarily by Isaac Newton. It introduced concepts including spacetime as a unified entity of space and time, relativity of simultaneity, kinematic and gravitational time dilation, and length contraction.

In the field of physics, relativity improved the science of elementary particles and their fundamental interactions, along with ushering in the nuclear age. — Wikipedia

Encyclopædia Britannica

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


What is relativity? Einstein’s mind-bending theory explained (Dan Falk, Mach, NBC News)
The Theory of Relativity (Ask an Astronomer, Cornell University)






The Collected Papers of Albert Einstein (California Institute of Technology)


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




Special Relativity Course (Minute Physics)

Crash Course Physics (YouTube)

Einstein, Oppenheimer, Feynman: Physics in the 20th Century (MIT OCW Physics)
Introduction to Nuclear and Particle Physics (MIT OCW Physics)
Relativity (MIT OCW Physics)
OER Commons: Open Educational Resources


Science Daily,, NPR Archives









Albert Einstein News -- ScienceDaily Albert Einstein in the News. Research institutes have been testing Albert Einstein's theory of special relativity and general relativity. Was Albert Einstein right?

  • Bose-Einstein condensates cannot currently detect...
    on December 12, 2018 at 6:50 pm

    The gravitational waves created in the depths of space indeed reach Earth. Their effects, however, are so small that they could only be observed so far using kilometer-long measurement facilities. Physicists therefore discuss whether Bose-Einstein condensates with their ordered quantum properties could also detect these waves. Astronomers have now looked at these suggestions and have soberly determined that such evidence is far beyond the reach of current methods. […]

  • Bringing balance to the universe: New theory...
    on December 5, 2018 at 2:37 pm

    New research could shed light on the 'missing' dark matter and dark energy that make up 95 percent of our universe and yet are wholly invisible to us. […]

  • Atomic clocks now keep time well enough to...
    on November 28, 2018 at 7:18 pm

    Experimental atomic clocks have now achieved three new performance records, now ticking precisely enough to not only improve timekeeping and navigation, but also detect faint signals from gravity, the early universe and perhaps even dark matter. […]

  • New finding of particle physics may help to...
    on November 13, 2018 at 4:04 pm

    With the help of computer simulations, particle physics researchers may be able to explain why there is more matter than antimatter in the Universe. The simulations offer a new way of examining conditions after the Big Bang, and could provide answers to some fundamental questions in particle physics. […]

  • Bose-Einstein condensate generated in space for...
    on October 31, 2018 at 4:49 pm

    Scientists have created a Bose-Einstein condensate for the first time in space on board a research rocket. […] - latest science and technology news stories internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine.

  • The epoch of planet formation, times twenty
    on December 12, 2018 at 8:12 pm

    Astronomers have cataloged nearly 4,000 exoplanets in orbit around distant stars. Though the discovery of these newfound worlds has taught us much, there is still a great deal we do not know about the birth of planets and the precise cosmic recipes that spawn the wide array of planetary bodies we have already uncovered, including so-called hot Jupiters, massive rocky worlds, icy dwarf planets, and—hopefully someday soon—distant analogs of Earth. […]

  • Why deep oceans gave life to the first big,...
    on December 12, 2018 at 6:10 pm

    In the beginning, life was small. […]

  • Verizon loses bet on digital ads, takes $4.6B...
    on December 12, 2018 at 4:00 pm

    Verizon's big bet on digital advertising isn't panning out. […]

  • European network of protected areas has not yet...
    on December 12, 2018 at 3:40 pm

    The Natura 2000 network of protected areas runs across the EU as a conservation network for biodiversity. However, only a few studies have so far analysed whether these refuges actually have a positive effect on species diversity. Studies have predominately focussed on birds and have not shown any clear trends. Using long-term data from the "Butterfly Monitoring Germany" citizens' research project, scientists from the Helmholtz Centre for Environmental Research (UFZ) in Halle, Germany, and the […]

  • Cheap oil is blocking progress on climate change
    on December 12, 2018 at 3:30 pm

    The relationship between supply and demand, a fundamental economic concept, holds that when the price of something rises, people use less of it. Similarly, when prices fall, they use more. […]