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
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
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
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?
Deconstructing Schrödinger's cat
on February 14, 2020 at 6:47 pm
Many physicists have attempted to explain the problem of quantum superposition, as exemplified by Schrödinger's cat. Now a French theoretical physicist proposes a novel possible solution, which combines two different approaches and brings in universal gravitation.
Quantum paradox experiment may lead to more...
on October 15, 2019 at 1:22 pm
More accurate clocks and sensors may result from a recently proposed experiment, linking an Einstein-devised paradox to quantum mechanics. A physicist said the international collaboration aimed to test Einstein's twin paradox using quantum particles in a 'superposition' state.
Quantum vacuum: Less than zero energy
on October 2, 2019 at 2:27 pm
According to quantum physics, energy can be 'borrowed' -- at least for some time. Energies lower than zero are possible, much like a bank account that can be overdrawn. There are, however, certain restrictions to that. Scientists have now shown that these restrictions are very fundamental properties of our universe and must be true for various possible quantum theories.
Laser prototype for space-based gravitational...
on September 18, 2019 at 4:45 pm
Researchers have announced a prototype for a laser at the heart of the first space-based gravitational wave observatory, known as the Laser Interferometer Space Antenna (LISA) mission.
The magic wavelength of cadmium
on September 16, 2019 at 2:18 pm
Researchers experimentally determined a property of cadmium called the magic wavelength which is considered essential for the development of the most accurate clocks ever envisaged. The researchers hope this may permit simple and robust atomic clocks so accurate they could be used to improve our understanding of current theories and even test for new physics.
Phys.org - latest science and technology news stories Phys.org internet news portal provides the latest news on science including: Physics, Nanotechnology, Life Sciences, Space Science, Earth Science, Environment, Health and Medicine.
Cracks make historical paintings less vulnerable...
on February 20, 2020 at 1:00 am
Historical wood panel paintings with developed craquelure patterns—networks of fine cracks in the paint- are significantly less vulnerable to environmental variations than previously assumed, according to a study in the open access journal Heritage Science. The findings offer a potential explanation as to why heavily cracked historical paintings remain stable in environments far from 'ideal' museum conditions.
What if we could teach photons to behave like...
on February 19, 2020 at 8:22 pm
To develop futuristic technologies like quantum computers, scientists will need to find ways to control photons, the basic particles of light, just as precisely as they can already control electrons, the basic particles in electronic computing. Unfortunately, photons are far more difficult to manipulate than electrons, which respond to forces as simple as the sort of magnetism that even children understand.
New mathematical model reveals how major groups...
on February 19, 2020 at 7:00 pm
Researchers at Uppsala University and the University of Leeds presents a new mathematical model of patterns of diversity in the fossil record, which offers a solution to Darwin's "abominable mystery" and strengthens our understanding of how modern groups originate. The research is published in the journal Science Advances.
Fish in the Sahara? Yes, in the early Holocene
on February 19, 2020 at 7:00 pm
Catfish and tilapia make up many of the animal remains uncovered in the Saharan environment of the Takarkori rock shelter in southwestern Libya, according to a study published February 19, 2020 in the open-access journal PLOS ONE by Wim Van Neer from the the Natural History Museum in Belgium, Belgium and Savino di Lernia, Sapienza University of Rome, Italy, and colleagues.
Five millimeter diameter motor is powered...
on February 19, 2020 at 5:01 pm
Researchers at the Faculty of Physics at the University of Warsaw, with colleagues from Poland and China used liquid crystal elastomer technology to demonstrate a rotary micromotor powered with light. The 5-millimeter diameter ring, driven and controlled by a laser beam, can rotate and perform work, e.g. by rotating another element installed on the same axis.