Energy & Green Tech

Renewable energy powers ahead in 2020: report

Renewable energy grew at its fastest rate in two decades, driven primarily by gains in China and wind power, the International Energy Agency said in a report Tuesday.

Security

FBI names pipeline cyberattackers as company promises return

Hit by a cyberattack, the operator of a major U.S. fuel pipeline said Monday it hopes to have services mostly restored by the end of the week as the FBI and administration officials identified the culprits as a gang of criminal ...

Energy & Green Tech

Chill out: Advanced solar tech runs cooler and lasts longer

Australian photovoltaics researchers have made a 'cool' discovery: Singlet fission and tandem solar cells—two innovative ways to generate solar power more efficiently—also help to lower operating temperatures and keep ...

Energy & Green Tech

Can energy-efficient federated learning save the world?

Training the artificial intelligence models that underpin web search engines, power smart assistants and enable driverless cars consumes megawatts of energy and generates worrying carbon dioxide emissions. But new ways of ...

Energy & Green Tech

Scientists report new synapse-like phototransistor

Researchers at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) developed a breakthrough in energy-efficient phototransistors. Such devices could eventually help computers process visual information ...

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Energy

In physics, energy (from the Greek ἐνέργεια - energeia, "activity, operation", from ἐνεργός - energos, "active, working") is a scalar physical quantity that describes the amount of work that can be performed by a force, an attribute of objects and systems that is subject to a conservation law. Different forms of energy include kinetic, potential, thermal, gravitational, sound, light, elastic, and electromagnetic energy. The forms of energy are often named after a related force.

Any form of energy can be transformed into another form, but the total energy always remains the same. This principle, the conservation of energy, was first postulated in the early 19th century, and applies to any isolated system. According to Noether's theorem, the conservation of energy is a consequence of the fact that the laws of physics do not change over time.

Although the total energy of a system does not change with time, its value may depend on the frame of reference. For example, a seated passenger in a moving airplane has zero kinetic energy relative to the airplane, but non-zero kinetic energy relative to the Earth.

This text uses material from Wikipedia, licensed under CC BY-SA