Gaining insight into the energy balance of earthquakes

Researchers at EPFL's Computational Solid Mechanics Laboratory and the Weizmann Institute of Science have modeled the onset of slip between two bodies in frictional contact. Their work, a major step forward in the study of ...

Fusion by strong lasers

Nuclear physics usually involves high energies, as illustrated by experiments to master controlled nuclear fusion. One of the problems is how to overcome the strong electrical repulsion between atomic nuclei which requires ...

Hydrogen research fuels new solar ideas for green energy

New research led by Curtin University explores the use of methanol as a storage for hydrogen fuel, providing a potential green option for the extraction and creation of this zero pollution energy source.

Natural gas drives record CO2 emissions in 2019

Global carbon emissions boosted by soaring natural gas use are set to hit record levels in 2019 despite a decline in coal consumption and a string of countries declaring a climate emergency, researchers said Wednesday.

Electron correlations in carbon nanostructures

New materials are needed to further reduce the size of electronic components and thus make devices such as laptops and smartphones faster and more efficient. Tiny nanostructures of the novel material graphene are promising ...

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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.

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