Energy & Green Tech

High-altitude wind power reaches new milestone

As part of the EU-funded REACH project, Dutch start-up Kitepower has successfully deployed its Airborne Wind Energy System (AWES) in the Caribbean. This is a landmark achievement for the company working to bring its Falcon ...

Energy & Green Tech

A thermosyphon heat transport device for novel solar cooking

Much of the developed world is focused on the conversion of natural resources, such as sunlight, wind, the turning of the tides, waves, and other phenomena into electrical power. However, conversions require sophisticated ...

Energy & Green Tech

Can we coordinate water sources to recover more water sustainably?

In many places, including Southern California, climate change has increased the threat of drought and the need for new and continuous water resources. Higher salinity water streams, and sometimes seawater, come into consideration ...

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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