Robotics

New energy-efficient algorithm keeps UAV swarms helping longer

A new energy-efficient data routing algorithm developed by an international team could keep unmanned aerial vehicle swarms flying—and helping—longer, report an international team of researchers this month in the journal ...

Energy & Green Tech

Holistic view of planning energy self-sufficient communities

Sustainable communities supplied by local renewable energy production are beginning to be established in the U.S. By using energy-efficient buildings and distributing means of energy generation, such as solar panels, throughout ...

Energy & Green Tech

Facebook invests in renewables with Texas solar project

Facebook is building a massive solar farm in West Texas that's believed to be one of the largest solar projects in the nation and the social media giant's first direct investment in renewable energy.

Energy & Green Tech

Magnetism: An unexpected push for the hydrogen economy

Humankind has entered uncharted territory: atmospheric CO2 levels have soared to a record-breaking 415 ppm for the first time in human history. The need to find a sustainable alternative to CO2-producing fuels is urgent. ...

Consumer & Gadgets

Researchers find ways to hackproof smart meters

Smart electricity meters are useful because they allow energy utilities to efficiently track energy use and allocate energy production. But because they're connected to a grid, they can also serve as back doors for malicious ...

Energy & Green Tech

Pioneering 3-D printed device sets new record for efficiency

A new 3-D printed thermoelectric device, which converts heat into electric power with an efficiency factor over 50% higher than the previous best for printed materials—and is cheap to produce in bulk—has been manufactured ...

Security

Protecting our energy infrastructure from cyberattack

Almost every day, news headlines announce another security breach and the theft of credit card numbers and other personal information. While having one's credit card stolen can be annoying and unsettling, a far more significant, ...

Energy & Green Tech

Floating power plants

Paper, tin cans, glass—the world recycles as much as possible. So why not declare the greenhouse gas carbon dioxide (CO2) a recycling product as well? Liquid fuels based on carbon will continue to play an important role ...

Energy & Green Tech

New organic flow battery brings decomposing molecules back to life

After years of making progress on an organic aqueous flow battery, Harvard University researchers ran into a problem: the organic anthraquinone molecules that powered their ground-breaking battery were slowly decomposing ...

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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