Business

Researchers build supply chain model to support hydrogen economy

Over the past decades, the need for carbon-free energy has driven increasing interest in hydrogen as an environmentally clean fuel. But shifting the economy away from fossils fuels to clean-burning hydrogen will require significant ...

Engineering

Innovative batteries put flying cars on the horizon

Jet packs, robot maids and flying cars were all promises for the 21st century. We got mechanized, autonomous vacuum cleaners instead. Now a team of Penn State researchers are exploring the requirements for electric vertical ...

Engineering

Bringing order to hydrogen energy devices

Researchers at Kyoto University's Institute for Cell-Material Sciences (iCeMS) have developed a new approach to speed up hydrogen atoms moving through a crystal lattice structure at lower temperatures. They reported their ...

Electronics & Semiconductors

Making batteries live longer with ultrathin lithium

Our lives today are governed by electronics in all shapes and forms. Electronics, in turn, are governed by their batteries. However, the traditional lithium-ion batteries (LIBs), that are widely used in electronic devices, ...

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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