Ultrapure copper for an ultrasensitive dark matter detector

In February and March, three batches of copper plates arrived at Fermilab and were rushed into storage 100 meters underground. The copper had been mined in Finland, rolled into plates in Germany and shipped across land and ...

Assessing the viability of small modular nuclear reactors

Small modular nuclear reactors could provide nuclear power to small communities and rural areas currently served by environmentally damaging fossil fuel energy-sources. Assessing the potential of these reactors means keeping ...

Identifying biomolecule fragments in ionising radiation

When living cells are bombarded with fast, heavy ions, their interactions with water molecules can produce randomly scattered 'secondary' electrons with a wide range of energies. These electrons can then go on to trigger ...

Single-atom alloy: Superb cocatalyst for photocatalysis

Photocatalysis, converting solar energy into chemical energy, has been recognized to be a very promising solution to current energy and environmental issues. The performance of the photocatalytic system depends largely on ...

Renewable energy targets can undermine sustainable intentions

Renewable energy targets (RETs) may be too blunt a tool for ensuring a sustainable future, according to University of Queensland-led research. Ph.D. candidate Scott Spillias, from UQ's School of Earth and Environmental Sciences, ...

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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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