Related topics: electricity

Magnetizing laser-driven inertial fusion implosions

Nuclear fusion is a widely studied process through which atomic nuclei of a low atomic number fuse together to form a heavier nucleus, while releasing a large amount of energy. Nuclear fusion reactions can be produced using ...

The realization of a single-quantum-dot heat valve

While many research teams worldwide are trying to develop highly performing quantum computers, some are working on tools to control the flow of heat inside of them. Just like conventional computers, in fact, quantum computers ...

Quantum heat engine behaviour observed in a qubit

Although many of today's accepted theories of classical thermodynamics predate even the industrial revolution they helped to propel, many open questions remain around how these ideas translate to the level of single quantum ...

Less is more for Maxwell's Demon in quantum heat engines

Over 150 years after the famous Scottish scientist James Clerk Maxwell first introduced the idea, the concept of Maxwell's demon continues to perplex physicists and information scientists. The demon he dreamed up in a thought ...

Designing surfaces that make water boil more efficiently

The boiling of water or other fluids is an energy-intensive step at the heart of a wide range of industrial processes, including most electricity generating plants, many chemical production systems, and even cooling systems ...

page 1 from 40


In physics and thermodynamics, heat is the process of energy transfer from one body or system to another due to a difference in temperature. In thermodynamics, the quantity TdS is used as a representative measure of the (inexact) heat differential δQ, which is the absolute temperature of an object multiplied by the differential quantity of a system's entropy measured at the boundary of the object.

A related term is thermal energy, loosely defined as the energy of a body that increases with its temperature. Heat is also loosely referred to as thermal energy, although many definitions require this thermal energy to actually be in the process of movement between one body and another to be technically called heat (otherwise, many sources prefer to continue to refer to the static quantity as "thermal energy"). Heat is also known as "Energy".

Energy transfer by heat can occur between objects by radiation, conduction and convection. Temperature is used as a measure of the internal energy or enthalpy, that is the level of elementary motion giving rise to heat transfer. Energy can only be transferred by heat between objects - or areas within an object - with different temperatures (as given by the zeroth law of thermodynamics). This transfer happens spontaneously only in the direction of the colder body (as per the second law of thermodynamics). The transfer of energy by heat from one object to another object with an equal or higher temperature can happen only with the aid of a heat pump, which does work.

This text uses material from Wikipedia, licensed under CC BY-SA