Related topics: electricity

Mercury climbs as Europe braces for summer scorcher

Temperatures were climbing on Sunday as Europe braced for a blistering heatwave with the mercury set to hit 40 degrees Celsius (104 degrees Fahrenheit) as summer kicks in on the back of a wave of hot air from North Africa.

High temperature records will be 'smashed' in coming century

Climate change will cause some regions of the world to "smash" high temperature records every year in the coming century, researchers warn. That will push "ecosystems and communities beyond their ability to cope," according ...

This is what the ground looked like after inSight landed on Mars

When InSight landed on Mars on Nov. 26th, 2018, it deployed a parachute to slow its descent through the thin Martian atmosphere. As it approached the surface, it fired its retro rocket to slow it even more, and then gently ...

Heat wave hits Iraq—and sparks begin to fly

Hospital ventilators shut down, football matches with obligatory water breaks and food spoiling in fridges without power: Iraq's notorious summer has arrived.

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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.

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