(PhysOrg.com) -- With its complete lack of atoms, a vacuum is often considered to be the best known insulator. For this reason, vacuums are regularly used to reduce heat transfer, such as in the lining of a thermos to keep ...
Researchers at ETH Zurich have demonstrated in the lab how well a mineral common at the boundary between the Earth's core and mantle conducts heat. This leads them to suspect that the Earth's heat may dissipate sooner than ...
Earth Sciences
Jan 14, 2022
4
601
Researchers at CU Boulder report that they may have solved a geophysical mystery, pinning down the likely cause of a phenomenon that resembles a wrench in the engine of the planet.
Earth Sciences
Oct 1, 2018
1
408
The search for habitable, alien worlds needs to make room for a second "Goldilocks," according to a Yale University researcher.
Astronomy
Aug 19, 2016
11
2361
Tea drinkers have been saying it for years. Water heated in a microwave just isn't the same.
Condensed Matter
Aug 4, 2020
4
642
Uranus and Neptune both have a completely skewed magnetic field, perhaps due to the planets' special inner structures. But new experiments by ETH Zurich researchers now show that the mystery remains unsolved.
Astronomy
Mar 31, 2021
0
1254
The composition of the Earth's core remains a mystery. Scientists know that the liquid outer core consists mainly of iron, but it is believed that small amounts of some other elements are present as well. Oxygen is the most ...
Earth Sciences
Nov 23, 2011
12
1
On Pluto, icebergs floating in a sea of nitrogen ice are key to a possible explanation of the quilted appearance of the Sputnik Planum region of the dwarf planet's surface.
Space Exploration
Jun 1, 2016
0
409
Earth's magnetic field is crucial for our existence, as it shields the life on our planet's surface from deadly cosmic rays. It is generated by turbulent motions of liquid iron in Earth's core. Iron is a metal, which means ...
General Physics
Jan 28, 2015
14
2327
How did the chemical makeup of our planet's core shape its geologic history and habitability?
Earth Sciences
Jul 6, 2020
10
1407
Convection is the movement of molecules within fluids (i.e. liquids, gases) and rheids. It cannot take place in solids, since neither bulk current flows nor significant diffusion can take place in solids.
Convection is one of the major modes of heat transfer and mass transfer. Convective heat and mass transfer take place through both diffusion – the random Brownian motion of individual particles in the fluid – and by advection, in which matter or heat is transported by the larger-scale motion of currents in the fluid. In the context of heat and mass transfer, the term "convection" is used to refer to the sum of advective and diffusive transfer. Note that in common use the term convection may refer loosely to heat transfer by convection, as opposed to mass transfer by convection, or the convection process in general. Sometimes "convection" is even used to refer specifically to "free heat convection" (natural heat convection), as opposed to forced heat convection. However, in mechanics the correct use of the word is the general sense, and different types of convection should be properly qualified for clarity.
Convection can be qualified in terms of being natural, forced, gravitational, granular, or thermomagnetic. It may also be said to be due to combustion, capillary action, or Marangoni and Weissenberg effects. Due to its role in heat transfer, natural convection plays a role in the stucture of Earth's atmosphere, its oceans, and its mantle. Discrete convective cells in the atmosphere can be seen as clouds, with stronger convection resulting in thunderstorms. Natural convection also plays a role in stellar physics.
This text uses material from Wikipedia, licensed under CC BY-SA
