Why does an object transfer its energy

New quantum effectSwirling energy transfers heat despite the vacuum

How does heat get from one place to another? Well, says physicist King Yan Fong of Berkeley University in California, there are three mechanisms.

"Thermal conduction, convection and thermal radiation. With thermal conduction, vibrating atoms pass on their kinetic energy to their neighbors. With convection, the thermal energy is transported by a flowing medium, a liquid or a gas. And with thermal radiation, an object can be heated by being simply irradiated with electromagnetic waves. "

Doctrine refuted

Objects in a vacuum can only be heated with thermal radiation. Because the other two mechanisms - heat conduction and convection - need a medium for the transfer of heat. And that doesn't exist in a vacuum. So much for the doctrine. But King Yan Fong and his boss Xiang Zhang have succeeded in an experiment at California's Berkeley University with which they refute textbook knowledge.

"We have two membranes facing each other at a distance of 300 nanometers. We heated one membrane, the other stayed cold. When we pushed the two closer and closer together, the heat transport started: the warm membrane got colder and the cold one warmer. And finally both were the same temperature. "

Ghostly quantum effect ensures heat exchange

In numbers: At the beginning of the experiment, one membrane was 25 degrees warmer than the other. After the approach, both were equally warm without touching. And mind you, both membranes were in a vacuum chamber that was pumped almost completely evacuated. A seemingly magical result, because there was no exchange of radiation between the two membranes. But how did the heat get from A to B? Through a ghostly quantum effect, explains King Yan Fong.

"The vacuum we are talking about here contains no matter, no molecules, no light. Yet there is something - quantum fluctuations, a kind of energy wobble in the void. And these fluctuations cause one between the two objects in the vacuum weak force works, the Casimir force. "

Phenomenon limited to the tiniest dimensions

This force is well known in physics, it has been proven several times. Here it acts like an invisible steel spring stretched between the membranes. This spring is set in motion by the rapidly vibrating atoms in the warm membrane. The spring then transfers this movement to the atoms in the cold membrane. As a result, they begin to vibrate faster and the cold membrane becomes warmer. So the whole thing happens according to the mechanism of heat conduction - just not mediated by a medium, but by a quantum force. However, the phenomenon is limited to the tiniest dimensions.

"In order for the effect to work between two objects, they have to be very close together, on the order of nanometers, that is, millionths of a millimeter. But in such dimensions the effect is really significant."

This is exactly what inspires the Californian team to start thinking about possible applications, for example in nanotechnology. An example:

"In microelectronics, thermal management is now a big issue. Today's processors get so hot that you have to dissipate their heat with fans. With our new mechanism of heat conduction, components are conceivable with which the heat can be dissipated much more efficiently."

In order to achieve this, the processors would have to be designed differently than before, otherwise the new effect will not work. After all, King Yan Fong and his people created the basis for this.