Determining Heat Flow for Small ObjectsCategory: Science & Technology
Posted: July 17, 2013 06:22PM
A mechanic present almost everywhere in Nature is one to achieve equilibrium. This is the mechanic at the heart of heat being transformed from one object to another, or to the environment, which is critical for keeping our computers cool. The rules for how heat is radiated were first described by Max Planck in 1900, but what he developed does not work in the general case. Researchers at the Vienna University of Technology though have recently performed a study to find the general theory.
Planck developed his theory considering bodies that absorb all radiation and then re-emit it according to the body's temperature. Sufficiently small objects though will not absorb all radiation, and thus how they re-emit what energy they absorb will not obey Planck's law. To find out how such small objects behave, the researchers sent light through ultra-thin optical fibers just 500 nm wide. They then measured how much light was converted to heat and radiated into the environment by the fiber, finding it would take longer to radiate all of the absorbed energy than Planck's law predict. However, it does fit a general theory of fluctuational electrodynamics, which can be applied to any body size and geometry.
This discovery could have great impacts on quantum computing and aerosol physics. Quantum information networks may use similar ultra-thin optical fibers, and one would not want them to burn out during regular use, while aerosol physics deals with tiny particles in the atmosphere, and how they radiate heat.
Source: Vienna University of Technology