Crackling noise during growth
Globules of fat in homogenised milk, dust particles in the early solar system and small magnetic domains in ferromagnets are all examples of small parts coming together to form one whole, like "birds of a feather"; or, in this case: particles of the same size flock together. Scientists from the Max Planck Institute for Dynamics & Self-Organization, the University of Göttingen and Azarbaijan Shahid Madani University in Iran have demonstrated that such growth processes "crackle". What this means is that during growth, the individual parts perform jumps that are randomly distributed in terms of size. This random distribution is subject to the same statistical laws as the intensity of the sound made by a sheet of paper being crumpled. The new models help scientists understand, among other things, the jerky magnetisation of ferromagnets.