Flowing particles in liquids act as a filter to suppress long-wavelength waves but allow short-wavelength ones to be supported, according to physicists at Queen Mary University of London (QMUL).
Liquids are the least understood state of matter and for a long time it has been believed that they can sustain both gas-like waves with long wavelengths and solid-like waves with short wavelengths, but it wasn’t clear just how solid-like waves propagate in liquids.
The researchers found that a gap emerges in the liquid wave spectrum. This gap implies that only short-wavelength solid-like waves can propagate. This understanding will allow researchers to develop the theory of the liquid state and opens new avenues of research into liquids.
Using the predictions from their recent theory, the researchers have performed an extensive modelling study to ascertain the gap and discuss its properties in the journal Physical Review Letters.