[ad_1]
Viscosity (η) is the resistance of a liquid to flow. Liquids thicken when cooled and become wetter when heated, but how liquid can become liquid if we continue to heat it?
At one point, the liquid reaches a specific temperature; It passes between the liquid and gas state and has a minimum viscosity value.
The higher the viscosity, the slower the liquid flows. Similarly, the lower the viscosity, the faster the liquid flows.
However, it is quite difficult to calculate viscosity from theory because it is highly dependent on liquid structure, composition and interactions, as well as external conditions in a complicated way. This difficulty has been compared to the difficulty of calculating fundamental physical constants, the constants that shape the fabric of our Universe.
Despite this difficulty, scientists at Queen Mary University of London and the Russian Academy of Sciences have developed an equation to calculate the viscosity of the liquid.
They show that two fundamental physical constants govern how liquid a liquid can be. Physical constants, or constants of nature, are measurable properties of the physical universe that do not change.
The equation relates the minimum value of elemental viscosity to the Planck constant, which governs the quantum world, and the ratio of proton mass to dimensionless electron.
Professor Kostya Trachenko, lead author of the article from Queen Mary University of London, said: “This result is surprising. Viscosity is a complicated property that varies greatly for different liquids and external conditions. However, our results show that the minimum viscosity of all liquids turns out to be simple and universal. “
There are practical implications of discovering this limit as well. It could be applied when a new fluid is required for a low viscosity chemical, industrial or biological process. An example where this is important is the recent use of supercritical fluids for ecological and ecological ways of treating and dissolving complex waste products.
In this case, the discovered fundamental limit provides useful theoretical guidance on what to aim for. It also tells us that we should not waste resources trying to exceed the central limit because Nature’s constants will shape viscosity at or above this point.
Fundamental physical constants and dimensionless constants (fundamental constants that do not depend on the choice of physical units) are believed to define the Universe in which we live.
This balance provides a narrow “habitable zone” where stars and planets can form, and life-supporting molecular structures can emerge. Slightly change one of the dimensionless fundamental constants, and the Universe becomes very different, without stars, heavy elements, planets, and life.
Professor Trachenko said: “The lower fundamental limit reminds us of how the fundamental constants of nature affect us on a daily basis, starting with making a cup of tea in the morning and extending its rule of thumb to specific, albeit complex, properties such as liquid viscosity.”
Vadim Brazhkin, senior co-author of the Russian Academy of Sciences, added: “There are indications that the fundamental lower limit of liquid viscosity may be related to very different areas of physics: black holes, as well as the new state of matter, quark-gluon plasma, which appears at temperatures and pressures very high. Exploring and appreciating these and other connections is what makes science so exciting. “
Magazine reference:
- Minimum quantum viscosity of fundamental physical constants. DOI: 10.1126 / sciadv.aba3747
