In the vast universe, the search for life's origins often leads us to the stars, where nuclear reactions create the building blocks of biology. But a recent study has unveiled a surprising new requirement for life as we know it, one that brings us back to Earth and the humble cup of water.
The Liquid Flow of Life
Professor Kostya Trachenko, a physicist at Queen Mary University of London, has delved into the world of liquid flow and its profound impact on cell chemistry. Proteins, nutrients, and molecular motors all rely on the unique viscosity of water to function. A slight change in this viscosity can disrupt cellular processes, and Trachenko wondered if this fundamental property was governed by the same constants that shape the universe.
A Viscosity Floor
Trachenko's research revealed an intriguing phenomenon: every liquid has a viscosity floor, a minimum value that cannot be lowered, regardless of temperature or pressure. This floor is determined by the Planck constant, electron mass, and electron charge - the deepest constants in physics. Water, helium, mercury, and molten metals all adhere to this rule, confirmed by decades of data.
Blood and the Viscosity Window
The study then focused on human blood, which operates within a narrow viscosity range. A deviation from this range can lead to cardiovascular issues. Trachenko's calculations showed that a mere change in the Planck constant or electron charge could push blood viscosity beyond this healthy range, rendering cellular chemistry impossible.
The Bio-Friendly Window
Here's where it gets fascinating. The fundamental constants of physics seem to be finely tuned to create a 'bio-friendly' window for liquid viscosity. Outside this window, life as we know it cannot exist.
"Understanding water flow in a cup is intricately linked to understanding the fundamental constants," Trachenko explains.
Beyond Stars and Atoms
Fine-tuning arguments have traditionally focused on star formation and the production of heavy atoms. But Trachenko's work takes us 15 orders of magnitude below a star's core, revealing that the flow of liquids is just as crucial for life.
A separate study on liquid behavior at tiny scales supports this idea, showing that everyday fluid dynamics is governed by the deepest physical laws.
Multiple Rounds of Tuning?
Trachenko's findings suggest that the constants may have been tuned multiple times, separately, to create sustainable structures - first atoms, then stars, and finally, the perfect viscosity for liquid-based life. This idea parallels biological evolution, where unrelated lineages can develop similar traits independently.
Implications for Physics and Biology
For physicists, this study adds a new constraint to theories explaining the values of fundamental constants. For biologists, it provides a framework to understand how changes in viscosity affect life processes, from pharmacology to the search for life on other worlds.
In conclusion, the deepest laws of physics are not just abstract concepts but are reflected in the simple act of water flowing through a glass.
This study, published in Science Advances, opens up a new and exciting chapter in our understanding of the universe and our place in it.
