Researchers at Queen Mary University of London have proposed a striking idea that links the deepest laws of physics to the existence of life itself. Their work suggests that the Universe’s fundamental constants sit within an extremely narrow range that allows liquids to flow in ways living cells depend on. If those constants were even slightly different, water, blood, and other life-supporting fluids could behave so differently that complex organisms might never have emerged at all.
The study, published in Science Advances in 2023, builds on earlier work by physicist Kostya Trachenko and colleagues showing that liquid viscosity is tied directly to fundamental physical constants. That finding established a lower limit for how “runny” liquids can be. The newer research extended the idea into biology, asking whether the same physical rules that shape the cosmos may also quietly determine whether cells can function.
Why Liquid Flow Matters for Life
Life depends on movement at microscopic scales. Nutrients must travel through cells, proteins need to fold correctly, and molecules constantly diffuse through watery environments. All of this relies on viscosity, the property that determines how easily a liquid flows.
According to the researchers, the Universe appears to operate within a surprisingly narrow “bio-friendly” window where viscosity and diffusion remain suitable for life. If the constants governing physics shifted by only a few percent, liquids essential to biology could become dramatically thicker or thinner.
“Understanding how water flows in a cup turns out to be closely related to the grand challenge to figure out fundamental constants. Life processes in and between living cells require motion and it is viscosity that sets the properties of this motion. If fundamental constants change, viscosity would change too impacting life as we know it. For example, if water was as viscous as tar life would not exist in its current form or not exist at all. This applies beyond water, so all life forms using the liquid state to function would be affected.”
The team says the consequences would extend far beyond drinking water or oceans. Human blood, cellular fluids, and the chemistry that powers life all rely on carefully balanced flow properties.
“Any change in fundamental constants including an increase or decrease would be equally bad news for flow and for liquid-based life. We expect the window to be quite narrow: for example, viscosity of our blood would become too thick or too thin for body functioning with only a few per cent change of some fundamental constants such as the Planck constant or electron charge.” Professor of Physics Kostya Trachenko said.
A New Twist on Cosmic Fine-Tuning
Physicists have long debated why the Universe’s constants appear finely tuned. Tiny differences in values such as the electron charge or the strength of fundamental forces could prevent stars from forming heavy elements needed for planets and life.
What makes this research unusual is that it shifts the discussion from stars and galaxies down to the level of living cells. Previous fine-tuning arguments often focused on nuclear reactions inside stars. This work argues that even if stars and heavy elements still formed, life might remain impossible if liquids could not flow properly inside organisms.
That introduces a second layer of fine-tuning. The constants not only appear compatible with a universe full of matter, but also with biological systems that depend on delicate liquid dynamics.
The researchers even suggest that multiple stages of tuning may have occurred. In the paper, Trachenko compares the possibility to biological evolution, where traits emerge independently over time. The idea remains speculative, but it raises the possibility that nature may favor stable physical structures in ways scientists do not yet fully understand.
Later Research Expanded the Idea
Since the original publication, scientists have continued exploring how viscosity, diffusion, and fluid behavior connect to fundamental physics. Follow-up theoretical work reviewed how liquid motion inside cells may place additional limits on the values of physical constants, especially in systems involving biochemical “machines” such as molecular motors.
Other researchers have also examined how viscosity itself may arise from deeper physical laws. A 2023 analysis highlighted growing evidence that liquid viscosity may be linked to universal physical limits rather than simply being a property measured in laboratories.
Together, these studies are helping reshape an old scientific mystery. Instead of viewing the constants of nature only through the lens of cosmology and particle physics, scientists are increasingly asking whether the conditions needed for flowing liquids and functioning cells should also be part of the equation.
Could Physics and Biology Be More Connected Than We Thought?
The idea remains highly theoretical, and many physicists would caution that there is still no accepted explanation for why the constants of nature have their observed values. But the research opens an unexpected path for thinking about one of science’s biggest questions.
For decades, the mystery of fundamental constants was mostly explored through black holes, stars, and subatomic particles. This work suggests the answer may also involve something much closer to everyday life: the simple ability of liquids to flow through living cells.
