Researchers at Queen Mary University of London have proposed a surprising idea that links the deepest laws of physics to the existence of life itself. Their work suggests that the fundamental constants of the universe fall within very narrow ranges that allow liquids to flow in the way that living cells depend on. If those constants were even slightly different, water, blood, and other life-sustaining fluids might behave very differently, and complex life might never have emerged.
This study scientific progress In 2023, the study builds on previous work by physicist Kostya Trachenko and others that showed that a liquid’s viscosity is directly tied to fundamental physical constants. This discovery establishes a lower limit on how “soozy” a liquid can be. A new study extends this idea to biology, asking whether the same physical laws that shape the universe might also silently determine whether cells can function.
Why is fluid flow important to life?
Life depends on movement on a microscopic scale. Nutrients must move through the cell, proteins must fold correctly, and molecules must constantly diffuse into the watery environment. All of this depends on viscosity, the property that determines how easily a liquid flows.
Researchers say the universe appears to operate within a surprisingly narrow “biologically friendly” range, where viscosity and diffusion remain suitable for life. Changes of just a few percentage points in the constants governing physics can dramatically thicken or thin the fluids essential to biology.
“It turns out that understanding how water flows in a cup is closely related to the grand challenge of uncovering fundamental constants. Life processes within and between living cells require movement, and viscosity determines the properties of this motion. As fundamental constants change, viscosity changes as we know it. For example, if water were as viscous as tar, life would not exist in its current form, or it would not exist at all. ”
The researchers say the effects will extend far beyond drinking water and oceans. Human blood, cellular fluids, and the chemicals that power life all depend on carefully balanced flow characteristics.
“Any change in fundamental constants, including increases or decreases, would be bad news for flow and fluid-based life forms alike. We expect the range to be very narrow. For example, a change of just a few percent in some fundamental constants, such as Planck’s constant or electron charge, would make the viscosity of blood too thick or too thin for the body’s functions,” said Professor of Physics Kostya Trachenko.
New developments in fine-tuning the universe
Physicists have long debated why the constants of the universe appear to be finely tuned. Small differences in values such as the charge of electrons or the strength of fundamental forces can prevent stars from forming the heavy elements needed for planets and life.
What is unusual about this study is that it takes the discussion from stars and galaxies to the level of living cells. Up until now, fine-tuning discussions have often focused on nuclear reactions inside stars. The study argues that even if stars and heavy elements were still forming, life may still be impossible if fluids cannot flow properly within living organisms.
This introduces a second layer of fine-tuning. These constants appear to be compatible not only with a matter-filled universe, but also with biological systems that rely on delicate fluid dynamics.
The researchers even suggest that multiple levels of adjustment may have occurred. In his paper, Trachenko likens this possibility to biological evolution, where traits emerge independently over time. The idea is still speculative, but it raises the possibility that nature may favor stable physical structures in ways that scientists don’t yet fully understand.
Subsequent research expanded on the idea
Since its first publication, scientists have continued to explore how viscosity, diffusion, and fluid behavior connect to fundamental physics. Follow-up theoretical studies considered how intracellular fluid movement can impose additional constraints on the values of physical constants, particularly in systems involving biochemical “machines” such as molecular motors.
Other researchers have also investigated how viscosity itself arises from deeper physical laws. The 2023 analysis highlighted growing evidence that liquid viscosity is not simply a property measured in the laboratory, but may be related to universal physical limits.
Together, these studies are helping to reconstruct old scientific mysteries. Rather than viewing the constants of nature solely through the lens of cosmology and particle physics, scientists are increasingly asking whether the conditions necessary for flowing liquids and functioning cells should also be part of the equation.
Are physics and biology more connected than we think?
This idea is still very theoretical, and many physicists would caution that there is still no accepted explanation of why the constants of nature have the observed values they do. But this study opens up an unexpected avenue for thinking about one of science’s biggest questions.
For decades, the mysteries of the fundamental constant have been explored primarily through black holes, stars, and elementary particles. This study suggests that the answer may have to do with something much closer to everyday life: the simple ability of fluids to flow inside living cells.
