Laplace’s Law describes the relationship between pressure, radius, and surface tension in curved structures like spherical membranes, bubbles, blood vessels, and alveoli in the lungs. It explains how internal pressure is required to balance the tension in a curved surface.
For a spherical surface (like a bubble), Laplace’s Law states that the internal pressure difference across the wall is directly proportional to the surface tension and inversely proportional to the radius of the sphere. This means:
- Smaller spheres require greater pressure to maintain their shape,
- Larger spheres require less pressure if the surface tension remains the same.
Key implications of Laplace’s Law:
- In soap bubbles, the inner pressure increases as the radius decreases.
- In alveoli (tiny air sacs in the lungs), smaller ones would collapse into larger ones without the presence of surfactants to reduce surface tension.
- In blood vessels, especially arteries and capillaries, the law helps explain how pressure and wall tension are related to vessel size.
Laplace’s Law is crucial in biophysics, fluid mechanics, and medical physiology, offering insight into how nature and technology manage pressure in curved and flexible structures.