The 3/4 metabolic scaling law is about waves, not just geometry

A new paper argues that the universal 3/4 metabolic scaling law in biology comes from how waves move through an organism's body, not just the shape of its internal networks. This means the way blood and other fluids pulse through vessels is more important than how those vessels are arranged.

For decades, scientists thought that the 3/4 scaling law, which describes how an animal's metabolism relates to its size, was mainly about minimizing friction in its internal transport systems. This paper says that idea is wrong for larger animals. It means that the dynamic physics of pulsing fluids, like blood, sets the fundamental limits on how big an organism can get and how much energy it uses.