Non-dimensional numbers may sound like a scary, incomprehensible term reserved for scientists in a laboratory, but you have more experience with them than you know. The Mach number measures the speed ...

Expansive growth is defined as a permanent increase in cell volume. Expansive growth of walled cells (e.g. algal, fungal and plant cells) depends on interrelated biochemical and physical processes.

One branch of science, rheology, has invented a dimensionless number. It’s called the Deborah Number, and it is meant to quantify the motto of the science: “Everything flows.” Put another way, ...

I disagree with your suggestion to promote the radian to the International System of Units (SI units) to address the confusion over dimensionless numbers (Nature 548, 135; 2017). On the contrary, this ...