Today is

Pi Day but as scientists, should we even care? It's really more of a math thing, am I right? Well, maybe. It certainly is if you only consider π as the mathematical constant, the ratio of a circle's circumference to its diameter, usually truncated to 3.14159 (it has been calculated to more than one trillion digits beyond its decimal point, which seems a bit irrational to me).

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Authors: John Reid & Arpad Horvath, Wikimedia Commons[/caption]

But we non-mathematicians can get in the spirit of the day with our own "pi" definitions.

pI: Called the

isoelectric point, this is the pH at which a molecule has a net neutral charge. If you work with peptides and proteins, you’re probably really into pI!

Pi (π) bond: A bond formed by the overlap of p orbitals on adjacent atoms, perpendicular to any sigma bond(s) between the same atoms.

Pi (π) donation: This phenomenon occurs when an atom with a lone pair of electrons forms a pi bond with an adjacent atom of appropriate hybridization.

PI: A

principal investigator is the holder of an independent grant administered by a university and the lead researcher for the grant project, usually in the sciences, such as a laboratory study or a clinical trial. (Source:

Wikipedia)

So embrace 3/14 fellow scientists because mathematicians have only one pi but we have four!