Max Planck
From Tardis Wiki, the free Doctor Who reference
Max Planck was known to the First Doctor as one of the notable scientists in Berlin in the 1930s. (AUDIO: The Alchemists)
Planck's quantum of action was one of the universal constants. (PROSE: The Secret in Vault 13) A fundamental unit of time to do with light traversing across a distance was known as Planck time. (AUDIO: Interstitial)