Subject
3 entries
Chemistry
Bookmarks
It Takes 275 Water Molecules to Make Ice
Scientific American podcast item: researchers determined that a cluster of exactly 275 water molecules is the minimum required to form an ice-like crystalline structure — a finding that probes the boundary between bulk and nanoscale physics in water.
Patent Goo: Self-Replicating Paxil
Nick Szabo's 2005 essay on pharmaceutical polymorph patents — how drug companies patent different crystal structures of the same molecule to extend exclusivity. Uses the Paxil case and the 'ice-nine' metaphor to explain how crystal contamination can eliminate a polymorph's commercial value.
Ice Polymorphs
John Carlos Baez's Azimuth post on the extraordinary diversity of ice crystal structures — at least 15 distinct phases of solid water exist under different pressure and temperature conditions. The ice-nine trope from Vonnegut has a real crystallographic basis.