Magazine content is available exclusively for TIME subscribers.Science: Heavy Waters
Every molecule of pure "heavy water" contains two atoms of deuterium, which is hydrogen of the double-weight form identified in 1931 by Columbia's Harold Clayton Urey. Deuterium is not rare in nature. It is present in ordinary water to the extent of one part in 4,500.* Thus when suitable methods for separating it were worked out, high concentrations of heavy water became common. Nowadays one or two chemical manufacturers list and sell heavy water 99.5% pure.
The case of tritium, triple-weight hydrogen, is different. Its discovery was foreshadowed by the somewhat dubious magneto-optic...
Email, Password or Region is incorrect
A required form parameter was missing.
The System is currently down. Please try again in a few minutes.
Email Address is invalid
Password is blank
Most Popular »
- JC Penney and Ellen, Lowe's and All-American Muslim: A Tale of Two Bigotries
- Four Ways the U.S. Could End Up at War with Iran Before the Election*
- The Art of Nazi Hunting: How Israel's Mossad Found Adolf Eichmann
- Study: Zapping the Brain Boosts Memory
- College Endowments: Why Even Harvard Isn't As Rich As You Think
- Bradying: The Poor Man's Tebowing
- Pentagon Rules 'Shift' on Women in Combat
- Twimmolation Alert: Roland Martin Gets His Ascot in Hot Water at CNN
- House Pulls the Plug. Too Soon or Too Late?
- Why We Need a New Definition of 'PC'
- The Upside Of Being An Introvert (And Why Extroverts Are Overrated)
- The Brain: How The Brain Rewires Itself
- Egypt's NGO Crisis: How Will U.S. Aid Play in the Controversy?
- Friends With Benefits
- Seoul Searching
- New York City: 10 Things to Do
- Pentagon Rules 'Shift' on Women in Combat
- In Singapore, Finding Peace Among the Pain of Thaipusam
- Haiti Papers Over the Past: The Rebranding of 'Baby Doc' Duvalier
- The Street Fighter
More News from Our Partners
Top Stories on TIME.com
Quotes of the Day »
