In 1944, German chemist and physicist Arnold Eucken considered the thermodynamics of Earth condensing and raining-out within a giant protoplanet at pressures of 100–1000 atm. In the 1950s and early 1960s, discussion of planetary formation at such pressures took place, but Cameron's 1963 low-pressure (c. 4–10 atm.) model largely supplanted the idea.