2007/01/01 by Philip England, Péter Molnár, Frank M. Richter · 4 citations
Biochemistry, Genetics and Molecular Biology · Physics and Astronomy · #Geomagnetism and Paleomagnetism Studies #Astro and Planetary Science
paper · pdf · doi:10.1130/gsat01701a.1
openalex publication_date 2007/01/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/04
Many readers know the tale of how William Thomson (later Lord Kelvin) calculated the age of the Earth from physical principles and adhered for over 50 years to an estimate that was far younger than geologists' estimates, despite the virtually unanimous opposition of the geological community of the time. The prevalent version of this tale alleges that the discovery of radioactivity simultaneously provided the demonstration (through radiometric dating) that Kelvin had greatly underestimated the age of the Earth and the explanation of why he was wrong (radioactivity being a source of heat that invalidated Kelvin's calculation). We show this popular story to be incorrect; introducing the known distribution of radioactivity into Kelvin's calculation does not invalidate its conclusion. In 1895, before the discovery of radioactivity, John Perry showed that convection in the Earth's interior would invalidate Kelvin's estimate for the age of the Earth, but Perry's analysis was neglected or forgotten, with the consequence that a powerful argument in favor of mobilism was overlooked during the first few decades of debate about continental drift.