LOS ANGELES (AP) — A letter Albert Einstein wrote to one of his sons in 1945 explaining the connection between his theory of relativity and the atomic bombs that had just been dropped on Japan has sold at auction for $62,500.

The letter was one of 27 by Einstein that were auctioned Thursday by Profiles in History. In all, they fetched more than $420,000.

READ MORE: VA Provides Veterans Experiencing Homelessness With Showers, Meals At Mini Tent City

Others included two that Einstein wrote in the 1940s, explaining his thoughts on God to a man who had written to ask. They sold for $28,125 and $34,375, respectively.

READ MORE: Gov. Newsom Extends Drought Emergency Declaration Statewide

Still others covered Einstein’s thoughts on McCarthyism, Nazism and personal matters.

Profiles in History founder Joseph Maddalena says the letters were collected over several years by a seller who wishes to remain anonymous. They were purchased by various individuals.

MORE NEWS: New Parking Structure Opens At LAX

(Copyright 2015 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.)