Posted: Jun 20, 2017 8:50 am
Floating ice insulates the water body. If ice sank there would be no insulation and nothing to stop the water body progressively freezing.
Lifeboat for the rational mind :D
http://www.rationalskepticism.org/
http://www.rationalskepticism.org/viewtopic.php?p=2562261#p2562261