Warm water freezes more quickly than cold water. Sir Francis Bacon said that almost four hundred years ago. But few people believed him until 1970. In that year a Canadian scientist George Kill proved the English professor was right. Dr Kill filled an open oil pail  with cold water. He filled another with warm water. He put both in the same low temperature. The warm water froze first. The lack of covers on the pails is the secret. Some of the warm water changed into vapor. This meant that less of the warm water was left to be frozen. And so the warm water froze faster than the cold water even though it had a greater temperature drop to make. Hundreds of years ago, Sir Francis Bacon found   _  .
the temperature of warm water drops faster than that of cold water warm water is heavier than cold water warm water has the same temperature as cold water warm water is not as useful as cold water