The original riddle about the tree in a forest is intended to illustrate the difference between philosophical idealism and materialism. A dog whistle depends o

The original riddle about the tree in a forest is intended to illustrate the difference between philosophical idealism and materialism. A dog whistle depends on the concepts of dogs and whistles, which don’t exist outwith the human semantic framework. Historically, science has been heavily materialist but quantum physics has brought idealism back to the table. Another thought experiment is 2 people at opposite ends of a room that contains a total vacuum. Ignoring breathing difficulties, if one spoke to the other, would he make a sound?