Today’s Zippy, with birds and software:
A pun on tweet, bird song vs. Twitter message, with an old philosophical conundrum as the vehicle.
According to the Wikipedia entry, the topic goes back at least to Berkeley:
Philosopher George Berkeley, in his work, A Treatise Concerning the Principles of Human Knowledge (1710), proposes, “But, say you, surely there is nothing easier than for me to imagine trees, for instance, in a park [...] and nobody by to perceive them. [...] The objects of sense exist only when they are perceived; the trees therefore are in the garden [...] no longer than while there is somebody by to perceive them.”
Later versions, which might or might not be traceable to Berkeley, frame things as a question:
In June 1883 in the magazine The Chautauquan, the question was put, “If a tree were to fall on an island where there were no human beings would there be any sound?”
… The current phrasing appears to have originated in the 1910 book Physics by Charles Riborg Mann and George Ransom Twiss. The question “When a tree falls in a lonely forest, and no animal is near by to hear it, does it make a sound? Why?” is posed along with many other questions to quiz readers on the contents of the chapter, and as such, is posed from a purely physical point of view.
For Zippy, it’s all about Googling things.