Stop for a second and look out your window. You’ll likely see a tree somewhere outside. Do you know its species? How often should it be watered? Is it healthy? Pietro Perona imagines a world where you ...

The Irish philosopher George Berkely, best known for his theory of immaterialism, once famously mused, "If a tree falls in a forest and no one is around to hear it, does it make a sound?" What about ...