Why did ET need a moving tree to operate that machine?
Seems like they could've just made it work by moving the switches themselves.
shareNot really sure but maybe the tree acted like some kind of radar for the signals (from ET’s world) to bounce off. The signals needed a receptor and the tree was it.
share
I'm sure it was all done just for effect but ...
... maybe E.T.'s race timed their signal broadcasts to sync up with "natural rhythms" like gusts of wind, swaying trees, etc.
That way they'd be harder to detect and fit in with E.T.'s own affinity for nature.