Answer:
Dies half its life. Lives the rest. Dances without music. Breathes without breath.
This is in a realm of true and in a realm false, but you experience me as you turn and toss.
I am never quite what I appear to be. Straight-forward I seem, but it's only skin deep. For mystery most often lies beneath my simple speech. Sharpen your wits, open your eyes, look beyond my exteriors, read me backwards, forwards, upside down. Think and answer the question...
What kind of nut is empty at the center and has no shell.
Without this, eating food and Steven Spielberg's career would be very different.
I'm the source of all emotion but I'm caged in a white prison.