1) an as-yet-undiscovered theory unifying many scientific field
theories into one understanding of how the universe operates
2) something
unattainable, much as finding an actual unified field theory has
baffled scientists for decades
Einstein spent the last two decades of his life trying to develop a unified field theory.
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Person 1: John keeps asking
Sarah out, but she's not
biting.
Person B: She's his unified field theory. Ain't gonna happen.