Time Travel: What Physics Actually Allows - Deep Dive

Time travel—what physics actually allows. In this deep dive we separate sci-fi from science: real time dilation (forward travel) from speed and gravity; the math behind closed timelike curves (wormholes, cosmic strings, Tipler cylinder); why they seem to demand exotic negative energy; and how paradoxes meet fixes like Novikov self-consistency and many-worlds. We cover Hawking’s chronology protection, quantum limits (no faster-than-light signaling, no-cloning), and what evidence would truly move the needle. Clear, no-hype: what the equations say—and what nature likely forbids.

#time #science #timetravel #paradox #explainer