Looping around two orbiting black holes creates closed timelike curves, allowing backwards time travel per general relativity math.

General relativity allows spacetime to be warped in ways that, in principle, could create closed timelike curves—paths that loop back to their own past. In theoretical models, such curves arise in several exotic setups, from rotating universes to the interiors of highly spinning black holes. The math does not rule out the possibility that time could twist enough to let a worldline return to an earlier moment, even if we never encounter such curves in everyday reality.

When you add two black holes orbiting each other, the situation becomes dynamically complex. The strong gravity and the frame-dragging effects from their movement could, in principle, warp spacetime in intricate ways. Some theoretical explorations suggest that, under highly idealized conditions, paths around a binary could in principle form closed timelike curves. But this is a highly speculative scenario, and there is no consensus or experimental evidence that such time loops would arise in a real binary black-hole system or that they would be accessible to anything outside the event horizons.

A key caveat is that there are significant physical obstacles to turning such curves into usable time travel. Many proposed CTCs lie behind horizons, or require energy conditions and spacetime configurations that are unlikely to occur in nature. Quantum effects are expected to intervene before any macroscopic time machine could function, which is part of Hawking’s chronology protection idea: the universe may have built-in safeguards that prevent causal paradoxes from arising in practice.

Even so, the discussion illuminates a fascinating facet of general relativity: gravity doesn’t just bend space, it can bend time in ways that stretch our everyday sense of cause and effect. Exploring these ideas helps physicists probe the limits of GR and its interface with quantum physics, and it keeps the imagination engaged with what the universe might permit under the most extreme conditions.