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Event Horizons



We humans are drawn to the unknown and the mysterious. And what's more mysterious than black holes? Not much.

An event horizon (a.k.a. a point of no return) is a boundary in spacetime where an outside observe cannot be affected by anything beyond it. In other words, a gravitational pull is so strong that nothing can possibly escape it. Light emitted from beyond the black hole's event horizon can never reach an observer outside of the horizon.

If you, an observer, are looking towards one of these horizons, an object approaching it from your side will never quite reach it - it will appear to slow down as it approaches nearer. However, to the traveling object, no strange effects are felt - it passes through the horizon in a finite time (0.0001 seconds for a black hole of 30 solar mass). This time is proportional to the mass.


So, as said before, from an observer's perspective an object approaching a horizon will never appear to reach it - it will just appear to slow down. Interestingly enough, for an object near to horizon to appear stationary to the observer, a force must be applied - and as the object gets nearer and nearer the event horizon, this necessary force increases without bound, becoming infinite.


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