# Time Travel, CTC and Causal Loop

What is the difference between a closed timelike curve and a causal loop?

If someone is travelling in a closed timelike curve, are they also in a causal loop?

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A causal loop is, as far as I'm aware (it's not 100% a standard term), a sequence of events that form a loop. It is not quite a physical concept (it's more likely to pop up in the philosophy of physics, like in the books of Reichenbach or Earman), but it does apply to a variety of physical theories. For instance, a basic one would be that given two events $$A$$ and $$B$$, you have that $$A$$ causes $$B$$ and $$B$$ causes $$A$$, which is considered pathological in causal chains. In our experience, an event cannot be ultimately caused by itself.