[AntiGuv]

And another thing: the bare statement "faster than light travel is equivalent to time travel" does not presuppose time travel into the past as you appear to be doing! Time travel into the future raises no causality issues of its own accord.

[PatrickHenry]

And another thing: the bare statement "faster than light travel is equivalent to time travel" does not presuppose time travel into the past as you appear to be doing! Time travel into the future raises no causality issues of its own accord.

While waiting for Physicist to comment, I'll play with this one. While I agree that travel into the future raises no causality issues, it's also irrelevant to FTL communications. As has been pointed out, such communications are always received (by the recipient) before the sender's transmission date, and thus they always involve travel into the past. (This is in the context of the ship and the earth being two different frames of reference.) This isn't a "presuposition," as you suggested. Rather, it's an inevitable conclusion of the way we now think the universe is put together.

[Physicist]

And another thing: the bare statement "faster than light travel is equivalent to time travel" does not presuppose time travel into the past as you appear to be doing! Time travel into the future raises no causality issues of its own accord.

Nor would it constitute a "striking feature" of special relativity.

Please, please, please read the page you linked.