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Comment by jonathankoren | Hacker News Reader

> Nikk Effingham’s book is an exploration of all things time travel (where time travel is to be read as backwards time travel, that is, travel to an earlier time).

I'd be interested to know if forward time travel is easier than backwards time travel. Seems to avoid a lot of paradoxes.

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It happens to me every night. Gets old pretty fast though…

That's "relatively" easy to do. Get in a space ship that could quickly get to a fraction of c, travel for a short amount of time and then return back to the starting point. You would have traveled to the future from the point of view of some one at the starting point.

This is actually harder to do in practice and is a common misunderstanding of the twin paradox, which is resolved by incorporating acceleration into the model.

You'll have better luck with gravity wells.

It’s not only not a misunderstanding of the twin paradox, but is correct and verified by experiment.

forward time travel is perfectly consistent with the laws of physics and in fact we've done it experimentally. backwards is only possible observationally (ex. building a big telescope we can look at the past) but we cannot effect it

That'd correct. Not only, that we can not influence it, we also know that it has already happened.

Not so fast. (Or slow.)

https://plato.stanford.edu/entries/qm-retrocausality/

That was a favorite joke of my kids: I’ve invented time travel, but I can only go in one direction at regular speed.

Just go into the mountains to speed up a bit. Where "a bit" is measured in nanoseconds per day; nevertheless... it does work.

Forward travel is easy. Go really fast or just hibernate. The physics is easy. It’s just an engineering problem.

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