[z5h]

In order to experience/measure something, you must interact with it. Any interaction changes both sides. You can't experience the same ship twice.

[defen]

That's not really satisfying on a human level, though. I can't take your car and claim that it's no longer "your" car since some atoms changed.

To generalize, physical identity seems to be an important part of ownership, so how does that interact with this concept?

[z5h]

Just accept unsatisfying, impractical truths, and despite that, allow yourself to have an illogical intuitionistic sense of things. That's what I do. :)

[scott_karana]

I love this insight. Thank you.

[coldtea]

Also thank Heraclitus (535 B.C) -- which goes even further: even time changes things, so you can't experience the same ship twice even without interacting with it.