> They cannot both be the original Riker

We don't experience the future, which means our sense of continuity can only be a result of something in the present and/or the past. That isn't violated by teleportation or duplication. When two copies step out of a duplicating teleporter, they are both a continuance of the same person. The "original" Riker is the original in the same sense as you exactly one moment ago are the origin of you in this moment.

For reference the episode is Second Chances [1].

[1]: https://en.wikipedia.org/wiki/Second_Chances_(Star_Trek:_The...

And why can’t the logical conclusion be that either one of them could be the original Riker? Why does the original have to be gone?

I play the Ship of Theseus problem card and I follow up with the argument there never was an original Riker to begin with.

https://en.wikipedia.org/wiki/Ship_of_Theseus

This is where I always end up with these kinds of things. Riker didn't die, and in fact neither life nor Riker ever really existed as a coherent entity.

I believe it takes about seven years for every particle in our bodies to be swapped out; all the atoms in your body today are different from those of seven years ago. In a sense, we're never truly "original".

Every particle in your body doesn’t get swapped out which is how they can do molecular analysis on things like teeth and bones to try and pin point where you grew up.

Even if every cell in your body is replaced over a 7 years period which they don’t since not all cells actually undergo mitosis or are even replaced through stem cells not every molecule in your body needs to be replaced for that to happen and in fact it doesn’t it would be exceedingly wasteful and impractical.

So the many if not most hydrogen molecules you were born with are still probably somewhere in your body.

In the Star Trek world, I think the transporter and the replicator are the same technology just applied differently. When transporting goes wrong, they mention things like “pattern buffers”, where (presumably) information about how to reconstruct the person’s matter is held until all info arrives. I suspect you hold on to the pattern buffers for things you want to replicate. Unanswered by this… where does the matter come from? Maybe just reconstituted energy from the engines.

From the technical manual: raw stock for replicators is stored in the form of a sterilized organic particulate suspension that has been formulated to statistically require the least quantum manipulation to replicate most finished foodstuffs.

on the next episode of TNG: the sterilized organic particulate suspension tank leaks, forcing the crew to decide whether to teleport the captain back to the ship or eat steak for one more meal

As in, either could be the original, and as we have no way of telling them apart it does not matter which? Okay, that sounds reasonable. However, if we know that at least one of them is a clone, we know that transporters are built with the ability to create clones of people. It seems hard for me to believe that transporters would be built to have that ability unless that is the way they always work.

There's an Outer Limits episode with a transporter-like device, but it merely makes an exact "copy" of the person and the machine automatically destroys the "original".

I don't recall the episode name off-hand, or want to give away too much of the plot, but I thought that was better than the duplicate Rikers.

Also: two Crichtons in Farscape, although that wasn't due to a transporter-like accident but a "normal" clone.

It's "Think Like a Dinosaur", based on the short story by James Patrick Kelly [0]. It deals more or less with the transporer issue described in the linked article.

I remembet having read it when it was first published in Asimov's SF magazine. God I'm old.

[0] https://en.wikipedia.org/wiki/Think_Like_a_Dinosaur

The Prestige (major spoilers to follow) has the same idea. A stage magician invents a trick that appears to instantly teleport him across the room and nobody knows how he does it. The "trick" is that a duplicate is created and the original is dropped into a locked container of water to drown.

Maybe both are the original? Think of the turnstile in tenet. A person who enters while traveling backwards seems to appear twice, traveling in two directions of time, but clearly both are the original. If one then reverses and catches up to the other, they are still both the original, even though they can shake each other’s hand.

What if the transporter malfunction causes the same for riker, except both rikers now travel forward in time right from the start. Therefore, they are both one and the same original riker, but they inhabit the same points in time at different points in space and therefore they will diverge as soon as they exit the transporter.

As a hypothesis go, it’s worth stating, but only since it leads directly to a conservation-of-mass problem and is therefore disproved by contradiction, a problem that Tenet does not encounter (it has its own problems of course, most obviously causality issues from the conflation of pataphysical outcomes with thermodynamic constraints).

Therefore neither are the original Riker, which was evidently terminated in the most horrifying fashion the first time it stepped into a transporter beam.

In fantasy stories, we don't know how technology works and thus can't make logical inferences about how it works.