Science Fiction YouTubers often like to propose novel concepts of possibilities out there in the far reaches of the universe, which is great – it is, after all, the reason those of us interested in the genre listen to these sorts of things. But there are a few logical fallacies that mildly irritate me, especially as they continually crop up as sort of archetypes of Sci-Fi absurdities.

The most obvious example of this is the von Neumann probe, or von Neumann machine. This hypothetical device is named for John von Neumann, a preeminent mathematician of his day who proposed such a device as a means of mining off-world celestial bodies, and it would function by seeking out raw materials to make replicas of itself. This would optimise its capabilities and efficiencies without earth-based engineers having to create an army of spacecraft to complete a specific task.

The Sci-Fi adaptation of this gets a bit silly. It often involves humorously theorising that one potential means of human extinction would be an out-of-control, alien von Neumann machine whose only purpose is to make paper clips. This machine would eventually reach our solar system and cause the apocalypse by dismantling everything therein for paperclip-making materials.

Sure, it’s possible – in theory. But plausible? Not remotely. Any alien civilisation advanced enough to construct a functioning von Neumann probe would quite clearly possess the logical reasoning to foresee such an eventuality and take steps to avoid it. Even had it inexplicably not taken these steps, it would still, logically, be advanced enough to go and destroy the damned things once it realised its mission had been corrupted. They could even send out new von Neumann machines whose only purpose is to turn von Neumann machines into von Neumann machines which exist solely to destroy von Neumann machines.

This scenario also implicitly relies on another logical fallacy of science fiction, and science in general to be fair, which assumes that whatever could possibly happen will happen in an infinite universe, given enough time, and that these possibilities will happen infinitely often by the very definition of infinity. Setting aside some philosophical issues I have with the concept of infinity, I still think this is a pretty silly way of framing many scenarios.

Maybe there are infinite copies of me out there who spend their entire day repeatedly hitting their toes with a sledge hammer. After all, it’s possible and therefore happening. However, we can only judge these scenarios by the likelihood of our ever experiencing the absurd possibilities of an infinite universe. We know from our own experience that the human mind is blessed with varying degrees of logical reasoning, and we also know, because it’s bloody obvious, that there is no logical route through which one can arrive at the conclusion that smashing one’s toes repeatedly with a sledge hammer is in any way a good idea.

Thus, the likelihood of us ever coming across such a thing is so close to zero it becomes totally meaningless.

I’m not against the contemplation of absurd possibilities, especially in the context of fiction. But for the suspension of disbelief to really apply, any story should at least pass the test of being logically acceptable.