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> The chances of any one of them ever encountering anything larger than a grain of dust before the heat death

This is why no civilization would randomly fire off Von Neumman probes in random directions. They would understand that this is a problem.

If you want to efficiently use them, you fire them at nearby stars. They will either find materials and restart the process, or they won't (and potentially report this, but it's not required). A non-zero number of them may encounter sufficient material (given how plentiful planets seem to be, that's a fair assumption). Those star systems would now fire off a bunch of probes, at near stars. Rinse and repeat. It's a slow process, initially, but given the exponential nature, it should be surprisingly quick.

"Aiming" at star is not something that's too complex even for us. It might require mid-course corrections to account for errors, but we could build a probe that would conceivably reach a star. Ensuring it would be alive and operational by then is more challenging, but it is an engineering one. Actually entering the star's orbit might be even trickier depending on relative speed. But that's peanuts for a civilization that could build such things.

> The lack of a universe awash in Von Neumann probes is not a strong argument against the existence of life or advanced civilization in the universe, it is, itself, a strong argument against the feasibility of Von Neumann probes.

It is. But that's assuming we can even recognize one.

Sorry I still don't get what you are saying - wouldn't the probes be sent off to the nearest "interesting object" rather that onto a straight line into nothingness?

> It sends these Von Neumann probes out into the universe in all directions. The chances of any one of them ever encountering anything larger than a grain of dust before the heat death of the universe is practically zero.

Haha okay. I think most would view this as a pretty uncharitable assumption (appears contingent on these civilizations not having telescopes or AI), but if that's your view I can understand why we disagree.

Why are you assuming that such a probe is not targeted? Targeting radically changes the results. An interesting middle ground to explore is untargeted probes taking gravity into account

Targeted probes would be more complex, and thus more prone to mechanical or software failure, or copy failure across generations. Untargeted probes could remain dormant in interstellar space, whereas targeted probes would have to remain active (and thus consume energy) in order to course-correct and continue to approach their target.

If the goal is to mine the resources of one specific location, then a targeted probe makes sense. But if the goal is to proliferate and explore (or consume) as much of the universe as possible as efficiently as possible, then targeted probes seem less likely to succeed over the scale of time necessary.

> Targeted probes would be more complex, and thus more prone to mechanical or software failure, or copy failure across generations

I'd argue that your argument is either

a. not intrinsically true of complex probes or

b. just a modified version of the great filter argument

You could imagine an advanced civilization that creates an artificially intelligent probe that is pretty effective at problem solving and resilient to these sorts of failures. Even if targeted probes have to remain active, there is no reason they couldn't consume energy harvested from their origin world to course correct.

If your claim is that every form of intelligence will inevitably fall to mechanical or software failure, etc. then that claim seems to just be identical to the great filter claim.

> targeted probes seem less likely to succeed over the scale of time necessary.

Your own GP seems to provide a very compelling reason why this is not true.

Is "targeting" really a large requirement to add on to a device that needs to be able to fabricate spacecraft from raw materials wherever it lands?

>But if the goal is to proliferate and explore (or consume) as much of the universe as possible as efficiently as possible, then targeted probes seem less likely to succeed over the scale of time necessary.

Less likely than non targeted ones that you say wouldn't get past the first generation?