quarantine 'em

The probes in the story are just people, having conversations. The bulb, however, like the REAL probes, is inanimate. That's crucial

Deep space probes represent the width of the physical footprint which humans have left on the universe. They are our high-water mark

They are (from one particular angle), uncontestably, the most significant thing humans have ever done

There are of course many ways to gauge and compare the significance of human activities. But "distance from home" can't not be one of them

And I think there's a tragedy in here somewhere with these probes but I can't really articulate why I think that

But I do know that the tragedy hinges on the probes being, like the light bulb, and unlike the probes in the story, inanimate

Unaware of their significance or rarity or feebleness or distance or unrecoverability

It bears noting at this point that Pioneer 9 and Pioneer 10 are both, right now, in reality, lost.