Or perhaps “Their greatest gift to the universe was the need to speak of them in the past tense.”

Consider a machine capable of assembling commonly-available materials and constructing an exact copy of itself. Such a machine already exists in nature, DNA, so we have no guarantee it couldn’t be devised. In fact, it could be argued that human beings, indeed, all life-forms, are self-replicating machines designed for colonization and exploration. DNA is just the operating software.

No matter how benign we tried to design such a machine, it would essentially be alive, and living things not only metabolize and reproduce, they also evolve. They respond to their environment by adapting to it. Sooner or later we would have a machine that was lethal to all other life, either through direct hostility, or because it competed with other life for matter, energy, or space. You could even hypothesize an ecology of such machines, feeding on each other, competing and cooperating, a cosmic coral reef or rain forest.

Writer Fred Saberhagen based an SF series on such machines, which he called “Berserkers”, originally created by an organic race for use as a weapon in an ancient interstellar war. But the Berserkers escaped from their original programming and safeguards and turned on their creators, and against all other organic life in the Galaxy.

The idea is not that ridiculous, a malfunctioning homing torpedo or missile can turn on its own side, and we already know how to make weapons which remain a threat to all the survivors of any future war, even after the cessation of hostilities, such as landmines, or nuclear fallout. And those primitive Berserkers do not even require a malfunction. We’re just too stupid not to make them.

In Frank Herbert’s “Dune” universe, the entire galaxy-wide human society and culture is the result of a great war which had been fought against intelligent machines which escaped human control: the Butlerian Jihad. The war had been won by humanity, but at enormous cost, and resulted in a philosophy and religion determined to never let it happen again.

“Thou shalt not make a machine in the likeness of Man.”

In fact, it could be argued that any species experimenting with artificial intelligence or self-reproducing automata is inherently suicidal. It is also a threat to everybody else.

If I were a member of a highly advanced space-faring civilization, and I found out that the dim-witted monkey-men of Sol 3 had made a discovery that could put a dent in the universe’s day…well, drink up, ladies and gentlemen, the party’s over.

Edit: by which to say, if we prove ourselves sufficiently dangerous, could we blame “them” for putting an end to us?

And this is not a Flame, nothing personal, not to be taken personally, is limited to a very small area, I might, may, nothing certain, just possibly could trust his a bit more than yours.

No offence, please. It’s just the time he has available to him to ponder the issue compared to you. You are more of a Renaissance Man, he is more limited in his field of endeavor.

If we were sailing, for instance, I’d say screw him. Even navigating. I would trust you far more than Hawking.

But even though the ability to destroy the universe is only an idle speculation, the ability to destroy our own little piece of it is not. And super science will not be necessary to do it.

Then again, perhaps some other space-faring lifeform will beat us to the cataclysmic punch…

It’s a pretty big Universe.