Getting Rid of Precursors

[Sindri]

So having Precursors in science fiction is handy they let you introduce technology above the current level of advancement, have terraforming or uplifting done in the past, and just generally add interest to your timeline

However quite often you want them to arrive, do their stuff and then get out of the way for the younger races. The standard space operatic method is for them to turn into pure psychic energy or something similarly bafflingly unphysical. High ultratech civilizations are pretty hard to wipe out so what's a more reasonable excuse?

They could withdraw from the area but while that has the advantage of actually being possible it feels somewhat implausible for a culture that gets to precursor levels of achievement just leaving. I suppose you could have them leave for the same reason the designer wants them to: after having set up everything they could leave it alone to see what the younger races do.

War is a great way to wipe out precursors but it has difficulty not leaving you another set of precursors in the same area. A war waged solely for the purpose of exterminating the precursors would work but that has a tendency of leaving glassed instead of nice t-shirt planets. I suppose if the precursor's enemies' biochemistry is sufficiently different from the precursors then their terraformed planets might be unsuited to them and they might just be ignored. They could also be eliminated while their (semi?)automated terraforming project was in it's early stages

They could also wipe themselves out by terribly lax safety rules with strangelets or whatever but that also leaves uninhabitable planets. Also it requires them to be idiots for a while and it seems hard to eliminate more than one planet or moon or space station that way.

I suppose some kind of anti-technological movement might cause them to diminish in importance as well

EDIT: The beginings of a taxonomy of precursor killers

I Internal

A Accident

B Civil War

1 Between Precursors

2 Rebellion by oppressed non-Precursors

C Withdrawal

1 Prime directive (do not interfere with species development past a certain point)

i Lensman Gambit(Need new race to exceed their current status e.g. because have hit technological wall

ii Ethical Issues

2 Technology loss

i Anti-technological movement

ii Ultra-tech leads to loss of intelligence

a Intelligence neither needed nor encouraged

b Precursors deliberately revert to presapient form (similar to Lensman Gambit)

3 Virtual Reality

4 Area of setting does not support/is not considered suitable for precursors

i Resource depletion

a Renewable

b nonrenewable

ii Lack of high energy resources nearby

iii Signal delay

iv Breakdown of key technology (such as FTL)

5 Pocket universe/ascension/otherwise leave normal space

6 Religious mandate to leave

7 Population issues

i Failure to recover from population crash. (though the cause of the crash may be external the failure is what really removes the precursors.)

ii Low birthrates plus something happening to extremely old precursors

a Die or leave due to boredom

II External

A Hostile action

1 Gengineered disease

2 War

i Unrecoverable total war(strangelet or black hole weapons)

ii Longterm recoverable war

iii Precursors were located in space so war does not damage planet

3 Preemptive flight from enemies

B Natural

1 Some kind of nasty natural thing like a black hole or strangelet asteroid comes along and wrecks the local precursors

[sir_pudding]

Originally Posted by Sindri

However quite often you want them to arrive, do their stuff and then get out of the way for the younger races. The standard space operatic method is for them to turn into pure psychic energy or something similarly bafflingly unphysical.

I think that "being wiped out by machine intelligence/themselves/galactic cycles" is even more common, Benford's Galactic Center books, Traveller, Mass Effect, Hyperion, just off the top of my head all have this trope.

[Sindri]

Originally Posted by sir_pudding

I think that "being wiped out by machine intelligence/themselves/galactic cycles" is even more common, Benford's Galactic Center books, Traveller, Mass Effect, Hyperion, just off the top of my head all have this trope.

Yeah that's pretty common as well and I don't have any statistical basis for which is more.

The question is why isn't the thing that wiped them out hanging around where the precursors used to be. (not that those examples necessarily lack a reason.)

[Flyndaran]

Originally Posted by Sindri

Yeah that's pretty common as well and I don't have any statistical basis for which is more.

The question is why isn't the thing that wiped them out hanging around where the precursors used to be. (not that those examples necessarily lack a reason.)

Doomsday machines that only turn on when exposed to a pre-programmed threat? Your new species doesn't qualify for some reason.

[Miles]

They're still out there, but they withdrawn into their virtual reality playgrounds and never leave except for reasons of PLOT. Seek them out at your peril, for they will almost certainly treat you like a colony of ants or some other pest fouling up their home.

[Sindri]

Originally Posted by Flyndaran

Doomsday machines that only turn on when exposed to a pre-programmed threat? Your new species doesn't qualify for some reason.

That works really well. It doesn't stop someone else from killing them but it does stop them from moving in and if they were doing the whole shepherd of new lifeforms thing it makes sense that they would somehow immunize the younger races.

Originally Posted by Miles

They're still out there, but they withdrawn into their virtual reality playgrounds and never leave except for reasons of PLOT. Seek them out at your peril, for they will almost certainly treat you like a colony of ants or some other pest fouling up their home.

It's hard to fit together a culture that travels immense distances and spends large amounts of resources terraforming and stuff with one that sticks around in virtual reality. I suppose a cultural change after they do all the stuff they need to could accomplish it.

[sir_pudding]

Originally Posted by Sindri

That works really well. It doesn't stop someone else from killing them but it does stop them from moving in and if they were doing the whole shepherd of new lifeforms thing it makes sense that they would somehow immunize the younger races.

This is usually the way this trope works. Something wiped them out and it's just now that galactic civilization has re-triggered the apocalypse machines. Duh, duh, dun!

It's hard to fit together a culture that travels immense distances and spends large amounts of resources terraforming and stuff with one that sticks around in virtual reality. I suppose a cultural change after they do all the stuff they need to could accomplish it.

That seems to be the case with the whole Involved->Sublimed progression in the Culture books.

[Flyndaran]

Gengineered diseases might work.

[David Johnston2]

Originally Posted by Sindri

War is a great way to wipe out precursors but it has difficulty not leaving you another set of precursors in the same area. A war waged solely for the purpose of exterminating the precursors would work but that has a tendency of leaving glassed instead of nice t-shirt planets.

That's short term thinking. Pop all their planets with RKVs or fry them with induced solar instability and while all the large animal life may go the way of the dodo, but it's not likely to get all the microorganisms. Precursors start at at 10 thousand years gone and on up to millions of years. That gives planets time to cool down from whatever horrible thing they did to it.

They could also wipe themselves out by terribly lax safety rules with strangelets or whatever but that also leaves uninhabitable planets. Also it requires them to be idiots for a while and it seems hard to eliminate more than one planet or moon or space station that way.

I note that the humans of Star Trek are theoretically well on the way to extinction as of TNG.

Consider that in "The Menagerie" Captain Pike encountered a species that was in decline because they had developed illusion powers so potent that they could all live in dreamworlds divorced from the realities of survival (and notably reproduction). Now humans have developed holodecks and are showing an increasing tendency to retreat into them even when matters of life and death are going on in the real world. At the same time, wear and tear caused by warp drive is making interstellar travel increasingly impractical. At some point, it will simply have to be abandoned for a lengthy period of time to let the space-time fabric "heal". The Federation is abandoning fringe worlds as more trouble than they're worth, evacuating them or just leaving them unprotected to be wiped out.

Even without apocalyptic warfare, it doesn't seem unlikely that humanity will undergo a demographic collapse that will leave most of it's inhabited space abandoned, turning us, and the other species that face the same problems with holodecks and space travel into the precursors of the next bunch of idiots.

[Sindri]

Originally Posted by David Johnston2

That's short term thinking. Pop all their planets with RKVs or fry them with induced solar instability and while all the large animal life may go the way of the dodo, but it's not likely to get all the microorganisms. Precursors start at at 10 thousand years gone and on up to millions of years. That gives planets time to cool down from whatever horrible thing they did to it.




I note that the humans of Star Trek are theoretically well on the way to extinction as of TNG.

Consider that in "The Menagerie" Captain Pike encountered a species that was in decline because they had developed illusion powers so potent that they could all live in dreamworlds divorced from the realities of survival (and notably reproduction). Now humans have developed holodecks and are showing an increasing tendency to retreat into them even when matters of life and death are going on in the real world. At the same time, wear and tear caused by warp drive is making interstellar travel increasingly impractical. At some point, it will simply have to be abandoned for a lengthy period of time to let the space-time fabric "heal". The Federation is abandoning fringe worlds as more trouble than they're worth, evacuating them or just leaving them unprotected to be wiped out.

Even without apocalyptic warfare, it doesn't seem unlikely that humanity will undergo a demographic collapse that will leave most of it's inhabited space abandoned, turning us, and the other species that face the same problems with holodecks and space travel into the precursors of the next bunch of idiots.

It seems to me that a culture will either ignore the real world and not leave their solar system or keep an interest in the real world and go on to do precursorey things. Still I suppose it's possible for there to be a major cultural change among the local precursors that causes them to lose their cultural adaptations to prevent withdrawing.

It's quite true that life can deal with things that can kill civilizations but that does have disadvantages

1 It means the precursors can't have any direct effects on the sentient species
2 Depending on the state of terraforming it could wreck the machinery or destabilize it
3 At 10 thousand years to millions of years keeping any artifacts or machinery around that happened to survive the precursor-killer weapon is rather difficult even for optimistic apocalypse proofing.