How can a star-faring race get extinct?

[Zixinus]

It is common in sci-fi: ancient aliens die out for some mysterious reason but leave their stuff behind for us to loot/study/cause havoc.

But, if we are realistic for a second, how could this happen? How would it be possible for a race to die out altogether and leave entire solar systems empty?

Plague? Across solar systems? Even with cheap FTL travel, isolation from it would be trivial.
Technology back-firing? Unlikely as well, as it is likely that different cultures will adopt different technological standard.
Interstellar war? Then where are the attackers?
Economy screwing up? You don't develop multi-solar-system wide and not become self-sufficient.

Just some thoughts to start off. I would like to see a debate on this topic.

[Big Orange]

I wouldn't think a advanced space faring race would be exterminated unless it was intentional genocide by another hostile race.

[Zixinus]

Which leaves the question where is the other race that committed genocide? If we meet them, then the answer is obvious, but if we find the remains of both, like in some sci-fi, what then?

[Zixinus]

Correction: if we find only the remains of both, or only one, then what?

[Peptuck]

Well, it depends on the super-advanced aliens in whatever series. For example, in Halo, we know how the Forerunner were wiped out; they killed themselves with the Halo array. In Marathon,t he Jajaro are never really explained. In Halo, the majority of the ancient Chozo simply "ascended" and moved beyond space and time, with the exception of a few tribes, like the ones who raised samus or the ones on Tallon IV.

[General Zod]

In Halo, the majority of the ancient Chozo simply "ascended" and moved beyond space and time, with the exception of a few tribes, like the ones who raised samus or the ones on Tallon IV.

I assume you mean Metroid and not Halo?

[Brother-Captain Gaius]

The Asgard committed mass suicide. There's one way to do it.

And the Ancients all disappeared for various reasons. Some died from disease, and most of the others 'ascended,' though that's admittedly not very relevant to sci-fi in general.

[CaptainChewbacca]

A long-term retrovirus like HIV could do it, giving it time to pass between star systems before it is detected.

[WesFox13]

There's alos the tiny probability of a Gammy Ray burst hitting the capital planet if most of the opoulation is on there. The resulting power vacum might be enough for there to be a large civil war that if not stopped could destroy all of the civilization. This is just a worst-case secnario type of deal anyway.

[WesFox13]

Getto Edit: D'oh! That's supposed to be Gamma Ray not Gammy Ray

[Peptuck]

In Halo, the majority of the ancient Chozo simply "ascended" and moved beyond space and time, with the exception of a few tribes, like the ones who raised samus or the ones on Tallon IV.

I assume you mean Metroid and not Halo?

Morning + no coffee + lack of edit button = oops. My apologies XD

[General Zod]

There's alos the tiny probability of a Gammy Ray burst hitting the capital planet if most of the opoulation is on there. The resulting power vacum might be enough for there to be a large civil war that if not stopped could destroy all of the civilization. This is just a worst-case secnario type of deal anyway.

Any space-faring civilization would be able to likely build protection from said burst after studying their sun enough so they could predict when they occur. If the bursts happen with a sufficient frequencies that prediction is needless then why would life develop there at all?

[CaptainChewbacca]

Any space-faring civilization would be able to likely build protection from said burst after studying their sun enough so they could predict when they occur. If the bursts happen with a sufficient frequencies that prediction is needless then why would life develop there at all?

Really there is no way to protect a planet from a GRB. It doesn't come from your own sun, but from a star system hundreds or thousands of light-years away. The 'beam' itself is about as wide as a solar system, it persists for days or weeks, and it will completely devastate anything in its path.

[Admiral Valdemar]

The Inhibitors were pretty good at this thing, even if it wasn't really what they should've been doing. It may take decades or several millennia to accomplish, but they literally made extinct countless thousands of sentient species over their several billion year watch.

During the Dawn War not long after the Milky Way came into its prime, there were so many races spreading so fast (without FTL), that within a few millennia, they were running into each other and squabbling over resources or general petty matters like what humanity fights over today.

[speaker-to-trolls]

Without FTL travel then standing too close to a supernova could do it, if the star in question is big enough it could take out everyone for more than a hundred lightyears all around it (if I remember correctly).

Once you've got FTL travel effective enough for a civilisation to move out of the way in time that becomes less likely. You could have a war where the enemy blows up all their victims colonies then releases a plague on the homeworld, or releases a plague onto all of their planets. Most effective would be the type where, as someone already suggested, you don't know it exists until it's too late. There's also weird esoteric quasi-sci-fi things like mass telepathy induced suicide.

[OmegaGuy]

In David Weber's Empire from the Ashes, the Fourth Imperium was wiped out by a plague that would completely kill any type of organic life, and was spread by the 4thI's teleportation technology undetected until it was too late.

In Freespace, the Ancients were destroyed by the Shivans.

In Steven Baxter's Manifold: Space, various races were wiped out by hypernovae and gamma ray bursts, as well as wars over resources.

[fgalkin]

Any space-faring civilization would be able to likely build protection from said burst after studying their sun enough so they could predict when they occur. If the bursts happen with a sufficient frequencies that prediction is needless then why would life develop there at all?

Really there is no way to protect a planet from a GRB. It doesn't come from your own sun, but from a star system hundreds or thousands of light-years away. The 'beam' itself is about as wide as a solar system, it persists for days or weeks, and it will completely devastate anything in its path.

Actually, they last from milliseconds to a few minutes, and they do not "devastate anything in its path." Earth was hit at least once, and it did not even stelizie the planet (although it did cause a mass extinction event, probably due to damage to the ozone layer). GRBs are not some uber cosmic ray of doom.

Have a very nice day.
-fgalkin

[Admiral Valdemar]

That was because we weren't close enough, off the top of my head, that event was several thousand light years distant. If you have a GRB go off a dozen light years away from you and directed right at your planet, you are fucked.

[Master_Baerne]

In Ringworld, by Larry Niven, didn't the Engineers eventually succumb to the common flu? They built the Ringworld without any form of disease, so their immune systems atrophied. One of their ships brought back some plague from a world it visited, and with no defense...

[Zixinus]

In Ringworld, by Larry Niven, didn't the Engineers eventually succumb to the common flu? They built the Ringworld without any form of disease, so their immune systems atrophied. One of their ships brought back some plague from a world it visited, and with no defense... Sad

Would it be a reasonable assumptions that the race that could build a ring the size of a small planet's fucking orbit could have some basic knowledge and technology for medicine? I also recall that in the original Ringworld novel, not the saga that comes after that, the bacteria damaged important technology not the people. Without the important technology and no resources to fix it or replace it, the civilization descended to barbarism. However, it did not go extinct, at least not until later. I think.

[speaker-to-trolls]

If memory serves I think it was just the Ringworld spanning Floating City Civilisation that vanished because the Puppeteers introduced a microbe that ate their superconductor wire. The people were still there, Louis Wu hooks up with one at the end of Ringworld.

[Beowulf]

In Ringworld, by Larry Niven, didn't the Engineers eventually succumb to the common flu? They built the Ringworld without any form of disease, so their immune systems atrophied. One of their ships brought back some plague from a world it visited, and with no defense...

The Ringworld Engineers are... weird. They have another stage of life brought on by exposure to a certain virus. That stage is extraordinarily protective, and so managed to wipe all each other out to the last. The earlier stage in their life cycle stayed intact and kept breeding. Eventually it mutated to fill most evolutionary niches. So, the species still exists, but forgot all about how to do tech, and ended up redoing it from scratch (several times).

[bilateralrope]

Without FTL travel then standing too close to a supernova could do it, if the star in question is big enough it could take out everyone for more than a hundred lightyears all around it (if I remember correctly).

But would that leave much in the way of remains ?

[speaker-to-trolls]

Without FTL travel then standing too close to a supernova could do it, if the star in question is big enough it could take out everyone for more than a hundred lightyears all around it (if I remember correctly).

But would that leave much in the way of remains ?

If they're not actually in orbit of the star in question then, yeah, I think so, the death would all be from high-energy radiation.

[Sikon]

Often people tend to approach gamma ray bursts from a perspective of assuming the interstellar civilization is like today's civilization, living on a planet with the limited protection of its atmosphere. (For example, destruction of a planet's ozone layer with extreme NOx production is not good for plants on the surface).

In contrast, for example, gamma ray bursts can be survived in the middle of the mass shielding of an asteroid. Gamma ray bursts can also include cosmic rays more penetrating than the gamma rays themselves, with secondary radiation like penetrating muons, but it is just a matter of the particular number of meters of rock sufficient. Have enough, and survival is possible against any gamma ray burst at a range really possible to occur.

Besides, gamma ray bursts don't come up out of nowhere. For example, an advanced interstellar civilization with good enough astronomical observation should know eons in advance if there are any neutron stars within a small number of light years approaching collision.

That gives time to get behind sufficient mass shielding or move out of there.

A similar situation can also apply with supernovas.

Even when sub-lightspeed travel takes years to move people over light-years of distance, it is still like a blink of an eye in geological or astronomical timeframes; a star heading towards becoming a supernova could be identified millions of years in advance.

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An interstellar civilization constantly partially moving or expanding could very well approach immortality. For example, even if the civilization in its original system was somehow wiped out, there could be colonization starships in the interstellar void already long enroute to new star systems, and so on.

Expand enough, star system by system over the eons, and it is possible for the cumulative result of shorter journeys to add up to an enormous distance. As an analogy, a snail species on earth may have spread over an area a thousand kilometers in diameter over many past generations without any individual snail crawling that far itself. A starfaring race could eventually have opposite points on its expanding sphere of existence be a thousand years, a million years, or more years of travel apart.

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It is common in sci-fi: ancient aliens die out for some mysterious reason but leave their stuff behind for us to loot/study/cause havoc.

A possible extinction-like scenario resulting in artifacts being left behind would be if the starfaring race all moved on to another location, deciding to do so for whatever reason. For example, given advanced enough technology, it's possible for interstellar migrants to travel from star to star, using some resources in a star system for an eon, then move on to the next, not running out of star systems in a trillion years (if the universe as we know it lasted that long). There's the question of why nobody stays behind, but imagination can be creative there. Perhaps nobody wants to be left behind outside of realtime communication with the uber internet or the great quasi-telepathic link.