Lich, Draugr, Poltergeist, and Phobetor: a neutron star system

[stevebowers]

I think there would be a lot of planets, especially around white dwarfs, that have had their previous atmospheres and surfaces eroded and replaced by material ejected from the star when it left the Main Sequence. In the EWoCS classification these planets would be classified as Ragnorokian, I think. According to that table, Ragnarokian planets might be rich in carbon, nitrogen, lead, mercury, barium molybdenum and a bunch of other interesting elements.

[Bear]

So far, I've only heard of this "Island of Stability" in terms of prospects for creating heavy elements whose half lives are measured in microseconds rather than nanoseconds. As such, I wouldn't expect to find them anywhere in sufficient quantities to be a "substance" as opposed to an isolated scattering of short-lived atoms.

Unless people are Just Plain Wrong about what the island of stability means, it would seem to me that anyone experiencing time at the same rate we do would find them too ephemeral to be valuable.

[Everything4404]

So far, I've only heard of this "Island of Stability" in terms of prospects for creating heavy elements whose half lives are measured in microseconds rather than nanoseconds.  As such, I wouldn't expect to find them anywhere in sufficient quantities to be a "substance" as opposed to an isolated scattering of short-lived atoms.

Unless people are Just  Plain Wrong about what the island of stability means, it would seem to me that anyone experiencing time at the same rate we do would find them too ephemeral to be valuable.

Not microseconds. Potentially up to tens(hundreds?) of million years.

[iancampbell]

Neutron star planets' composition would be even weirder than carbonaceous (adamanean?) planets. All those rare heavy elements mixed with oddball transition elements, but starved of the light ones like oxygen and carbon.

So far, I've only heard of this "Island of Stability" in terms of prospects for creating heavy elements whose half lives are measured in microseconds rather than nanoseconds.  As such, I wouldn't expect to find them anywhere in sufficient quantities to be a "substance" as opposed to an isolated scattering of short-lived atoms.

Unless people are Just  Plain Wrong about what the island of stability means, it would seem to me that anyone experiencing time at the same rate we do would find them too ephemeral to be valuable.

Not microseconds. Potentially up to tens(hundreds?) of million years.

There's also the point that with current technology, it's really hard to make the most stable isotopes of the heaviest transuranics. The reason is that the heavier the nucleus is, the higher the optimum proportion of neutrons is. Given that we currently make the really heavy stuff by bombarding heavy actinides with fairly big nuclei, we still come up quite a few neutrons short. As an example, one of the syntheses recently was done with calcium ions, using californium as a target.

[ProxCenBound]

I think there would be a lot of planets, especially around white dwarfs, that have had their previous atmospheres and surfaces eroded and replaced by material ejected from the star when it left the Main Sequence. In the EWoCS classification these planets would be classified as Ragnorokian, I think. According to that table, Ragnarokian planets might be rich in carbon, nitrogen, lead, mercury, barium molybdenum and a bunch of other interesting elements.

It would be so cool if white dwarf or neutron star planets had a habit of hosting exotic biospheres because of unusual element abundances. Well, in real life too, but barring real-world reasons to think it's impossible, it would be cool to have in the setting naturally occurring biosphere(s) based on (typically rarer) heavy elements, even if just a brief mention (maybe at the Garden World article). I know about Samael, but there have got to be a few others that don't have a sophont species or even are just microbial (but still biochemically exotic).

[AstroChara]

I think there would be a lot of planets, especially around white dwarfs, that have had their previous atmospheres and surfaces eroded and replaced by material ejected from the star when it left the Main Sequence. In the EWoCS classification these planets would be classified as Ragnorokian, I think. According to that table, Ragnarokian planets might be rich in carbon, nitrogen, lead, mercury, barium molybdenum and a bunch of other interesting elements.

It would be so cool if white dwarf or neutron star planets had a habit of hosting exotic biospheres because of unusual element abundances. Well, in real life too, but barring real-world reasons to think it's impossible, it would be cool to have in the setting naturally occurring biosphere(s) based on (typically rarer) heavy elements, even if just a brief mention (maybe at the Garden World article). I know about Samael, but there have got to be a few others that don't have a sophont species or even are just microbial (but still biochemically exotic).

Does it have to be natural?

[ProxCenBound]

I think there would be a lot of planets, especially around white dwarfs, that have had their previous atmospheres and surfaces eroded and replaced by material ejected from the star when it left the Main Sequence. In the EWoCS classification these planets would be classified as Ragnorokian, I think. According to that table, Ragnarokian planets might be rich in carbon, nitrogen, lead, mercury, barium molybdenum and a bunch of other interesting elements.

It would be so cool if white dwarf or neutron star planets had a habit of hosting exotic biospheres because of unusual element abundances. Well, in real life too, but barring real-world reasons to think it's impossible, it would be cool to have in the setting naturally occurring biosphere(s) based on (typically rarer) heavy elements, even if just a brief mention (maybe at the Garden World article). I know about Samael, but there have got to be a few others that don't have a sophont species or even are just microbial (but still biochemically exotic).

Does it have to be natural?

Not necessarily, but an artificial exotic biosphere can be created anywhere regardless of element abundances. Part of the fun (for me at least) with hard sci-fi is the idea of "you can't prove this is impossible", so the idea that exotic biospheres around these exotic stars could really arise naturally and just be waiting to be discovered is cool. Exotic biospheres created by advanced civilizations would also be cool, but that's a different concept.

Then again, maybe some such a civilization would prefer to do such a thing where heavy elements are already abundant. Still, I like the idea that even before sophont agency gets in the mix, the universe is spectacularly creative.

Not sure if the above will make sense to others, but it's my thoughts anyway. I don't mean to suggest that an artificial biosphere shouldn't be done.

[dangerous_safety]

Re: Ragnorokian worlds, Phoenixian worlds and elemental enrichment,
So in addition to ragnorkian worlds, those which survive the death of their star, there are also phoenixian worlds, which form around stellar remnants. In addition to these, it is also possible for worlds in adjacent systems, or even entire star forming molecular clouds, to be seeded in the elements produced. This would be most common for very high mass stars, which often die while still inside star forming regions.

Going a bit further, what elements are enriched will depend on what star(s) died:
- Around white dwarfs, planets will be as described by Steve. They would be rich in carbon, nitrogen, and some heavier elements. Because of the non-violent deaths producing white dwarfs, this material might not have much of an impact on neighboring systems.
- Supernovae from massive stars don't seem like they'd result in very unusual compositions, besides possibly being metal poor. Giving the presence of Al26 in the early solar system, a short lived isotope of aluminium, it seems like our own solar system is an example of a system enriched by a supernova from a high mass star to some extent. It should be noted that for any planets present around the high mass star, assuming they survive, they would most likely be ejected into interstellar space, so some weird Stevensonian and Odyssian may also exist (albeit very rarely).
- Supernovae from white dwarfs, either by accreting material from a donor star, or by the collision of two white dwarfs, should be enriched in things like iron, nickel, sulfur, and calcium produced in the supernova, as well as carbon and oxygen already present in the white dwarf(s). As far as I'm aware, this is most likely the type of enrichment that should be seem in the Lich system, as it seems the most conducive to forming a second wave of planets.
- Merging neutron stars will enrich nearby systems with heavy elements, particularly in the platinum group. This would also be where you would most likely see the production of superheavy elements and/or various types of quark matter. Because this can affect other systems more easily, this is probably the source of heavy elements found on Samael.

Re: Super heavy elements on planets around stellar remnants,
From what I can tell, estimates for isotopes in the island(s) of stability range from mere minutes potentially all the way up to millions of years, with the upper bound seeming to be quite optimistic. Adopting the optimistic upper bound, all of these super heavy elements will be all but completely gone less than 50 million years, too short to be noteworthy in any way. Other conjectured islands of stability at higher atomic numbers also seem to have either similar, or shorter half-lives.

There is also a possible "continent of stability" but that pertains to quark matter rather than nuclear matter, and as such is really a whole different creature. There isn't a lot of literature of this variety of quark matter though, so its hard to say anything concrete about it.

Re: Biospheres incorporating heavy and/or super-heavy elements,
Something to keep in mind is that even if certain elements are present, they may not be beneficial for an organism. But I agree that its weird that the only example of molybdenum biology. You'd expect that for there to be a sophont variety of this type, there's be dozens of similar worlds with non sophont life.

Hope this helps

[Everything4404]

Re: Ragnorokian worlds, Phoenixian worlds and elemental enrichment,
So in addition to ragnorkian worlds, those which survive the death of their star, there are also phoenixian worlds, which form around stellar remnants. In addition to these, it is also possible for worlds in adjacent systems, or even entire star forming molecular clouds, to be seeded in the elements produced. This would be most common for very high mass stars, which often die while still inside star forming regions.

Going a bit further, what elements are enriched will depend on what star(s) died:
- Around white dwarfs, planets will be as described by Steve. They would be rich in carbon, nitrogen, and some heavier elements. Because of the non-violent deaths producing white dwarfs, this material might not have much of an impact on neighboring systems.
- Supernovae from massive stars don't seem like they'd result in very unusual compositions, besides possibly being metal poor. Giving the presence of Al26 in the early solar system, a short lived isotope of aluminium, it seems like our own solar system is an example of a system enriched by a supernova from a high mass star to some extent. It should be noted that for any planets present around the high mass star, assuming they survive, they would most likely be ejected into interstellar space, so some weird Stevensonian and Odyssian may also exist (albeit very rarely).
- Supernovae from white dwarfs, either by accreting material from a donor star, or by the collision of two white dwarfs, should be enriched in things like iron, nickel, sulfur, and calcium produced in the supernova, as well as carbon and oxygen already present in the white dwarf(s). As far as I'm aware, this is most likely the type of enrichment that should be seem in the Lich system, as it seems the most conducive to forming a second wave of planets.
- Merging neutron stars will enrich nearby systems with heavy elements, particularly in the platinum group. This would also be where you would most likely see the production of superheavy elements and/or various types of quark matter. Because this can affect other systems more easily, this is probably the source of heavy elements found on Samael.

Re: Super heavy elements on planets around stellar remnants,
From what I can tell, estimates for isotopes in the island(s) of stability range from mere minutes potentially all the way up to millions of years, with the upper bound seeming to be quite optimistic. Adopting the optimistic upper bound, all of these super heavy elements will be all but completely gone less than 50 million years, too short to be noteworthy in any way. Other conjectured islands of stability at higher atomic numbers also seem to have either similar, or shorter half-lives.

There is also a possible "continent of stability" but that pertains to quark matter rather than nuclear matter, and as such is really a whole different creature. There isn't a lot of literature of this variety of quark matter though, so its hard to say anything concrete about it.

Re: Biospheres incorporating heavy and/or super-heavy elements,
Something to keep in mind is that even if certain elements are present, they may not be beneficial for an organism. But I agree that its weird that the only example of molybdenum biology. You'd expect that for there to be a sophont variety of this type, there's be dozens of similar worlds with non sophont life.

Hope this helps

This continent of stability matter, also known as udQM, i don't really expect to see it anywhere. It is likely very rare because it has so much protons and neutrons needed to form it

[dangerous_safety]

Not really. The continent of stability can in principle supercede the nominal island of stability, as it could start with atomic masses as low as around 300-400 u. For comparison the highest mass isotopes of Tenessine and Oganesson have atomic masses of 294 u, and predictions for heavier elements thought to be on or near the island of stability like unbinilium and unbihexium are thought to be most stable with atomic masses around 320 u.