A Nature paper by Micheli et al demonstrates that outgassing is one plausible explanation for the subtle changes being measured in Oamuamua's trajectory. It also happens to visually look like a comet, though with much more silicate than organic material on the surface. There's less and less distinction between asteroids and comets - that is, a "primitive" (wet, not-yet-burned-off) body like Ceres is more comet-like than a drier body like Vesta. More here on the (now established) phenomenon of interstellar mixing and what it means, more speculatively, for von Neumann probes and/or the panspermia hypothesis.
Note: I refuse to use the apostrophe for Oamuamua because it misses up alphabetical order, and also, is dumb. Sue me, Hawaiians.
Thursday, June 28, 2018
Saturday, June 23, 2018
Another Interstellar Asteroid - This One a Permanent Resident of the Solar System
Asteroid BZ interested astronomers right away, because it is retrograde, in a 1:-1 resonance with Jupiter - suggesting that it was captured from outside the solar system just as ours formed, and is therefore older than the rest of the solar system.
But more interesting than that, it took several unlikely events for it to be captured and continue in a stable resonance over time (see last paragraph in the Orbit section.) This very strongly suggests that there are interstellar objects passing through the solar system all the time. For such an object to be captured so quickly, so early in the history of the solar system means that there must be enough of them to get trapped by freak aligments. Another way of looking at it is that fast = likely.
This is consistent with a similar argument made about Oamuamua, an interstellar asteroid that is currently passing rapidly through the solar system. Within a year of the first telescope that could detect such an object being activated, it found such an object. Good luck? Or constant interstellar material passing through? (It didn't take long to find BZ either, once we started looking.) The relevant point is that while the vast distance between stars is often cited as a form of quarantine for macroscale beings like us, it is certainly not such a quarantine, even on brief geological time scales, between pools of organic molecules. More here about periodic close passes between stars and interstellar mixing here and here, and (most speculatively) that if von Neumann probes exist, they are likely to interact with comets and asteroids with organics, rather than planets.
But more interesting than that, it took several unlikely events for it to be captured and continue in a stable resonance over time (see last paragraph in the Orbit section.) This very strongly suggests that there are interstellar objects passing through the solar system all the time. For such an object to be captured so quickly, so early in the history of the solar system means that there must be enough of them to get trapped by freak aligments. Another way of looking at it is that fast = likely.
This is consistent with a similar argument made about Oamuamua, an interstellar asteroid that is currently passing rapidly through the solar system. Within a year of the first telescope that could detect such an object being activated, it found such an object. Good luck? Or constant interstellar material passing through? (It didn't take long to find BZ either, once we started looking.) The relevant point is that while the vast distance between stars is often cited as a form of quarantine for macroscale beings like us, it is certainly not such a quarantine, even on brief geological time scales, between pools of organic molecules. More here about periodic close passes between stars and interstellar mixing here and here, and (most speculatively) that if von Neumann probes exist, they are likely to interact with comets and asteroids with organics, rather than planets.
Labels:
asteroid,
comet,
fermi paradox,
von neumann
Thursday, June 21, 2018
The Trigon Disunity by Michael P. Kube-McDowell - Emprise, Enigma, and Empery)
I'd always wanted to do a blog post on this really solid series from the 80s, which I just learned on going back to read about, was nominated for some awards. There's always some satisfaction learning that the books you liked most as a kid, and stayed with you because they had some substance, get some recognition. I wouldn't call it space opera or hard sf per se, mostly because Kube-McDowell demonstrates a real knowledge of human dynamics and psychology that make the story better and keep his characters from being mouthpieces for ideas. The story is central here - but there are really interesting ideas spread throughout. Much like I rue that there is no good thrash metal being recorded today (despite the occasional band that will claim to be writing the next mid-to-late-80s-sounding Metallica album - and then never delivers), I wonder if a series like this could be written today. Its technology, historical and social sensibilities put it squarely in the 80s but not in a bad way. If I had to put it in a genre, I'd call it "late paleo space opera". It also has cool cover art. To this day I have an aversion to science fiction that is NOT in a small paperback with cool cover art, and was shocked as a kid to learn that hardbacks are somehow more prestigious.
It's been 30 years since I read this so I may be getting some details wrong, but in any event what I like about the series is some of the ideas - like science fiction pearls. The ability to create and include these ideas is why the genre exists.
In short: the first book opens in an exhausted, resource-depleted, post-half-assed World War III near future Earth that starts getting signals from a ship approaching the Solar system. Soon it's determined that the signal is binary, and based on a very simple code - 1 for the letter A, 2 for B, etc. And (spoiler) it turns out the aliens are not aliens, but rather humans. Earth is indeed the homeworld of humanity, but there was actually a first technological civilization that predates our own, and sent out colonies. There was a collapse after an attack from the Mizaris (I think; described below) and all the colonies were cut off. The humans entering the Solar system were the first ones to reconstruct the technology needed to make the trip back. Subsequently, Earth's governments unify, and in partnership with the other humans that came home, we begin exploring our corner of the galaxy to re-contact the other isolated colonies. There ARE aliens - the D'shanna, and and the aforementioned Mizari.
So far this seems very similar to Left Hand of Darkness (which is also great), although unlike in Leguin's novel, the contact teams in these stories were not so coy about introducing themselves when they found a new lost colony. What I liked at the time, and remember today, are those little nuggets. Without further ado, here they are (again, major spoilers.)
It's been 30 years since I read this so I may be getting some details wrong, but in any event what I like about the series is some of the ideas - like science fiction pearls. The ability to create and include these ideas is why the genre exists.
In short: the first book opens in an exhausted, resource-depleted, post-half-assed World War III near future Earth that starts getting signals from a ship approaching the Solar system. Soon it's determined that the signal is binary, and based on a very simple code - 1 for the letter A, 2 for B, etc. And (spoiler) it turns out the aliens are not aliens, but rather humans. Earth is indeed the homeworld of humanity, but there was actually a first technological civilization that predates our own, and sent out colonies. There was a collapse after an attack from the Mizaris (I think; described below) and all the colonies were cut off. The humans entering the Solar system were the first ones to reconstruct the technology needed to make the trip back. Subsequently, Earth's governments unify, and in partnership with the other humans that came home, we begin exploring our corner of the galaxy to re-contact the other isolated colonies. There ARE aliens - the D'shanna, and and the aforementioned Mizari.
So far this seems very similar to Left Hand of Darkness (which is also great), although unlike in Leguin's novel, the contact teams in these stories were not so coy about introducing themselves when they found a new lost colony. What I liked at the time, and remember today, are those little nuggets. Without further ado, here they are (again, major spoilers.)
- Ever wonder what it would be like to have "the answers in the back of the book" - for all of reality? The D'shanna I mentioned were energy beings that humans on one colony communicated with. When the contact team found that planet, they were only able to contact an unfriendly diplomat sort of fellow who kept stalling them. Finally they landed despite his objections, and realized the planet was all but abandoned, with this lone gentleman the only human on it. It turns out that the D'Shanna gladly gave this colony the final answers to all reality, and this so drained the humans on this planet of meaning and the will to live that they all perished (just stopped having families vs mass suicide, can't remember.) I liked this idea a lot, because it was something I've thought about too much - an actual objective truth machine. Much to their chagrin, in the D'Shanna, the humans effectively found one.
- If you write a book with humans already mysteriously spread across the galaxy, and they did it on their own, you have a problem to solve - Either
- Earth is NOT our homeworld, and there are powerful progenitors - in which case since the 1990s you had to explain why we're related to everything here. Larry Niven wrote these kinds of stories in the 60s and 70s, and I wonder how or if he ever solved it (he didn't feel the need to go back and re-write Mars stories where there was nitric acid everywhere, I think in a very wise decision.) The Aliens franchise doesn't really fully explain this problem either but then I don't want to see what dumb explanation they might come up with.
- OR, Earth IS our homeworld, and we're the progenitors - in which case, where are the ruins of spaceports and rayguns? Here, it's solved by making all of the first civilization's technology ice-based and melting, which leaves no trace. (G.I. Joe stole this idea later.)
- The simple code used by the first human ship back to Earth was actually noted by a scientist's daughter. One scientist is completely ruined by having missed it, and ends up reading six levels of complex interpolation into the code, thinking that the approaching beings are antennaed moth-men (which obviously they turn out not to be.) Interesting reflection on the psychological impact and compensation mechanisms for missing something right in front of you, as well as a comment on reading too much into things.
- The author creates a social custom for one of his planets of adolescents having rubbing stones. Every day you rub them with your fingers, and you're an adult once they're finally smooth. Of course some adolescents don't have the discipline to keep rubbing, and they remain rough; others try futilely to accelerate the process, only to end up with bloody finger tips. This stayed with me for some reason.
- He includes really alien aliens. I understand why on Star Trek they have aliens whose only difference is a forehead ridge (the reason rhymes with "schmudget".) But in a halfway serious science fiction novel, it's inexcusable, and if that's the best you can do when you have no such constraints you might as well just include elves and dwarves while you're at it. The D'Shanna are truly alien as well, energy entities who mostly inhabit another dimension and can see all of our reality (like Tralfamadorians in Slaughterhouse Five, but much cooler and nicer) and the Mizari are electric domes of rock covering the surface of a planet orbiting Mizar (the star that makes the bend in the Big Dipper.)
- The initial mission to go meet the aliens that turned out not to be aliens had a crew consisting of:
- A white European scientist
- A black American minister
- A south Asian military/political guy (he was in charge I think)
- A Chinese crewmember, who I can't remember what he did
I thought it was interesting how the different strands of human experience were also represented by different ethnic backgrounds.
- In near-future science fiction, you really can improve your verisimilitude by including a familiar setting, which Kube-McDowell does occasionally, mentioning his native Pennsylvania a few centuries hence - the Susquehanna Spaceport! He now lives in Indiana and in Alternities uses that setting.
Mizar (the brighter one), home of some really alien aliens. (from skyandtelescope.com)
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