Sunday, July 29, 2018
Implications for Panspermia: Metazoans Can Survive Freezing Under Natural Conditions
Nematodes were frozen in Siberian permafrost 42,000 years ago, and were thawed in a lab, showing behaviors like feeding. This has implications for panspermia. In another unintentional experiments, other roundworms on the space shuttle survived uncontrolled re-entry and were found on the ground weeks after the accident. Stars regularly make close passes on time scales on the order of 100,000 years. 70,000 years ago, there was a star less than a light year away (Scholz's Star.) Large meteor strikes regularly (on geological timescales) send material into space. Are there thaw-able Earth nematodes (and many other things) now in order around Scholz's Star? There are definitely extraterrestrial objects in this solar system, but only in one case have we checked for biochemistry - and we at least found amino acids.
Tuesday, July 24, 2018
Look for RNA-World Rock Strata on the Moon
Schulze-Makuch and Crawford show in Astrobiology that that the Moon may have briefly been habitable - either (two options) about 4.5 billion years ago, or 3.5 billion years ago, for a few tens of millions of years, with an atmosphere and some liquid water (Gizmodo digest here.) Since the moon was formed after an impact with the early Earth, we should assume they had many of the same starting materials. The moon had less surface area and less time, and split from the Earth prior to even the earliest suggested prebiotic activity around 4 billion years ago, so it would have had to develop its own life - it could not have been "seeded."
The Moon with life (although terraformed.) From Techeblog.
Recent work by Tashiro et al suggest that a 4 billion year old rock stratum on Earth shows evidence of biological activity and may even be the fossil result of an RNA-World stage in the evolution of life on Earth. If it existed on Earth, it also could have existed on the Moon. It's not as though that rock stratum is exposed everywhere on Earth (the Tashiro people used samples from northern Labrador, Canada.) But it's interesting to think that the same stratum could have existed on the Moon if prebiotic chemistry took a similar course - and that those strata may be much easier to find and more widespread given the inactivity of the Moon relative to Earth.
The Moon with life (although terraformed.) From Techeblog.
Recent work by Tashiro et al suggest that a 4 billion year old rock stratum on Earth shows evidence of biological activity and may even be the fossil result of an RNA-World stage in the evolution of life on Earth. If it existed on Earth, it also could have existed on the Moon. It's not as though that rock stratum is exposed everywhere on Earth (the Tashiro people used samples from northern Labrador, Canada.) But it's interesting to think that the same stratum could have existed on the Moon if prebiotic chemistry took a similar course - and that those strata may be much easier to find and more widespread given the inactivity of the Moon relative to Earth.
Sunday, July 22, 2018
Attempts at Interstellar Communication: Receipts and Responses Within Your Lifetime
tl;dr Lots of scientists are on record saying that broadcasting messages to nearby stars is dangerous. If you take other low-probability high-consequence existential risks seriously, you should consider joining the effort (resources here.) Compared to some of the problems the X-risk community is used to thinking about, it would be relatively easy to stop active SETI (METI) and protect the future of life on Earth.
A very philosophically-minded Native American in the pre-Columbian era, sitting on the beach at night, might have thought: there might be a beach just like this one, far across these waters. And if we set up large bonfires, we can let them know we're here! What a joy it would be to meet and exchange culture and technology! We know how the exchange actually played out; if it had come a few centuries earlier, it would have been the Norse landing in New England and Virginia, and likely would have been even worse. In any event, if our pre-contact philosopher would've known exactly how friendly those people across the water would be, he would've abandoned his plan.
This was the result of contact between two groups of the same species that had been briefly (in biological terms) separated. Based on simple evolutionary psychology, contact between two completely unrelated species would likely be much, much worse. But in contrast, revealing the strangely and hypocritically self-flagellating psychology of certain people, you don't have to look far for arguments that contact between humans and aliens would necessarily be beneficial to us - because we humans are so dirty and sinful (except for the people pointing out how sinful we are of course), and any aliens technologically advanced enough to visit us[1] would necessarily be morally advanced as well (again inconsistently, morally advanced as evaluated by the sinful human making the argument.) There's no valid argument in favor of METI, and every reason to think it should be considered suicide for Earth's entire ecosystem, not just for humans. And yet it's been done repeatedly, sometimes for reasons as silly as art projects.
Consider the following list of stars that have been targeted for such contact attempts, and which are close enough that a response (or a visit, if they can travel at light speed) could be received in the medically optimistic lifetime of someone born recently.
*Where there are asterisks, numbers of asterisks = # of contact attempts
This is by no means an exhaustive list of all messages, only those for which we can receive a response by 2110 - and only those which are publicly reported.
The argument against active SETI (or METI; Messaging ET Intelligence) is simple. Any aliens which receive the message and have the ability to travel to our solar system are very likely far advanced. Whether or not they intend to harm us - if they, it, etc. even has "intentions" - is immaterial, as any contact with them is overwhelmingly likely to be catastrophic for Earth's ecosystem as a whole, including the human race. Arguments that the aliens will be (or for some reason must be) "nice" are comically narrow-minded and provincial.
The best arguments in FAVOR of active SETI appear to be 1) if we remain silent, then we can infer other species are likely to have made the same decision and it's inconsistent to remain silent but keep listening. 2) Advanced species probably already know about us, and these efforts don't much increase the chances of being detected.
To #1, even assuming the self-indication assumption-reasoning here doesn't demand bizarre causality as Nozick argued with respect to Newcomb's Paradox, given the likely severe consequences of a visit from a species more advanced than our own, I think joining in with all the silent species and being part of the problem (i.e., leading to the Great Silence) is quite a good trade. Notice that in our own ecosystem, most animals are quiet, unless they can quickly escape by flight or into burrows, are hidden by darkness, or are surrounded by conspecifics. Those of us who assume that aliens must be friendly somehow always insist that natural selection stops applying to advanced species and across interstellar space.
To #2, if the best argument really is that "they already know we're here so we're not increasing our chances of detection by potentially destructive aliens THAT much", which is literally the argument made by Jacob Haqq-Misra, Chief Scientific officer of the Lone Signal project, then that tells you a lot about how well-thought -through the whole enterprise is. What's more, it's absolutely false. The C-index is a quick and dirty measure of our detectability - if there were a twin Earth, giving off the same amount of electromagnetic noise that we are, how close would we have to be to detect it? Currently, about 3 LY, meaning we wouldn't even be able to hear ourselves from the next closest star. A powerful directed message on the other hand would be much easier to detect from a longer distance - so these messages are in fact likely increasing the probability of our detection substantially, at least at the target stars. Otherwise why are they even sending them?
These projects are ongoing. The problem has been discussed at conferences with approaches including a moratorium backed by international law (so far only talk.) These things are slow. One approach may be to go directly to the telescopes sending the messages, as there are a limited number of such installations. In decreasing magnitude of offense with those messages, they are:
Eupatoria (Crimea, Ukraine) - 7 targets, 11 transmissions
Arecibo (Puerto Rico, USA) - 4 targets, 4 transmissions
EISCAT (Tromso, Norway) 1 target, 1 transmission (an art project!)
Jamesburg (Carmel, California, USA) 1 target, 1 transmission (crowdfunded!!)
In addition, Alexander Zaitsev is a Russian astronomer who is far and away the individual most responsible for driving METI efforts. Douglas Vakoch is a METI proponent here in the US.
Lots of scientists are on record saying that broadcasting messages to nearby stars is dangerous. If you take other low-probability high-consequence existential risks seriously, you should consider joining the effort (resources here.) Compared to some of the problems the X-risk community is used to thinking about, it would be relatively easy to stop METI and protect the future of life on Earth.
[1] I purposely avoid the word civilizations, because that is a term which describes an entity with certain characteristics that humans can collectively form. Whatever activities groups of aliens form, it will not appear like any "civilization" we would recognize. "School", "herd", "flock", "swarm" are all terms that are at least as likely be useful to human impressions to describe the collective entities that we see.
A very philosophically-minded Native American in the pre-Columbian era, sitting on the beach at night, might have thought: there might be a beach just like this one, far across these waters. And if we set up large bonfires, we can let them know we're here! What a joy it would be to meet and exchange culture and technology! We know how the exchange actually played out; if it had come a few centuries earlier, it would have been the Norse landing in New England and Virginia, and likely would have been even worse. In any event, if our pre-contact philosopher would've known exactly how friendly those people across the water would be, he would've abandoned his plan.
This was the result of contact between two groups of the same species that had been briefly (in biological terms) separated. Based on simple evolutionary psychology, contact between two completely unrelated species would likely be much, much worse. But in contrast, revealing the strangely and hypocritically self-flagellating psychology of certain people, you don't have to look far for arguments that contact between humans and aliens would necessarily be beneficial to us - because we humans are so dirty and sinful (except for the people pointing out how sinful we are of course), and any aliens technologically advanced enough to visit us[1] would necessarily be morally advanced as well (again inconsistently, morally advanced as evaluated by the sinful human making the argument.) There's no valid argument in favor of METI, and every reason to think it should be considered suicide for Earth's entire ecosystem, not just for humans. And yet it's been done repeatedly, sometimes for reasons as silly as art projects.
Consider the following list of stars that have been targeted for such contact attempts, and which are close enough that a response (or a visit, if they can travel at light speed) could be received in the medically optimistic lifetime of someone born recently.
| Star | Sun-like? | Planets? | Earliest Response |
| Teegarden's Star | red dwarf | possible | 2036 |
| GJ83.1 | red dwarf (flare) | no evidence | 2040 |
| GJ273b | red dwarf | YES, SUPER EARTH IN HABITABLE ZONE | 2043 |
| Gliese 581 | red dwarf | YES, POSSIBLY IN HABITABLE ZONE | 2050 |
| Altair | white (A) | no evidence | 2051 |
| GJ526 | red dwarf (flare star) | unlikely | 2059 |
| HIP 4872 | red dwarf | no evidence | 2069 |
| Kappa Ceti | YES, but frequent flares | no evidence | 2069 |
| HD 245409 | cool orange/hot red dwarf (K-M) | no evidence | 2077 |
| 55Cancri**** | YES | YES, POSSIBLY IN HABITABLE ZONE | 2085 |
| HD 10307 | YES | unlikely (companion) | 2085 |
| 47 UMa** | YES | possible | 2093 |
| Gl 777 | YES | possible | 2103 |
This is by no means an exhaustive list of all messages, only those for which we can receive a response by 2110 - and only those which are publicly reported.
The argument against active SETI (or METI; Messaging ET Intelligence) is simple. Any aliens which receive the message and have the ability to travel to our solar system are very likely far advanced. Whether or not they intend to harm us - if they, it, etc. even has "intentions" - is immaterial, as any contact with them is overwhelmingly likely to be catastrophic for Earth's ecosystem as a whole, including the human race. Arguments that the aliens will be (or for some reason must be) "nice" are comically narrow-minded and provincial.
The best arguments in FAVOR of active SETI appear to be 1) if we remain silent, then we can infer other species are likely to have made the same decision and it's inconsistent to remain silent but keep listening. 2) Advanced species probably already know about us, and these efforts don't much increase the chances of being detected.
To #1, even assuming the self-indication assumption-reasoning here doesn't demand bizarre causality as Nozick argued with respect to Newcomb's Paradox, given the likely severe consequences of a visit from a species more advanced than our own, I think joining in with all the silent species and being part of the problem (i.e., leading to the Great Silence) is quite a good trade. Notice that in our own ecosystem, most animals are quiet, unless they can quickly escape by flight or into burrows, are hidden by darkness, or are surrounded by conspecifics. Those of us who assume that aliens must be friendly somehow always insist that natural selection stops applying to advanced species and across interstellar space.
To #2, if the best argument really is that "they already know we're here so we're not increasing our chances of detection by potentially destructive aliens THAT much", which is literally the argument made by Jacob Haqq-Misra, Chief Scientific officer of the Lone Signal project, then that tells you a lot about how well-thought -through the whole enterprise is. What's more, it's absolutely false. The C-index is a quick and dirty measure of our detectability - if there were a twin Earth, giving off the same amount of electromagnetic noise that we are, how close would we have to be to detect it? Currently, about 3 LY, meaning we wouldn't even be able to hear ourselves from the next closest star. A powerful directed message on the other hand would be much easier to detect from a longer distance - so these messages are in fact likely increasing the probability of our detection substantially, at least at the target stars. Otherwise why are they even sending them?
These projects are ongoing. The problem has been discussed at conferences with approaches including a moratorium backed by international law (so far only talk.) These things are slow. One approach may be to go directly to the telescopes sending the messages, as there are a limited number of such installations. In decreasing magnitude of offense with those messages, they are:
Eupatoria (Crimea, Ukraine) - 7 targets, 11 transmissions
Arecibo (Puerto Rico, USA) - 4 targets, 4 transmissions
EISCAT (Tromso, Norway) 1 target, 1 transmission (an art project!)
Jamesburg (Carmel, California, USA) 1 target, 1 transmission (crowdfunded!!)
In addition, Alexander Zaitsev is a Russian astronomer who is far and away the individual most responsible for driving METI efforts. Douglas Vakoch is a METI proponent here in the US.
Lots of scientists are on record saying that broadcasting messages to nearby stars is dangerous. If you take other low-probability high-consequence existential risks seriously, you should consider joining the effort (resources here.) Compared to some of the problems the X-risk community is used to thinking about, it would be relatively easy to stop METI and protect the future of life on Earth.
[1] I purposely avoid the word civilizations, because that is a term which describes an entity with certain characteristics that humans can collectively form. Whatever activities groups of aliens form, it will not appear like any "civilization" we would recognize. "School", "herd", "flock", "swarm" are all terms that are at least as likely be useful to human impressions to describe the collective entities that we see.
Tuesday, July 3, 2018
Complex Organics from Enceladus
The work is driven by a chemical species that is hard to explain as other than the result of the reaction of these other complex molecules, and they build a model for how it's getting from inside Enceladus out into the plumes. Cassini detected it both in the E ring and the plume itself. Figure 10 from the paper (!!!):
Bonus points for one of the cooler names for a peer-reviewed paper ever. Points off for everyone who's touched this data and not noticed this before! What are you doing over there! You're giving fits to us bio/chemical types who are following this work. SciAm writeup here.
Frank Postberg, Nozair Khawaja, Bernd Abel, Gael Choblet, Christopher R. Glein, Murthy S. Gudipati, Bryana L. Henderson, Hsiang-Wen Hsu, Sascha Kempf, Fabian Klenner, Georg Moragas-Klostermeyer, Brian Magee, Lenz Nölle, Mark Perry, René Reviol, Jürgen Schmidt, Ralf Srama, Ferdinand Stolz, Gabriel Tobie, Mario Trieloff & J. Hunter Waite. Macromolecular organic compounds from the depths of Enceladus. Naturevolume 558, pages564–568 (2018)
Bonus points for one of the cooler names for a peer-reviewed paper ever. Points off for everyone who's touched this data and not noticed this before! What are you doing over there! You're giving fits to us bio/chemical types who are following this work. SciAm writeup here.
Frank Postberg, Nozair Khawaja, Bernd Abel, Gael Choblet, Christopher R. Glein, Murthy S. Gudipati, Bryana L. Henderson, Hsiang-Wen Hsu, Sascha Kempf, Fabian Klenner, Georg Moragas-Klostermeyer, Brian Magee, Lenz Nölle, Mark Perry, René Reviol, Jürgen Schmidt, Ralf Srama, Ferdinand Stolz, Gabriel Tobie, Mario Trieloff & J. Hunter Waite. Macromolecular organic compounds from the depths of Enceladus. Naturevolume 558, pages564–568 (2018)