Cancer Posted August 16, 2018 Report Share Posted August 16, 2018 Not a place you want to be Exoplanet atmosphere detected, including atomic titanium and iron vapor. (The star itself is spectral type A0, with an effective temperature of about 10000 K.) DShomshak and tkdguy 2 Quote Link to comment Share on other sites More sharing options...
Lawnmower Boy Posted August 17, 2018 Report Share Posted August 17, 2018 These are, of course, the kind of worlds that the universe's advanced civilisations like. Too bad for us snow people, who will never quench our thirst with a cool glass of molten titanium. Quote Link to comment Share on other sites More sharing options...
tkdguy Posted August 18, 2018 Author Report Share Posted August 18, 2018 Mini-moons DShomshak 1 Quote Link to comment Share on other sites More sharing options...
Cancer Posted August 18, 2018 Report Share Posted August 18, 2018 13 minutes ago, tkdguy said: Mini-moons Related to that ... Limits on small, close natural satellites of Earth (1986!) It made interesting reading, seeing as that's based on declassified NORAD radar data. Nothing larger than 40 cm within 10,000 km. pinecone and tkdguy 1 1 Quote Link to comment Share on other sites More sharing options...
Cancer Posted August 23, 2018 Report Share Posted August 23, 2018 CubeSats going interplanetary That is labeled "Full Access", so I think that should not be locked behind the subscriber wall, but I have been deceived about that before. CubeSats (that's a Wikipedia link) are small spacecraft intended to be cheap and relatively easy to make. Originally single cubes 10 cm on each edge, later versions include spacecraft made of several cubes. The point is that you can launch lots of them all at once for cheap, often as hitchhikers on some other launch. Bunches of them have been sent into Earth orbit. It was originally intended that there was no engine aboard them: they just went into whatever orbit they happened to land in; there's useful things that can be done (both science, and engineering testing) with that sort situation. And it is cheap. There are several now going on interplanetary missions, and the concept of sending many tiny, inexpensive interplanetary missions is very interesting for planetary science. Quote Link to comment Share on other sites More sharing options...
archer Posted August 23, 2018 Report Share Posted August 23, 2018 2 hours ago, Cancer said: CubeSats going interplanetary That is labeled "Full Access", so I think that should not be locked behind the subscriber wall, but I have been deceived about that before. CubeSats (that's a Wikipedia link) are small spacecraft intended to be cheap and relatively easy to make. Originally single cubes 10 cm on each edge, later versions include spacecraft made of several cubes. The point is that you can launch lots of them all at once for cheap, often as hitchhikers on some other launch. Bunches of them have been sent into Earth orbit. It was originally intended that there was no engine aboard them: they just went into whatever orbit they happened to land in; there's useful things that can be done (both science, and engineering testing) with that sort situation. And it is cheap. There are several now going on interplanetary missions, and the concept of sending many tiny, inexpensive interplanetary missions is very interesting for planetary science. I understand the usefulness of the darned things but I just cringe at the idea of putting even more things which are too small to be detected/avoided into Earth orbit. Quote Link to comment Share on other sites More sharing options...
archer Posted August 23, 2018 Report Share Posted August 23, 2018 'Nuff said. https://xkcd.com/1992/ pinecone, Lawnmower Boy, DShomshak and 1 other 2 2 Quote Link to comment Share on other sites More sharing options...
Lord Liaden Posted August 24, 2018 Report Share Posted August 24, 2018 Giant "rogue planet" discovered in interstellar space Personally I think this is where the Great Old Ones hang out. tkdguy, DShomshak, pinecone and 1 other 3 1 Quote Link to comment Share on other sites More sharing options...
Cancer Posted August 25, 2018 Report Share Posted August 25, 2018 Could be that's how they get around, and their preferred hangout spots are things we haven't recognized yet. Quote Link to comment Share on other sites More sharing options...
L. Marcus Posted August 25, 2018 Report Share Posted August 25, 2018 Using a planet as a space ship? That's metal. Quote Link to comment Share on other sites More sharing options...
tkdguy Posted August 26, 2018 Author Report Share Posted August 26, 2018 Didn't Ming the Merciless control Mongo like that ? Quote Link to comment Share on other sites More sharing options...
DShomshak Posted August 26, 2018 Report Share Posted August 26, 2018 On 8/25/2018 at 7:43 AM, L. Marcus said: Using a planet as a space ship? That's metal. See also: Fritz Leiber, The Wanderer; E.E. Smith, Lensman series; and Olaf Stapledon, who probably started the idea (and about half of SF as a whole), Star Maker. Especially Stapledon. Later writers built entire careers around ideas he tossed off in a paragraph. Dean Shomshak Quote Link to comment Share on other sites More sharing options...
DShomshak Posted August 26, 2018 Report Share Posted August 26, 2018 On 8/24/2018 at 4:23 AM, Lord Liaden said: Giant "rogue planet" discovered in interstellar space Personally I think this is where the Great Old Ones hang out. Or it is a Great Old One. See Ramsay Campbell, The Tugging," in Disciples of Cthulhu, or the Chaosium CoC module Spawn of Azathoth. Dean Shomshak Quote Link to comment Share on other sites More sharing options...
Cancer Posted August 28, 2018 Report Share Posted August 28, 2018 In the August 1 Astrophysical Journal Letters: They have detected carbon monoxide, water vapor, and hydrogen cyanide in the atmosphere of the "hot Jupiter" planet HD 209458b. That planet is not Earthlike (it's between Saturn and Jupiter in terms of mass, but it is in a 3.5 day orbit around its star) but seeing that stuff in the atmosphere, especially HCN, gives you more of a handle on what the chemistry in such an atmosphere might be like. "They" here are four authors, G A Hawker, N Madhusudhan, S H C Cabot, and S Gandhi. Another one, which I can only link (it says "open access") because the concept would never have occurred to me: The Search for Extra-Galactic Intelligence Signals Synchronized with Binary Neutron Star Mergers *If* you can predict accurately when and where a binary neutron star event is going to occur, *then* you could send a signal appropriately synchronized with the neutrino etc. signal of the subsequent merger event so that a civilization in another galaxy could detect your signal and know you were there. I note without further comment that it is likely that any species that actually detects your signal will not have evolved to sapience yet at the time you send your signal, and who knows what will have happened to your own species in that interval of time anyway, but .... EDIT: The neutron star merger event that was detected last year was in NGC 4993, which is about 145 million light-years away. I note that at this time, Order Primates is believed to be only about half of 145 million years old. So it goes deeper than just "species" .... tkdguy, L. Marcus, DShomshak and 1 other 4 Quote Link to comment Share on other sites More sharing options...
Old Man Posted August 30, 2018 Report Share Posted August 30, 2018 Literally duct tape Quote Link to comment Share on other sites More sharing options...
archer Posted August 31, 2018 Report Share Posted August 31, 2018 11 hours ago, Old Man said: Literally duct tape Well, they could have fixed it with literally any old crap.... Quote Link to comment Share on other sites More sharing options...
archer Posted August 31, 2018 Report Share Posted August 31, 2018 https://xkcd.com/1583/ pinecone 1 Quote Link to comment Share on other sites More sharing options...
Cancer Posted September 26, 2018 Report Share Posted September 26, 2018 Dust storms seen on Titan The place seems more like home all the time. Too bad the rocks are water. L. Marcus, DShomshak and tkdguy 3 Quote Link to comment Share on other sites More sharing options...
DShomshak Posted September 30, 2018 Report Share Posted September 30, 2018 September's issue of Scientific American had only one space-related article, a rehash of Ward and Brownlee's "Rare Earth" argument by John "Jupiter Effect" Gribbin. The dust storms on Titan give me additional reason to think the Rare Earth argument is a load of dingo's kidneys. That a world that is much smaller, much colder, and with radically different chemical composition, nevertheless displays so many Earthlike features, suggests that planets may not be so sensitive to initial conditions that any deviation from any feature of Earth changes everything so much to make complex life impossible. With just one example of a life-bearing planet to study, Rare Earth is just ridiculously cocksure. Dean Shomshak Quote Link to comment Share on other sites More sharing options...
Zeropoint Posted September 30, 2018 Report Share Posted September 30, 2018 Yeah, my basic approach to the question, and the Fermi Paradox is "we're not qualified to have an opinion yet". When we've put biologist boots on the ground on all the accessible bodies in our solar system, then we'll have enough data to START speculating. Quote Link to comment Share on other sites More sharing options...
Cancer Posted September 30, 2018 Report Share Posted September 30, 2018 The last significant paradox in astronomy was Olbers Paradox, which began with four (iirc) reasonable (for the mid-19th Century) assumptions which led inescapably to the conclusion that the entire sky should be as bright and hot as the surface of a star. It worked out that all of the initial assumptions were invalid, and invalid for reasons that could not be supported at all when the paradox was formulated. On that basis, I am not yet willing to speculate on what's gone wrong with the Fermi Paradox. Unfortunately, almost all the alternatives I have seen bandied about seem far too superficial, and/or far too convenient (even smug) for us humans, for me to take seriously. There seems to be far too deficient an understanding of how life got started, or even how you define life at the closest-to-the-edges situations, for simple statements to be made about where we might find it. Even if we find microbial life on Mars (and I am coming to think that better than an even-money bet), I expect it'll be a lot like terrestrial life. I won't view that as conclusive for purposes of the Fermi Paradox because still (again, I expect) we won't know where it -- and Terrestrial life -- originated: we know there has been material from Mars reach Earth, and it's overwhelmingly likely material from Earth has reached Mars (and I am discounting the things our technology has put there). If that is all true, then we really can't be certain how abiotic origins of life happened. Quote Link to comment Share on other sites More sharing options...
archer Posted October 1, 2018 Report Share Posted October 1, 2018 We make a hell of an assumption in thinking that the laws of physics are the same everywhere in the universe. I'm not arguing that we shouldn't make that assumption, just that we should remain aware that it is an assumption. As for other aspects of the Fermi paradox, I wouldn't be surprised if aliens had visited the planet in the past. Look at our exploration of the moon. Astronauts landed there in a couple of places, explored a tiny area of it, then left for various reasons including that it wasn't convenient for them to stay. If you had no idea where to start looking for the evidence that man had visited the moon, it might take you a very long while before you found one of the landing sites. And that's on a globe that's 1/4th the size of the earth and which has no weather, population, or tectonic activity to obscure the landing sites. And even if the aliens had only two simple rules such as "don't litter and don't upset the natives", any civilization which was advanced enough to make the trip today could avoid the ridiculously minimal efforts our civilization currently makes to detect aliens. Quote Link to comment Share on other sites More sharing options...
archer Posted October 1, 2018 Report Share Posted October 1, 2018 1 minute ago, archer said: duplicate Quote Link to comment Share on other sites More sharing options...
dmjalund Posted October 1, 2018 Report Share Posted October 1, 2018 5 hours ago, archer said: We make a hell of an assumption in thinking that the laws of physics are the same everywhere in the universe. I'm not arguing that we shouldn't make that assumption, just that we should remain aware that it is an assumption. It's not just an assumption, it is based on observing the observable universe (big clue is that spectral emissions from the most distant of visible galaxies match those of nearby stars and emissions done n the lab) Quote Link to comment Share on other sites More sharing options...
Cancer Posted October 2, 2018 Report Share Posted October 2, 2018 Well, it is an assumption, but some aspects of the assumption are testable (and have been tested insofar as possible). We can't test anything outside our horizon (or at least AFAWK we can't), though there are some folks out in the theoretical boondocks that assert we can, albeit indirectly. The hot Big Bang model is successful well into the era of nucleosynthesis (about 200 seconds after time zero) and almost as certainly further back. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.