Cancer Posted June 28, 2021 Report Share Posted June 28, 2021 I cannot now recall where I heard this, but someone pushed numbers around and it seems that radiolysis of water (breaking water apart, generally into protons and hydoxyl ions, usually by gamma rays or X-rays, but other radiation can cause this to occur as well) and other substances at depth in the Earth can produce the sort of chemical disequilibrium that chemosynthetic bacteria would employ both as an energy source and as source for needed nutrients. Protons and sulfate ions are the two big ones in the discussion I remember; we know of archaeans that get by on just those ions in terms of energy source. Radiolysis will go on in within Earth for a long, long time, with thorium-232 having a half-life of 14 Gyr. The amount of water in the mantle isn't something I was able to find estimates for, but there is some. Whether or not you could get life started in the deep interior is unknown, but once it invades that part (survivors of organisms that rode the subducted oceanic plates down) it could be there for keeps. You won't make metazoans that way, but the idea that every planet might have a deep biosphere of at least this sort is worth thinking about. DShomshak and Lawnmower Boy 2 Quote Link to comment Share on other sites More sharing options...
DShomshak Posted June 30, 2021 Report Share Posted June 30, 2021 Happy Tunguska Day! Dean Shomshak Cancer, Beast, Lawnmower Boy and 1 other 3 1 Quote Link to comment Share on other sites More sharing options...
Cancer Posted June 30, 2021 Report Share Posted June 30, 2021 Astrophysical Journal Letters paper on two detected black hole-neutron star merger events ... and the two events were only ten days apart. Probably unreadable for most people, but this is the paper all other articles about this stuff are drawing from. Open access. If you do try reading it, the stuff likely to be of most interest (and perhaps most readable) is in section 5 and to a lesser extent in some parts of part 6, while the recap in part 7 states ultimate results with minimal background. pinecone and tkdguy 1 1 Quote Link to comment Share on other sites More sharing options...
pinecone Posted July 7, 2021 Report Share Posted July 7, 2021 Not sure where to post this. But this is a fun video about Spin. The fundimental force we don't understand! Quote Link to comment Share on other sites More sharing options...
pinecone Posted July 8, 2021 Report Share Posted July 8, 2021 Personally...I strongly suspect that Spin is why the Time Arrow, only points one way. Quote Link to comment Share on other sites More sharing options...
tkdguy Posted July 12, 2021 Author Report Share Posted July 12, 2021 Richard Branson takes a ride on his space ship. pinecone and Amorkca 2 Quote Link to comment Share on other sites More sharing options...
tkdguy Posted July 21, 2021 Author Report Share Posted July 21, 2021 Not to be outdone, Jeff Bezos launches into space. Quote Link to comment Share on other sites More sharing options...
archer Posted July 21, 2021 Report Share Posted July 21, 2021 11 hours ago, tkdguy said: Not to be outdone, Jeff Bezos launches into space. And inadvertently ticks off a lot of his employees and customers by thanking them for financing his junket into space.... Quote Link to comment Share on other sites More sharing options...
Beast Posted July 22, 2021 Report Share Posted July 22, 2021 3 hours ago, archer said: And inadvertently ticks off a lot of his employees and customers by thanking them for financing his junket into space.... And how long has he been funding Blue Origin? Tesla paid for Elon Musk to launch HIS personal car into space for a grand tour of our local orbit some people need to get a life of course since he sold all interest in Amazon How many will stop buying from Amazon or drop their Prime accounts? not many is my guess, or enough to make a dent like what happened to Disney+ over Gina Quote Link to comment Share on other sites More sharing options...
Terminax Posted July 22, 2021 Report Share Posted July 22, 2021 Slight correction. Bezos still owns a little over 10% of Amazon stock. He's behind Musk, but he'll catch up. Like Musk is doing with Starlink, he's planning to put up a satellite internet network. Quote Link to comment Share on other sites More sharing options...
Ninja-Bear Posted July 22, 2021 Report Share Posted July 22, 2021 23 hours ago, archer said: And inadvertently ticks off a lot of his employees and customers by thanking them for financing his junket into space.... It’s funny how people feel entitled on how you should spend your money. Beast 1 Quote Link to comment Share on other sites More sharing options...
DShomshak Posted August 24, 2021 Report Share Posted August 24, 2021 My local library is open again, so I'm getting caught up on space stories in Scientific American. December 2020: Supernovae are more complicated than previously thought. When a really big star goes boom, not only are there multiple mechanisms for its core to collapse (all depending on the star's mass), but the star can blow off shells of material shortly before the explosion (maybe mere days), and there can be jets of plasma shot out from the collapsing core. If such a jet is fast enough (99.995% the speed of light!) and aimed in our direction, we see it as a gamma-ray burst. (That's the guess, anyway.) A slower jet might be caught in the shell of cast-off gas, heating it to produce a briefer but brighter supernova. If the core turns into a neutron star, its magnetic field can also interact with the expanding plasma of the explosion in various ways. Much more observation is needed to obtain a sufficient population of supernovae observed in greater detail -- including before the star actually explodes -- in order to work out the factors and processes that lead to these various results. Dean Shomshak Quote Link to comment Share on other sites More sharing options...
DShomshak Posted September 1, 2021 Report Share Posted September 1, 2021 The cover story for the April, 2020 issue of Scientific American was "New View of the Milky Way Galaxy." Astronomers have long been pretty sure the Milky Way is a barred spiral galaxy, but many details have been unknown -- notably, just how many spiral arms the galaxy has. The Bar and Spiral Legacy (BeSSeL) Survey attempted to answer that question by using radio astronomy to find the distance and direction of star-forming regions, where you find the hot, blue stars that define the spiral arms. (You can't see those regions throughout the galaxy: Dust obscures them. But those stars stimulate distinctive radio emissions that penetrate the dust... and by using a clever technique that turns a set of radio telescopes into a single telescope the size of the Earth, distance can be found directly by parallax.) BeSSel finds that the Milky Way has four major arms, plus the fragmentary Local Arm that holds the Sun, and the 3 Kpc Arm, a ring that surrounds the central bar. The Sun is 8,150 +/- 150 parsecs from the center, and very close to the central plane of the galaxy. Here's a,link to the BeSSel report: Results | The Bar and Spiral Structure Legacy Survey bessel.vlbi-astrometry.org/results This image of the Milky Way is based on 200 trigonometric parallaxes for masers in massive star forming regions from two large radio astronomy projects, the Bar and Spiral Structure Legacy (BeSSeL) Survey and the Japanese VLBI Exploration of Radio Astrometry (VERA) to survey the Milky Way from the inside out. It has a gorgeous illo of the Milky Way based on the results, but it exceeds the size limit for the forum software. Dean Shomshak Quote Link to comment Share on other sites More sharing options...
tkdguy Posted September 6, 2021 Author Report Share Posted September 6, 2021 SpaceX to launch all-civilian crew to space Of course, it also has to start a Netflix documentary about the mission. 😐 Quote Link to comment Share on other sites More sharing options...
Lord Liaden Posted September 8, 2021 Report Share Posted September 8, 2021 Perseverance rover collects very first sample of Mars rock for return to Earth Spence, tkdguy and DShomshak 3 Quote Link to comment Share on other sites More sharing options...
DShomshak Posted September 8, 2021 Report Share Posted September 8, 2021 Heard on All Things Considered the other day that the little helicopter has also performed well, scouting the route for Perseverance to take. NASA is already working on another exo-helicopter... to fly on Titan! Low gravity + dense atmosphere means this one can be the size of a small car. But I imagine that building something that can function in such a cold environment will be a challenge. Dean Shomshak Quote Link to comment Share on other sites More sharing options...
tkdguy Posted September 14, 2021 Author Report Share Posted September 14, 2021 Star swallows black hole and is consumed from inside pinecone 1 Quote Link to comment Share on other sites More sharing options...
pinecone Posted September 16, 2021 Report Share Posted September 16, 2021 This is a fun video on some new work on "warp" drives. No math unless you want to follow the links. Quote Link to comment Share on other sites More sharing options...
dmjalund Posted September 16, 2021 Report Share Posted September 16, 2021 3 hours ago, pinecone said: This is a fun video on some new work on "warp" drives. No math unless you want to follow the links. It annoys be that the use an x-wing in the stills. Star Wars uses Hyperdrive rather than Warp drive. Tom Cowan 1 Quote Link to comment Share on other sites More sharing options...
Cancer Posted September 20, 2021 Report Share Posted September 20, 2021 Why is the solar corona so hot? I don't think there's anything really new here, but it's a solid discussion. And, I got acquainted with the author at a scientific meeting back in 1988, where he gave a talk after he slept under a bridge after being too inebriated to find his lodgings. It was a good talk, too. tkdguy, Lawnmower Boy and DShomshak 3 Quote Link to comment Share on other sites More sharing options...
Spence Posted September 21, 2021 Report Share Posted September 21, 2021 On 9/13/2021 at 10:25 PM, tkdguy said: Star swallows black hole and is consumed from inside That is what they want you to believe. It was really an alien mother ship crashing into an different alien civilizations home world. We are next in a few million years when they get around to us. Quote Link to comment Share on other sites More sharing options...
tkdguy Posted September 27, 2021 Author Report Share Posted September 27, 2021 Quote Link to comment Share on other sites More sharing options...
Ragitsu Posted October 15, 2021 Report Share Posted October 15, 2021 tkdguy 1 Quote Link to comment Share on other sites More sharing options...
tkdguy Posted October 26, 2021 Author Report Share Posted October 26, 2021 Space Adventures cancels its planned Crew Dragon flight China may have a hypersonic vehicle Quote Link to comment Share on other sites More sharing options...
DShomshak Posted November 18, 2021 Report Share Posted November 18, 2021 NOVA has been showing another astronomy m ini-series, "Universe Revealed," with episodes about Stars, the Milky Way, Alien Worlds, Black Holes, and (upcoming) the Big Bang. The CGI has been pretty. Milky Way and Alien Worlds had some information that was new to me, such as that the GAIA mission found a population of stars that orbit gthe Milky Way in retrograde, from which astronomers infer a galaxy (dubbed GAIA-Enceladus) that the Milky Way absorbed several billion years ago. But the programs are marred by not enough airtime spent explaining why astronomers believe various results are true, and too much airtime on astronomers waving their arms while saying how amazing something is. Plus the usual banalities about Knowing Where We Came From and Why It Matters. (Note to science program writers: We wouldn't be watching if we didn't already think it was cool and it mattered. So don't waste our time selling the subject.) Some attempts to explain things in "common person" terms, such as comparing black holes to waterfalls, were more bizarre than useful. And some information was, if not false, then sufficiently lacking in context that I consider it misleading. Maybe all the background explanations are given in supplemental material online, making the aired program a sort of extended trailer to entice people to the real content. I didn't look to see, because I would still consider that bad writing. All in all, "Universe Revealed" has been a disappointment. Dean Shomshak Quote Link to comment Share on other sites More sharing options...
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