Codraroll

Aha, that complicates matters. Still, it can easily be un-complicated. Just remove that preference from the mission parameters for Luna-27. Make it an optional goal instead.

I would think they have planned the program in advance, and that each mission is not dependent on the success of the previous one. Even before they launched Luna-25, they must have known there was a certain chance it would not succeed, and take that into account when planning the way forward. If Luna-26 has any concrete plans at all, there's probably a whole chapter about what happens if Luna-25 does not deliver as intended.

Oh, confirmation: https://www.reuters.com/business/aerospace-defense/russias-moon-mission-falters-after-problem-entering-pre-landing-orbit-2023-08-20/

It would be a tremendous PR hit if the mission were to fail, at a time where the Russian government really doesn't need more PR hits. So that might compel them to do the quality assurance process properly to maximize the odds of success. Then again, it could also be that the desperation for a PR win compels them to launch it now, odds of success be damned. Bad news can always be buried.

Not sure, but I think spacescifi has made a thread or two about it.

I suspect that when we finally find the aliens, by tapping into the network of communication they use instead of moving about in physical space like common cavemen, we'll be like a kid who logs into a chat room for the first time. "Hi, we're the humans of Earth ..." "Dude, there's some new kids in the Main channel. Mods, can you direct them to the Introductions section?" "This is the president of the UN speaking on behalf of humanity ..." "Whatever. Can you please stop interrupting our discussion on the latest trade policies of the Federation?" "We live on a small, blue planet in the outer spiral arm of ..." MOD EDIT: Personal home address removed. Five minutes later, another civilization makes the same breakthrough and is likewise ignored.

Fair point. The rest of the world aren't going to restrict their station's orbit to the rather limited set of parameters that can be reached by that 1960's piece of junk either.

Sounds to me like an admission that external funding would be required for this prestige project to get off the ground. The problem is that most of the G20 countries would rather throw their money in with the ISS than with Russia. Or in the case of China, do their own thing instead.

I wouldn't say the paper has any major flaws, but I would be very careful with when to consider its conclusions applicable. As far as I can tell, it exclusively cites biomedical research for examples, where most studies follow a rather set and rigid pattern of the type "Does A correlate with B? Given the number of interactions between A and B, a correlation would be C percent likely to be observed. We did D and E to A and B, and observed a correlation that is F percent likely to be a coincidental product of random chance, with a margin of error of G ...". Then it sets up a mathematical model (which has been critizized for exaggerating the reduction of the "credibility" of the research results) to show that the study result is H percent likely to be wrong if C, E, and F are so-and-so large, and due to the methodology H is almost always a pretty big number. It also leaps to some strange conclusions elaborated in the criticism paper. It doesn't say outright that "most science is wrong". Nor does it give any basis for overthrowing conclusions in any scientific fields. There is also a rather large leap from "statistically speaking, most science results are likely to be wrong" to "any study presented is likely to be wrong", and yet a larger one to sweeping conclusions about the state of science in general.

Disputing the procedure. A competent researcher would not draw numbers directly from Wikipedia, and a competent journal would never let that slip past peer review. It follows that neither the researcher nor the journal have their procedures in order, which might indicate that the rest of their work is similarly flawed. The link @JoeSchmuckatelliposted also highlights other major flaws with the paper that the authors did not address despite being specifically asked for it. The fact the paper has not been withdrawn on the basis on these flaws does not reflect favourably upon the journal. [snip]

[snip] You don't cite a research paper on stuff like this, but you find something way more reliable and permanent than Wikipedia.

No, not really this time either. Unfortunately, Bloomberg has put their excellent "What's warming the world" graphic behind a paywall, but NASA has a (slightly less elegant) page with the same data. It shows that none of the other factors we can think of that would explain the warming, have evolved to the degree that would result in the warming being observed. And if the cause is actually something we haven't yet found or imagined, we'll really have to wonder why we haven't yet seen it despite it being powerful enough to accelerate the warming of the world to such an unprecedented degree, and also why all the anthropogenic carbon emissions haven't resulted in the warming we'd expect from it. After all, the thermal properties of CO2 have been known for more than a century (Arrhenius predicted that the world's rising coal consumption would eventually cause global warming as early as 1896), and loads of very sensitive industrial processes are based on a very precise understanding of those properties, so we can't have gotten them fundamentally wrong because the processes really do work. Everything we know about the stuff tells us that if we put a certain number of gigatons of it into the atmosphere, there would be heating, and now we have the gigatons and observe the expected heating. The probability that we've got CO2 this wrong, that the world has warmed for some other reason at the same time, and also that we've failed to identify the actual cause of the warming, is extremely unlikely. At some point, an honest skeptic would have to realize he's grasping at incredibly thin straws in his quest not to believe the data laid before him. I'm pretty sure I've seen a version of that Bloomberg/NASA graphic with error bars somewhere, showing that even the 99.99% confidence intervals for the "natural" and "anthropogenic" figures have no overlap, but despite a lot of googling I can't find it. Anybody else? EDIT: I duh'ed, it's Figure 1 in the AR6 Summary for Policymakers: With the figure text: With "very likely", they mean "probabilities in a range of 90-100%", so I presume the error bars represent the 95% confidence interval.

The urban heat island effect is well known, and compensating for it when doing measurements has been standard practice for ages. There's a nice article about it here: https://skepticalscience.com/BEST-October-2011.html Also, quoting a relevant figure, where they looked at very rural temperature measurements compared to all temperature measurements: To the degree that you are insinuating, it absolutely would. Evidence of global warming is visible everywhere you look, too much for all of it to be faked. To give an example, I'm a building scientist myself. Some colleagues and I recently did some work on the melting of snow on rooftops in Norway, to assess the risk of icicle formation (icicles falling on you from three stories up is like being whacked in the head with a hammer by a strong guy, and approximately as healthy). We set up a model to calculate the conditions most likely to facilitate ice formation. It requires that there's a few centimeters of snow, so that the insulating effect of the snow combined with the heat transfer through the roof causes the bottom layer to melt, while ambient air temperatures are lower than 0 °C so the snowmelt freezes once it runs off the roof. We pored over weather station data from various locations to see where such conditions occurred the most often. What we found was that the frequency of such conditions had been decreasing all over the country since the early 1990s, since the number of days with snow cover and temperatures below 0 °C had gone down drastically. The number of days without any snow at all had increased everywhere except the very northernmost cities - where it previously had been too cold to snow very much. What used to be once-every-two-years cold spells are now once-a-decade. Reports of icicle damage in building defect cases have also diminished, although that's probably partially due to higher insulation requirements. But we are seeing an uptick in extreme rain events, which is consistent with the predictions of climate science. Neither did "computer technician", but here we are.

Where did you get that idea? Actual evaluations of old models to predict the then-future climate show that most of them align quite well with what was later observed. https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2019GL085378 To quote the most relevant figure: Note also that there is inherent uncertainty at play there. To predict how the climate will develop over the next X years, you have to make assumptions of how greenhouse gas emissions will develop, and that's mostly down to inherently unpredictable politics.

Because the mechanisms that add snow (and by extension, ice) to the interior of the continent are rather different from the mechanisms that keep the glacial shelves in place. The ongoing collapse of the Larsen ice shelf happens due to warming of the sea underneath the shelf, whereas the additions to the Antarctic ice cap occur elsewhere on the continent.

After all, it only snows when the temperature is within a range of a few degrees around 0 °C. Too much warmer than that, it rains instead. Too much colder, and the air doesn't hold enough humidity to form snow. Certain high-altitude regions are expected to see more snow in a warmer climate, because it was usually too cold to snow there before.

I'm not sure if that would even be possible. Any little bullet moving at extremely high speed would make a roughly spherical crater in the big one (which, I believe, has something to do with the spread of the shock wave in the material, which is why impact craters are circular even if meteorites hit at an angle), and if the crater were deep enough to pierce all the way through the big bullet, it would probably just tear the big bullet apart entirely instead of creating a tunnel. Then again, if the big bullet was made of some soft and foamy material, I guess it could be done. Nobody said the big bullet had to be a good bullet.

It's for something she did sixty years ago, but better late than never I guess.

Aha, I was afraid I had made some kind of horribly basic mistake. I read your post along the lines of "You know enough to do the numbers, but then you make this stupid assumption at the end?", and thought I had missed something obvious.

D'oh, bit of a mistake there. To be fair, it was way past midnight. 2584 J/ (128 J/kgK * 0,032 kg) =630 K. Add the 300 K from the ambient air, and we're way above the melting point (600 K), even if some of the hottest flakes shatter away and disappear with a lot of kinetic and thermal energy. Uh, see the bit above with the time of posting. Still, I don't quite see the problem. If we assume a symmetrical collision, what happens to each ball is exactly half of what happens to both. The energy of two identical balls that stop each other in mid-air, divided by two balls, equals the energy of one ball that stops by itself in mid-air. Disregarding spin, fragmentation, and other such effects, of course.

@TheSaint made a great reply already, but let's do the math anyway. So a Minié ball weighs approximately 1.14 ounces, that's 32.3 grams or 0.0323 kg. It flies at approximately 1200 ft/sec or 400 m/s. That gives it a kinetic energy of 2584 Joules. As far as I can tell, those balls were mostly made of iron, which has a specific heat capacity of 0.451 J/(g*K). That's at room temperature, but we assume it stays somewhat constant. At 32.3 grams, the heat capacity of the ball is 14.57 J/K. We can assume all 2584 J of kinetic energy are converted to heat. That ought to be enough to heat the ball by 177 degrees K. Of course, that assumes uniform heating across the entire ball, and the impact happens at such a short time span that that won't happen. If the impact only heats, say, a tenth of the ball, that tenth would briefly be heated by 1770 K. Then its temperature would go from battlefield temperature (~300 K) to the melting point (1811 K) in a flash, still with some left over to account for the bullet slowing down before collision or fragments shooting away with some of the kinetic energy. It's likely that spontaneous welding would happen in such an event. Of course, there's more energy than that involved in the collision between two moving balls, but there's also twice as much mass to heat, so you can just assume symmetry and disregard the other ball entirely.

What a missed opportunity for them to blur out the stats, so that space nerds would have to buy the T-shirts to get the numbers.

Always a joy to see authoritarian dictatorships fail. Let's hope for a peaceful and democratic reunification of Korea soon, so the country can put a unified effort into a space program. South Korea has the tech, while North Korea has ... uhh ... remote facilities from which to launch, I guess.

Weird that he chose to publish it on the internet without any redactions. Isn't he worried about identity theft?

Can you even get an FTS "off the shelf"? Aren't those custom made to the rocket, always?