Nikolai

Well, no, but there's not a frequently-used common noun "mars", either. "Earth" is not only the name of our home planet; it's also a synonym for "soil". So I use "Earth" in most contexts, but "the Earth" when I want to make it clear that I'm talking about the planet and not the dirt.

A very common pattern in three-child households of American sitcoms is to have one smart kid, one stupid kid, and one weird kid. That's an interesting thing to try to fit into our three starting Kerbals.

Thanks, RainDreamer. I'll have to see if I can find a copy for my Nook.

I really enjoy the anime. Where would you recommend that I get the English-language books?

Rocket Girls! It's a silly little high school anime in a lot of ways, but I really enjoy it.

How about some kind of cruise control that attempts to keep the rover within a band around a speed that you set, applying throttle and brakes as necessary?

DOSBox claims to be able to handle it. http://www.dosbox.com/comp_list.php?letter=N

Well, yes, true. But we're talking about someone who "doesn't have the knowledge to judge if the evidence is real or fake... And she doesn't care", according to hugix. Thankfully, you don't need to know details of space exploration to determine whether Apollo actually took humans to the Moon or not. There might be a fair number of specific claims you have to admit ignorance about, but there's still a lot of evidence you can assess.

That's true, but I'm not sure it's an excuse. I know how to create a tourniquet in case of profuse bleeding. I hope I never need to use it, but I still think that knowing stuff leaves me better off than not knowing stuff, because life is inherently unpredictable. To put it more roughly, ditch diggers and hair dressers need to process reality, because they vote, and voting (indirectly) determines policy and response to change.

Oh, yes. But then, I tend to put myself out there in a space educational capacity, so I'm practically begging for the people who think they know better because they know what's really going on to introduce themselves. And the ones who think it's a waste of time and money, and the ones who think we need to fix all of our problems on Earth before we are "worthy enough" to explore space. Most distressingly, though, my wife was an elementary school teacher when Fox aired its Moon landing conspiracy special... and there were serious discussions in the teachers' lounge about how the special made some excellent points, and you can never really know. Headdesk, headdesk, headdesk, headdesk...

I just had a huge amount of fun listening to a radio drama of Space: 1889. For those not familiar, in a nutshell, I was listening to a radio drama (which no one listens to anymore) based on a tabletop RPG which utilizes an alternate model of physics. I was in nerdvana, until I realized how odd this combination was.

Seven words: "Imperial battleship, halt the flow of time!"

Change in angular momentum. If you want to stop a spinning thing, you need to reduce its angular momentum to zero.

My first was a Color Computer 2 with 16K (!) of memory. Nine colors, including black. 256x192 resolution, if you were willing to pare things down to two colors (including black). I also remember an old episode of Doctor Who that focused on the Doctor retrieving a frightfully important paper from a filing cabinet in an interstellar spacecraft. Nowadays, we'd probably send up a five-gallon jug full of microSD cards, which would give us a lot more storage space (even allowing for redundancy to reduce storage errors to some negligible level). (Heck, New Horizons is using solid-state memory -- several gigabytes' worth.)

Absolutely. Derming is somewhat naive, likes to whistle a lot, and doesn't mind spending long periods by himself. That's why he's got a debris-collecting ship and his own little space station (clamped to an asteroid) in Kerbin orbit. Sontrey is maintaining his space station and lab in orbit around Vall less for the science and more in the hope that someone will come along and appreciate his disco lighting scheme. Gildos has made it his personal mission to drive every rover they send him (on Dres) into a particular canyon. He likes to bail at the last minute and watch the explosions they make on the way down before heading back to his lander and waiting for the next one. And so on.

Just to add some fuel to the fire: http://www.news.iastate.edu/news/2015/01/26/kepler444 Five planets, all small and rocky, orbiting an ancient star -- 11.2 billion years old, give or take a billion. While none of them would be comfortable for Life As We Know It, this would seem to indicate that, at least conceptually, Earthlike planets could have formed quite early in the Universe's history (as compared to Earth). As you were, then.

They weren't rotating very fast. And it's extremely rare for something to have zero angular momentum. For whatever little it's worth, I think they met the end of the parachute lanyards at an angle, and the lanyards used their centripetal force to bend their path. In other words, the axis they pulled "down" through would run from the connecting point of the lanyards to where they got tangled in them. The odds that it would be exactly parallel to the rotational axis of the station are slim. The difference between the two vectors has some angular momentum. We simply see that manifested when the centripetal force of the lanyards changes the direction of the individual components. Consider a smaller example -- a tennis ball tied to a larger, long mass through a shoelace. The whole system is in freefall. You gently throw the tennis ball. Unless you manage to match the longitudinal axis of the long mass precisely, there will be some angular momentum in the system, and different parts will twang and rotate. EDIT: Fixed a nonsensical phrase ("For whatever little" to "For whatever little it's worth"), and added an example.

Or -- wildly speculating here -- perhaps there's another reason we don't see time travelers from the future: Our present is too boring. If you had a time machine, would you go see cavemen? Sure, perhaps. Would you go see cavemen at specific points in their history they deemed significant? No, probably not -- firstly, because we've lost all record of the significance of those times (so we'd have to find them through trial and error), and second, because caveman advancement proceeds really slowly, and from an anthropological point of view, there are vast stretches of sameness. So perhaps, once the race is technologically advanced enough or scientifically sophisticated enough to accomplish time travel into the past, we're the cavemen.

Yeah. And you know why? Because an atmosphere that goes through orders of magnitude in density and pressure is also going to have its behavior change by orders of magnitude. Which should have been obvious to me at the outset. Thanks for setting me straight. And apologies, everyone, for being borderline belligerent.

You don't need to integrate to get close to that. It's pretty much a straight line; the Pythagorean theorem is sufficiently "close". Yeah. Once I realized the density was only about 3% of the value I plugged in, I realized the cascading problems it would present.

Dynamic pressure. Q = (rho)(v^2)/2, where rho is the density of the medium and v is velocity. ... And now I'm realizing that I used pressure instead of density. <dope slaps self> Well, that changes everything. My apologies. Yeah, you really shouldn't have. Thanks for checking.

No, I hadn't forgotten that. It's kind of irrelevant even if my BOTE calculation is off by several orders of magnitude; the thickness of the atmosphere won't change appreciably over a few tens of meters. (Unless you can demonstrate that the integration approach yields remarkably different results.) What I think is the limiting factor here is the amount of stress the spacecraft would have to endure if it were to slow down to orbital velocity in the space that Pluto's atmosphere offers. It has to slow from 11 km/s to 0.8 km/s in about 960 km(*), meaning an average acceleration of some 6.5 gees -- which would naturally be much higher near the front end of the deceleration. --- (*) EDIT: Assuming the atmosphere is as deep as Earth's (100 km), that gives us a maximum of about 480 km to aerobrake through. Of course, there's a much easier way to think about this. What happens when things going 11 km/s -- roughly Earth's escape velocity -- hit the upper atmosphere, long before the pressure gets to 0.3 Pascal? That's the pressure at approximately 89 km above sea level, way below where meteors like the Perseids burn up.

And he's saying that it was. Stellar occultations in 2002, observed and analysed by teams led by Bruno Sicardy of the Paris Observatory, James L. Elliot of MIT, and Jay Pasachoff of Williams College yielded an atmsopheric pressure of 0.3 Pascal. That density, combined with the estimated speed of New Horizons with respect to Pluto at closest encounter (roughly 11 km/s), yield a maximum dynamic pressure of approximately 18 megapascals. I'd have to calculate the cross-sectional area of the probe to find the total force precisely, but it's commonly compared to a grand piano, so you can multiply that by two or three to get the total force on a go-for-broke aerobrake. Let's say two for 36 meganewtons of force. Combine that with the probe mass (487 kg at launch) and you have a maximum acceleration of 74,000 m/s. That's enough to bring New Horizons -- or whatever survives of it -- to a dead stop in only about a millimeter. EDIT: I failed to account for the force correctly, since it would decrease as the probe slowed down; an accurate accounting would involve integration to account for this. But this BOTE calculation still seems to support the idea that New Horizons could potentially aerobrake to orbit if they really wanted it to and if the probe could withstand the mechanical stresses. Also, I forgot to divide by the final velocity squared when coming up with that distance.

A man once suffered from having a metal belly-button. No matter what he tried, or what doctor he went to, he couldn't get rid of the metal belly-button. It was driving him a little crazy. After years of ineffective therapies, he finally decided to throw his lot in with a fortune teller on the outskirts of town. "You're in luck," the fortune-teller said. "Metal belly-buttons are my specialty." She went into a back room and came back with a small cookie. "Eat this before going to sleep tonight." It was worth a try. That night, he ate the cookie before going to bed. And when he slept, he had the most amazing dream! There was a stool in the middle of a white room. On the stool was a purple screwdriver, with a card that read, "For use with metal belly-buttons." He worked the metal belly-button with the screwdriver, but before he could tell whether or not it was doing any good, he woke up. A quick glance at his abdomen revealed the happy truth. His metal belly-button was gone! He was so overjoyed and excited that he leaped out of bed... ... and his butt fell off.

If you honestly think they're open to being convinced by some kind of evidence-based argument, perhaps it's better to turn the question on its head. To wit: Are you open-minded enough to know exactly what kind of evidence it would take to convince you? If so, what is that evidence, and why is that level of evidence reasonable? Because the simple fact of the matter is that there is piles of evidence out there. Pictures. Videos. Minerals that would be difficult (if not impossible) to manufacture on Earth. Congratulations from political enemies with the technological wherewithal to verify for themselves whether the missions were real or faked. Meticulous documentation of every technical detail, so that those with the plausibility can be verified by those with the proper knowledge of such things. Public revelation of scientific findings, so that they can be compared with future discoveries and checked for consistency. Countless published memoirs. And so, so much more. This might be a little more difficult for you, since you might find yourself needing to do some homework. But if the goal is education, at least someone stands to benefit from the conversation, even if the conspiracist remains stubborn.