Wikipedia:Reference desk/Archives/Science/2013 October 8

= October 8 =

Going to Space
A small group of us are getting together to try and launch something into space, by any means necessary. So far, we seem to have settled on the idea of getting a big helium balloon, but as far as I can tell, that'll only get us 20 miles or so up, rather than all the way into actual space. I'm wondering if there's any better alternatives, maybe a stronger balloon, perhaps if it had a lower pressure of gas to survive the inevitable expansion, perhaps if we could launch a rocket from the balloon once we're up in the thin air there, are any of these ideas actually feasible? Has anyone managed such an amateur launch all the way across the boundary of space before, and how did they do it?

213.104.128.16 (talk) 11:24, 8 October 2013 (UTC)


 * Outer space is, by definition, a vacuum. No matter what you fill your balloon with, or what you make it out of, it will never be lighter than nothing, so you can't float into space on a balloon. You can launch rockets from balloons and aircraft, but it's only of marginal benefit. Do you really just want to get to space, or to orbit?  Of those, only orbit is particularly useful, and to do that you need to get orbital speed, which is thousands of mph, something which can only be attained (with current technology) with a substantial rocket. -- Finlay McWalterჷTalk 11:33, 8 October 2013 (UTC)


 * As Randall Munroe puts it: "...getting to space is easy. The problem is staying there." — PhilHibbs | talk 15:10, 11 October 2013 (UTC)


 * Space is, by definition, 62 miles high, where air pressure is low enough to prevent winged aircraft from flying. The aim is to cross that line with some sort of altimeter and return with evidence. Getting into orbit can wait for a later project. 213.104.128.16 (talk) 11:49, 8 October 2013 (UTC)


 * I think that seemingly precise figure of 62 miles deserves clarification, especially since this is the Science Desk. The link is to the Kármán line, which is actually at an altitude of 100 kilometres, and is very much an approximation. For Americans this gets rounded to 62 miles, which sounds precise, but isn't. HiLo48 (talk) 01:05, 9 October 2013 (UTC)


 * See rockoon, which outlines launching rockets from balloons. The benefit is off course that you don't spend fuel getting up the first few thousand meters, saving weight and cost. WegianWarrior (talk) 11:57, 8 October 2013 (UTC)
 * A liftoff from a rockoon sounds like it might be rocky. μηδείς (talk) 01:00, 9 October 2013 (UTC)
 * See the Brooklyn Space Program, which used balloons to send an iPhone into space, recording the entire trip. For inspiration, see this amazing video of the iPhone's journey to space and back down to earth, with pretty awesome footage of both outer space and our planet on the way down. Zunaid 12:48, 8 October 2013 (UTC)


 * I support the concept of a rocket launched from a balloon as the best way to get into space and then come right back down. However, you do need to be careful where you do this, as a plane might crash if it runs into the balloon.  So, you want to do this far from commercial routes, and also ensure that the balloon collapses and falls right down after the rocket is launched, rather than floating around posing a continued hazard to navigation.


 * Also, you might want to use hydrogen rather than helium. It's cheaper and has better lifting power.  It is flammable, but as this is an unmanned craft, the risk is minimal.  StuRat (talk) 13:52, 8 October 2013 (UTC)


 * Risk is minimal once launched. If you use hydrogen you should certainly consider the risks when filling the balloon, as well as storage and transportation. -- Q Chris (talk) 14:55, 8 October 2013 (UTC)


 * It doesn't seem any more risky than flammable fuels, like gasoline, to me. Indeed, leaking hydrogen quickly dissipates in the air, while gasoline forms a flammable puddle that persists for quite some time. StuRat (talk) 16:26, 8 October 2013 (UTC)


 * The current record is 53 km, so just into the mesosphere. Perhaps a two stage balloon would work better. You can put a very small amount of hydrogen gas in a huge balloon so that at sea level it isn't inflated at all. This is then carried folded up on board a helium balloon. The folded balloon is held firmly in its shape to prevent it from expanding as the balloon rises and air pressure drops. Then when some target height is reached (say 30 km), the folded balloon is let to expand. The volume increases by itself because of the low pressure, it's size will be much larger than the balloon that carried it at 30 km. At that height the pressure in the original balloon is no longer equal to the air pressure, but the big balloon won't be completely inflated, the pressure of the hydrogen gas inside will be the same as the atmosheric pressure. This means that the big balloon will be able to rise a lot higher than the original balloon. Count Iblis (talk) 14:33, 8 October 2013 (UTC)
 * What nonsense is this? A balloon, filled with a lighter than air gas, prevented from expanding, is just harder to lift than one that isn't. 1.122.124.206 (talk) 14:48, 8 October 2013 (UTC)
 * In fact slightly harder as you would not get the benefit of the increasing buoyancy of the balloon as it expands. -- Q Chris (talk) 14:56, 8 October 2013 (UTC)
 * And the Kronig-Causius equation (for any gas, the volume occupied is a function only of the number of molecules, the temperature, and the pressure) shows us that a balloon that allows the pressure inside to equall the pressure outside will, if boyant at any given altitude, will be boyant at all altitudes. So no point in having two different balloons.  1.122.124.206 (talk) 15:01, 8 October 2013 (UTC)


 * No, that's not the point here. You have to release the constraints in the stratosphere, it can't be used at low altitudes, because the aerodynamic forces due to the varying wind speeds over its length will be very large. Count Iblis (talk) 15:11, 8 October 2013 (UTC)
 * If you carry an uninflated balloon on another balloon, because you have not achieved maximum possible boyancy, the whole assembly has be larger and/or ascend slower, so wind issues are worse, not better. And horizontal drift due to wind is not relevant to wanting to achieve a maximum altitude anyway. 1.122.124.206 (talk) 16:17, 8 October 2013 (UTC)

The problem is to reach very high altitudes where you need extremely large balloons to be able to lift a light object. Then it looks like you could just lift off with such a balloon from ground level. When the balloon hasn't fully inflated, the buoyancy force will approximately stay the same. But this won't work, because at ground level you'll have that enormous balloon that will be compressed into a sheet with an enormous surface area. While the buoyancy force acting on this is indeed able to lift an i-phone of, say, a few hundred grams, that thing likely won't go far. It will be blown by the wind into some nearby obstacle. It cannot lift very fast because the huge surface area will lead to large frictional forces at even low velocities. Also, if there is some downdraft, it won't lift at all.

The buoyancy force, after all, is the integral of the pressure over the surface area, which is equal to the weight of the displaced air, but with that huge surface area, the aerodynamic forces completely swamp this out. So, in practice, you need a better ratio between the volume and the surface area, which means that the thing should actually be inflated more. Obviously you can't start with such a better inflated balloon at gound level as then you won't reach the desired height. So, the best solution is to lift of with a smaller balloon that will carry a larger weight to an altitude of, say, 30 km, where the bigger balloon will both be inflated and where the winds don't pose a problem like they do in the troposphere. That bigger balloon will only lift the i-phone, the buoyancy force acting on it will be much smaller than that on the smaller balloon. Then it will lift from 30 km altitude without problems, compared to ground level the air is much less dense, which means that the aerodyamic forces acting on its huge surface area are less of a problem. Count Iblis (talk) 17:10, 8 October 2013 (UTC)


 * Balloons won't work. your only option is a sounding rocket.217.158.236.14 (talk) 15:13, 8 October 2013 (UTC)


 * Balloons ALONE won't work. StuRat (talk) 16:24, 8 October 2013 (UTC)


 * This could be a really exciting project. I think that key to making it more exciting, and more feasible, would be to do some careful research into what little is known about the mesosphere.  There are so-called atmospheric tides and other density variations that could give you a substantial boost in pressure, improving your odds with any space shot depending on balloons or aircraft to get much of the height.  I know nothing much about them, but if you can find a way via NASA to get real-time data about these, you'll have a leg up.


 * Personally, I think it would be especially interesting if you could include a camera module (people have used cell phones, even for modules launched from genuine NASA missions), and try to coordinate your launch in advance of a line of thunderstorms. The area you want to go is prime territory for Sprite (lightning) effects, and the potential, however uncertain, for getting a fairly close up view of the effect would be something that could really drum up interest in your mission and make it more than "just some more kids shooting off rockets", which could also be of help when it comes time to try to get the FAA to authorize your shot, etc.  (I don't recommend shooting missiles without doing so, as they tend to be remarkably paranoid about such things)  Of course, trying to shoot in advance of a thunderstorm also means trying to deal with or avoid very problematic weather conditions.  And I really don't have any idea whether their effect on the upper atmosphere would help or hinder you; my assumption is that updrafts ought to improve the density at a high level, but...


 * You already propose having one sensor (an altimeter), presumably run off the cell phone; you'll also want to look into what other sorts of sensors would be useful to explore atmospheric phenomena. If you get anywhere near really trying this, you ought to write some mesosphere/sprite researchers, send them an attachment with your plans, try to get professional feedback and collaboration.


 * I should also point out that even much less ambitious ideas have gotten huge publicity: see http://www.wired.com/gadgetlab/2009/09/the-150-space-camera-mit-students-beat-nasa-on-beer-money-budget/ . I'm sure I actually saw footage from this in a TV ad at some point, which presumably means somebody made some serious money out of it.
 * Come to think of it, you might even manage to get some commercial sponsorship before the launch, if you can come up with a good enough plan. The manufacturer of the cell phone is one possibility... also, it dawns on me that you need to get the absolute thinnest possible weather balloon that is sturdy and reliable - maybe you should talk to a condom manufacturer and see if they'll fabricate you a prototype in exchange for having their logo on it. :)


 * Also... please, set up an account here so people can correspond with you! If you're going for this project, set up a page with your plans as you develop them (maybe Wikiversity is the best WMF project for it, but advertise it here), get more input and involvement. Wnt (talk) 17:03, 8 October 2013 (UTC)


 * LOL @ condom idea. However, they might find off-the-shelf weather balloons to be far cheaper.  Here's info on a 17-mile high launch using weather balloons: .  You could use that as a starting point, then make it a cluster of weather balloons supporting a launch fixture for your rocket.  BTW, you will likely need a multi-stage rocket to go as far up as you have in mind, even starting from 20 miles up.  Also, assuming the rocket launches sideways to avoid hitting the balloons, you will need a guidance system that can turn it upwards once it clears the balloons.  As for the camera, you might want to only put that on the balloon, as it's far simpler to have a camera functioning there than on the rocket.  Of course, this means you wouldn't get pictures from the highest point.  This video shows the type of rocket I have in mind:, and they did manage to attach cameras to theirs.  StuRat (talk) 17:43, 8 October 2013 (UTC)


 * Heh, I'm back looking at this again. It has a fascination about it...  To begin with, the best balloon altitude so far is still only 53 km, though the manufacturers aspire to 60 km  (based on, which I'll admit doesn't actually have anything to do with condom manufacture that I can see) -- which, unfortunately, suggests that one heavy-assed rocket is going to be needed, which means a really gigantic balloon, and the amount of helium involved, with the prices going up and up -- yipes!  Nor is the notion of playing with huge amounts of hydrogen with such a rocket appealing either.  But Orbital airship indicates that some people are dreaming of getting to the mesosphere this way, presumably by factoring in some kind of propulsion... Wnt (talk) 18:07, 8 October 2013 (UTC)


 * Notice that the Rockoon article doesn't have much to it - I think the mass problem you mentioned explains a lot. Making the rocket bigger to get through 20 extra miles of air is probably a lot cheaper and simpler than engineering a reliable design for a combination rocket/balloon platform. However, I know balloons are a common hobbyist method of getting things "near" space and getting some rather incredible photos from cell phone cameras. I don't know if there are more restrictions (or what the cost is) for launching sounding rockets outside of a research institution. Maybe we could find some resources on what options there are for a hobbyist sounding rocket launch. K ati e R  (talk) 18:16, 8 October 2013 (UTC)


 * One option is to lower your aspirations - even getting to/near 50 km, if you can score an elite balloon, might give good sprite viewing. Competing to make an orbital airship seven times the size of the Hindenberg is not an option.  And then... there are the weird ideas.  After racking my brain for an hour, the best I can come up with is, "what if you could make some kind of device that can ionize air (at 40 km or so) or capture the right kind of ions (from the lower edge of the ionosphere) and use electrical charge to propel them off at high velocity, thereby creating a rocket thrust from stored or captured energy without needing to carry the propellant with you".  With the desired add-on that you use some kind of infrared laser beam locked onto the cell phone's GPS and altitude telemetry to provide the power, because  batteries are heavy.  So far the only thing I found on Google was a description of something like this means of "electromagnetic propulsion", apparently designed for lower altitudes, in a kid's AP Physics paper  but the diagram looks remarkably good to be his own, I think.  We need a real rocket scientist, dammit! Wnt (talk) 18:47, 8 October 2013 (UTC)


 * Wouldn't that be an ion engine ? A laser from the ground wouldn't work, as it would dissipate in the atmosphere.  A nuclear power source might provide the needed energy, so long as you skip the pesky safety shielding.  :-) StuRat (talk) 23:23, 9 October 2013 (UTC)


 * There has been one suborbital hobbyist launch already - see Civilian Space eXploration Team. Rmhermen (talk) 19:13, 8 October 2013 (UTC)


 * | The Straight Dope explains how to make your own spaceships, including Civilian Space eXploration Team's project above. Such a project could cost Between $500 to $2.5 billion, depending on your pocket. OsmanRF34 (talk) 21:46, 8 October 2013 (UTC)

1999 gmc yukon slt
specs on 1999 gmc yukon slt — Preceding unsigned comment added by 184.34.89.19 (talk) 18:45, 8 October 2013 (UTC)


 * You mean besides what you can find with just a cursory search on Google? Sebastian Garth (talk) 21:27, 8 October 2013 (UTC)

I have a chemistry question: If you mix hydroxycitric acid and Atropa_belladonna together in a bowl what will happen?
I have a chemistry question: If you mix hydroxycitric acid and Atropa_belladonna together in a bowl what will happen? Venustar84 (talk) 22:05, 8 October 2013 (UTC)


 * You will have a wet, sour plant. Please sign your posts, and refrain from nonsense, as you have repeatedly promised to do so. μηδείς (talk) 21:51, 8 October 2013 (UTC)
 * Mixing that acid with atropine, which is derived from the Atropa plant, might have some chemically interesting results. It would need to be in pure form and roughly proportional. I would think that a small quantity of Atropa wouldn't have enough juice to do anything. ←Baseball Bugs What's up, Doc? carrots→ 00:30, 9 October 2013 (UTC)


 * Forgot to sign and log in. Sorry about that. I fixed it. Venustar84 (talk) 22:06, 8 October 2013 (UTC)


 * And you forgot to indent. Don't forget to indent. OsmanRF34 (talk) 22:20, 8 October 2013 (UTC)


 * Is that better? Venustar84 (talk) 22:22, 8 October 2013 (UTC)


 * Yes. OsmanRF34 (talk) 22:23, 8 October 2013 (UTC)


 * We should treat this as an honest question. Hydroxycitric acid does have a whole lot of oxygens in positions that allow for the possibility of interesting reactions.  I'm seeing commentary online about various "reactions" it undergoes with other substances such as DMSO and various herbs - one source is ; I haven't really made a serious search though.  The OP may be under the impression he is taking Atropa belladonna if it is being marketed as a homeopathy formulation, even though such formulations often contain no actual atoms of the herb (and I'd bet money they're dispensed using a water tap and a label printer!) Wnt (talk) 02:49, 9 October 2013 (UTC)


 * And a good thing too, because the actual herb is dangerously toxic! Anyway, when you react hydroxycitric acid with atropine, you could get a whole bunch of competing reactions -- acid-catalyzed hydrolysis, Fisher esterification, even polycondensation (not to mention more mundane reactions such as acid-base reactions).  It all depends on the relative concentrations of the reagents and on the reaction conditions (and perhaps on the phase of the moon as well). 24.23.196.85 (talk) 03:01, 9 October 2013 (UTC)


 * I just heard about the mixing of these ingredients from an old Halloween episode in the 90's: http://myrottingbrain.wordpress.com/2013/09/30/halloween-review-the-tale-of-the-sorcerers-apprentice/

The teenage boy in the story was mixing these elements and I was merely curious. Have people ever mixed those ingredients before?Venustar84 (talk) 06:09, 9 October 2013 (UTC)


 * IF it's from a work of fiction, especially a TV show episode, then it's meaningless. The script writers took some random scientificky sounding words and put it in the script.  It has no basis in fact, and it's quite amazing they actually went through the trouble to pick words that describe real things as opposed to completely made up words, but that's of little consequence.  As others have indicated above, there's no valid reason to mix that plant with that particular chemical, and nothing of consequence comes of such a mixing.  -- Jayron  32  01:54, 11 October 2013 (UTC)

The question, to my mind, is if you had half a bowl of the acid, what volume of the plants would be needed to extract roughly half a bowl of atropine? The articles don't seem to speak to that question. If the concentration in a given plant is fairly low, it seems unlikely that you'd get very much of a chemical reaction. As regards the Halloween episode, keep in mind that fiction writers come up with all kinds of bizarre stuff. Such as the notion that placing a fairly small cake of dry ice in a sealed bedroom would cause the sleeper to suffocate. ←Baseball Bugs What's up, Doc? carrots→ 14:18, 9 October 2013 (UTC)

Good alcohol, bad alcohol
Is there a difference in the alcohol of cheap beverages and expensive beverages? I know that fermenting and distilling alcohol are two different processes, but what else can be different? Is the link cheap wine/headache just fiction? OsmanRF34 (talk) 22:28, 8 October 2013 (UTC)
 * You might be interested in the article on fusel oil (though that's primarily about distilled spirits, not wine). --Trovatore (talk) 23:51, 8 October 2013 (UTC)
 * Also congener (alcohol). --Trovatore (talk) 23:54, 8 October 2013 (UTC)


 * Ethanol is ethanol is ethanol is ethanol. Unless you're going so cheap that you've got methanol contaminating your drink, the nature of the alcohol doesn't differ between beverages.  As others have noted, it's the other stuff in your drink that causes issues. --Carnildo (talk) 00:19, 9 October 2013 (UTC)
 * Penny -- Whad'll ya have?
 * Sheldon -- Alcohol
 * Penny -- Could ya be more ... specific?
 * Sheldon -- Ethyl alcohol.
 * --Trovatore (talk) 00:42, 9 October 2013 (UTC)


 * Note that it's not the type of alcohol which differs from cheap wines to expensive wines, it's everything else. Specifically, the presence of sulfites can cause headaches, and they are often added at an inappropriate level to give cheap wines a longer shelf life. StuRat (talk) 17:37, 9 October 2013 (UTC)
 * Actually, the 'sulfites in wine cause headaches' story is mostly urban legend. It is more likely that other naturally-occuring components of wine – particularly the tannins and histamines in reds – cause most wine-associated headaches.  From here, for instance:
 * The "typical allergic reaction to sulfites," says Dr. Mary C. Tobin, director of the Division of Allergy and Immunology at Rush University Medical Center, "is hives, itching, flushing, swelling, nausea, diarrhea and low blood pressure." All bad, but no headache.
 * People who think they are reacting to sulfites with a headache are probably reacting to something else in the wine&mdash;or suffering from an unfortunate nocebo effect. TenOfAllTrades(talk) 19:30, 9 October 2013 (UTC)
 * Some of that "everything else" (especially the sweet stuff) can cause bonus gutrot and nausea, which can lead to indigestion headaches. All alcohol generally dilates blood vessels, so that factors in. But the price of all kinds of booze is mostly dependant on image. Crown Royale sounds so much snazzier than hooch, and a French bottle of wine from 1761 has a certain je ne sais quoi that an American box from Tuesday doesn't. InedibleHulk (talk) 19:13, 9 October 2013 (UTC)

Suppose the entire observed and extropalated universe
that we're fairly sure of, some 40 billion light years across, were just a tiny mote near the event horizon of a black hole with schwarzchild radius of about 10^(zillion^zillion) light years. If we observed that the expansion of the observed universe was speeding up(as we actually did observe in the 1990s), could the fact of being near this very large black hole explain the speedup? Like from tidal forces or from time dilation, say. Thanks, Rich Peterson199.33.32.40 (talk) 23:37, 8 October 2013 (UTC)
 * And just where do you s'pose we'd get enough matter for such a huge black hole, eh? 24.23.196.85 (talk) 02:54, 9 October 2013 (UTC)
 * by resorting to deficit spending, heh.76.218.104.120 (talk) 08:03, 9 October 2013 (UTC)
 * i apologize for my thoughtless silliness above. My original question was meant seriously.76.218.104.120 (talk) 08:48, 9 October 2013 (UTC)


 * There are ideas about the universe where it is all a "black hole" in the sense of being closed rather than open, but for the observable universe to be a mote falling into one just out of our field of view should imply some anisotropy in observations. We should see some differences when looking toward or away from the center, I think.  (I'm not sure how that scales as you start thinking about an infinitely large hole infinitely far away, and a more knowledgeable answer is still needed here) Wnt (talk) 15:34, 9 October 2013 (UTC)


 * The acceleration is consistent with mass/energy that fills the visible universe uniformly (the dark energy). As far as I know, it's not consistent with the long-distance gravitational field of any distant object. Among other things, any such field would cause tidal distortion (often called "spaghettification" when talking about black holes) which would be visible as anisotropy in the sky, as Wnt said. -- BenRG (talk) 20:12, 9 October 2013 (UTC)


 * Here are a whole bunch of recent articles on 4D black hole speculation. Probably all trace to one paper. μηδείς (talk) 21:43, 9 October 2013 (UTC)


 * How do you know it isn't already? ←Baseball Bugs What's up, Doc? carrots→ 00:27, 10 October 2013 (UTC)