8 ms·
Flying with Machine Guns?
- unchocked 12y agoRelevant video at 0:24 https://www.youtube.com/watch?v=FRp3S8OOeZc https://www.youtube.com/watch?v=FRp3S8OOeZc
- prestonbriggs 12y agoAn alternative video: https://www.youtube.com/watch?v=uKOrpyO0z48 https://www.youtube.com/watch?v=uKOrpyO0z48
- monksy 12y agoI'm going to file this under: I've always wanted to know this, but never knew I did.
- dietrichepp 12y agoThere is a jet aircraft, the A-10, with a gun so powerful that it provides more thrust than the jet engines.
- nether 12y agoAnd the A-10, SR-71 circlejerk begins.
- Gracana 12y ago"The average recoil force of the GAU-8/A is 10,000 pounds-force (45 kN), which is slightly more than the output of one of the A-10's two TF34 engines (9,065 lbf / 40.3 kN each). While this recoil force is significant, in practice a cannon fire burst only slows the aircraft a few miles per hour in level flight" Source: http://en.wikipedia.org/wiki/GAU-8_Avenger http://en.wikipedia.org/wiki/GAU-8_Avenger
- digi_owl 12y agoAnd then thanks to a certain XKCD what if article: https://what-if.xkcd.com/21/ https://what-if.xkcd.com/21/ We learn about a certain russian gun: https://en.wikipedia.org/wiki/Gryazev-Shipunov_GSh-6-30 https://en.wikipedia.org/wiki/Gryazev-Shipunov_GSh-6-30 That can apparently produce 40G of recoil force... Towards the end of it all, it is starting to look like the premise of a certain mobile game: https://play.google.com/store/apps/details?id=com.halfbrick.jetpackjoyride https://play.google.com/store/apps/details?id=com.halfbrick....
- TheLoneWolfling 12y ago> The airframe vibration led to fatigue cracks in fuel tanks, numerous radio and avionics failures, the necessity of using runways with floodlights for night flights (as the landing lights would often be destroyed), tearing or jamming of the forward landing gear doors (leading to at least three crash landings), cracking of the reflector gunsight, an accidental jettisoning of the cockpit canopy and at least one case of the instrument panel falling off in flight.
- abfan1127 12y agoIt also used to produce so much oxygen-free gas that the engines would flame-out. The engines were modified to deal with it. Its in the same wikipedia article.
- Audiophilip 12y agoSome guys used exactly this effect to land the A-10C on an aircraft carrier in a flight simulator: https://www.youtube.com/watch?v=fteYkPabLTA https://www.youtube.com/watch?v=fteYkPabLTA Very entertaining.
- winslow 12y agoXKCD did a whole article along with the math about this topic specifically. Great read. https://what-if.xkcd.com/21/ https://what-if.xkcd.com/21/
- speeder 12y agoIt is written on this article that the article was inspired by the XKCD post.
- winslow 12y agoAhh I didn't catch that at first look. I love when people break down absurd things like this in myth busters style.
- digi_owl 12y agohttps://what-if.xkcd.com/imgs/a/21/jetpack_speeding.png https://what-if.xkcd.com/imgs/a/21/jetpack_speeding.png Best part.
- deleted 12y ago[deleted]
- HCIdivision17 12y agoI've just realized that it's curious how the cop pulled him over. Pretty sure tanks aren't fast enough or durable enough to make pursuit, and unless he stops firing while changing lanes, he likely strafed the cop getting off the road. Frankly, I think the scenario is just too unbelievable. Perhaps a souped-up SWAT van clad with ablative plating and 12 inch thick laminated windshields, but definitely not just some ordinary cruiser.
- acadien 12y agoReminds me of that Neal Stephenson book, Anathema, that had a space ship that was propelled by setting off nuclear bombs just outside its hull.
- necubi 12y agoHe didn't make that up. As crazy as it sounds, NASA considered exactly that idea in the 1950s: http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsion) http://en.wikipedia.org/wiki/Project_Orion_(nuclear_propulsi....
- digi_owl 12y agoWell it was the 50s. Both sides of the cold war tried to come up with various uses of nuclear power. From civilian cars to military strategic bombers. Never mind using nukes to dig harbors... https://en.wikipedia.org/wiki/Project_Chariot https://en.wikipedia.org/wiki/Project_Chariot And would it surprise anyone that a champion of this project was Edward Teller?
- lutorm 12y agoDon't disparage the idea. It's by far the most efficient high-thrust rocket engine we could build with any technology we know exist.
- roywiggins 12y agoMy favorite is Project Pluto: http://en.wikipedia.org/wiki/Project_Pluto http://en.wikipedia.org/wiki/Project_Pluto Which is nuclear ramjet, which has the small side-effect of spewing large amounts of radiation as it flies.
- pavel_lishin 12y agoYou mean, a convenient feature. For everyone who's scrolling through this thinking, "Hey, this is pretty morbid," you ought to read http://www.infinityplus.co.uk/stories/colderwar.htm http://www.infinityplus.co.uk/stories/colderwar.htm which kicks that feeling up to 11.
- joshcrews 12y agoI think someone could have a hit building a flappy-bird clone off this concept.
- noobermin 12y agoI was thinking of a sort of violent version of _Up_, in which Carl launches his house by shooting an assortment of machine guns attached to the bottom his house to propel it upwards instead of using balloons.
- sp332 12y agoIn the game Jetpack Joyride, you start with a "machine gun jetpack". http://jetpackjoyride.wikia.com/wiki/Machine_Gun_Jetpack http://jetpackjoyride.wikia.com/wiki/Machine_Gun_Jetpack
- ajuc 12y agoThere's this old split-screen real-time worms clone called liero, it has rifle weapon that allows this in-game. They play with reload times set to 0, so this is a little extreme, but just to give an idea: https://www.youtube.com/watch?v=C6rfXFyssbE#t=695 https://www.youtube.com/watch?v=C6rfXFyssbE#t=695 This game is great BTW, very playable, strange that nobody did html5 online clone.
- moron4hire 12y agoOoooooh, give me about a week and your wish will be my command.
- darsham 12y agoHe's playing against the ridiculously bad AI in that video. Here's the more impressive "mortars only" style in the LieroX remake: https://www.youtube.com/watch?v=kx3ivYFY4ig#t=67 https://www.youtube.com/watch?v=kx3ivYFY4ig#t=67 I had a couple of years at uni where we played this on LAN in one of the computer labs during every lunch break. We even made some maps!
- lmm 12y agoMaybe not html5, but teeworlds is a free clone with modern graphics and network play.
- bra-ket 12y agothat's the idea behind Project Orion (nuclear propulsion): http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propulsion%29 http://en.wikipedia.org/wiki/Project_Orion_%28nuclear_propul...
- nickpinkston 12y agoGreat reference! A thermonuclear explosion drive - not elegant, but damn would that be a sight to behold! Bonus points for EMPing vast swaths of the launch region.
- arethuza 12y ago"but damn would that be a sight to behold" I imagine it would be quite something to experience as well!
- rtkwe 12y agoFrom inside the ship you wouldn't really know that you were being propelled using nuclear bombs. Between the pusher plate and the ship are extensive shocks that would be designed to smooth out the pulsing power of the bombs into a smooth acceleration. Anything else wouldn't work very well and induce loads of stresses up the ship.
- NoMoreNicksLeft 12y agoNot all nuclear detonations cause EMP. It requires a particular set of circumstances.
- prezjordan 12y agoGreat way to use up all those nukes we have lying around.
- mirkules 12y agoMy first thought was a space propulsion drive based on machine guns, much like ion propulsion. If humanity decided to get rid of all firearms (ha!), we could probably send them to space and drive a few spacecraft cheaply, easily and for a very long time (there are a lot more bullets than nuclear weapons) Thermonuclear propulsion, as cool as it is, would be very powerful but uncontrolled acceleration, whereas a firearms-based drive could be controlled a lot more. It would be fun if someone did a comparison on how long, fast and far nuclear versus bullet drives would get us in space.
- AceJohnny2 12y agoThe article directly refers to Munroe's What-If article, and Munroe is pretty clear that he relies heavily on Wolfram Alpha for his calculations (see end of "Falling With Helium" [1]) So it's rather amusing to me that things are coming full circle, and that Worlfram's guys are now using Munroe's topic to demonstrate SystemModeler, another Wolfram product. [1] https://what-if.xkcd.com/62/ https://what-if.xkcd.com/62/
- mintplant 12y agoThe page you linked says that he normally uses Mathematica, and fell back to Wolfram|Alpha for that piece when it started locking up. While researching this article, I managed to lock up my copy of Mathematica several times on balloon-related differential equations, and subsequently got my IP address banned from Wolfram|Alpha for making too many requests.
- AceJohnny2 12y agoThat was an example. If you have to be pedant, then here are his other references to it: https://www.google.com/search?q=wolfram%20site%3Awhat-if.xkcd.com https://www.google.com/search?q=wolfram%20site%3Awhat-if.xkc... Compare with his (currently) 2 references to Mathematica: https://www.google.com/search?q=mathematica+site%3Awhat-if.xkcd.com https://www.google.com/search?q=mathematica+site%3Awhat-if.x...
- lmartel 12y agoMathematica and Wolfram|Alpha are developed by the same company, if you weren't aware.
- logicallee 12y agoOh, suuuuuure, some kind of magic mathematics company run by a reclusive genius who got a Ph.D. from Cal Tech when he was twenty, and/or college dropout and/or megalomanaic bald silicon valley mogul. answer for those following along: all of the above :)
- soneca 12y ago
- lutorm 12y agoHe seems to make it unnecessarily complicated. Average thrust (momentum flux) is m_bullet x v_muzzle x fire rate, which needs to be higher than m_rocket x g for it to work.
- dietrichepp 12y agoThe point here is to advertise Mathematica, not to solve a problem.
- damoncali 12y agoTrivia: the rifle's momentum comes not only from (M_bullet x V_bullet), but also significantly from (M_gunpowder x V_gunpowder). The burnt gunpowder is often 1/3 to 1/2 the weight of the bullet, and traveling faster than the bullet.
- cmsmith 12y agoThis analysis and the xkcd one linked below both neglect the concept of staging - which could get you higher. As a first order try you could replace the human on the bed of guns with a smaller bed of guns supporting a squirrel - now you're twice as high! Of course at that point there is nothing stopping you from reaching the moon except for your gun budget and how much unobtanium you can get for the bed connecting structure.
- lmm 12y agoCome now, everyone knows you use asparagus staging for this kind of thing. What happens when you start jettisoning empty machine guns as you go?
- maxerickson 12y agoThe ammunition mass is a more effective way of increasing your stored energy than extra rifles, so it is at least addressed implicitly in the section that examines the ammo to carry (1 gun with 2 bullets obviously beats 2 guns with single bullets, I guess more complicated situations would follow). You always want to fly with the minimum number of guns necessary to provide your desired thrust and then as much ammo in addition to that.
- lmm 12y agoYeah, but the optimal amount of thrust need decreases as your mass decreases.
- xasos 12y agoThere is a game that puts this into concept called Jetpack Joyride (made by creators of Fruit Ninja): https://appsto.re/us/TybrB.i https://appsto.re/us/TybrB.i. My physics class actually did a lab report to find the relationship between the # of bullets and distance propelled in the air with the game. While it was nowhere near as accurate as this simulation, it was definitely interesting to see the results.
- bitwize 12y agoAn automatic-fire weapon in Cave Story also allows you to fly by firing it downward (though there is a separate jet pack item available as well).