Explosion noise

Why don't people hear the bomb that blows them up? What would an X-wing pilot actually hear when the photon torpedo goes off? I ran these ideas by a couple of people with degrees in physics, and they said that they seemed reasonable enough, and if that isn't thorough research then I don't know what is. In truth, I suppose that I do know what might be, but am scandalously content to upload this on the flimsy evidence I have. My excuse is that talking about such things is fun, even when they may be wrong. I do not set myself up as an expert on these matters.
www.LloydianAspects.co.uk

[@theCodyReeder]

My guess was that your neurons dont register the noise before you are knocked out but your explanation does make sense.

[@SamZweighaft]

Fancy seeing you here. Love your channel

[@RijuChatterjee]

I think the people in question here are ones who weren't knocked unconscious

[@terorvlad]

+Cody'sLab Codyyyyy !!!!

[@paulmag91]

Maybe when you are so close to the explosion the pressure wave is so strong that you are immediately deafened for a short while.

[@thomasr.jackson2940]

+PaulMag It is both. The blast wave is supersonic, so it arrives before the sound does. That can rupture eardrums or trigger a stapedius reflex making one mechanically deaf (or close to it) either temporarily or permanently. It can also cause neural damage to the labyrinth with more permanent damage. However, memory registration is complicated and it isn't uncommon for blast victims not to recall the moments around the time of a blast even when they do not appear to have lost consciousness. This is sometimes ascribed to a psychological effect of trauma, but I think it is better explained by memory registration error, or simply a loss of consciousness not effecting wakeful decision functions (I favour the latter but can't point to any experimental evidence).

[@rafaelalexie2417]

I find it hard to hear an explosion when I'm near it because my head keeps flying off.

[@eggmeister6641]

somehow there are no comments here, so i thought id fix that

[@rafaelalexie2417]

@@eggmeister6641 Why, thank you !

[@bl4cksp1d3r]

i have the same problem, darn heads aren't fixated properly :/

[@altalector9351]

if mythbusters taught me anything, 99% of all (non cgi) Hollywood explosions are gasoline, all flame no bang.

[@ABaumstumpf]

+alta lector Gasoline sometimes, mostly gasses like propane - and lots of aluminium for the sparks.

[@alexkfridges]

+alta lector i mean, it makes sense, right

[@RealCadde]

Not just flame. It's an air cannon with a fuel charge that is ignited as the cannon fires.

[@JanjayTrollface]

I'd be very hesitant to learn anything from mythbusters.

[@ABaumstumpf]

JanjayTrollface Science -yeah. But about Hollywood special effects? nah - there they know their stuff.

[@lurkingghillie]

I died laughing at the little "PIFF" of the Death Star exploding xD

[@lastmanstanding5423]

it was brilliant, was it not... lool

[@DavidSmith-vr1nb]

I thought it sounded like a very short "pew". Any thoughts?

[@sorsocksfake]

What I was wondering is, where did they find these guys who had stood in the middle of an explosion? Then I realized, they're here...and here...and there....and there...and over there...

[@undyingUmbrage]

+sorsocksfake, i see what you did there. and there. and over here.

[@sorsocksfake]

Vincent Van der velde Krillin! Too soon!

[@TheCompleteMental]

@@sorsocksfake is that his brain?

[@stephencampbell2735]

Ba dum tss

[@SylversVolpe]

Your channel remains one of the few that I've seen on youtube to boast such a large number of intelligent, well spoken commenters. It speaks highly of your viewer base and your content.

[@Boborbot]

It's a niche channel, which has a higher brow entertainment value than others. I would also think that in other channels, perhaps more comedic ones, the crowd might have a similar intelligence, but after watching one or more of comedy videos, they aren't likely to comment something eloquent or profound, or more likely, a dick joke.

[@SylversVolpe]

Boborbot True enough. I'm tempted to prove you right (/wrong?) but then I am just not a dick joke kinda guy.

[@SylversVolpe]

imademynamereallylongandwithoutspacestoannoyyousry​ Is this a question? Statement? Mid life crisis?

[@premiershit9924]

A meme

[@DrJigglebones]

No, simply an idiot.

[@ashwalk85]

sound engineer here. If you're close enough to the blast, what hits your ears is a shockwave. Go a bit further, and that turns into a sound wave. The difference is that a shockwave is a highly non-linear pressure profile, so if you're close enough, what hits your eardrums is something similar to an extremely slow/long soundwave (maybe close to 1hz), but with high energy. But shockwaves would hit the ground and other objects, which would vibrate and you _would_ hear, only fractions of a second later thsn the explosion itself. If those victims don't hear anything is probably because they blacked out or something immediatelly after the explosion. But most probably they just got temporarily deaf, either physiologically or neurologically. Actually I'm amazed that people can survive actual shockwaves. Are you sure this is real?

[@PeterBarnes2]

That's pretty much what he said, but more accurate.

[@waltgrisly509]

And what do you think about the space explosions ? It seems reasonable.

[@driesvanoosten4417]

Physicist here. I think the reason is dispersion and therefore the explanation in the video is more or less correct. The shockwave is an actual step in pressure, which is technically a superposition of all frequencies. But due to the fact that they arrive simultaneously at you eardrum, you don't percieve it as sound. It is simply to short. However, not all frequencies travel at the same speed, which means the step will be smeared out into something that is in fact percieved as a bang. The reflection from the ground and other objects add to this dispersion.

[@matthewdunham5235]

it's also the concussion sound being turned from pressure force (with a range of 6m) then after it passes that it starts to dissipate by turning itself into sound energy

[@Xsidon]

im so glad we have ppl like you guys in this community

[@TheKindGamers]

Star Citizen has actually worked around this quite wonderfully. A ship's computer will actually simulate sounds based on information it receives, like what type of engine something has, when they're firing lasers, and so on. If your ship's computer is damaged enough, that simulation can actually go kaput and you're left with the cold silence of space and the crying of your dying ship.

[@Staysa001]

+The Kind Gamers That's been a thing for some time.

[@SteelWalrus]

+The Kind Gamers Didn't realize they had touched on that. Makes sense, though. Those guys are ridiculously thorough.

[@recursor9469]

+The Kind Gamers I kind of wish that system was disabled by default so I could enjoy a more realistic space environment. By the way, how close is that game to finally being finished?

[@SteelWalrus]

recursor94 Alpha 2.0 is out now. It's a prototype for the PU. Just one system, but it's cool. I'd say around a year, depending on how they manage their time and funds. That being said Sq 42 should be out first quarter of next year if I remember the timeline correctly.

[@emmettochrach-konradi2785]

+The Kind Gamers thats stupid

[@mace8873]

"Filling something with vacuum"... It's like trying to radiate cold, or making shadows by turning on your flashdark...:-D

[@JimFortune]

Maybe all the sounds in the cockpit are part of the VR system giving aural feedback to the pilot...

[@Dudeguyforeverlulz]

+Jim Fortune wouldn't that be an AR system. (Augmented Reality) not a VR system

[@jeremygillespie4203]

+Dudeguyforeverlulz I would argue that augmented reality is a subcategory of virtual reality.

[@rollingthunder1043]

+Jim Fortune But what benefit would that give? Why would a space-fighter pilot benefit from augmented/virtual reality so he can hear explosions that his onboard systems are more than capable of telling him about, which take up A) space in the ship and B) computer processing time that could be put to other uses?

[@JimFortune]

Cassie Moorecock Have you ever met a fighter jock? If the machines don't make the swoosh bang wham sounds, they do it themselves.

[@nunya7502]

+Cassie Moorecock One purpose it might serve, is to alert the pilot of the immediate hazard on a trained level, triggering a trained response. This is actually a technique in cybernetics, and is used by some games, too. However, it's usually an artificial sound chosen for its ingrained response in humans, like a siren is. The point here is to make you flinch in a useful way when you might be ignoring the hazard in your focus on a target. This is a common human failing called target fixation, that's been known to cause pilots to ignore radar targeting warnings (like the guy in Top Gun) and even to fly straight into the ground while strafing or bombing (this is half of why German Stuka dive bombers automatically dropped the bomb and pulled out of a dive at a certain altitude, no matter what the pilot did).

[@lonewanderer1328]

Shock waves kill people, not usually flames themselves.

[@yetanother9127]

Shrapnel and debris tend to kill even more people. Even in a nuclear explosion, you're more likely to be killed by the collapsing building than by the thermal flash.

[@lonewanderer1328]

Jonathan Hughes If someone seems to be unharmed, it was the internal trauma that killed them. The trauma is caused by the shock wave.

[@ScienceDiscoverer]

+Jonathan Hughes mb shock wave wont kill you, but it can destroy your ears drums. And in very close distance it will certainly kill you. Watch mythbusters explosions experiments for this.

[@garethworthy2818]

+Lone Wander This is something that comes up for debate. There is a flaw to both sides of the argument... what is exploding, and how far away is the subject? The shockwave drops rapidly, meanwhile the shrapnel also loses momentum, and spreads our more thus less likely to hit you. But it will be lethal at a longer range. Flames, well, once again depends on what is exploding. A grenade has no flames, however a fuel tank (that is not full, so that it has enough air to burn) will cause a lot of flame, and the flame may well be what kills you.

[@yetanother9127]

***** You'd be surprised at how well the human body regulates pressure. For instance, a tornado might shred a house, but have little or no affect on a human standing nearby. One identifier for a genuine high-explosive detonation is that people who were standing nearby are unharmed (externally, anyway) but have had their clothes shredded on the side facing the blast. In the case of an actual sudden drastic pressure increase, the really fragile bits will go before everything else: eardrums, eyeballs, sinuses, et cetera. Otherwise, though, victims tend to be (relatively) unharmed.

[@scirrhia_kruden]

Star Wars doesn't have any photon torpedoes, Lloyd. It has proton torpedoes. Photon torpedoes are the giant flashbangs from Star Trek.

[@stevendeamon]

Eipok Kruden None of them make any sense (the proton or the photon "torpedoes")

[@scirrhia_kruden]

Steven Deamon True, but the canon explanation for proton torpedoes is slightly less silly than for photon torpedoes. Proton torpedoes are supposed to just be shaped nuclear explosives that somehow use protons in their detonators.

[@ericlanglois9194]

Eipok Kruden while probably not the canon explanation for photon torpedoes, I do know that a photon torpedo uses an matter/anti-matter reaction to cause a massive explosion, so I like to think they are called photon torpedoes because of the bright flash they would give off with the explosion. Quantum torpedoes though, that's the unusual one, never really saw any explanations on how they work but something tells me it has little to do with quantum mechanics...

[@scirrhia_kruden]

Eric Langlois That IS the canon explanation for why they're named that. It's just fucking stupid. It's an obvious retcon, put in place when even the writers realized that "photon bomb" made no fucking sense and they couldn't come up with any actual explanation for the name, but of course they didn't have the balls to retcon it entirely and come up with a new name.

[@ericlanglois9194]

I'm glad they didn't give it a new name... Anti-matter Torpedo would have been too generic in my opinion. One of the charms of sci-fi is you can come up with cool sounding technical names, even if they don't make sense and simply appeal to the "fiction" half of "science fiction" :)

[@isodoublet]

That's just not how it works. The wave equation is a linear differential equation, meaning it satisfies the superposition principle. So we can restrict ourselves to considering a point-like sound source and obtain more general solutions by integrating. What you need then is what is called a Green's function for the wave operator, and that's something you can easily find in a physics textbook. What you find is an oscillatory wave decaying spherically from the source. No matter how close you are to it, it ALWAYS oscillates. It's not going to change frequency just because you're next to it -- the pressure wave IS the sound, and is composed of several frequencies traveling independently, which you then hear. It's way more likely that this phenomenon is a result of shock, adrenalin, or people not remembering the events correctly when writing them down.

[@irontarkus3977]

gogerychwyrndrobwll Thanks Solaire.

[@isodoublet]

Elite Cleric Praise the sun!

[@TheBaconWizard]

Or your brain shuts-off your hearing having been hit by the very first enormously destructive peak of the waveform, which is a longer wavelength than your distance from the source of the sound.

[@nkorslund]

The wave equation doesn't apply close to the explosion as there is too much bulk movement of air. The wave equation is only an approximation for relatively stationary air where the molecules act as harmonic oscilators.

[@isodoublet]

nkorslund It is a better approximation within the ear because it is a narrow tube that's shaped funny. In any case, once the explosive goes off there should be a rapid increase in pressure in the surrounding area, with a subsequent decrease. This acts as the source for the wave equation in more distant air and therefore these nonlinear effects have no bearing on the frequency perceived by an observer.

[@MickeyCuervo36]

Correct or not, I now want to add my own sound effects to the movie just for a giggle. A giant fireball of light aaaand....! *piff*

[@inthefade]

I think the sound of an explosion in space while in a spaceship would be like the sound of hitting a piece of paper with a wooden stick. It would be a fast burst of full spectrum noise, and it would end almost immediately.

[@shurdi3]

Except... the expanding gas would lose its energy much quicker, and over a much smaller diameter, that it you wouldn't be able to hear it after say... a couple of meters away from the explosion. It would just dissipate almost instantly, the pressure would go down incredibly fast. Also, it would be possible that you can hear the explosion that kills you (as in it vibrates you drum), but it's too high of a frequency for you to be able to hear.

[@ivyssauro123]

Or too low.. Or so loud that it you go deaf imediatly

[@BasMeek]

I had the same hypothesis, you would be able to possibly hear the explosion of something in space if you were very very dangerously near it since, as you stated, the expanding gasses will go in every direction so the possibility of hearing it would fizzle out disappointingly quickly

[@ICrashALot]

"This is the way the death start ends: Not with a bang but a whimper."

[@lindybeige]

I agree that if the communications with the craft cannot exceed light speed, then controlling them from planets far away will not work, but if the Death Star (or The Gallactica) is right next to the battle, then this is not a limitation.

[@DanijelTurina973]

I always thought the tie-fighter sound can be explained by the same principle that creates noise in speakers when you have a cell phone on the desk making a high-power contact with the base station; the electromagnetic wave or a magnetic field created by the tie-fighter induces electricity into the speakers in the cabin.

[@krixpop]

Danijel Turina could also be just that the pilot's cabin is not entirely soundproof , and he hears the engine ,.. same for ship's blasters ... and since the audio ambient of the movie is the cabin , the spectator hears a / multiple voice/s , the engines and the guns.

[@PwnEveryBody]

+krix pop The whole deal with not being able to hear anything in space is that there is nothing for sound to propagate in. There is nothing for sound waves to travel in in space, so if a source of sound is separated from you by space you will not hear it. Whenever TIE fighters (and indeed X-wings, Y-wings, shuttles, or whatever the fuck else) are in atmosphere they make quite a lot of noise, and rightly so. The issue was never what exactly makes the sound, but rather that sound literally cannot propagate in space. I know you posted this comment almost a year ago, but I just had to comment.

[@krixpop]

Magnus Anthun haha no problem , I agree with you entirely... I just pointed out that sound does propagate inside the cabin. Thus the pilot could, to and extent, hear the noise of his guns / blasters firing ...

[@PwnEveryBody]

krix pop Oh, they'd hear their own blasters alright. But not anyone else's, unless they were talking to someone over some sort of intercom or whatever. I thought you were talking about ships that weren't connected on some sort of intercom, as that is (I assume) what Lloyd is talking about.

[@franohmsford7548]

Star Trek has Photon Torpedos. Star Wars has Proton Torpedos.

[@Rob-bn9ib]

I wouldn't worry about it. He's clearly a nerd in a different direction.

[@AliothAncalagon]

Your point about explosions in space is not bad, but you shouldn't forget that space is very very empty. You need to be extremely close to the explosion and/or the explosion has to bring an incredible amount of gas out to have an actual effect. So far away as the X-Wing pilots e.g. were there wouldn't be any gas left that could hit them.

[@alexv.d.h.7331]

Elviondel its funny because the comment above this one is from codyslab. and i can see the verified check

[@noneck8166]

Space isn't empty.

[@AliothAncalagon]

No Neck Empty enough.

[@noneck8166]

Alioth Ancalagon Define empty...define nothing....do you see an empty glass and say nothing is in there?

[@AliothAncalagon]

No Neck When I am looking for something to eat, yes. When you want to hear something space is empty.

[@joeanspach539]

"and you find yourself laying over there... and feeling a bit startled." yea. just a wee bit.

[@SarahExpereinceRequiem]

"Why can't a robot fly a space ship?" Well, space is big. Really, really big meaning engagements could well be over a very large area. You'd either need a massively advanced robot (which some settings don't have) or it would need to be remote controlled. Let's say you remote control from a base or mothership once the fighter gets ~300000 KM away (slightly less than the distance to the moon) from the controller you'd have two seconds of input lag as well as the pilots reflexes to deal with making dodging sort of pointless. And that's assuming they don't find a way to interrupt the signal somehow.

[@EmergencyChannel]

Using Star Wars as a reference, they had ships that were autonomous in the prequel trilogy and autonomous war fighting robots as well. Why the resistance doesn't have autonomous aircraft probably has more to do with lack of resources. The Empire didn't use robots because they had a large supply of clones left over from the clone war so why bother?

[@bestliutr]

+360deeman And the robots they had ("roger roger") were both expensive and non-effective in combat as demonstrated in the clone wars.

[@mrwindupbird101]

+360deeman Just to point a few things out, most of the clones were actually...disposed of. Only the 501st (Vader's personal contingent) remained and most of them were killed on the first Death Star. The rather crappy reason they give why they don't use robots is because they don't trust them because they can be hacked. It isn't because they can't just simply because they don't want to.

[@EmergencyChannel]

The new Star Wars film references the "new empire" wanting to make more clones but they implemented a system of raising kids from birth as soldiers instead. Which seems silly, clones follow orders perfectly well, and even better when they have a functioning biochip as order 66 demonstrated. Obviously the new empire is not using chips in their soldiers, because the main protagonist defects quite easily, unless his chip malfunctioned and it's yet to be shown? Anyway, the point still stands that robot soldiers, at least in the Star Wars universe are a dumb idea.

[@JackPhoenixCz]

It's because unmanned drones (both AI based and remote controlled) make for terrible main characters. When was the last time you've heard about Predator drone fighting the bad guys with plasma swords and crying at the discovery that bad guy is its father??

[@warrensmith2902]

"What do you hear Starbuck? Nothing but the rain. Grab the cat and come home" - Battlestar Galactic

[@mobrage]

I would imagine that any explosion close enough to push an eardrum to the point of maximal distension would also rupture it, therefore disrupting one's hearing. In space, though, I doubt that effective explosive weapons would put much of their energy into expanding gasses. Rather; I'd expect a survivable explosion in space to be perceived as the sound of the target vessel's hull being impacted by shrapnel. Which would only happen in a pressurized spaceship. Considering the dangers of sudden decompression, starfighters (if such a concept was viable) would probably be ambient, in this case, zero pressure, with the pilot in his pressure suit only feeling "bumps" from the pilot seat, instead of actual sound.

[@adrixshadow]

Actually on high pressure it might actually seal the canal.

[@pjnlsn]

Kevin J. Dildonik Specifically as far as missiles not hitting anything, that would seem to be an idea by a person who had no knowledge of guided missiles. Presumably spaceships would get quite hot in full flight and so a simple heat guided missile (being manufactured by dozens of countries right now) would hit them dead on.

[@simping4jesus]

pjnlsn It's definitely possible to use guided weapons in space (and would probably be the most reliable way of actually hitting something, due to the distance involved). They would have to change how the guidance works, though, to account for the vacuum and the orbit of the target. I've read some ideas about making guided missiles without any explosives, and instead just make the warhead really heavy. Since there's no air in space, there's nothing to ignite an explosion, which means the warheads have to either have a store of oxygen (could work) or be nuclear (expensive), and either way, they won't hit with nearly as much kinetic energy (since there's no air to carry a shockwave or expand from the heat), and instead will be mostly thermal and radiation. The lack of air also means the kinetic missiles can reach absolutely ridiculous speeds, which means plenty of kinetic energy to tear through a ship.

[@wikieditspam]

I thought that the saying was that you don't hear the artillery that kill you, and that the assumption there was that the projectile would be supersonic by the time it hits you. I was pretty sure that this was something to either something to make soldiers paranoid, or to make them think that they'd be alright if they heard the doppler effect of shells either approaching or passing them.

[@blackdeath4eternity]

pjnlsn missiles would have to be manoeuvred via thrusters & fins would be obsolete but i would assume they could be made... although all turns would use the missiles fuel quickly.

[@havareriksen3395]

I think Lloyd is on the right track here. Another point is that if you fire a gun with a suppressor mounted, if the projectile is going at super sonic speeds, then you will get a loud crack that is the sonic boom generated by the projectile. However, if you fire a supersonic projectile into a target just a couple of meters away, there will be no sonic boom. This is because the boom is generated by a wave, and the wave is generated by pushing air out of the projectile's way. This will be the same effect Lloyd is describing here. And as for sounds in space. I have been thinking much the same as Lloyd here, too. Energy can not disappear. It can only transform into other states. So the energy released in an explosion can not disappear. Spacecraft close to an explosion will be exposed to the energy released, Some will be electromagnetic radiation, such as as light or heat. So the spacecrafts will be pummeled by radiation, expanding gas and possibly some shrapnel or debrie. All of this can transform into some sort of sound in the air filled cockpits.

[@AAmirkhanov]

I'm probably late to the party, but having fired a lot of guns and set off some explosives(frag grenades, claymore mine) in my time I think it's not difficult to understand what is happening. If you fire just a simple handgun without ear protection, what will suddenly happen is you will find your ears are ringing, almost simultaneously as you hear the crack of the round. Obviously if a 9mm or .38 cartridge is enough to induce this effect, the explosion of a mortar bomb or artillery round is definitely going to deafen you before you even know what happened.

[@MWSin1]

I think, when the blast is close enough to actually cause you serious harm, the overpressure is so great and moving so fast that it deafens you (temporarily or permanently) quicker than your ear can actually resolve a sound.

[@Liggliluff]

(2:50) I don't think people disagree on that you could hear the explosions _on_ your ship. But what people disagree with are the explosions that are _away_ from your ship. You shouldn't be able to hear the second ship over exploding, but you could still hear particles hitting your ship afterwards.

[@JayneCobb88]

Soldiers not hearing explosions is not a physical thing... not a purely physical thing. It's more like a tremendous flashbang grenade, if the explosion doesn't kill then the violence of it exceeds human tolerances and our senses are momentarily shut down and our nervous system is scrambled.

[@JayneCobb88]

it's also why soldiers don't feel the initial pain

[@JayneCobb88]

Athaeus if you're mentally prepared, you can "eat" a flashbang. 1st man in the stack does it to enter a room that much faster. I've done it. It sucks, but you can keep on going. Still have to close eyes though. But it's still largely mental. There are also people who can largely ignore tasers. That I can't do. But I can ignore CS gas and pepper spray. And it really is a mental thing. The effectiveness of less than lethal force and ambushing lies in the hope that the recipient of such force isn't prepared for the onslaught. But being mentally ready changes the game

[@stephenandersen4625]

you're correct, if you are close enough to an explosion and/or if the material has a high enough detonation velocity, , the shock wave (the part that wacks you) will hit you before it dissipates and/or the expansion wave (the part that goes BOOM) catches up with it.

[@neurofiedyamato8763]

Seems legit on the sound of the death star exploding. But you would still need to be closer than you would in Earth to hear it since the gas would expand rapidly to a point where the molecules are so far apart sound doesn't travel very well for you to hear.

[@al35mm]

The reason you won't hear an explosion that you are within is simple. The sound you hear from a distant explosion is caused by the supersonic expansion of gas and the air around it being pushed away. It's a sonic boom similar to thunder. If you are within the explosion you are exposed to a rapid increase in pressure - not sound. It's similar to flying a supersonic plane where people on the ground hear a sonic boom as you go by, but you don't hear that from within the plane.

[@Caldera01]

I'm calling bollocks on this one. Gases do NOT have hidden potential energy within them. What your test tube experiment showed was how pressure difference works with gases. When you have a tube full of gas, it has pressure, like a balloon, or a tire, and when you then open the barrier between a vacuum tube and a tube full of gas, the gas will rush out of the tube into the vacuum until there is no pressure gradient. How violent this is depends on several factors such as the width of the tube and how high the pressure difference is. However, with an explosion in space, there is no tube. Unless you're using a missile, but even then that tube is gone once it explodes, which is kind of the point of it really. This means that any gases released by ANY explosion in space would not suddenly go into hyper speed. It would form a gas cloud which expands at the speed at which the explosion hurled it out into space with. Granted, if the gas cloud is thick enough and you have a space craft in it, you would hear the explosion, but it wouldn't take long distance wise until the gas gets too thin to convay sounds properly. You are right about the rattle of any bits of debree hitting the outer walls of your ship though.

[@Caldera01]

***** You're talking about individual particles. I was talking about flowing dynamics. You're mixing 2 different fields together.

[@Caldera01]

***** I can see you're more of a particle physicist than an aerodynamics person. You are however mistaken. When you talk about flow mechanics (Aerodynamics, water flow through a pipe, or gas expansion in a barrel of a gun) Van der Waals and other such minute forces are ignored and set at 0 to simplify the equations from the get go. This is done because such minute forces do not have a applicable significance and would unnecessarily complicate an already complicated equation systems. You might not be aware of this, but a lot of corrective multipliers and terms used in flow mechanics are purely derived from experience and are not backed by any science whatsoever. And let me tell you, Van der Waals force is definately not a term we use in such equations. So yes, while in principle you have a point, you are still talking 2 different things, semantics rather than actual application.

[@Caldera01]

***** What? NO! I was saying that the notion of "hidden energy" is bollocks. Gas expands due to pressure differences and the law of enthropy. If we're talking about a missile, the explosion itself will give any gas clouds a speed boost to expand further, but the gas wont suddenly start picking up speed on its own once the explosion has passed just because it's in a vacuum, that's ludicrous.

[@Caldera01]

***** Yes, I know YOU'RE not trying to say that, but the video did, which I was refuting. Also, gases do not 'suddenly rush' away when being unconfined in a vacume. Gases disperse at a varying mostly static speeds towards varying directions. Acceleration requires an INPUT of energy and potential energy only works when you have some sort of storage of it. Height vs gravity, or pressure vs vacume, or mechanical energy such as a bent bow, rigged to hurl an arrow. Granted in the case of solar wind you might have a sudden rush of gases suddenly rushing somewhere, but this doesn't happen on its own surely.

[@Caldera01]

***** What I'm saying is that I wouldn't personally use the word 'rush'. Not that gas cloud doesn't disperse when unconfined.

[@lindybeige]

Yes, the gas would have to encounter something, which in turn was connected in some way to your ear. If you were free-floating in space with no space-suit, then some vibrating gas might enter your ear, but the sound would probably be very faint. If there were lots of gas moving fast, the first effect I described might occur.

[@barghestblue731]

The reason there are pilot's in modern fighter planes is because drones aren't effective fighters due too pilots being able to react to something better when they're actually present, and computers process things in a way that is inferior to the human mind in a combat situation, so pilots are better. I guess they haven't fixed that problem in star wars.

[@franohmsford7548]

Partial fix with X-Wings and Y-Wings in that both use Astromech Droids like R2 to do the calculations that a human mind cannot {as well as being able to make quick repairs to the outer casing of the fighters in battle}. A and B-Wings however removed the Astromechs...Guessing because the Internal Computer was more powerful so that Astromechs were less necessary. {As well as the B-Wing being much more heavily shielded and armoured than X or Y wings while the A-Wing relies on its great speed and Basic Shielding {Faster even than Tie Fighters while also being shielded which Tie Fighters aren't!}. In some ways Star Wars technology isn't that far ahead of our own - It's just gone in a different direction. Bacta is an I believe Plant Based Cure All that has only recently {pre Empire Strikes Back when we first see it used} replaced Ryll {an hallucinogenic Drug} as the Galaxy's main medicine - And Ryll was probably just a strong painkiller/Anaesthetic with some slight regenerative properties that aided in natural healing. Remember that apart from Ryll and Bacta The Empire's Medical knowledge consisted of Cybernetics! Star Wars ships DO have Shields - Something that is constantly forgotten or ignored by those who keep stating that Trek Ships are better {they're not!}. Tie Fighters are the only Fighter Craft without Shields! The Empire considered Tie Fighter Pilots expendable and Tie Fighters generally weren't equipped with Hyperdrives or even air {why the pilots wore full helmets!} either! if their Fleet ships were destroyed the Tie Fighter Pilots who survived the battle would die soon after from lack of Oxygen! Darth Vader's Tie Advanced is an exception as are some Tie Interceptors {which still didn't have air but may have had Hyperdrives and Shielding} as the Empire realised the rebels had the better fighters. Lasers are mentioned many times in Star Wars and yes TNG {I believe it was TNG} announced that Lasers were useless against The Enterprise's Shields. But they're generally useless against the Shields of Star Destroyers too - It takes a full Proton Torpedo Barrage to take down a Star Destroyer's Shields in one spot {Overload} - Then the Lasers and more Proton Torpedos get to work on the Hull. We can also assume that the term Lasers is outdated today and that what Star Wars actually used was something else entirely just called Lasers.

[@barghestblue731]

True What I meant by the inferior way of processing things that computers have is that fighter pilots have instincts that help them make decisions and such when in actual combat (it is always treated with suprise when an astromech can successfully fight their fighters themselves) this is mainly due to the way the droids in Star Wars are shown to see things, and how the pilots perceive things. And when you actually go into the lore, the main weapons they use in Star Wars aren't actually lasers, even lightsabers, which are sometimes referred to as laser swords, don't actually use lasers. Lightsabers use plasma essentially for the blades, and blasters are a weird type of energy weapon, the blaster bolts themselves don't generate heat, that's entirely from friction and such, it's really weird and one of the few pieces of tech that we can't actually do in real life.

[@franohmsford7548]

Yes, I should have been more specific as I wasn't talking about Blasters {which I've never considered to be lasers anyway} but about Turbolasers which do have that word in the name and which are the reason why Trek fans keep making this mistake about Star Wars. Essentially Turbolasers have just kept the name from who knows how long in the past and aren't actually Lasers at all {Just like Blasters aren't Lasers and Lightsabers aren't Lasers.}.

[@barghestblue731]

Yeah if the writers for Star Wars (both books and movies) could stop sticking "Laser" onto everything that'd be great :p

[@lucasvarela9088]

I actually believe that it's because they haven't been able to make an A.I capable of emulating fear, without fear there's no survival sense, and without survival sense there's no actual improvisation, desire to keep living, and thus just caring about "wining" a fight and not having any other factor in mind.

[@partriarch]

Speaking from personal empirical experience, you are correct about not "hearing" a detonation in your immediate proximity. In Vietnam, while on a patrol, one of the men in the moving column just ahead of me tripped off a multiple boobytrap which injured those in his immediate area. I was unaffected by the shrapnel because of thick bamboo grove we were moving through, but the blast was immense and caused imbalance in my stride. My ears were so overamped by the waves of sound, that they heard nothing until several seconds after the blast occurred. It was only when hearing returned that I could hear the moans and cries of pain ahead of me. In a personal diagnosis, I have come to believe this explosive burst has resulted in "tinnitus", or ringing in the ears, ever since. It is not debilitating, but it is nonetheless ever present. That was half a century ago.

[@dartbeard7108]

Post traumatic retrograde amnesia explains many instances.

[@SuperGlucose]

"Why can't they just do it remotely?" vis a vis space fighters. Two main reasons: 1) Build the remote control that can't get hacked :P 2) "Space" fights would take place on massive, massive scales. On earth you might be a few miles away from your target. In space, it would be unlikely that you'd be much closer than a light second away from your target. Try playing a video game against someone who's in Tokyo and compare it to pljaying a video game with someone who's in your living room.

[@gabriellaroberts5090]

Getting hit with a blast wave in space would make a thump sound. From personal experience in Afghanistan: Explosions in real life sound like a very loud "crump." Bullets flying close to you sound like a really loud chinese noise maker firework "snap" sound. Richochets, shrapnel, and subsonic bullets make the whizzing and whirling sounds.

[@florbengorben7651]

+Yolo !!! Shut up its cool to hear about

[@lobsterbark]

+Yolo !!! The explosion releases gasses for sound to travel in.

[@lobsterbark]

+Yolo !!! The explosion releases the air needed.

[@lobsterbark]

+Yolo !!! Do you not now how explosives work? They just produce a lot of gas really quickly.

[@florbengorben7651]

lobsterbark show him up man

[@PlasmaHH]

Handgranade behind a 1m high wall, approximately 1m away from me on the ground: Besides feeling the actual shockwave, there is some sensation of sound. I found it hard to describe, but it is like a very loud, very short white noise, kind of a "cracking woosh" sound followed by a weird silence that makes you hear yourself. Then for quite a while some multi frequency beeping while your hearing very slowly comes back. I think the main problem is that due to the shockwave all hair cells are triggered at once, with maximum amplitude, and that the brain that then processes this sound, has never heard anything like that, and as such is unable to provide you with a proper sensation of "what it sounds like".

[@ThunderChunky101]

Depends of the distance... They'd have to be close enough for debris to hit them.

[@ChucksSEADnDEAD]

Without an atmosphere to offer resistance, fragments would travel far and retaining most of it's speed.

[@ThunderChunky101]

Filipe Amaral But it depends on distance ad to whether or not anything would hit you at all! And no explosion would be isometric either... Na. If you were a few kilometres away you'd likely not be hit by a single thing larger than a stamp. If you were a hundred, nothing at all. A thousand? A million?

[@ChucksSEADnDEAD]

Sal sean Well, the context was small scale fighters in a cluttered airspace like in sci-fi movies, and I assume the explosion would be triggered by proximity sensors. In this case, all the near misses that would destroy/cripple the target aricraft would also pepper the whole battlefield with dangerous shrapnel. The chances of being hit by a single fragment would be low, but there would be multiple explosions, each one sending thousands of stray fragments that were not stopped by the intended target spacecraft. >"And no explosion would be isometric either" I don't know if you're referencing the 3d nature of space combat or equal pattern of fragment dispersion.

[@ThunderChunky101]

Filipe Amaral Nothing you said there refuted anything I said... Did it?

[@ChucksSEADnDEAD]

Sal sean You talked about distance, and if there's explosions going off everywhere you'll get high velocity fragments everywhere. If the debris retain almost all of their initial velocity and there's a million pieces flying everywhere, you get hit unless you're so far you're not even in the fight. If you're not fighting, you don't usually get hit, but that goes without saying.

[@GoranXII]

Explosions in space fade off quickly, because there's no air to carry the pressure, so unless you're right on top of it (like within metres, at which point you'll be much to busy worrying about the damage to bother with the sound), all you're likely to hear is a brief thud, like someone stamping their foot next door.

[@martyb999]

If you’re close enough the blast takes the sound away from you. My mum was nearly hit by a V2 rocket back in WW2 and the first she knew about it was when all the windows around her (seemingly spontaneously) shattered and she swears there was no BANG!

[@TheKJMalice]

The experiment his teacher used with the bromine doesn’t sound like an explanation of energy, but the effects of two different pressures acting with each other. Of course the bromine gas moved instantly to the top of the cylinder that was vacuum sealed, the vacuum creates a simulated negative pressure within normal atmospheric conditions (i.e. your classroom) while the bromine has to be injected into the second cylinder, replacing the atmospheric gases usually within, creating an extremely negligible, but still existent, positive pressure above normal atmospheric conditions. I get that there was a high/low energy state that the two spaces had compared to each other, but by themselves they were effectively inert until acted upon by an outside force (the different energy states provided by differing pressures of gas), displayed by the first portion of the experiment that had the “empty”, non-vacuum cylinder at the top. You can do the same sort of experiment by taking an air compressor tank, sticking an blowgun attachment to the end of the compressor hose, and releasing the air an inch away from your skin. As soon as the pressure inside the tank drops, so too does the effect it has on your skin, until there’s no more pressure differential and the effect becomes nil

[@AudieHolland]

I think you don't even have to be very near to an actual explosion to experience the (almost) no sound phenomena. This may not be what you actually meant, but people who were wounded in a serious car crash can't even remember the impact so no sound. I myself was once hit by a car who did not yield as he should have, luckily I was in a bigger vehicle, a person van (or whatever it's called in English). I also carried a single passenger sitting further to the back (only three or four rows of double seats I think) and when the car hit us at a degree of about 90 degrees horizontally, it hit right beneath my driver's door. While unharmed and undazed I was of course shocked by the collission but for some reason I didn't believe the car hit us that hard. Why? I didn't hear any loud bang or crashing sound like in the movies. What I can recall I actually heard was something like, clunk! About the same when your car goes over a speedbump a bit too fast. If you reverse your car and accidentally hit the car behind you I think you'd hear a louder sound. But at the same time I was not sure so I asked my passenger, an elderly lady, if she had heard any loud bang or crashing sound. Yes, she answered, she heard a mighty bang. So I think I just suffered from sensory overload right when the car hit my van. My mind was very busy thinking all kinds of thoughts like "no, he isn't-what the-hey watch out you-" so I didn't hear the loud bang.

[@dfpytwa]

When I was a kid and living in Indiana me and some buddies hiked out to some state owned woods next an old land fill to do some hunting and an overnight camp. There was an abandoned rail road there too that a coal train had wrecked on decades ago and the hills on one side of the tracks were actually piles of stoker coal. This was in the winter and cold out so we dug a pit then dug a few sandbags of that coal up from the old rail bed and carried it over to use for fuel. Just a few bags of that stuff in a hole with a wood fire built on top of it to get it going will burn hot as hell all night like a big cigar. The coal and the wood we gathered was damp and we were having trouble getting it to light and stay lit. One of my buddy's had kicked around the dump and found a half full can of 50 year old or more paint thinner. The cap was rusted shut so we had to poke a hole in it and drained it into the fire pit. Now that stuff was boiling and steaming out of our pit and I knew it was going to flash up once I through a match in it so we all stood back I and tossed the match. It made a big whoosh that knocked us all on our asses but that was it. We just laughed it off and our coal started burning good. After we got our camp set up that's when the county cops rolled and the fire department. They were like WTF are you guys doing? Hunting with dynamite? I guess what sounded like a whoosh to us had made a huge boom that was heard and rattled farm house windows for miles.

[@Fiddling_while_Rome_burns]

Many years ago I was in the English Civil War Society and they had the largest firing cannon in Britain, I stood pretty close to that when it fired and you get a lot less sound up close than you do nearby. Your eardrums go numb and just stop working, like a loud speaker they will only vibrate up to a certain noise level then just overload and stop vibrating.

[@roycemeyer2391]

So Lindybeige, something that might improve your similar analyses here is the knowledge that the speed that sound travels (commonly called the speed of sound) is actually determined by the speed of the gas particles in that medium. I want to go back to your example with the bromine gasses. You were comparing the rate at which gases mix to the speed at which the particles travel, which doesn't quite work. You were right (or rather your teacher was) that these gasses mix slowly because the air pressure is also pushing against the lower gas, but even then, if you tap on the glass, the sound would transfer from one particle to another at roughly the average travel speed of the particles, which may differ between the 2 mediums. The speed that you saw the gas travel through that vacuum was the same as the speed at which sound travels through that gas, which is the same as the speed at which the individual particles tend to travel. In the death star explosion scene, that gas would be traveling at the speed of sound -- for that gas at that termperature (quite likely a whole lot faster than speed of sound here) but yes, it's likely that they'd hear a sound from it nonetheless.

[@SkullKing11841]

On Combat by Dave Grossman something like this happens with gun shots in gun fights as well, were at most it can sound like little popping noises and the physiological reason is when in a high state of fight or flight your ear closes up and loud noises get reduced significantly.

[@lindybeige]

It isn't a shock wave. It cannot be a shock wave because there is no medium for carrying the wave. It is the gas itself. All the choatic vibrations within the gas will be encountered in very rapid succession as the gas passes by.

[@ShuRugal]

my uncle once smashed a roll of toy pistol caps with a 1lb sledge on an anvil.. he described it as " the loudest sound I never heard". It was so intense and so close that it rendered him temporarily deaf. this is one of the reasons you don't hear the shell that kills you.

[@mileskittman]

To expand on this, the reason that one does not hear a sufficiently large explosion when it is close enough is mostly because the sound of the explosion is outside the frequency range for human hearing. That frequency range is from 20 Hertz (one Hertz is one cycle per second) to 20 KiloHertz. At extremely short distances (relative to blast size, as this phenomenon has been reported by survivors of both Hiroshima and Nagasaki) the sound of explosion is still moving at very low frequency, and thus is below the range of human hearing. A shock-wave is a sound wave, and though it may appear to exceed the speed of sound in some fashion, it does not, in a localized sense. The speed of sound is something of a misnomer, as it is not constant. Both the medium of transfer of sound waves and the temperature of that medium effect the local speed of sound. From this it can be determined that though the speed of a shock-wave from an explosion exceeds the velocity of 343 m/s it does not actually exceed the speed of sound in the sense of the definition. The reason that the sound can be heard at greater distances has to do with a rather common property of sound, namely that as the radius from the origin point of the sound doubles the area of the wave that delivers the sound increases by a square (where the distance from the explosion is r and the surface area of a sphere is 4*pi*r^2, and this works loosely even when portions of the blast's expansion are impeded by the ground as the ground will be absorbing similar portions of the energy to what the air would if it were an air-burst). Say that you move from a radius of 2 meters to a radius of 4 meters, then the surface area of the shock-wave increases from 16*pi square meters to 64*pi square meters. Keep in mind that when the shock-wave expands from one position to the next the amount of total energy it carries remains constant.

[@JoaoXii]

spot on on your educated guesses. Cody's Lab made a recent video experimenting with explosions and vacuum where you can actually hear what you just described

[@lindybeige]

I don't think any significant explosion in space has ever been filmed. They would presumably expand and disperse far more rapidly than explosions in air. Flying debris would not slow down.

[@skwrk]

The answer is that wavelength is longer and longer while increasing the distance. This means that tones are lower and lower. You cannot hear above some waivelength and belowe some. That is why thunder far away is so deep. Close explosion may cause not only hearing damage, but wavelenght is so high that it is out your hearing range. Plus mental shock, plus mentioned ears damages.

[@professorbellorum]

yeah, shockwaves are still loud... I suspect that their eardrums are being blown deaf instantly, leaving no time for sound to oscillate in the cochlea.

[@flintmcallister]

Your absolutely correct. I thought about this, but I have two thoughts, first if the ships travel very fast maybe 1/60 the speed of light then after a couple minutes of battle they could be to far away to get good latancy time. Another reason they may choose not to is that having a human right there to repair any minor problems or run the craft if the computer gets an emp. Remember at the beginning of Gallactica all the ships with computers running the main work shut down.

[@lindybeige]

But the passing-by of the gas would have duration, even if that duration were short, and within the gas I imagine there to be a chaos of vibrations rather than a uniform mass all moving identically. That chaos, though, would rapidly decline in relevance as the gas dispersed, so the noise might be that of a single buffet to the hull, but one with duration.

[@DavidEllis94]

You're correct about the explosions in space bit. An impact on a spacecraft would create a sound in the material and atmosphere in any pressurized compartment. I don't think it would sound like a boom, though. I suspect it would sound more like a large impact on the exterior of your craft, like..... I'm not sure, as if a wave of something simply smacks into you. The gases would get very diffuse very quickly, so you definitely would not hear or feel any sort of detectable impact particularly far from the center of the explosion. Despite the fact that there *is* gas expanding, there simply isn't enough of it.

[@jbroom5075]

Lindy's story about the bromine gas has given me a realisation: vacuums don't suck, as I had always blithely assumed - it's just that air pressure pushes, and when that is removed, everything just expands and disintegrates to where it wants to be...

[@Highbrowser]

1) If you're close enough to get smacked away by an explosion, you will be knocked pretty hard. People hit by cars or other massive objects often report amnesia for the impact itself, which comes about basically because your entire brain is disrupted by the force of the impact. So, it might just be that the explosion just knocks you so hard you forget it. 2) the pressure wave from an explosion isn't just positive pressure, it's also the vacuum created by that much gas expanding that quickly, so there is a huge sound. It may just be that the human ear is just not equipped to handle that kind of pressure fluctuation. It's only after distance attenuates the pressure difference that it registers as anything more than just deafening overpressure.. 3) As for sound in outer space? The main problem with this idea you put forward is that the explosive is expanding into literally nothing. Now, the example you give was energetic, but it was also in a tube, not expanding into an infinity.

[@Highbrowser]

If you were close, maybe it would create a sound, but from further away, there'd just be very little gas left to make the pressures shift that would convey sound to the cockpit of the space vehicle. So, what other options exist? Alright, imagine this: the chief liability of a person flying in a space vehicle would be that what they couldn't see, they would be unprepared for. So, how to deal with that? Translate something, like readings off of the engines, radar ranging, or something else into sound. Then, if the ship's sensors could pick it up, the pilot would have the benefit of being able to track things in his environment that weren't immediately in front of him or her.

[@kotsifis250]

Physicist here,yeah what you describe makes sense and people in the comments have pointed that out.A shock wave is so powerful and because of the nature of it you can't hear it if you are right next to the source.For the" bang" sound to formulate you need a certain distance apart.Nice thinking lloyd

[@B.D.E.]

If you are close enough, the pressure wave is so powerful that it basically overloads your ear drums, and yeah, you don´t really hear it. Everything goes silent for a while and then a ringing slowly starts and becomes louder. If you are lucky then your hearing will return without any lasting damage, but it´s generally something you want to avoid.

[@MrLittlelawyer]

I once made some nitroglycerin in my back yard. Not a lot, just a few drops. I put it on a paper towel, set that on a brick, and after securing my faceshield and mentally preparing myself, I struck it. I felt like someone had put a pad over one ear, and I heard a ringing sound. The brick was shattered to a thousand pieces. I gain a new respect for high explosive chemicals. I think I remember hearing a pop, or a faint noise, in my other ear, but tbh is very foggy, and the whole experience caused me a great deal of panic and adrenaline. That brief silence and the quiet ringing I remember very well though, because I had expected it to be very loud.

[@rolfkarlsson276]

The velocity of an explosion is typically around 7000m/s (for TNT). The velocity of sound is about 340m/s (in air). If you are close enough to be harmed by the explosion, the harm will kick in long before you hear the sound. Shock or physical harm to the eardrum will therefor take place before you can register the sound, and as such you can't remember hearing it, or hear it at all. The energy of an explosion diminishes over 1/r^2, where r is the distance between the spectator and the center of explosion. Considering that 1kg of TNT ("standard metric") is 4xe6 joules, I think you would have a better chance of hearing your co-pilot fart than to hear an explosion 100 meters from your spacecraft. An astonishingly powerful HE is about twice as powerful as TNT, so add 1 to the resulting decibel. If you are thinking in terms of sci-fi, 10 times that of a TNT and you add 10 decibel. That is, disregarding the sound of the eventual shrapnel. I am sorry for using plebish units.

[@myth-termoth1621]

Yep, im going with Codys Lab, i think if you are that close that your neurons are goung to be disrupted by the shock wave overpressure before they can register the sound. In effect, i am sugesting that you are too stunned to hear and remember the sound, even though this stunned state may not last very long.

[@jimwolford7294]

For high explosives, the blast wave ( the dangerous bit ) and the shrapnel ( the nasty bits) move faster than the speed of sound. The "bang" moves at the speed of sound and isn't as dangerous as the other bits.

[@lindybeige]

Were the hull stupendously hard, then it would not deform at all, to transmit noise, but the craft would be given a sudden push, which would be bound to cause some sound somewhere aboard.

[@valhalla83]

Much like your final statement, in the MMO EVE Online, the capsules that pilots are in, have sound synthesisers which re-create the sounds of explosions and gunfire, etc. to allow the pilots to react with that sense... At least, that is what the official fiction says :)

[@zanobi]

no friction dissipation, but the gas is expanding presumably in a sphere. where the mass is very dense in the center the wave is stronger. after a few miles the molecules would be too spread out. it's similar to launching to hammers of different weights. assuming they land at the same velocity they exert different amounts of force. the "hammer" (explosive force) "weighs" less as it gets farther from the epicenter. but it doesn't slow down.

[@coggzi5865]

Check out Cody's lab. He did s video on explosions in vacuums. He concluded that the actual atoms of the gases from the explosion are able to slam into whatever is around much faster in a vacuum than at normal atmospheric pressure.

[@TheEveryDayC]

The thing with the bromine gas and air becoming homogenous is called the point of highest entropy. The reason for the bromine gas being suckied into the vacuum was because of this idea: The gas is being put under extreme pressure. The gas is exerting the same amount of pressure outward. The vacuum exerts no force, and so when the barrier was removed the force of the gas was much higher than that of the vacuum, resulting in the gas continuing to push out to fill all remaining space, which appears as it rushing up extremely quickly.

[@onepunch9203]

Interesting stuff, as always. A rebuttal: Your fighter pilot who hears the explosions from just outside his ship isn't really in "space". He's in a pressurized cockpit. "Space" is what's outside the walls of his ship.

[@jypsridic]

The shockwave that throws them is the sound. At a certain level of volume the differences in pressure between the peaks and valleys of the sound wave reach a critical level and start forming a shockwave. People further away hear it because the energy of the wave has dissipated enough to stop being a shockwave and return to soundwave.

[@MaxxTheMerciless]

Speaking as a military helicopter pilot, or former one, I say that often times you can't hear much of anything anyway over the rotor-wash. In films, you can hear explosions clearly, but when I got hit by an RPG, I didn't even feel it (cuz I was in an AH-64D Apache), and it barely fazed the aircraft, but the aircraft knew it was hit from all the alarm bells going off.

[@aceyoyodude]

you would not hear the explosion in space as in order for there to be sound there must be particles hitting each other, if something exploded in space the "gases" as you call them, would expand but not hit anything. thereby not travelling to the hull of the craft and thereby not alerting the pilot to the explosion

[@14USMA]

A lot of times they do not hear the explosion, because it is loud enough to render them temporarily (or permanently deaf). I have had this happen to me when an instructor detonated an artillery simulator near me during a training exercise. I never heard the explosion, just the immediate high pitch ringing in my ears from the blast. Also, I think a lot.of accounts are referring to the whistle of an incoming mortar or artillery shell. That sound is caused by the Doppler effect, and can only be heard if the shell is not coming down on your position. If the mortar or artillery round is coming down directly towards you, you would be unable to hear that whistle, and probably not the ensuing blast either.

[@killerstickkenobi6768]

Awesome how the Video explains in depth gas expension in Space and there doesn't seem to be any sort of bias. But in the end, it's about Star Wars.

[@nekomasteryoutube3232]

I guess that would make sense that a large explosion in a vacuum or space would make some sound, as the pressure wave from its own gases would push outwards. Though I imagine that you'd only hear an explosion that was close enough to have any effect on your craft or vessel.

[@Altorin]

The explosive force that blows them up is the sound. That's what sound is. It probably has nothing to do with the physics of the explosion and more to do with the psychology of remembering the explosion that blows you up. If an explosion happens nearby, the noise is the novel part of the event. It's the thing that alerts you that a thing has occurred, and it's dangerous, so your brain records it very clearly, and you don't have the gross physical shock of your body to get in the way of your recollection. If you're actually caught in an explosion (assuming you survive to have any recollections at all), the fact that your eardrums are damaged is really not a primary cause for concern in your brain. It's simultaneously dealing with the shock of your body being torn apart. That sort of injury is far more novel to the brain then a loud noise, and so it remembers those things more then a sound (directly after the explosion you're pretty much deaf anyway, so you won't be having any other sound input, your brain will probably just shut that off in your recollection)

[@arthipex8512]

During my time in the army, I had the luck to become a demolition specialist. When we were blowing up doors, we usually stood very close to them (approximately 2 meters). It is actually true that you don't really "hear" the explosion - probably due to the exact reason Lloyd pointed out. You definitly feel the shockwave hitting you, but the only noise you really hear is just after the explosion, when the building is still vibrating.

[@jmcr71795]

I've experienced morter rounds hitting the tree canopy above me, and can confirm that I didn't hear the explosions. Rather, I heard them firing in the distance, then found myself face down in the mud, with my ears ringing. Cody, from the KZbin channel "Cody's Lab", tested the explosion in a vacuum, and it did make a noise.

[@EvelynNdenial]

it would probably be much more akin to the sound of turbulence in a plane since any explosion close enough to cause a significant enough impact to cause a distinct sound would also destroy the craft itself. while further away the gasses created in the explosion would have expanded into the vacuum surrounding, washing over a ship shaking it with its turbulence. just what i figured though, has anyone done tests to record what it actually sounds like?

[@miguelbatacan]

Hahahahahah. Granted I'm not an astronaut but I'm not entirely sure that's how it works, but the end bit did have me laughing hysterically.

[@ashenlongbow1482]

True or not this is a beautiful video with a glorious final sentiment. Star Wars will never be the same again.

[@pugnate666]

The problem about that explanation is the gas cylinders your teacher used were "extracting" the gas in only one direction. In space the gases of the explosion are expanding in all directions simultaneously and are thinned very quickly (quicker than the noise can travel (it's a very slow wave compared to other ones)). So what you might hear - as said, only if the explosion is very close - if a VERY dampened silented Version of the actual explosion

[@garethworthy2818]

Something that works along with this, is when firing things like a Carl Gustav, the number two (or loader, or what ever you wish to call him/her) hugs the firer when the shot is fired. Besides that in Canada we tend to be doing this in the winter, so it is much warmer, the reason for this is because if you are a little ways away the shock wave of firing a recoilless rifle hits you like a kick in the chest, if you are right up against it, you pretty much don't feel anything.

[@justgot2go4now]

I think the reason why they can't hear explosions when they are close is because it blows their eardrums out aka they go deaf. Another reason I can think of is forgetting a traumatic event, it happens frequently with people who suffer abuse and intense combat. For example someone maybe able to recall their parent hitting them but not a specific moment for when it happened.

[@alanowa123]

4:08 that's why vacuum cannons are so crazy. You can shoot thing with enormous speed (close to speed of sound) without any explosions or fuel. Only vacuum in tube (barrel) and hole behind bullet...

[@TunnelRodent]

well the problem is that we dont like to repeatedly, if at all, subject modern spacecraft to such explosions. Math can describe how the gases in an explosion could expand but that being said, shrapnel is also a very chaotic variable and can wind up changing many things and as for the sound you'd hear in the space craft i would think that is very much based on the orientation of the craft

[@TrapperAaron]

My guess is that the pressure wave (explosion) is traveling faster than speed of sound. U get knocked down by the time u realize what happened the sound wave (slower than the explosion) has already passed u and is a few hundred yards away

[@kyrusmama2398]

Idk if I like the given explanation for why one doesn't hear a near by explosion. Certainly, while sound waves don't cause air particles to move in the direction of the sound, sound can travel through moving air. I suspect that the shockwave put out by the blast would also be vibrating and, while it may cause a pressure against your eardrums, would still cause the eardrums to vibrate. Perhaps it has something to do with the speed of sound being less than that of the speed of the shockwave, coupled with a neural reason?

[@509Gman]

Sorry if I'm repeating points already made. I was in Iraq and Afghanistan; the legend we kept hearing (and made sense to us) was not that you didn't hear the explosion, but the whistling of the shell as it flew through the air if it was going to hit near you. Maybe it was bs just to get you to do your job under fire (I was never blown up, came close many times). Now for people who were blown up and didn't hear it, I would blame auditory exclusion (that means you go deaf or have selective hearing under high stress. My first parachute jump I heard absolute silence as I went out the door even tho there was a jet engine only about thirty feet away from me).

[@donaldmcclellan4949]

Bit late I know, but we have an actual example of an explosion in space that was survived and reported. Apollo 13. Don't know how much flame there was, but it was Oxygen ignited by an electrical short.

[@MrMonkeybat]

In a vacuum the gases of an explosion will rapidly disperse due to the inverse square law. As the pressures of a high explosive are many times greater than 1 atmosphere the effects backpressure are much less than the airs assistance as a shock wave medium. As a shockwave is the area of a sphere rather than the volume of its gasses it is much longer range. The shrapnel in space of course keeps on going, a shrinking risk but just as deadly until you far enough away to detect and avoid it.

[@supafly345]

This is making it sound like the explosion would dissipate away from the ship, as that is the path of the least resistance and where all the vacuum is.

[@SoralTheSol]

Just the thought that the destruction of the moon sized ship known as the Deathstar came across as a tight, high, whiny "Pew!" Makes me giggle.

[@maxpayne5941]

An explosion has a sound but the energy waves coming from it are soundless, so if in space an energy wave from an explosion would touch your ship you would hear your ship cracking from energy wave but not the actual explosion. Correct me if I'm wrong cuz just guessing

[@lindybeige]

If the gas were thin, the amplitude would be low, but you could have sensors/amplifiers aboard the craft.

[@petere7197]

It would have been easier to state (up to @01:33) that a shock wave from an HE shell (if you are close enough) will be travelling at greater than the speed of sound ["No no no" you say: "a shock wave cannot travel faster than sound" - well it can, and they do]; so the shock wave blows you off your feet before the sound wave arrives at your ear. It is hardly surprising then, that so many servicemen never heard the explosion that knocked them down. A similar bomb exploding in the next field, however, will very quickly attenuate from a supersonic shock wave into a sonic (Mach 1) wave, which will barely ruffle your hair, and be heard, a fraction of a second later, as a BOOM.