Paladin Posted September 7, 2004 Report Share Posted September 7, 2004 I doubt you would be able to actually live at 20 atm pressure for long, it sounds BAD to have all bodily fluids at that pressure; like getting your capillaries' walls damaged, etc.Then again, it's really serious business, and those considerations would prevent Xcom aquanauts from participating in ANY surface-based terror site, unless they can keep their suits pressurised... hence too filled-up to move Oh, but not with the ION ARMOR! It's not to keep water from coming in, it's to keep the pressurized water from coming out! Actually, liquids are incompressible... They take the same amount of volume regardless of the pressure... The only problem comes from the Gases in our blood stream. CO2 is actually transfered back to the lungs by being dissolved into carbonic acid (unlike Oxygen, wich is transfered attached to the Hemoglobin molecules in the red globules, the hemoglobin is what makes them red, because it's got iron), which is basically what's in any gazeified drink... the bubbles are actually the CO2 that's not soluble enough anymore due to the sudden lack of pressure. And, well, that's exactly what happens to a diver that comes out of the water too quickly, or someone that walks out in the vacuum of space, in less than 2 minutes (if he's not frozen solid first), it goes like this: 20 atmospheres is not that bad to handle per se, the air is denser, hence it'S easier to exchange oxygen molecules with it... Otherwise, it's like coming down the Everest and wlaking on the seabed... Your ears can hurt if you're coming down too fast (as in diving in a deep pool), but otherwise you're fineIt's going up too quickly that's bad... (see above) As I said before , the problem comes from going deeper than 50m (or so), where the Nitrogen/Oxygen becomes toxic because it's so full of oxygen per volume... It's like rusting inside out while on narcotics (so you don't actually realise it at first). That is handled by using different gas mixes, Helium/less Oxygen is the most commonly used by PROFESSIONNAL divers, because Helium is a chemically inert gas, it just makes your voice sound funny on the surface (because the air density is different), but down there it makes all foods tasteles... I dunno why but it does...And yes, considering that divers that go to depths of more than 100m need 2-3 weeks of decompression when coming out (they stay in their compressed container), well they gotta eat during that time... Re: Ion ArmorsOh, and keeping the pressure out is FAR easier than keeping it in, because of the structural stress. When you think about it, a spaceship only have ONE atmosphere to keep out, the same kind in pressure difference you'd feel under 10m of water, but inside out... If you're in the deepest waters of the world' like the mariana Trench (near the Philipines, I think), that's a stagering 13km deep, just do the math and think very carefully about how much more pressure there is down there... Even in the "relatively safe" typical atlantic floor, where it's basically 3-5km deep, a nuclear submarine that was lost was actually squished it's cylinders inside themselves like a folding telescope once the pressure was too great... But once it's all filled with water, then no damage can be done (like on the Titanic), since there's no gas to compress inside it... Then, since we're discussing water-physics and how BADLY they were implemented in this game, the aberrant throwing comes to mind here, as well as the effect of underwater explosions (I mean, with that kind of pressure, explosions are absolutely DEVASTATING underwater, and they destroy a LOT further). That level of pre-school physics is almost even worse than the movie Armageddon... :o(Yes, I know that's VERY low, particularly for a big budget movie...) Re: Main topic, Yes, as I said, it's not worth it to equip each and every base with soldiers, just fill 2-3 bases with them, and use lots of defenses on the others... much more efficient that way, esp. if you take teh time to equip your soldiers decently... Then again, a HWP or two can make all the difference in the world... Link to comment Share on other sites More sharing options...
centurion Posted September 7, 2004 Report Share Posted September 7, 2004 Actually, liquids are incompressible... They take the same amount of volume regardless of the pressure... Actually, liquids ARE compressible, just on the same scale as solid objects, so you don't notice.20 atmospheres is not that bad to handle per se, the air is denser, [...]Well the air will be 20 times denser, adjusted for helium it's 5 to 6 times more dense than air at normal pressure. I'm sure your lungs will not like that extra work.Re: Ion ArmorsOh, and keeping the pressure out is FAR easier than keeping it in, because of the structural stress. When you think about it, a spaceship only have ONE atmosphere to keep out, the same kind in pressure difference you'd feel under 10m of water, but inside out... And a bus' wheel holds more than 5 atm pressure, yet is not comparable to a spaceship ... The structural advantage of the "outside" arc as compared to the "inside" arc is not so great, if steel is used (it's important with materials like bricks and concrete, which behave real badly wrt tearing).Then, since we're discussing water-physics and how BADLY they were implemented in this game, the aberrant throwing comes to mind here, as well as the effect of underwater explosions (I mean, with that kind of pressure, explosions are absolutely DEVASTATING underwater, and they destroy a LOT further).You won't get much stronger explosions underwater, as you will get essentially the same amount of energy to start with. Link to comment Share on other sites More sharing options...
Paladin Posted September 8, 2004 Author Report Share Posted September 8, 2004 (edited) Ok, looks like we have a nice, BIG reply coming up... O:) Actually, liquids are incompressible... They take the same amount of volume regardless of the pressure... Actually, liquids ARE compressible, just on the same scale as solid objects, so you don't notice.I'm not so sure about that, because no matter what the pressure, a solid object will occupy the same volume, and a given quantity (or weight) of liquid will not be denser becasue of the pressure... both WILL, however be subjected to changes in volume due to the temperature, as are gases... But my point remains valid IMO.20 atmospheres is not that bad to handle per se, the air is denser, [...]Well the air will be 20 times denser, adjusted for helium it's 5 to 6 times more dense than air at normal pressure. I'm sure your lungs will not like that extra work.The funny hting is: Your lung WON'T have ANY extra work... it's actually easier for them to exchange the gasses, since the gaseous molecules are more tighly packed...If you mean your Diaphragm (the muscle that makes us breathe) will be more strained, then I'm sorry but you are dead wrong, it wil have nothing more to do, as long as we don't suffer catastrophic decompression, aka instant explosive death. Respiration is actually a simple thing, like you'd use a "blower", to light up a fire... it works by the difference of pressures created by the movement we apply to it, but it works equally well with more or less pressure, as long as our air does not turn liquid, there really is zero difference... Re: Ion ArmorsOh, and keeping the pressure out is FAR easier than keeping it in, because of the structural stress. When you think about it, a spaceship only have ONE atmosphere to keep out, the same kind in pressure difference you'd feel under 10m of water, but inside out... And a bus' wheel holds more than 5 atm pressure, yet is not comparable to a spaceship ... The structural advantage of the "outside" arc as compared to the "inside" arc is not so great, if steel is used (it's important with materials like bricks and concrete, which behave real badly wrt tearing).Hmmm, you got a point here... Then again, 5 atmospheres is the equivalent of... 50m underwater or so? (the "very shallow" in Tftd)My point was that if your soldiers are accustomed to depths of 1000m (or 100 atmospheres, that's pretty hard to contain inside a suit without explosive decompression... I figured 1000m is not so bad compared to the 5000m to 8000m more their suits have to endure for them to go even deeper... My realism point is, some soldiers should be in decompression for at least a week after deep dives, otherwise they'd die...Then, since we're discussing water-physics and how BADLY they were implemented in this game, the aberrant throwing comes to mind here, as well as the effect of underwater explosions (I mean, with that kind of pressure, explosions are absolutely DEVASTATING underwater, and they destroy a LOT further).You won't get much stronger explosions underwater, as you will get essentially the same amount of energy to start with.That's very wrong, because when underwater, the water pressure makes YOU the softest spot where MOST of the energy will be directed against... The water pressure actually holds the energy more effectively, but it will be released through anything that's not at the same pressure in the viccinity. Oh, and since the speed of sound (and of explosions) is far greater underwater (it's denser material than air), the explosions will devastate further...Hence, submarines are VERY vulnerable to depth charges the closer they get. That's also why british bombers used underwater bombs to destroy electric dams in Germany, because they'd have needed ten times the explosive power to merely dent the other side... I hope this clears out any disagreements in underwater physics... Was'nt this post on Soldiers in each base btw? Edited September 8, 2004 by Paladin Link to comment Share on other sites More sharing options...
centurion Posted September 8, 2004 Report Share Posted September 8, 2004 I'm not so sure about that, because no matter what the pressure, a solid object will occupy the same volume, and a given quantity (or weight) of liquid will not be denser becasue of the pressure... both WILL, however be subjected to changes in volume due to the temperature, as are gases... But my point remains valid IMO.When the pressure increases, the solid/liquid/gaseous objects all compensate by getting their molecules closer together, so that they repel each other more. The only difference is that in liquids/solids the molecules are already quite close to each other, so even small compression produces great pressure.The funny hting is: Your lung WON'T have ANY extra work... it's actually easier for them to exchange the gasses, since the gaseous molecules are more tighly packed...If you mean your Diaphragm (the muscle that makes us breathe) will be more strained, then I'm sorry but you are dead wrong, it wil have nothing more to do, as long as we don't suffer catastrophic decompression, aka instant explosive death. Respiration is actually a simple thing, like you'd use a "blower", to light up a fire... it works by the difference of pressures created by the movement we apply to it, but it works equally well with more or less pressure, as long as our air does not turn liquid, there really is zero difference... You have to move more mass around, if you try to use a blower with water instead of air (if you had uranium-hexafluoride, that would be even better as a heavy gas), it will break faster. You have to produce more pressure to get out more mass in the same time interval. This can be countered by keeping the oxygen concentration of the air (so that you won't have to inhale the usual amount of air per breath), but then you would get oxygen concentration wildly differing in the different portions of the lungs, which is not good either.My point was that if your soldiers are accustomed to depths of 1000m (or 100 atmospheres, that's pretty hard to contain inside a suit without explosive decompression... I figured 1000m is not so bad compared to the 5000m to 8000m more their suits have to endure for them to go even deeper...And my point was that it isn't much harder to keep pressure in than out with metallic armor.Then, since we're discussing water-physics and how BADLY they were implemented in this game, the aberrant throwing comes to mind here, as well as the effect of underwater explosions (I mean, with that kind of pressure, explosions are absolutely DEVASTATING underwater, and they destroy a LOT further).You won't get much stronger explosions underwater, as you will get essentially the same amount of energy to start with.That's very wrong, because when underwater, the water pressure makes YOU the softest spot where MOST of the energy will be directed against... The water pressure actually holds the energy more effectively, but it will be released through anything that's not at the same pressure in the viccinity. Oh, and since the speed of sound (and of explosions) is far greater underwater (it's denser material than air), the explosions will devastate further...Hence, submarines are VERY vulnerable to depth charges the closer they get. That's also why british bombers used underwater bombs to destroy electric dams in Germany, because they'd have needed ten times the explosive power to merely dent the other side...Once you are underwater, you're at the same pressure as everything else, the extra strain is almost the same as in air.The range of explosions is not dependent so much on the speed of sound as on the environment's ability to absorb the explosion's energy; this is somewhat higher in air, but even in water you get the quadratic decay of the explosion's strength with distance, which limits the range no matter what is the environment.Subs: of course they are more vulnerable the closer they get, what do you want to illustrate?Dams: it's logical that it's way easier to destroy a dam from the direction where the pressure's already on it than from the other side, where the water's pressure will help keep the dam intact. Was'nt this post on Soldiers in each base btw? Yes, and we're discussing how are those soldiers actually living in those bases Link to comment Share on other sites More sharing options...
Paladin Posted September 8, 2004 Author Report Share Posted September 8, 2004 Ok, here's a quickie for ya 1) I agree solid/liquid molecules get closer under pressure, but really, is it significant at oceanic depths? We're not in a neutron star here :: My point was simply that it will not make any notable diference on liquids, where it is devastating on gasses... Wich WILL turn liquid if the pressure is great enough, even solid... (man, I don't want to imagine the kind of pressure it takes to get solid hydrogen at hot temperatures... ) 2) I agree you have to move a bit more mass if the gas is compressed, but really, it's nothing compared to a liquid... Then again, if you want your guys to get down the Mariana trench's pressure, that might be the case... and they won't survive that of course... 3) Well, it might be possible to survive intense internal pressure with metallic armor, but the fact is that a round form is much stronger in resisting pressure form the outside... All I'm saying is that it's really not the same design... 4) You're not necessarily at the same pressure than everything else, if your suit is keeping some of the pressure off your back, then you WILL suffer a lot more trouble from explosions... then again, aquatic aliens might not be affected as much (as THEIR pressure is equalised), but still...I perfectly agree with the quadratic decay that limits range, my point was simply that explosions are more devastating underwater, because the speed of sound is greater, hence the sonic blast of the explosion is more intense...Subs were just added in to illustrate the fragility of underwater low pressuriastion...Dams: Quite right, that's why an explosion on the outside of a sub/aquanaut wil be more devastating than one on the inside... I hope everyone enjoys this conversation asmuch as I do Link to comment Share on other sites More sharing options...
centurion Posted September 8, 2004 Report Share Posted September 8, 2004 1) According to this page, water compressibility is 4.5E-10 Pa^-1, so at 1 km depth (100 atm pressure) water gets comressed by around half of a percent in volume.On gases going liquid/solid, just a remark: if you try to get a gas to be solid just by increasing the pressure, there won't be a phase change between solid and liquid. The liquified gas will just get denser and denser, and its properties will change continuously; that's why it's always called "liquified", even when its properties would be close to those of solid objects.2) Well, in the 20 atm example, there was a 5-fold increase in mass; at 1 km, you get 25 times the mass, and the human lung is IMO too delicate to handle that amount of stuff.3) A round form is only as much stronger in resisting pressure from outside than from inside as its material is stronger wrt compression than tearing; for example, metals can usually withstand similar forces when they are pushing and when they are pulling, so the shape effect would not be as dramatic as, say, in architecture. Not the same design, but not that much different.4) If your suit can keep pressure out, it can keep shockwaves out as long as its structural integrity is not compromised. Link to comment Share on other sites More sharing options...
[Blehm 98] Posted September 11, 2004 Report Share Posted September 11, 2004 okay, not sure what order these posts are supposed to be in, but please continue water physics discussion here, not in the soldiers in bases thread Link to comment Share on other sites More sharing options...
centurion Posted September 11, 2004 Report Share Posted September 11, 2004 I sure hope you can split posts (or just copy them and let us edit them to have only the relevant info).And anyway, the discussion seems to be passing out Link to comment Share on other sites More sharing options...
Paladin Posted September 13, 2004 Author Report Share Posted September 13, 2004 Yeah, we kinda reached a kind of agreement here... Besides, the discussion got WAY further than that Link to comment Share on other sites More sharing options...
Jonaleth Irenicus Posted November 9, 2004 Report Share Posted November 9, 2004 One quick note, I thought what the divers experienced when coming up from too deep too fast was something about a mild portion of the gasses (nitrogen? CO2?) turning to liquid, and if you did not decrease the pressure slowly (so small amounts of liquid turn back into gas and you give them off from your lungs) a big portion of the liquified gas could turn back into the gas state, blocking capillaries and such. Link to comment Share on other sites More sharing options...
[stewart] Posted November 10, 2004 Report Share Posted November 10, 2004 God I love nerd fights. :: Link to comment Share on other sites More sharing options...
BattleKnight Posted January 11, 2005 Report Share Posted January 11, 2005 Also, how do you explain grenade throwing underwater? I tried throwing a ball under water (I'm a diver), but the thing didn't get too far. So, how would you explain the olympic throws the aquanauts can do? A propelled grenade? Frisbee-like grenades? Link to comment Share on other sites More sharing options...
Blood Angel Posted August 3, 2005 Report Share Posted August 3, 2005 It's called the magna-blast grenade, is it not? Therefore I'd imagine it would have at least some degree of electromagnetism. Therefore, the combination of being thrown and a degree of wanting to go towards the nearest metal thing will propel it further. Although I've just realised this would mean that a grenade would go back at the person who threw it. The other solution: It's a game... Link to comment Share on other sites More sharing options...
Exo2000 Posted August 3, 2005 Report Share Posted August 3, 2005 It's a game. Physics need not apply. Mostly, it's a very OLD game, and only just now are realistic physics being implemented. As for the moving to a target, or seeking, I'm afraid the best you'll get there is the Boomeroid from X-COM 3. Link to comment Share on other sites More sharing options...
Guest Azrael Posted August 3, 2005 Report Share Posted August 3, 2005 *Shakes head as people insist in attempting to revive very old discussions* Link to comment Share on other sites More sharing options...
Blood Angel Posted August 3, 2005 Report Share Posted August 3, 2005 For the second time in as many minutes. sowwy Link to comment Share on other sites More sharing options...
[Blehm 98] Posted August 3, 2005 Report Share Posted August 3, 2005 it is only hard to throw grenades underwater because they are light, if you were to throw a heavy ball underwater it would go pretty far, although not that far(as in air, that is)i should have locked this back when they said it was over, then i could have reopened it and moved the grenade questions here, then relocked it when grenade discussions were done, there isn't much moderating stuff here, XCOM1 has most of it Link to comment Share on other sites More sharing options...
Recommended Posts
Please sign in to comment
You will be able to leave a comment after signing in
Sign In Now