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Space travel is hard man. To get anywhere in a hurry, you need a shitload of energy to do it. Maybe that's the Great Filter - some civilization tries to go interstellar and vaporizes itself in the process.
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Apr 19, 2016 07:28
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So here's a fun chemical contribution courtesy of Batman '66 https://twitter.com/BatLabels/status/722231347482337280 I'm guessing the formula is just a bunch of random junk mashed together, though it reminds me a bit of "The Dip"
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Apr 19, 2016 08:47
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Segmentation Fox posted:So here's a fun chemical contribution courtesy of Batman '66 They’re real compounds, sodium dichromate and potassium ferrocyanide. Who knows what they’re doing in that episode, though. Maybe the set dressers just lifted the formulæ from the film processing lab. Platystemon has a new favorite as of 09:04 on Apr 19, 2016 |
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Apr 19, 2016 08:56
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Platystemon posted:They’re real compounds, sodium dichromate and potassium ferrocyanide. Yeah, it's got AgN... going around the side of the barrel, definitely just lifted chemical names from the film lab. 
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Apr 19, 2016 09:37
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Bad Angus! Bad!
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Delivery McGee posted:Yeah, it's got AgN... going around the side of the barrel, definitely just lifted chemical names from the film lab. There's letters after the N - probably an O, for AgNO3 - which would actually be in the film lab.
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Apr 19, 2016 15:56
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Platystemon posted:Of course. Pages 177–179 of Ignition!:
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Apr 19, 2016 21:49
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I'd just like to note, that Newton's second law, while still applicable, can no longer be written F = ma for relativistic speeds. Using relativistic mass, the derivative of momentum over time happens to be this formula.. On top of that, an impact at those speeds will be many orders of magnitude faster than 0.1 seconds, which increases the force by the same factor. I'm not gonna bother exactly calculating it, but putting those two things together, anything being hit by a relativistic iPhone is going to go boom even harder than any numbers posted so far suggest.
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Apr 20, 2016 06:30
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It would be interesting to run the numbers on how much of that energy would be dissipated on the way through the atmosphere, and how much is left when it actually hits the ground.
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Apr 20, 2016 06:52
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How much of, what, is left when it hits the ground? The twenty mile streak of plasma?
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Apr 20, 2016 13:01
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Someone get Randall Munroe on the case, he seems to have this sort of time and curiosity.
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Apr 20, 2016 13:12
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All I'm hearing is a win win for planetary defense and e-waste disposal 
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Apr 20, 2016 13:20
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Jabor posted:It would be interesting to run the numbers on how much of that energy would be dissipated on the way through the atmosphere, and how much is left when it actually hits the ground. Intuition (and I am not a physicist, just a nerd, so take that for whatever it's worth) tells me that a sufficiently massive object hitting the earth at relativistic speeds would be like detonating a multi-gigaton fusion bomb and the question of how much of that was from the atmosphere vs impact with the surface would be an academic one, except all of the academics who weren't hiding in mineshafts would be incinerated or frozen in the ensuing nuclear winter.
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Apr 20, 2016 14:50
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Rather like firing a bullet into something, if it has sufficient density it'll just penetrate to some depth, spraying up a bit of ejecta and melting a bunch of crust/mantle on its way. Not much of its energy will be dissipated anywhere the surface cares about. Honestly, whatever its density, it'll be much like that; mostly penetration. At that speed/surface area ratio it's going to blast straight in unless it's no denser than air.
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Apr 20, 2016 18:22
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ArcMage posted:Rather like firing a bullet into something, if it has sufficient density it'll just penetrate to some depth, spraying up a bit of ejecta and melting a bunch of crust/mantle on its way. Not much of its energy will be dissipated anywhere the surface cares about. It's not like firing a bullet into something, though. A bullet is strong enough to withstand the mechanical stresses it encounters when it hits the target. Nothing made of real-world materials traveling at relativistic velocities can do that; at .86c the object's kinetic energy alone will be equivalent to its rest mass. The energy liberated at the moment of impact will be enough to convert the impactor in a very, very energetic plasma. All that energy isn't being liberated at the surface, but enough of it is to make anyone in the vicinity pretty unhappy, and that's if it doesn't just absorb enough energy while passing through the atmosphere to explode there. Even if it doesn't, on its brief journey through the atmosphere it's going to be surrounded by a viciously hot plasma radiating an enormous amount of energy; the atmospheric shockwave and thermal pulse would be immensely destructive. Phanatic has a new favorite as of 19:04 on Apr 20, 2016 |
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Apr 20, 2016 18:56
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Memento posted:Someone get Randall Munroe on the case, he seems to have this sort of time and curiosity. Would it surprise you that he's already done it? His very first What If, too. Not an iPhone and not .2c, but close enough. Spoiler: it explodes.
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Apr 20, 2016 19:43
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Wolfram Alfa man. I just entered this into it: "energy of an iPhone traveling at .5c" and got this: 
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Apr 20, 2016 20:07
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Shampoo posted:Wolfram Alfa man. I just entered this into it: So 1.557*1015 joules. Not actually as much as I thought; a 1 megaton explosion releases about 4.2*1015.
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Apr 21, 2016 00:58
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The XKCD guy's example might have a point though, this might not be a normal plastic collision where you can assume worst case scenario is that all that kinetic energy suddenly turns into thermal and things go boom, or else it could "punch through" something. Worst case scenario is instead all that kinetic energy is pointed in the direction of overcoming nuclear forces and liberating energy based on nuclear processes beside the kinetic energy.
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Apr 21, 2016 01:09
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zedprime posted:The XKCD guy's example might have a point though, this might not be a normal plastic collision where you can assume worst case scenario is that all that kinetic energy suddenly turns into thermal and things go boom, or else it could "punch through" something. Worst case scenario is instead all that kinetic energy is pointed in the direction of overcoming nuclear forces and liberating energy based on nuclear processes beside the kinetic energy. With enough iron in the hull that's a nonissue.
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Apr 21, 2016 01:13
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Tunicate posted:With enough iron in the hull that's a nonissue. That reminds me of the time that a scientist from the Californian Institute of Technology proposed cracking open the earth's crust and a week's worth of global iron production down it, with a probe in the middle housed in highly resistant metal. Archived copy of the proposal here. He did the maths!
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Apr 21, 2016 01:22
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zedprime posted:The XKCD guy's example might have a point though, this might not be a normal plastic collision where you can assume worst case scenario is that all that kinetic energy suddenly turns into thermal and things go boom, or else it could "punch through" something. Worst case scenario is instead all that kinetic energy is pointed in the direction of overcoming nuclear forces and liberating energy based on nuclear processes beside the kinetic energy. That fusion can occur is true but not all that significant. One carbon atom traveling at .5 c has almost 2 GeV of kinetic energy, even if it smacks into an oxygen atom and fuses the fusion energy is only a few MeV. Any fusion occurring at the baseball/air interface is insignificant compared to what else is going on. It's not liberated fusion energy that's vaporizing the pitcher and everything nearby.
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Apr 21, 2016 01:39
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A while back we were talking about octanitrocubane and other fun explosives and I swear someone mentioned one with a detonation velocity greater than earth's escape velocity but I can't find it.
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Apr 21, 2016 06:00
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Shampoo posted:Wolfram Alfa man. I just entered this into it:
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Apr 21, 2016 07:09
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Memento posted:That reminds me of the time that a scientist from the Californian Institute of Technology proposed cracking open the earth's crust and a week's worth of global iron production down it, with a probe in the middle housed in highly resistant metal. I'm torn between  and  . That's my kind of mad science
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Apr 21, 2016 07:23
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Rigged Death Trap posted:Laser beams cant melt space alloy hulls Antimatter Can't Melt General Products Hulls
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Apr 21, 2016 07:54
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chrisoya posted:I appreciate the result in gigawatt hours, as if someone out there is using high-speed iPhones as part of a power grid. It's not a bad way to say "we need a nuclear reactor running for this amount of time to launch an iphone at relativistic velocities".
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Apr 21, 2016 08:27
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Actually, the more I look at the concept ideas, the more nutty it gets. We're not talking about sending an Iphone. We're talking about building a giant 100 Gw beaming array, with corresponding death star laser to send an object that weighs less than a postage stamp to .2 C. Think I'm going to wait on that alcubierre drive.
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Apr 21, 2016 09:46
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Moist von Lipwig posted:A while back we were talking about octanitrocubane and other fun explosives and I swear someone mentioned one with a detonation velocity greater than earth's escape velocity but I can't find it. Octanitrocubane has the highest detonation velocity, 10.1km/s; escape velocity is 11.2km/s. I think that was when we were trying to work out the detonation velocity of hexadecanitrofullerene. And cackling madly.
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Apr 21, 2016 09:59
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DigitalRaven posted:Octanitrocubane has the highest detonation velocity, 10.1km/s; escape velocity is 11.2km/s. My god. Wonder what percentage of nitro'd carbon would make it go kaboom if another tried to get in on that.
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Apr 21, 2016 10:42
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DigitalRaven posted:hexadecanitrofullerene. I'm already running away. I fear that won't be enough.
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Apr 21, 2016 10:46
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DigitalRaven posted:hexadecanitrofullerene More like hexade-shouldyou-trofullerene am I right?
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Apr 21, 2016 14:11
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DigitalRaven posted:Octanitrocubane has the highest detonation velocity, 10.1km/s; escape velocity is 11.2km/s. Reporting from the land of "gently caress that infrared spectrometer and the building it sits in"...
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Apr 21, 2016 14:15
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This looks pretty fun: https://www.youtube.com/watch?v=9GulR31WzMU
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Apr 21, 2016 14:28
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I'm not a chemist- is there some layman's explanation somewhere about nitrogen groups and why they're so explosive? A lot of you react to these names with utmost horror but I don't know what they mean.
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Apr 21, 2016 14:32
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Luneshot posted:I'm not a chemist- is there some layman's explanation somewhere about nitrogen groups and why they're so explosive? A lot of you react to these names with utmost horror but I don't know what they mean. Nitrogen really really likes being in the diatomic nitrogen gas form. Nitro groups slapped onto things makes it really easy for the nitrogen in them to turn back into nitrogen gas. Since nitrogen gas is so darn stable, nitrogen gas being formed releases heaps of energy. You can get the same reactions with C-N bonds.
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Apr 21, 2016 14:41
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Luneshot posted:I'm not a chemist- is there some layman's explanation somewhere about nitrogen groups and why they're so explosive? A lot of you react to these names with utmost horror but I don't know what they mean. Sometimes the strait jackets come off in nice, controlled fashions like various biological processes who need nitrogen chemically available, which it is in that tenuous organic setting. Sometimes the strait jackets come off faster than the speed of sound. The difference is often in the execution, like how nitrogen fertilizer can either make a field grow things better or level an entire port in an explosion.
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Apr 21, 2016 14:44
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DigitalRaven posted:Octanitrocubane has the highest detonation velocity, 10.1km/s; escape velocity is 11.2km/s. Oh that sounds right  Thanks
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Apr 21, 2016 14:47
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DemeaninDemon posted:Nitrogen really really likes being in the diatomic nitrogen gas form. Nitro groups slapped onto things makes it really easy for the nitrogen in them to turn back into nitrogen gas. Since nitrogen gas is so darn stable, nitrogen gas being formed releases heaps of energy. LAYMAN ok so things like certain bonds, some like 2 some like 4 or whatever some things with certain bonds made by insane people become all unstable or more stable as gently caress poo poo gets weird then and they make bad things worse by magnitude level. which is a fuckton. so while nitro is bad and will blow up, octa, or deca nitro will go back in time and attempt to abort you for loving with them. the names you break down essentially into segments and each tells a story, some stories get rapidly terrifying when you add poo poo like nitro or floro im bad at chemistry but eh i layman interpret for a living. TehRedWheelbarrow has a new favorite as of 15:08 on Apr 21, 2016 |
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Apr 21, 2016 14:47
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Luneshot posted:I'm not a chemist- is there some layman's explanation somewhere about nitrogen groups and why they're so explosive? A lot of you react to these names with utmost horror but I don't know what they mean. Nitrogen atoms really want to be in N2 molecules --- that molecule has a triple bond, meaning it takes a lot of energy to break apart, and thus, it releases a lot of energy when it forms. Most explosive compounds have many nitrogen atoms in a larger structure, so they've got weaker bonds to the surrounding atoms. Add in the energy needed to weaken those bonds (the activation energy), and all of a sudden the nitrogen atoms' desire to be in a low-energy state overrides the existing bonds. They snap back to N2, releasing a lot of energy and generally going from a dense-ish solid to an expanding cloud of gas, both things that we give a poo poo about as people interested in the kind of chemistry that requires running shoes. The trick with nitrogen-based explosives isn't getting them to go bang, it's getting them to a state where the activation energy is high enough that they don't go bang when someone decides to open a bag of Doritos in the next building.
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Apr 21, 2016 14:53
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DigitalRaven posted:Octanitrocubane has the highest detonation velocity, 10.1km/s; escape velocity is 11.2km/s. I was hoping hexa-deca- would mean sixty, not sixteen  Are there any limits to how many nitrogens a molecule can have?
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Apr 21, 2016 14:56
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