14 KiB
ELI5: Could an unbreakable wire that is one atom thick slice through you and would it leave you in two separate pieces? • /r/explainlikeimfive
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Author: u/itisike Dragon Army*
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Score: 0
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Created: 2015-02-06T15:54:02
Post:
Comments:
u/None [+4] (22 hours later)
You can't have an unbreakable wire. All material objects have a tensile strength and shear strength dependent on their composition and thickness.
It can't be one atom thick. A wire one atom thick isn't even a monomolecule, it's a line of individual unbonded atoms. It dissolves immediately into monatomic dust.
It can't cut. On this scale, you would move some atoms and molecules around, but you probably would not damage any of the individual cells or separate them from each other. The line would pass between their constituent molecules, and those molecules would close back up behind it.
u/Solonarv [+3] Chaos Legion (a day later)
I think 'unbreakable' right here is just a shortcut for 'durable enough that it won't break under these circumstances'.
As far as I know, you're pretty much correct on that point. However, there's speculation that a chain of carbon atoms with alternating triple and single bonds could be stable.
Yes.
u/king_of_the_universe [+1] (2 days later)
About the third point: The atoms of the object would at least be shifted around a little. If this would happen to the object a few thousand times at exactly the same spot, changes on more macroscopic scales could emerge. As a visual image: It's like using the smear brush with a low pressure setting in a paint program. You have to apply it a lot of times to get a visual effect.
Affixing such a wire between two poles in between a lot of people walk through (e.g. entrance of office building) could over a long time result in worse health, kinda like an asbestos or weakly irradiated environment, if the people manage to get hit by the wire in the same place all the time, which is super unlikely.
u/None [+2] (2 days later)
No effect which is lower-impact than the normal Brownian motion at 300K is particularly worthy of worry to a macroscopic being evolved to live in that temperature environment.
u/king_of_the_universe [+1] (2 days later)
Good thinking. But what's the relationship in scale between what such a wire would do and what Brownian motion would do? And/or there's the following aspect: The motion due to thermal energy is chaotic and, I suspect, would keep the overall same energy level.
This wire would move everything in a few same-y directions, which introduces an information into the soup that wasn't there before, which might have a relevant energetic effect. As an example of what I mean, just imagine half of the atoms randomly bouncing in the exact same direction in parallel, that would be devastating to the macroscopic object.
Also, the wire would introduce energy into the system. Even if it's on the scale of Brownian motion, it would effectively be thermal energy. And too much heat is a thing.
u/None [+3] (2 days later)
I strongly suspect that there is a reason that doctors perform surgeries with scalpels rather than clubs, and a reason that wounds heal faster still the finer the scalpel and cleaner the cut they can make. I am personally familiar with the way even the deepest of papercuts can nonetheless heal and close alarmingly quickly and to no ill-effect, and that's with a jagged blade edge a significant fraction of a millimeter thick. You are proposing using a blade whose edge would be measured in femtometers.
While I cannot yet devise a strategy to verify this result empirically, I believe the trend in decreased bodily harm should continue to scale inversely to the width of the blade edge, for in the degenerate case whereby we are intersected by a flatlander, it shall be surely be impossible to notice at all even the existence of a flatland. Neutrinos shine up on us all night, a withering machinegun fire that leaves us riddled with innumerable paths of full peircing entry and exit wounds of negligible size - and we are none the worse for it.
I acknowledge though that passing a point through a solid to draw a line is not as effective as passing a line through it to draw a plane - while asking you to keep in consideration that on these scales even that analogy fails because humans are less a solid and more a liquid - or a void.
u/Charlie___ [+2] (4 hours later)
Depends, but probably not. At small scales, things are verrry sticky. Your bones would almost certainly stay intact just because they're so big and rigid that the cut edges are always pressed against each other. Not sure about soft tissue, and whether blood pressure would be enough to overcome stickiness.
u/rumblestiltsken [+3] (8 hours later)
Wrong scale. You aren't splitting cells, you are splitting molecules. Blood doesn't shoot out the holes between epithelial cells, so why would blood pressure so anything to a significantly smaller gap? A human red cell is something like a five orders of magnitude bigger than an atom. A simple protein is dozens of atoms.
I'm not convinced it would anime cut you either though. You break some bonds briefly and ... then what? They don't return to the lowest energy state and rebond? Sure, they might not rejoin exactly right and some cells might even die (not sure, cells are pretty robust to minor insults) but I really don't think a big separation is likely.
u/Nighzmarquls [+1] (9 hours later)
Hum... I know I mentioned above about speed (the ludicrous amount of which that would be needed to make the impact actually explode). But now I'm thinking we need to talk about that here too. I think if we did it slow enough exactly what you describe would happen. Maybe also there are some other time frames... but what about dragging segments of molecules along? I think we might actually need to know what atomic bonding properties this one atom thick slice of unbreakable would actually be.
Would it drag air molecules behind it? would that effect it any more or less?
u/696e6372656469626c65 [+2] I think, therefore I am pretentious. (9 hours later)
Er... why would speed make the cut "explode"? That doesn't seem at all obvious to me.
u/Nighzmarquls [+1] (12 hours later)
Everything explodes if you hit it fast enough with a solid. Relativistic explosions eventually are a factor but before that we probably could get pretty good splatter.
u/696e6372656469626c65 [+3] I think, therefore I am pretentious. (14 hours later)
Everything explodes if you hit it fast enough with a solid.
Unless you're taking "explosion" to mean the result of fusion-reaction temperatures being achieved by the kinetic energy transfer, no, it doesn't. In terms of an atom-thick wire, I'm not sure much kinetic energy would actually be converted into thermal energy; it seems as though the wire would more than likely just go through the body without substantially decreasing its velocity, meaning very little momentum will actually be retained by the body. This small amount will be lessened even further by the fact some of the energy will be used to sever molecular bonds. After all of that, I highly doubt that enough energy will be left to initiate fusion (although of course I don't actually have any numbers to back this up).
Relativistic explosions eventually are a factor but before that we probably could get pretty good splatter.
I'm not sure what you mean by "relativistic explosion", but an atom-thick wire probably wouldn't generate that much splatter, either. In terms of the cell membrane, well, that's made of a lipid bilayer that's not held together by any actual bonds; it's just surface tension similar to what you see in a soap bubble. If you pass the wire through fast enough, it's possible the membrane wouldn't even be disturbed that much; it'd simply reform as soon as the wire disappears. Internal cell structures such as organelles probably wouldn't fare so well, but I'd imagine very little splatter would actually occur.
u/Nighzmarquls [+1] (17 hours later)
Hmmm. You've changed my mind on my answer for this. Your physics points Match better with my understanding of physics then my own previous prediction.
Thanks.
u/derefr [+1] (9 hours later)
I have a feeling the results would be similar to very-high-energy, planar, one-atom-"thick" laser being slashed across your body. In other words, for all practical purposes, radiation damage.
u/rumblestiltsken [+1] (12 hours later)
Which wouldn't cut you at all. It would burn you or explode you depending on energy level. You could technically end up in separate pieces, but it would be ... messy.
And the hypothetical wire exerts no excitatory effect on the tissue, unlike a laser.
u/696e6372656469626c65 [+1] I think, therefore I am pretentious. (14 hours later)
Furthermore, the laser wouldn't penetrate all the way through the body, unlike a wire; instead, the photons from the laser would stop at the surface of the skin (or clothing). With sufficiently high energy, the laser could burn through a significant portion of your skin and possibly even penetrate to muscle, but the final effect would be nothing like that of a cut.
u/rumblestiltsken [+2] (a day later)
And at even higher temperatures the laser gets even less penetration because the surface of the target vaporizes and explodes before the burn can get any deeper.
If we are talking about a wire with a huge amount of kinetic energy the same would happen, but that still isn't cutting anything.
u/derefr [+1] (a day later)
Okay, maybe "laser" was the wrong word. How about a gamma-ray burst, in somehow coherentized form? It will go right through you.
u/derefr [+1] (a day later)
This is a very odd hypothetical wire. I'm not sure it could actually be specified in a sensible way given physics—like, not even if you were overriding the natural physics in some per-simulation-frame way.
Really, it's a question of what the atoms of the wire do when they interact with regular molecules. My expectation would be for the molecules to try to form chemical bonds to the wire (oxidizing it and so forth), and then for those bonded molecules to get dragged along as the wire continues to move.
One of the important questions to picture this more specifically: what temperature is the wire?
u/embrodski [+1] (10 hours later)
Dunno, seems a single-proton particle bean can still mess you up (as linked from the original discussion) http://en.wikipedia.org/wiki/Anatoli_Bugorski
u/rumblestiltsken [+5] (12 hours later)
I can tell you with one hundred percent certainty that a particle beam would act nothing like a mono-atomic edge of an inert material.
Source: medical radiation specialist
u/696e6372656469626c65 [+1] I think, therefore I am pretentious. (14 hours later)
I agree with the gist of what you're saying, but... one hundred percent certainty.
u/embrodski [+1] (a day later)
Ah. Very well then.
u/autowikibot [+1] (10 hours later)
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#### Anatoli Bugorski:
Anatoli Petrovich Bugorski (Russian: Анатолий Петрович Бугорский; born 1942) is a Russian scientist who was struck by a particle accelerator beam in 1978.
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Image ^(i) - Anatoli Bugorski after the accident, with a red line depicting the path of the proton beam.
^Interesting: ^Anatoly ^| ^U-70 ^(synchrotron) ^| ^Nuclear ^and ^radiation ^accidents ^and ^incidents ^| ^Phineas ^Gage
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u/illz569 [+2] (a day later)
A line of atoms will behave less like a wire cutting through flesh and more like a row of ping pong balls being pushed through a bush.
Edit: Also, why did you ask this here? Askscience would probably be more knowledgeable, or are you thinking about using this idea in a story?
u/itisike [+1] Dragon Army (a day later)
This is a cross-post.
I saw the post on the front page, and thought the /r/rational community would enjoy it.
u/Nighzmarquls [-5] (4 hours later)
Well if it was going really really fast you could explode but yeah other wise it will cut you up.
u/what_deleted_said [+1] (3 months later)