h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

I've read various SF books that featured diamond monofilaments. An Arthur C Clarke one had some bloke chopping his thumb off iirc. BUT..

if you moved it slowly enough, would it actually cut your finger off, of if you moved it through your body, would it cut you in half? Seems to me that the filament would be so thin that it wouldn't cut cells in half, so wouldn't do that much damage.

Any thoughts?

An unrelated observation, but in the recent x-men movie "First Class" nascent villain Magneto dispatches one character by pushing a coin *very slowly* through their head.

It struck me as I sat in the cinema watching this that it deserved not a Geoff Hurst but rather a Douglas Hurd for it's physics as it seemed to be in violation of Newton's F=MA rule, the mass of the tiny coin was moving very slowly so where did it acquire the force to punch through all that bone and tissue?

I confess myself, perplexed.

In the case of X-men, Magneto was using his control of metal to push the coin, so the force came from him. But strangely, having a coin pushed against his head did not cause the bad guy to fall backwards. Instead, he stayed still and the coin went into his head.

To the original question - 'diamond' microfilaments are tubes of carbon like a long narrow piece of mesh made of carbons which is then rolled up to make a tube. I suspect they'd be quite wide compared with the molecules they are cutting through, so they would break intermolecular bonds.

In the case of X-men, Magneto was using his control of metal to push the coin, so the force came from him.

Does he control metal or manipulate magnetic fields? If the former, it's a sci-fi conceit and fiction, if the latter - wouldn't the coin have sped up as the field strength increased to pull it through (or at least popped out the rear side and buried itself in the wall?)

He appears to be able to control metal because he can move any metal, not just magnetic ones.

So in conclusion: fiction.

Dagnabbit.

<< 'diamond' microfilaments are tubes of carbon like a long narrow piece of mesh made of carbons which is then rolled up to make a tube. I suspect they'd be quite wide compared with the molecules they are cutting through, so they would break intermolecular bonds. >>

But wouldn't that still be way smaller than a cell, and therefore be very unlikely to cause cellular damage?

Breathing in asbestos fibres is the nearest equivalent to getting nanofilament injuries - read up on asbestosis. Breathable asbestos fibres have a range of diameters from tens of nanometres to hundreds of nanometres upwards to a few microns. Fibre lengths are generally a few microns to hundred of microns.

What SF contains these nanofilaments and how are they being manipulated to cause the aforementioned damage? Such fibres will be strong along the axial direction but can be quite brittle perpendicular to the axis. Asbestos fibres scars lung tissue, rips open cells, damages DNA which can lead to cancer ...

"Magneto dispatches one character by pushing a coin *very slowly* through their head"

Seen the movie, forgotten the scene.

Is the victim's head braced against something? If so, no problem.

If not, then possibly still no problem. Overthoughtthrough geek rationalisation alert: if Magneto sensed fillings in the victims teeth, he could hold the head still in free space while pushing the coin through it as slowly as he liked.

I'm not clear on how eddy currents work, but I'm pretty sure that if you were Magneto you wouldn't be limited to ferromagnetic materials.

A particularly nasty and aggressive cancer at that! Mesothelioma.

Regarding pedro's question it does not matter that the monofilament is only nanometers thick. In order to pass through to body (or digit) it has to bisect something. Even if, by some miraculous process or stroke of luck it managed to avoid damaging all the cells it would still cut through interstitial spaces, connective tissue and fluid. It would open up all the vessels causing bleeding. The result would be that whatever the filament passed through would be cut in two.

Since cells in the body are not organised in any grossly regular way the likelihood of not damaging any of them would be vanishingly small.

t.

well, if it is *any* metal then presumably he can control the calcium content of the skull forcing that to stay in one place whilst pushing the coin through it.

I suspect the actually force/control interactions are all powered by narrative causality though

Shhh. Spoilers.
http://www.youtube.com/watch?v=nsk1IiIFM0k

As I recall now the scene in question comes about becuase Xavier is doing his 'freezing people in position' trick, which allows Magneto to steal Shaw's magic hat - he then does the coin trick as describe above - and now with pictures.

"As I recall now the scene in question comes about becuase Xavier is doing his 'freezing people in position' trick, which allows Magneto to steal Shaw's magic hat - he then does the coin trick as describe above - and now with pictures."
I'm not sure what the "freezing people in position trick" is, but the head would be knocked backwards in real-life. The amount it is knocked backwards would depend on the thickness and nature of the surface (as well as its composition). Get a coin and press it against the forehead to experiment.

ps standing up is not easy without proper muscular control (with rapid "twitching" of antagonistic sets of muscles). If all the muscles were frozen as in rigor mortis I would suspect the "frozen" person would topple over before the coin had sufficient force to penetrate the head.

pps The "frozen" person would likely topple over as soon as he was "frozen" - due to this loss of muscular control.

Xavier's freezing trick isn't a literal total muscular freezing, it's a mental freezing. Autonomic muscular functions continue. Otherwise it would be almost immediately fatal. Also, people don't *know* they've been frozen. It's a consciousness thing, not a muscle thing.

Yes, but a person who had been essentially given a mental command to stand still, could still topple over. I believe in X-Men 2, a person who is frozen is poked by another character and wobbles a bit back and forth.
At which point does Magneto manipulate non-magnetic metals? There's adamantium, but then who knows what kind of alloy that is. It might well be mainly steel.

"non-magnetic metals"

No such thing. You might mean non-FERROmagnetic metals, which includes stainless steel and aluminium, but you can set up eddy currents in those and make them into electromagnets... which is I assume what Magneto does when he needs to manipulate something that couldn't be used as a compass.

I really, really should get out more...

makes sense to me.

So assuming all of that is the case (consciousness freezing, non-ferrous electromagnets and so forth) how did that little coin moving so slowly punch through a skull twice?