

Iron Man 3 and the Human Chain - dsr12
http://www.wired.com/wiredscience/2012/10/iron-man-3-and-the-human-chain

======
Dove
There's that scene in Iron Man, in the desert, in which Tony Stark's first
attempt at a suit runs out of power and crashes into the sand after a fall
from a decent altitude. The first time I saw that, I thought, "They just
killed the hero in the first 10 minutes of the movie!" My mind raced, trying
to figure out how they were going to make this work. That was way too many
g's. He was surely very dead. Was he not actually in the suit? Was the story
going to focus on a protege of some sort? Was there a clone or twin or
something?

When he walked away from the wreck, I was disappointed. But I knew then with
certainty what sort of physics engine we were using.

~~~
jerf
I've long hypothesized that a normal human from the "superhero universes"
dropped in our world would still seem bizarrely sturdy, if not actually
superstrong.

Another similar one that really bothers me is Oliver Sansweet's fall in The
Incredibles. He attempts suicide by leaping off of a building, gets about
twelve stories down, then is "caught" by Mr. Incredible leaping at him and re-
entering the building he jumped from. Mr. Incredible exerts enough force to
instantly stop his downward descent _and_ enough force to also give him at
least a good 20mph horizonally, probably more, and from this Oliver gets... a
neck brace. That catch should have killed him, too. Yes, the maximum
acceleration might have been smaller than an impact with concrete since Mr.
Incredible could give him a very small buffer with his arms... though I see no
evidence he does. Mr. Incredible impacts Oliver and within two frames tops
Oliver has matched Mr. Incredible's velocity. Mr. Incredible also appears to
have incredible mass, as he does at several other points in the movie, as
Oliver's impact appears to leave his trajectory entirely unaffected. He seems
to mass at least 3 or 4 tons, probably more.

Oliver is an incredibly sturdy guy by our real-world standards.

~~~
psbp
Oh my god, these are comic book movies. Get over it.

~~~
Dove
Well, it's not really something you can turn off. When I saw Tony Stark crash
in the sand, the effect on me was very much the same as if I'd seen his head
disintegrated by a shotgun blast. I was viscerally _sure_ he was dead.

If you haven't seen it recently, here's the scene.
<http://www.youtube.com/watch?v=uZ1cyUN9RuY#t=5m01s>

I mean, I know it's a superhero movie, and I still wince at the force of the
impact. It's like watching someone get hit by a speeding bus -- only the
average superhero would destroy the bus and slow down over its length. The
sand actually _stops_ him.

------
peeters
The first section is a really roundabout and overly technical way of thinking
about the force exerted on each person, and as a result, even gets it
completely wrong:

> The sixth person in the human chain (the top person in a chain of six) would
> have to hold up a force of 660 pounds. This assumes an average human-chain
> person weight of 130 pounds

No. A chain of 5 would be a force of 650 pounds for the person on top (only
the hand they're grasping with matters, the force of the chain against a
link's ankle is pretty irrelevant, the human body has pretty good tensile
strength and can probably lift quite a bit before getting dislocated joints,
etc); a chain of 6 would be a force of 780 pounds.

This isn't rocket science, and really is so intuitive that this explanation is
just beating around the bush. Here's how you really calculate it:

> The force exerted on the top person is the total weight of the chain.

The end. A chain of two 130-pound people exerts the exact same force as a
"chain" of one 260-pound person.

------
podperson
This completely ruins this movie and its predecessors for me. Here I was
thinking that, say, everything the Hulk does obeys the laws of physics.

One major quibble -- why the hell does his chart's y-axis start at 100?!

~~~
CodeMage
For the same reason it ends at 700: because there are no data points outside
the range [100, 700] so he can crop the chart without losing any useful data.

~~~
podperson
Not the same thing at all. You're losing the relative scale, and the benefit
in this case is minor. If you're trying to emphasize near-term changes in a
range with a very high base (e.g. stock fluctuations) this might be justified
if you make the broken scale clear, but it's probably better in such a case to
make the graph into log change from baseline (which is how, for example, yahoo
charts stock prices).

In this case, for a very minor space saving and extra work the -- borderline
useless -- graph is made misleading.

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nthitz
Reminds me of Randell Monroe's new series What If? Really awesome to see this
major publication have some interesting math even if it's just for fun!

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coliveira
Interesting analysis, but this is just the initial shot. There is lots of CG
work ahead, and I would be surprised if this kind of thing is not included in
the effects necessary to make it more realistic.

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wazoox
Reminds me immediately of "Intuitor Insultingly stupid movie physics":
<http://www.intuitor.com/moviephysics/>

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sukuriant
Cartoonists would exaggerate a person's response when they're, for example,
hit by a mallet, or kicked hard. This is especially true in anime. In the real
world, a person isn't bent in half from a kick, they're lightly dented; but,
to emphasize the power of the kick, they'll bend the person in half. Why can't
this same thing occur in movies with real actors? Perhaps they thought this
bend would better convey the motion of flying, rather than a bunch of people
just hanging in the air. If they were just hanging in the air, the average
view would think something along the lines of "wow, that's a bad green-screen
effect" or "huh... they're not moving, they're just going straight up..." vs
"they're being carried to safety by Ironman! and they're having to cross
distance to do it!"

~~~
maxerickson
The woman hanging on Iron Man is holding up 4 people with 1 arm.

They could capture much of the scene by having them ride a girder or whatever.

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lnanek2
well, it's a superhero show, so just say human chaining ability is part of his
superpower. his suit makes little metal tendrils that reinforce the structure
or something

