Make: Volume 82

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make.co

Since that’s not very practical, we have created

a 3D-printed model to think about this (Figure

E

)

and put it in front of our red wall to show that it,

too, is a curve that rises as the square of its

position. (It’s a little shorter because the size of

our print bed did not allow us to go all the way to

5

²

.) We will give you a template to make a paper

one instead, but it is a little easier to see what is

going on with this translucent model. We can see

there that the smooth blue model is crossing

through the center of the top brick in each stack.

There is a part of the smooth blue model

sticking out toward us in Figure E. Let’s r ...