Let's use an 8x11 paper. Assuming that you can uniformly fold the paper equally in half at max 7 times, then the thickness would be:
1st fold: .5 + .5 = 1.0
2nd fold: 1.0 + 1.0 = 2.0
3rd fold: 2.0 + 2.0 = 4.0
4th fold: 4.0 + 4.0 = 8.0
5th fold: 8.0 + 8.0 = 16.0
6th fold: 16.0 + 16.0 = 32.0
7th fold: 32.0 + 32.0 = 64.0
So, you would have 64.0 inch. Damn. That's pretty thick. Let's assume that you are Superman. Also, let's assume that this is for the first set of fold and you're folding it half on the longer side (11). Now, say that you can fold it 2 more times on the shorter side (8).
1st fold: 64.0 + 64.0 = 128
2nd fold: 128 + 128 = 256
Now you'll have a paper that's 256 inches long! Then, all you have to do is convert it to feet, divide it with the building's height, then multiply your answer with the total number of folds. In this case, we have 9 folds.
Here's an interesting answer:
An interesting question! I tried this myself several times with different
kinds of paper and stuff, and here are my results. With an ordinary sheet
of paper, I could only get seven folds-in-half out of it. With a Kleenex, I
got eight. With a piece of tissue paper, I got nine folds, and with a big
bed blanket, I got six folds.
So what does this all mean? How does it relate to math? Well, here's the
deal. See, every time you fold the paper in half, you're making a new
structure whose thickness is twice the thickness of the previous structure.
So you can see that the thickness is going to get REALLY big, REALLY
FAST. That's the important thing here; when it gets too thick, you can't
fold it in half anymore.
This is an example of what we mathematicians call a Geometric Sequence.
Each term in the sequence is twice as big as the term before it. So we call
this a Geometric Sequence with common ratio 2. That just means that if
you take any term in the thickness sequence and divide it by the previous
term, you'll get 2.
Have you ever heard of the chessboard-rice problem? If you put one grain
of rice in the first square on a chessboard, and then two grains on the next
one, four on the next, eight on the next, then sixteen, etc., how many
grains of rice will there be on the last square? Or even on the fifteenth
square? As it turns out, there will be A LOT OF RICE! A way big huge
amount. And I'm not kidding. Geometric growth is fast.
Another interesting thing about this problem is that you'll get basically
the same number of folds no matter what kind of sheet you use. I mean,
I got 6, 7, 8, and 9 folds when I used vastly different materials. It's not
like we were getting twenty or thirty folds, or only two or three; they
were all around seven or eight. Which tells you something: the starting
thickness really doesn't affect things very much. The mathematician
would say that the first term of a Geometric Sequence doesn't affect its
growth rate very much. For instance, if you started with a piece of paper
that was twice as thick, you should be able to fold it one fewer time.
Not half as many times, but only one fewer. That's not much difference.
So that's what I have to say about paper folding. Actually, that's not ALL
I have to say; I'm kind of an origami nut. But that'll have to do for now.
You might think about the following questions: How does the size
(length and width) of the paper affect how many times you can fold it?
How many times could you fold it in thirds? In fifths?
Anyway, thanks for the question. Write back if you have more!
-Ken "Dr." Math
Facebook
Twitter