Naked Science Forum

On the Lighter Side => That CAN'T be true! => Topic started by: mar_mazz on 19/10/2005 09:18:00

Title: A piece of paper can take you to the Moon!
Post by: mar_mazz on 19/10/2005 09:18:00
Hi guys!

Does anyone know how many times I should fold a piece of paper (hei, I mean a NORMAL piece of paper, A4 size)... to cover the distance between Earth and the Moon?

have fun!

[:o)] Marzia
Title: Re: A piece of paper can take you to the Moon!
Post by: neilep on 19/10/2005 13:44:43
Isn't it something that you just wouldn't believe...like only fifty times ?...

Men are the same as women.... just inside out !! (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.zerogain.com%2Fforum%2Fimages%2Fsmilies%2Faction-smiley-075.gif&hash=84631c0c4a382b5e68463904b7b9fddf)
Title: Re: A piece of paper can take you to the Moon!
Post by: thefunkyaquarium on 19/10/2005 22:47:32
Something like that.

Except it's actually impossible to fold a piece of paper in half more than about 8 times.
Title: Re: A piece of paper can take you to the Moon!
Post by: Ultima on 22/10/2005 17:15:32
There's a set limit to how many times you can fold a piece of paper regardless of size or the type of paper (or anything) [:D] So the answer is you can't. If you wanted to work it out in theory, then the thickness of the paper doubles with every fold. Say the paper is a tenth of a millimeter thick. 0.00001m and the average distance to the moon is 382,500,000m..

Since im a computery person here you go:

Code: [Select]

#include <stdio.h>
#include <stdlib.h>

#define papthck 0.00001
#define moondst 382500000.0

/**
 *   getfolds.c
 *
 * Lets work out the paper folds to some distance!
 * Default to the number of folds to the MOON.
 *   Ultima (2005-10-22)
 * */

long getfolds (double start, double end);

/*
 * 1st arg thickness of material, followed by distance to reach.
 */
int main (argc, argv)
int argc;
char **argv;
{
   if (argc == 1) {
      printf("No. of paper folds to MOON: %ld\n",getfolds(papthck,moondst));
   }
   else {
      printf("No. of folds: %ld\n",getfolds(atof(argv[1]),atof(argv[2])));
   }
return EXIT_SUCCESS;
}

/*
 * Get that sassy value you want.
 */
long getfolds (start, end)
double start;
double end;
{
static long number = 0;
   if (start >= end) return number;
   start *= 2;
   number ++;
   getfolds(start, end);
return number;
}

The answer is 46 give or take a fold [;)]

http://mathworld.wolfram.com/Folding.html
Title: Re: A piece of paper can take you to the Moon!
Post by: neilep on 22/10/2005 20:51:06
...amazing...so my guestimate at 50 was pretty darn close  !!

Men are the same as women.... just inside out !! (https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fwww.zerogain.com%2Fforum%2Fimages%2Fsmilies%2Faction-smiley-075.gif&hash=84631c0c4a382b5e68463904b7b9fddf)
Title: Re: A piece of paper can take you to the Moon!
Post by: Ultima on 23/10/2005 00:45:29
Well that depends what you mean by close [:)] it would be 2^4 x <distance to the moon> out.
I was surprised it was so little and I know what exponential growth is like from programming [:D]. One thing to think about is bacteria populations grow in a similar manner [;)]
Title: Re: A piece of paper can take you to the Moon!
Post by: simeonie on 14/12/2005 17:32:13
You lost me at "hi"
Title: Re: A piece of paper can take you to the Moon!
Post by: Solvay_1927 on 14/12/2005 23:58:52
A related link, in case anyone's interested:
http://www.thenakedscientists.com/forum/topic.asp?TOPIC_ID=2946