Paper folding and the moon???

[longdogs]

Ok, so some of you might know the answer to the following question but for those that don't, have a wild guess before googling it or viewing the link below.

If it was possible to fold a sheet of paper an infinite number of times, how many folds would you need to make before the paper reached the moon?

http://scienceblogs.com/startswithabang/2009/08/31/paper-folding-to-the-moon/

 

[Newboy]

Somebody should tell NASA/ESA - all that mucking about with rockets wasn't necessary!

 

[gregers]

dont tell me,someone has been paid millions of dollars to have worked it out.

 

[longdogs]

dont tell me,someone has been paid millions of dollars to have worked it out.

Apparently, people have been working this out for years & years.

Anyone come up with an answer yet?

 

[gregers]

7 .but iirc myth busters managed 11.

 

[longdogs]

7 .but iirc myth busters managed 11.

7 is probably the most folds you could make in a piece of paper (apart from Mythbusters) but the total folds needed to reach the moon is.....




42

 

[Brigadier]

Depends on how thick your paper is to start with

 

[JBR]

Depends on how thick your paper is to start with

I remember some TV programme many years ago where contestants were in competition to be able to fold a piece of paper in half the highest number of times. They were given the choice of normal paper and tissue paper. Surprisingly, they both managed the same number of folds (I think it might have been something like seven).

 

[Dextraneous]

On a completely related point, if you put a penny on the first square of a chessboard, 2p on the second, 4p on the third, 8p of the fourth etc, then ho much money would you need to continue and complete the board?

 

[nflowers]

On a completely related point, if you put a penny on the first square of a chessboard, 2p on the second, 4p on the third, 8p of the fourth etc, then ho much money would you need to continue and complete the board?

Easy: (2^64)-1 pence which is £184,467,440,737,095,516.15

Nick

 

[EFLImpudence]

How do you get an odd number of pence?

 

[nflowers]

It's the -1, so any size board will always be odd in the pence e.g. a 2*2 board will have 4 piles of coins going 1,2,4,8 (i.e. (2^4)-1) = 15. A 3*3 will be (2^9)-1 = 511 pence i.e. £5.11 - always odd!

Another way of thinking about it is that the first pile is 1 coin - all subsequent piles will contain an even number due to the repeated doubling, so when we add them all together the first pile will always ensure it's an odd number.

 

[EFLImpudence]

Oh, of course, silly me.

 

[nflowers]

Oh, of course, silly me.

No problem, happy to help

Nick

p.s. maybe I should get out of academia and back to my old job as an Electronic and Electrical Engineer and do something a bit more useful....