Mathematics in base 13

Post by **johnriley1uk** » Sat Jul 30, 2005 1:46 pm

There's been a discussion on the PentaxUser forum that somehow got involved with Hitch Hiker's Guide to the galaxy. (Don't ask....)

Here's the question: In the book it's said that the ultimate answer is 42. The ultimate question is what do you get when you multiply 9 by 6? Hence "I always knew there was something fundamentally wrong with the universe".

There has been a reply that says "It actually works just fine if you work in base 13 instead of base 10. Perhaps Adams had three extra fingers?"

I'm sure we have some mathematicians out there who would care to explain this to me? :?

Post by **Mike** » Sat Jul 30, 2005 5:02 pm

I dont understand the answer very well but here is the forum with the information you require.

Maths Solution

Hope this clears up your problem.

Post by **johnriley1uk** » Sat Jul 30, 2005 5:12 pm

Wow. That is something I hadn't thought of and if it was intentional on the part of Douglas Adams, he was seriously more clever than I thought he was.

That is so interesting, perhaps i could get to be interested in maths! (Then it could be even sadder and more obscure than photography....)

Thanks, Mike! :D

mr_e · Post by **mr_e** » Sun Jul 31, 2005 11:26 am

Counting in different bases is generally pretty useless for everyday maths, unless you like computers and use base 16 (hexidecimal) a lot. The only real problem with different bases is representing them adequately, which is why "hex" has to use the letters a to f to fill in the extra digits needed.

To try and quickly explain the conversion to base 10:
Say we have C7, a hexidecimal.
C = 12, 7 = 7.
This is base 16, so, for the "C", instead of 12*10, it is 12*16 + 7*1.
This gives 192 + 7 = 199.

If you want formulas:
Base 10 figure = x*(b^(p-1)), repeated for every digit, where;
x is the digit as written, b is the base, p is position from the right, where the far right = 1 (assuming no decimal points).

Yay me.

Post by **johnriley1uk** » Sun Jul 31, 2005 12:47 pm

I thought somebody here would know...

So, Mr_e, do you agree with the supposition that in base 13 9x6=42?

And does this suggest that Douglas Adams may have known that most intelligent species in the Universe actually have 13 fingers?

Guest · Post by **Guest** » Fri Sep 30, 2005 1:09 am

Well mice have 16 don't they?