NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: napier and logarithms
From: J Cora
Date: 2009 May 28, 21:33 -0700
From: J Cora
Date: 2009 May 28, 21:33 -0700
The book mentions that Napier discarded this method of calculating logarithms. Raising 2 to the power 10000 by hand absolutely boggles my mind. I appreciate your explanation which was clear and demonstrates the genius and perseverance of Napier in knowing when to change his methodology. I worked the sqrt of 100000 in about 2 hours. Of course I knew the values ahead of time which saved a lot of time checking the work. I was dismayed with the number of errors I made squaring the terms. Squaring 7 digit numbers by hand does require rather intense concentration. I wonder why Napier settled on 7 decimal places for his table of logarithms? Also this leads to the question as to whether Napier or Briggs were able to find the value of log(2) or log(3) to 7 decimal places or did that have to wait for Euler. After receiving my slide rule in the mail and trying a few calculations, I have decided that weak eyesight precludes this method. So tables are once again the practical solution. On Thu, May 28, 2009 at 10:40 AM,wrote: > > A number with 3011 places must be between 1*10**3010 and 10*10**3010. Or equivalently, between 10**3010 and 10**3011. Since this is 2**10,000, let's take the 10,000th root of both sides. > > If lower end of range: > > 2**10,000 = 10**3010 > > take the root by dividing the exponents by 10,000: > > 2**(10,000/10,000)=10**(3010/10,000) > > 2**1=10**.3010 > > 2=10**.3010 > > log 2 =.3010 > > If upper end of range, same method; > > log 2 =.3011 > > So it's somewhere in between. Why not guess .30105? In fact, 10**.30105=2.000092126 or so. > > > > > --~--~---------~--~----~------------~-------~--~----~ Navigation List archive: www.fer3.com/arc To post, email NavList@fer3.com To , email NavList-@fer3.com -~----------~----~----~----~------~----~------~--~---