Re: [Phys-l] unit conversions

[John Denker <jsd@av8n.com>]

On 02/20/2009 01:01 PM, Hugh Haskell wrote in part:

>  ... then I asked 
> for 1 watt-hour in Btu, and instead of giving me an answer with the 
> same mantissa as the previous question, I was steered to several 
> sites which wanted to give me a tutorial on unit changes, but no 
> result.

1) Leave out the hyphen.  It's fussy about that.

  http://www.google.com/search?q=1000+watt+hour+in+Btu

====

Note that this is a feature of Google Calculator, which is a full
blown calculator that can do a lot more than conversions.

  http://www.google.com/search?q=4*atan(1)-pi


2) Also note that the Unix program called "units" provides another 
way of doing calculations, with due regard to units.  It is free and 
open-source.  It is not as smart as Google Calculator;  for instance
it chokes on 4*atan(1)-pi, which is hard to understand, given that
it understands either term separately.


3) Neither of these knows anything about dB units or pH units.