Problems of Symbol Congestion in Computer Languages

[Steven D'Aprano]

On Sun, 13 Mar 2011 00:52:24 -0800, Robert Maas, http://tinyurl.com/uh3t
wrote:

> Exercise to the reader: Combine those nine-decimal-digit and
> ten-decimal-digit numbers appropriately to express exactly how many
> wavelengths of the hyperfine transition equals one meter. Hint: You
> either multiply or divide, hence if you just guess you have one chance
> out of 3 of being correct.


Neither. The question is nonsense. The hyperfine transition doesn't have 
a wavelength. It is the radiation emitted that has a wavelength. To work 
out the wavelength of the radiation doesn't require guessing, and it's 
not that complicated, it needs nothing more than basic maths.

Speed of light = 1 metre travelled in 1/299792458 of a second
If 9192631770 periods of the radiation takes 1 second, 1 period takes 
1/9192631770 of a second.

Combine that with the formula for wavelength:
Wavelength = speed of light * period
  = 299792458 m/s * 1/9192631770 s
  = 0.03261225571749406 metre


Your rant against the metric system is entertaining but silly. Any 
measuring system requires exact definitions of units, otherwise people 
will disagree on how many units a particular thing is. The imperial 
system is a good example of this: when you say something is "15 miles", 
do you mean UK statute miles, US miles, survey miles, international 
miles, nautical miles, or something else? The US and the UK agree that a 
mile is exactly 1,760 yards, but disagree on the size of a yard. And 
let's not get started on fluid ounces (a measurement of volume!) or 
gallons...

The metric system is defined to such a ridiculous level of precision 
because we have the technology, and the need, to measure things to that 
level of precision. Standards need to be based on something which is 
universal and unchanging. Anybody anywhere in the world can (in 
principle) determine their own standard one metre rule, or one second 
timepiece, without arguments about which Roman soldier's paces defines a 
yard, or which king's forearm is a cubit.


Follow-ups set to comp.lang.python.


-- 
Steven