Proper Type for Dollar Amount

ruby-talk
1

this definition refers to a cesium atom in its ground state at a temperature of 0 K):

      The second is the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the cesium 133 atom.

What an interesting page! Thank you.
However, 0K is unattainable. What then? Extrapolation?

···

Daniel Carrera <dcarrera@math.umd.edu> wrote:
> Ha!
> This would make some interesting definitions:

> Speed of light (c): 299,792,458 meters per second.

> Meter (m): 1/299,792,458th of the distance that light travels in 1
> second.

> Second (s): The time that light takes to travel 299,792,458 meters.

Well, we all know that one of them should be wrong, right? In this case
it is the last one (for example, see
http://physics.nist.gov/cuu/Units/second.html\).

Regards,

Bill

2

Okay, we’re getting further and further off topic, but yes. The temperature
scale is linear, so it’s quite easy to extrapolate what 0 K must be. And you
can get within a fraction of a degree of it anyway.

Tim Bates

···

On Thu, 12 Dec 2002 05:15 pm, Ted wrote:

What an interesting page! Thank you.
However, 0K is unattainable. What then? Extrapolation?

–
tim@bates.id.au

3

“Ted” wrote:

What an interesting page!

Yes it is.

You may also be interested in the webpage of the source for all SI
definitions. It is the BIPM in Paris:

http://www.bipm.fr/enus/3_SI/base_units.html

“The kelvin, unit of thermodynamic temperature, is the fraction
1/273.16 of the thermodynamic temperature of the triple point of
water.”

If you look at the BIPM web page and go to ‘Brief history of the SI’
and then ‘Temperature scales’ you can read lots of detail.