[TML] Personal Armor Noise was Re: Current USAF fleet

[Timothy Little]

On Sun, May 04, 2008 at 10:08:31PM -0400, Jerry W Barrington wrote:
> But *anybody* can (in theory) make a highly accurate duplicate of
> *the* standard kg reference object.

There are such copies, all with slightly different masses and
different rates of change of their masses over time.  For very highly
precise measurements, this is a truly horrible situation.


> A major problem with using a sphere is that atoms don't line up in
> neat little spherical arrangements.  They do lattices.  Any lattice
> cut to a sphere has "jaggies" like a pixelated curve.

Even a perfectly aligned crystal surface has "jaggies" in that sense.
Even more so since silicon atoms aren't cubical pixels in a cubic
arrangement.  No surface is truly flat, and they're not expecting to
get subatomic precision anyway.

There are advantages to using spheres over cubes or other shapes.


- Tim