Is there anything in the world that is perfect

[mallymooface]

I read recently that there is a perfect kilo weight which is losing weight and so no longer is a perfect kilo weight. This made me think is anything else in the world able to be described as perfect. How for example do you get a perfectly round shape? How do we know an inch is exactly an inch?

[nix-j-c]

what is perfection?
if you dont know this than how can anything be perfect?

[THECORBYLOON]

The Weights and Measures Act 1985 defines One Yard as 0.9144 metres exactly and one inch is defined in the same act as being 1/36 Yard.

One metre is defined as the length of the path travelled by light in vacuum during a time interval of 1/299 792 458 of a second.

We can be certain then, that an inch IS an inch.

I heard a programme on the radio the other day and they are looking at a different method of defining the kilo because can vary if based upon a physical prototype

[squarebear]

My fiancee is perfect.

[wildwood]

I think I am married to your fiance, squarebear

[Azalian]

I think that things are "perfect enough" to whatever tolerances you desire or can measure.

When the need for improved accuracy becomes apparent then a new level of rigour in measurement is devised.

Witness the changes in the standard metre, defined originally as the distance between two marks on a metal bar in Paris, then later as the number of wavelenghts as stated above anf I beleive that they are considering a new standard now as the old one is not good enough.

[Azalian]

Also my spelling above, oops!

[tubeway]

The original metre was actually one ten-millionth of the distance between a point on the equator and the North Pole, with this line passing through the centre of Paris- The size of the metal bar was based on this. The problem with having a metal bar as a template is that its size will change with temperature.