nightcleaner said:
Hi Marcus and Kea.
Just wanted to let you know I am still lurking.
I have been trying to understand Kea's Z number and have gotten lost, somehow, diverted into studying the fine structure constant ...
several possible approaches to understanding the role of alpha
here is one. (maybe it is not the best, maybe kea has a better that she will supply, but this is at least one simple handle on it)
suppose you have two tennisball size balls suspended by thread and all safely protected and insulated so you can't get a shock
suppose each ball has a trillion extra electrons
what is the force between, if you dangle them close together?
In natural units the charges are E12 and E12 (the unit is the electron itself and E12 is a trillion)
and say the distance is 2E33 center to center (that is two handbreadth)
\text{force} = \frac{1}{137}\frac{E12 \times E12}{(2E33)^2}
THE FORCE IS ALWAYS 1/137 TIMES THE TWO CHARGES MULTIPLIED TOGETHER, DIVIDED BY THE SQUARE OF THE DISTANCE
so let's see how much it turns out to be, I didnt calculate it in advance.
\text{force} = \frac{1}{4 \times 137}\frac{E12 \times E12}{E66} = \frac{1}{548}E\text{-}42 \text{ natural force unit}
roughly speaking E-42 of natural force unit is about a "poundforce" (dont confuse with pound mass!) or the weight-force in normal Earth gravity of half a kilogram.
So this calculation says the force between the two tennisballs is extremely delicate, it is 1/548 of the weight of a pound of butter taken out of the fridge.
And I don't mean 1/137, I mean the real number 1/137.036...
But anyway, in very concrete terms that is a story of how 1/137 enters into our life. You dangle the two tennisballs close together and they repel with a delicate force. And the force is reckoned by the number 1/137 and knowing how many extra electrons (a trillion) on each ball
the natural force unit is ultimately what this thread is about. what happens if you actually use it as your unit... what kind of system of units do you get then and how does the system behave in uses.
I know the natural force unit mainly because when I stand still the force I feel on each sole of my feet is E-40 (this is a "hundredweight" force or the weight of a 50 kilo sack of something) My mass is about 200 pound and my weight-force is about 200 "poundforce". so on each footsole I feel E-40.
When I compare E-42 with the heft of a pound of butter, i am basically just dividing that E-40 that i know by a hundred and comparing it to something.
And that is how i get some idea of the force of repulsion between the two charged tennisballs.
[REPLY TO NEXT POST, ADDED IN EDIT: Hi Richard. I was delighted to hear about 8piG, in the next post. The whole post is very interesting. I'm answering just minimally and out of order here so as not to cover it up. I wish some other people like selfAdjoint would respond to it. several good perceptions and/or interesting ideas]