Sorry to start a thread on this, but I think #I must (seeing some of the posts here).

Please, any system which attempts to keep the metre is unacceptable. I know it is the most widely used unit but that is not justification for keeping it. It is not based on humkan things, but off what was considered a "natural constant" at the time which, now irrelevent, leaves the metre with no footing, as it were, in the real world. It is an historical relic- please let's drop it forever.

Might I also remind everyone here that 1/1000000000 the distance light travels in a vacuum in a second is an 11.8 inch measure.

cheers.

[Please, any system which attempts to keep the metre is unacceptable. I know it is the most widely used unit but that is not justification for keeping it. It is not based on human things, but off what was considered a "natural constant" at the time which, now irrelevent, leaves the metre with no footing, as it were, in the real world. It is an historical relic- please let's drop it forever.]

Any of us who wants can set up a message board with a narrow focus in which only systems of a specific type may be discussed. There is a lot to recommend that specialized approach. You could set up a board where it was unacceptable to consider a system with a meter-sized distance unit.

Unfortunately I have not thought through any set of "rules" for the board here and I cannot say that anything is unacceptable. the original aim was to focus on systems where the main constants of nature (c, hbar, G, k, e,...) are powers of ten. Neither your reformed anglo-roman nor the proposed "trimmed metric" fit that template but for various reasons it seems interesting to broaden the spectrum and get them clearly presented regardless of the original intent.

BTW you called attention to an absolute temp scale where freezing is 440, body temp is 500, and boiling is about 600.
The relative scale that goes with that would have about 160 steps between freezing and boiling, and pint drinker has pointed out that the Reaumur scale which was at one time predominant all over continental Europe had 80 steps between freezing and boiling. So your degree is almost exactly half of the Reaumur. This may or may not be useful information but it is the kind of odd thing that seems to come up if you allow open discussion and if people are not primarily motivated to quash one another's ideas (as they often seem to be on a couple of other units-boards, not to say that such brawling is altogether bad either!)

BTW pintdrinker's idea of trimming metric so that the speed of light is exactly 3E8 meters a second (and something similiar happens to planck's hbar constant) strikes me as interesting----and not totally different from your aims regarding anglo-roman units either. 3E8, that is to say 300 million, is admittedly not a power of ten but it is a good deal rounder and handier than the 299,792,458 that the metric system is based on at present.

Very interesting Bryan. I did not see this post when i came up with the nautical mile of EXACTLY 2000 yds (6000 feet), this entailing an increase of the length of the foot by 1.01260490586 percent (or just under 1/6 in) this would mean a new "trimmed foot" that is 12.1512588703 in. This does not square with your foot of 11.8 in which is based on the distance light travels in a specified period of time. It is based upon the prehended circumference of the Earth and is designed specifically for navigational purposes. I know you do not like metric at all, Bryan. Neither does Leonard. I am a bit less extreme on the matter, though fundamentally I think it [metric] is ridiculous also. The trimmed metric idea exists for the purpose of familiarizing some of these establishmentarian metric lunkheads to the idea of basing a masurement system on fundamental physical constants rather than vice versa. Metric in its present form is bad, yes-- but the "English system" of measuring the entire universe according to the length of a this, that, or another king's foot is nothing if not ludicrous! Don't you agree?

The King's foot- that is just a way to make people understand the unit. Anthropomorphic units are good.

Leonard, I am simply saying that the metre MUST be destroyed no matter what.

Pint drinker: check at bwma- I have done a lot of thinking about various sized new feet (some of which I have printed there)

That is to say that units based off our bodies are good, but they must obviously defined scientifically.

Hi Bryan, you have given me two things to go on:
mentioning that c is about E9 f/s
and that you are comfortable with a roughly 32 pound mass unit (conventional name: slug).

Although I prefer planckian units in which all the main constants of nature come out powers of ten, I do want to get a stable definition posted here of reformed anglo-roman units such as you might be satisfied with. I want stable comparable snapshots of three systems to compare.

I will assume that the second is the time unit
and that the foot is defined by saying
speed unit (f/s) = E-9 c

The action unit in any system of this type must be footpoundsecond. This is a consequence of your chosing second as time unit, foot as distance, and pound as force unit.

To make the poundforce indistinguishable from presentday poundforce, the definition would say

action unit (footpound second) = 1.28477E34 hbar.

By making the poundforce a bit larger you could get it to be 1.3 instead of 1.28477 or a bit smaller you could get it to be 1.25, but let's ignore that for now.

The way the system looks now is

time unit-----second
speed unit (foot per second)----E-9 c, a billionth of lightspeed
action unit (footpound second) ----1.28477E34 hbar, a certain exact multiple of the natural unit of action.

defined in this way the foot is independent of the metric unit, and if one must convert the foot is 29.9792458 centimeters instead of 30.48 centimeters but so what that is their problem.

defined in this way the pound of force is independent of the metric newton of force and comes out indistinguishable from the presentday pound force for as many significant figures as I care to calculate it.
If you wanted to make hbar have a nice value you
could make pound larger to get a 1.3E34 or make it smaller to get a 1.25E34. But here it is for now at least fully independent of metric.

For comparison, the trimmed metric definitions:

time unit----second
speed unit (meter per second) ---- 1/(3E8) of c
action unit (joule second) -----9.5 E33 hbar

the kilogram is by definition joule sq.(second/meter)
because in any coherent system the mass unit is always equal to the energy unit divided by the square of the unit speed----so the other things follow from those three.

For comparison, the centipace ounce definitions:

time unit ---- 54 millisecond
speed unit --- E-9 c ----one billionth of light
action unit ---- E30 hbar ---one nonillion times the natural unit of action.

Sorry if I appeared abrupt, Leonard.

Anyway, on ratios (other thread), how about a 450gr oz?

What is the distance between the nucleus and the electron shell of the hydrogen atom? Whither from the surface or from the center of the nucleus?

the NIST gives the radius of the H atom
as 0.529177...E-10 meters

hello p.d., glad to hear from you!
there is a nice formula for the radius
which uses the "fine structure constant"
and hbar and c. The fine structure constant
(they usually use alpha as a symbol for it)
is an interesting pure number, a little bit
like pi. Always nice when it shows up. I will
get the formula and calculate the radius
in planckian units and see what it is.

the fine structure constant is a pure number, approximately 1/137, or if you need more accuracy
1/137.036
It is the same in anybody's system of units, like pi is the same. Amazingly influential number, gets into many formulas. People say that it is lucky for us that it is around 1/137 because if it were one or two percent larger or smaller the universe would be unsuitable for life as we know it. Dont ask me why that is just what people say---I'll find some links to stuff online if you want but will not try to explain.

Anyway alpha is a neat number. And the bohr radius
is something you can calculate from alpha and the mass of the electron! Lets call the mass of the electron "m".

the radius, that you asked about, is just

hbar/alpha m c

hbar divided by (alpha x m x c)

In planckian units, c is E9 and hbar is E-30
so since alpha is just 1/137 (about) it should
be easy to calculate the bohr radius if I just
knew the mass of the electron. Maybe I will get it
in ounces (planckian ounces that is) and do the calculation.

m = 41.92258E-30 ounces

So the radius of the H comes down to

hbar/(alpha m c)

with hbar being E-30
so that will cancel the E-30 in the denominator!

so 137.036/(41.92258 x E9) centipace.

3.2688E-9 centipace.

BTW the planck mass (natural unit of mass) is a millionth of an ounce. That is nice enough. but nature is just constructed so the proton mass is 1/(13 quintillion) of planck mass and electron mass is
1/1836 of proton mass. These are mothernature's ratios and can't do anything about them. So can't make them powers of ten. We can make basic universals like speed of light be a powr of ten but then when you get down to the level of particular kinds of atoms and particular particles, nature takes charge and we just accept whatever. Like pi is 3.14 and not 3.15 or 3 or 10. Cant monkey with it. Hope all's well by you. Am beginning to suspect that Iraq is a kind of dress rehearsal for n.korea.