Paul has suggested *pennygauge* as an optional synonym for 1/16".

To help give this term currency it should be listed as a proposed addition in some on-line summaries of British units.

This particular length is a pivotal connection between British units and natural units.

It happens that 10**32 time the natural length unit is approximately equal to one pennygauge.

The mile, which by coincidence is also close to a power of ten time the natural length, happens to be about one million pennygauge.

Having a name for one 16th of an inch will help to highlight these connections with the units in nature.

Living languages and living systems of units have the common feature that they change, whereas dead ones don't. There has to be some point in the British system where change and proposed change shows up. Where is it?

This point is key: "Living languages and living systems of units have the common feature that they change, whereas dead ones don't. There has to be some point in the British system where change and proposed change shows up. Where is it?"

I think that we can encourage the use of this unit, and hopefully, BWMA will endorse the alternative name for a sixteenth- pennygauge.

Yes hopefully they will endorse it!

If they decline to, and the term does not catch on, then we shall have to retreat to the already established vernacular term "sixteenth".

People say "sixteenths" for short, when they mean "sixteenths of an inch."

So it won't kill us if we don't get BWMA support for pennygauge but it certainly would help (they are the most central and visible volunteer custodian of the British units and so in a sense they define the set of units as much as any association can.)

Strange thing: the BWMA website has no page that actually lists British units. It has links to other sites that "support" them and some of those supporting sites do in fact have lists of units. But BWMA seemingly does not have its own list, at least online.

Does this mean I should create a list (including pennygauge as proposed addition) at my site and ask BWMA to link to my list? Maybe that is how it would work.

I noticed this rather peculiar lack of a list of British units myself. Possibly, because of the history and what not, the list would be too long, with only very few units on the list being ones in actual use. Then they would have to give old Scotch measues and so on a mention, and end writing a kind of essay explaining what this apparent mess is. Therefore, they would perhaps turn people off, may themselves look like some kind of obscure cult or faction and may seem to be preaching. What would be acceptable, though, is if you created this list.

BWMA has never really been about the history of measurement, although certainly many members are. And over the years we've even drifted away from being about measurement per se and more towards the implications of their use and/or prohibition.

We could not support the pennygauge at this time, as our entire focus must be on protecting the existing main units.

Comments would be appreciated.
A link from BWMA to this would of course be much appreciated.

http://www.planck.com/British+NaturalHybridUnits/index.html

British+Natural Hybrid Units

Universal Natural Units

No set of physical quantities is more highly regarded and more basic in science than the universal fundamental physical constants. The NIST list thirteen such constants of which three are the planck mass, length, and time. To see the NIST (CODATA ) values for these constants use the Google search engine with the keyword [constants].

Simply typing "constants" into Google will get you the NIST site, where clicking on the first category "universal" will get you the short list of universal fundamental physical constants.

Reinforcing Traditional Units by Connection with Natural

It happens that a billion times the natural unit of mass is 48 pounds. The equality is exact to the accuracy with which the natural unit is measured. This is an odd coincidence and nothing comparable to it occurs in the metric system. In metric terms, the same mass, namely a billion times natural, is 21.767 kilograms with an uncertainty of 0.075 percent. This experimental uncertainty in measuring the natural mass unit, an uncertainty of a thirteenth of a percent, means that as far as we know a billion times the natural unit is exactly 48 pounds—the possibility cannot be excluded.

This odd coincidence allows us to validate and corroborate traditional units in an unexpected way: we simply give 48 pounds a name—dog for instance—and say that the avoirdupois pound shall be 1/48 dog. Nothing changes. But a billion times the natural mass unit, as accurately as may presently be measured, is now one dog.

The existing set of British units, with one additional unit adjoined, namely the 48 pound dog, is a simple example of a British+natural hybrid system. It is a traditional system which has been adjusted (by addition of one unit) to make the coincidence with natural units visible.

Central Importance of Sixteenth ("Pennygauge") and Mile

In connecting traditional and natural units the mile is important because, by a remarkable coincidence, it is a power of ten times the natural unit of length. If you use Google [constants] as suggested you will find that 10**38 times the natural length unit is 1616.04 meters. Again the uncertainty of measurement is about a thirteenth of a percent or 0.075 percent.

This is less than half a percent different from the ordinary mile. Accidental agreement to within half a percent is not usual. No fit with natural units occurs in the metric system that is anywhere near that close.

As it happens a millionth of a mile is roughly one SIXTEENTH of an inch and therefore the sixteenth is also approximately a power-of-ten multiple of the natural unit of length.

To reinforce traditional units by highlighting the connection with natural we would again consider naming the sixteenth. It happens to be a very handy and familiar unit—metal measuring tapes used in carpentry are commonly marked for their entire length in sixteenths, pennies are a sixteenth thick and so are music CDs. The length is pervasive and it appears to be a very fortunate coincidence that it turns out to be 10**32 times natural.

Paul Birch has proposed the name "pennygauge" for this unit.

In a British+natural hybrid system, the inch would be defined as 16 pennygauge, the foot as 12 inches, and so on. One would take the pennygauge as the principal length unit so as to highlight the connection with natural units.

Minor Importance of Pennyweight

The Troy pound was banned from use quite a long time ago and the Troy weight scale is of decidedly minor importance. However there is a peculiar coincidence that a million time the natural mass unit is equal to the accuracy with which the natural quantity is measured to exactly 14 pennyweight. The pennyweight referred to a silver penny and was 1/20 of a Troy ounce, there being 12 Troy ounces in a Troy pound. The Troy ounce possibly may still be used to weigh precious metal.

Paul Birch has suggested the name "nonce" for the small mass which is 1/1000 dog and therefore a million natural units. The nonce is nearly (about three quarters of) an avoirdupois ounce.

In a hybrid British+natural system, if a nonce unit were included as per Paul's suggestion, the pennyweight would appear as 1/14 nonce.

"Naturalness" of British units

The traditional British units are "natural" in several different senses. They have evolved through use by linguistically creative people for many centuries, and units have been added to the set and combined and modified in various ways to suit their various purposes. Inevitably these units have come to suit the dimensions and materials of life. But this is not the only way in which units can be natural.

The units (planck mass, length, time) listed as universal fundamental physical constants are natural in a different sense. These are units favored in certain branches of physics and cosmology which arise if one requires that the values of the main proportions in nature (G, c, h-bar) be one. Quantities such as the planck mass and planck length are implicitly present in light and gravity everywhere in the universe. Units such as mile and dog, which are power-of-ten multiples of planck units, are also natural (or at least "seminatural") in the sense that they arise if one requires that the main proportions in nature take on values which, though not one, are powers of ten.

All these things are natural in various senses and to varying degrees. The objective here is to put some of them together in a convenient way so that they can help each other collectively to be more understandable and enduring.