Roche Limit

Modern students, even those who have chosen to study advanced physics, cannot understand the full imperial system, and certainly are not able to calculate using them. This is occasionally demonstrated in class when a student complains that they can't relate to the metric SI units, and goes on to immediately demonstrate that they have no idea of how many ounces there are to the pound, or stones to the ton, or inches to the yard, or yards to the mile. They are certainly unaware of the coherent imperial unit of mass, the slug or the meaning of the fathom, acre or gallon, the chain, troy-ounce or nautical mile.

I strongly suspect that this is also the case with the UK Government which has claimed that a move back to imperial weights and measures is a key benefit of leaving the EU:

Since the [UK-EU Trade and Cooperation] agreement was signed [a year ago], the Government has sought to capitalise on new freedoms by cutting red tape for businesses, reforming EU rules and regulations and boosting trade abroad to create new jobs here in the UK. Key successes include:

”...forging ahead to remove the ban on selling in pounds and ounces and to restore the crown stamp onto the side of pint glasses.”

Prime Minister pledges to build on Brexit achievements in 2022

Liz Truss, the Foreign Secretary has claimed this week that we can now go back to buying Champaign in pint bottles, as if that practice hadn't died out long before the UK joined the Common Market predecessor of the EU. Of course, since imperial measurements were never banned, although they did have to be subsidiary to the metric ones on labels, there is no sense to claiming to have made them legal again. And beer has been sold by the pint in bars throughout the UK's EU membership.

Everyone under the age of 55 years has studied metric units exclusively in school, since the UK went metric in 1972, sixty-eight years after Lord Kelvin collected eight million signatures calling for the adoption of metric measures. That was a fifth of the population at that time.

Hansard records Lord Belhaven and Stenton, moving the second reading of the Weights and Measures (Metric System) Bill in 1904 as saying:

The metric system has been taught in the elementary schools under the Educational Code of 1900, but it is to be regretted that though the teachers give much time and trouble to teaching this new subject, in many cases the examiners have not asked any questions in that section of arithmetic. Therefore school teachers are very much disheartened when they find that inspectors seem to look upon it in a half-hearted way and they get no credit for the time they devote to the teaching of it. If this Bill passes it will be the means of infusing a great deal more energy into this particular subject.

and continues with

The second objection to our present system is the waste of time in teaching it to children. It is not alone the teaching of the tables which I have just referred to—it is the whole system of compound addition, subtraction, multiplication, and division, and the system of computation called “Practice.”

It is estimated, on high educational authority, that every child wastes one year of its arithmetical school time in learning these subjects and that in many cases the time lost is much greater. Last year inquiries were made of headmasters of schools on this subject, and 197 sent replies, of which 161 said that saving of time in teaching the metric system would be one year, thirty said it would be two years, and six that it would be three years. This gives a French or German child a great advantage over an English child, as the time saved can be applied to some more useful subject.

I should like to quote from one of the many letters received. The senior mathematical master of Edinburgh High School wrote— “An average scholar would save at least a year and a half, probably two. This saving is great in itself, but if it be considered how much he saves by not being subjected to a wearisome process of acquiring the knowledge, say, to convert ordinary yards to poles and vice versâ, or square yards to perches and give a rational remainder, and the wearing out of his nervous system—not to speak of the teachers'—I conceive it to be not only a saving of time but an economy of mental effort which is incalculable.” The objection does not lie only in the time which is wasted. The child is wearied and disheartened by the difficulties of the subject; and, in the case of boys at our public schools, many get such a distaste for arithmetic that they lose all desire to study mathematics afterwards, and I think this has much to do with the low standard of mathematical knowledge in this country.

Modern students, even those who have chosen to study advanced physics, cannot understand the full imperial system, and certainly are not able to calculate using them.

The Physicist, Mathematician and Engineer Lord Kelvin supported the Bill in 1904, noting in passing that the Metric system was a English invention:

While we are grateful to France for having given us the metric system, while we see France, Germany, Italy, and Austria rejoicing in the use of it, and benefiting every day by the use of it, it is somewhat interesting to know that, after all, the decimal system, worked out by the French philosophers, originated in England In a letter dated 14th November, 1783, James Watt laid down a plan which was in all respects the system adopted by the French philosophers seven years later, which the French Government suggested to the King of England as a system that might be adopted by international agreement. James Watt's objects were to secure uniformity and to establish a mode of division which should be convenient as long as decimal arithmetic lasted.

A hundred and twentyyears ago, elementary schools in England started to teach metric units, while the Germans changed over completely in two weeks without obvious difficulty.

A century later, the Luddites seem to be winning.