# Why is it better to use the metric system, rather than the English system, in scientific measurement?

Dec 6, 2016

The English system? I bought a $\text{kilogram}$ of bananas today in Tescos....And the urban speed limit is $50 \cdot k m \cdot h {r}^{-} 1$.

#### Explanation:

The US of A still clings to old imperial measurements: pounds, ounces, miles, perches, hogsheads, firkins. In fact, the $\text{US gallon}$ and $\text{US pint}$ (and other units) are different from the $\text{imperial gallon}$, and $\text{imperial pint}$. When physical sciences are taught in US high schools, and at universities, however, they routinely adopt the metric system.

So why is it better? Because you can measure most things on the basis of derived units of $\text{metres, kilograms, and seconds}$, and we can use powers of $10$, which is usually intuitive. And more importantly, one of the most basic laws of motion was proposed by Newton in the 17th century:

$\text{the time rate of change of momentum is proportional to the force applied}$

We get $F = k m a$. Where $k$ is a constant of proportionality. When appropriate units, such as $\text{SI}$ are used, $k = 1$, and thus $F = m a$.

Anyway, I'm off to insist my students report their acid concentrations in $\text{hundredweight per hogshead}$. Do you think I will be popular?