The Square Root of the Height of Eye (in feet) x 1.16 = the distance of the visible horizon in Nautical Miles.

The same formula would have to be applied to any object which the observer wished to see, and then added to the first distance above to obtain the theoretical maximum distance that the top of the object to be viewed would become visible.

I would likewise challenge JT’s seriousness if he were to take offense (on behalf of, say, Spaniards) at my statement that Spaniards are relatively ignorant of US customary units.

Look, when it’s just Myanmar and Liberia who are refusing to adopt the metric system, the phrase “metrically ignorant” might sting. But when the world’s last superpower wants to use another system of measure, then it’s hardly a niche system. And one would hope that U.S. citizens would be better at the U.S. system than at others. There’s nothing offensive about saying so.

If what you really wanted to say is that you are offended that anybody would dare comment on the average American’s lack of knowledge of the metric system — a system of measurement which has been an international standard since the early 1960’s — than you might have a bone to pick more with the Secretary of Education than with Erik or any other stater of the obvious.

In short, the internet is such that you will waste far too much of your life getting offended by off-the-cuff comments which don’t even apply to you. Spend some time in NYC, or any other major urban center, and you’ll quickly harden your skin to such inconsequential offenses.

If my neither my ramble nor Erik’s more rational explication soothe your abused feelings, maybe the Bard’s words will:

“If we shadows have offended, think but this, and all is mended, that you have but slumber’d here while these visions did appear. And this weak and idle theme, no more yielding but a dream…”

I strongly suspect that you are naively optimistic about our fellow countrymen’s knowledge of the metric system. If you gave the following test to random Americans on the street (not just 13-year-old science students) I’d be very surprised if more than 10% got them all correct.

1) Which is longer, a centimeter or a kilometer?

2) How many centimeters are there in a meter?

3) How much does a liter of water weigh in kilograms?

4) Which is bigger, a liter or a gallon?

Most Europeans wouldn’t get #4 of course, because they have no concept of what a US gallon is. And I suspect that only the scientifically minded might get #3. But every single European would know the more practical question of, “Is 100 kph too slow or too fast to drive on the motorway (interstate to Americans)?” Only Americans that had spent some time abroad would have any clue about that question.

Keep in mind that ignorant doesn’t mean stupid; it means lacking in knowledge.

“For the metrically ignorant Americans”

for I am an ‘American’ with a perfectly good mathematical sense of metric computing and can do it ‘in my head’, as I imagine most ‘Americans’ who stumble on this blog can, as well.

By The Way: Your tantalizing calculator at the bottom of the article doesn’t work for me on Firefox 3.5 or Safari 3.2

Cheers,

Jt