Comment by curl-up
Comment by curl-up 2 days ago
Can you please give some real-world example of why it's easier to do calculations? Not disputing what you say, just hard for me to imagine why it would be so.
Comment by curl-up 2 days ago
Can you please give some real-world example of why it's easier to do calculations? Not disputing what you say, just hard for me to imagine why it would be so.
The calculation in the metric system would not necessarily be more complicated, but it would be different because the reference points in the metric system are not directly aligned with the geography of the Earth.
"1 knot is about 100 ft/min which is very convenient for descent at a specific glide slope (i.e. for 100 knots ground speed at 5% slope you want 500 ft/min descent rate). Standard is 3° which is about 5%."
You are right. It's an easy calculation. But I would say its easy because its historically based on imperial units. Its easy to think about easy calculations like this in metric units like:
A 5% slope means descending 1 meter vertically for every 20 meters horizontally.
The gradient thing would work if ground speed and vertical speed were both in m/s, but km/h is more common in metric for a ground speed. You don't usually think in terms of hours during a climb/descent!
Glide slope of 3.6% would fit nicely though. Then, 100 km/h ground speed goes with vertical speed 1 m/s.
Metric navigation would use the fact 90 degrees of latitude is 10,000 km.
I suspect that the math is even easier using meters, meters, and meters per second than nautical miles, feet, and knots. I'll eat my hat if you can tell me the conversion from feet or inches to nautical miles without looking it up
This sums it up. Metric is nice and clean tenths, but the real world is seldomly easily expressed in clean tenths.
Another example: The feet is cleanly divisible in thirds, quarters, and twelfths, which is greatly appreciated in industry and particularly construction.
Also to be bluntly mundane, almost everyone can just look down and have a rough measure of a foot which is good enough for daily use.
Also, the "sterility" of metric doesn't do it any sentimental favours. Japan loves measuring size/volume in Tokyo Domes, for example.
If you're an amputee I truly am sorry for you and hope the handicap hasn't disrupted your life too much.
Jokes(...?) aside though, your absolute deference to precision is an example of why metric flies over people's heads. Feets, Tokyo Domes, arguably even nautical miles and so on are relatable at a human level unlike metric which is too nice and clean.
1 knot is about 100 ft/min which is very convenient for descent at a specific glide slope (i.e. for 100 knots ground speed at 5% slope you want 500 ft/min descent rate). Standard is 3° which is about 5%.
Knots are also handy for navigation as 1 nautical mile equals 1 minute of latitude. And of course a knot is 1 nautical mile per hour. So if you're doing 300 knots, that's 5 degrees of latitude per hour.
The units fit together nicely as a system.