ARMv8.1?

Martin, a question: Are they still selling appliances and power plugs separately in the UK?

In aviation, there is some sense in distances in nautical miles (1 arc minute on great circle) and speeds in knots.

Altitudes are measured in feet. The explanation was that on the altimeter 1000 m / revolution was too coarse and

Vertical speeds are measured in feet/minute.

As a born metric system user, I see aviation as a huge mess of all kinds of units, especially as American made aircraft have the manuals in inches and pounds.

There is, in a sharing community - maybe you're not familiar with those.

Base 12 counting is perfect for divvying out portions - especially when you don't have access to accurate measuring systems (like a picnic). The only numbers that are awkward for a small group are 5 and 7.

That's no wonder: In the inch-pound world, there are two kinds of gallons.

Not commonly, no. But you can still buy the plugs separately.

And the tonne is mentioned and used frequently in the UK.

Of course the best thing about Imperial units is they confuse foreigners so much :-) They bitch about them and so we use them just because we can whether that whether that makes life harder for us or not.

Things are now sold with an integral plug. I cannot recall when I last saw a new item sold without a plug.

At least we finally switched temperatures to Celsius (Canada got there long before the U.S. did).

The one that keeps me scratching my head is the way visibilities are reported in statute miles, while everything else is in nautical miles.

Ironically, HP decided in the mid-80s to forego proprietary networking and go with a global open standard, OSI.

By the early 90s, customers were rejecting HP for its "proprietary" OSI, in favor of _ad hoc_ TCP/IP!

Needless to say, HP rapidly switched to TCP/IP, led by its UNIX offerings, which rapidly became its dominant OS.

Standards can be either _de jure_ or _ad hoc_, based on market dominance. Networking is a kind of special case, since its essential value is in direct (or even quadratic) proportion to its interoperability.

Sometimes by virtue of utility or priority a particular technology achieves market dominance and resultant _ad hoc_ standardization--the "waterhole effect".

In other cases, multiple comparable competing technologies battle to a stalemate or continuing fragmentation. In such cases, a _de jure_ selection can provide real value to providers and consumers alike.

I was born with English units here in the US. I hate them. At work I was surprised to learn the mechanical engineers all still use the English units. It is mind boggling to me that we have not converted yet.

Some time ago, I believe in the 70's, we had an agreement with Canada to convert to metric. There were a number of stages, the first few being informational (make citizens aware of the project), educational (we still teach metric in schools) and some initial conversions (that's why we have km/hr on car speedometers). We got through those initial stages and told Canada, "You go on ahead and we'll catch up later". They did and we haven't. They are through the painful part and have been reaping the benefits for decades. Maybe we can get Trump to "Make America Metric".

When did the US switch to Celsius? Is that just aviation you mean?

I bought a cheap meter on ebay that includes a temperature probe. It didn't occur to me to check if it would read in Fahrenheit and it doesn't. lol

interesting as a SCUBA diver I use metric (Meters & Bar) because it makes the maths easier & at 30M+ the brain is not working too well :-)

There's a clue that the pins are too big: the sliding shutters inside the socket and/or the requirement for dummy blanking plugs to keep small fingers out of the socket.

The NZ plug is better. The wiping area on the pins is similar to the UK plugs, because the side areas are similar, but the pins are only 1.5mm thick, so the holes are far too narrow for inquisitive fingers, or many screwdrivers for that matter, to go in.

I know that are - in powered aircraft, but the variometers in UK gliders are always calibrated in knots because it simplifies calculation: dividing sinking speed by airspeed (ASIs are also calibrated in knots) gives glide ratio without needing conversion factors - something you need to know when calculating a final glide home.

By contrast, all European gliders are metric - rates of climb and height in metres, speed in km/h, distances in km, which makes the glide ratio calculation a bit harder.

OTOH all European powered civil aircraft use nautical miles, feet and knots in conformity with ICAO conventions.

Yes, you're right, but it can get even worse, with older American aircraft often have airspeeds measured in miles per hour rather than knots.

I think the ICAO approved units is a left-over from the aftermath of WW2. The ICAO was set up in 1944 with 52 countries signing the convention, so my guess is that the use of nautical miles, knots, feet and pressures stated as mm of mercury rather than bars dates from about then and which countries had operating civil airlines at the time, and so, with air traffic control needing the use a single system worldwide and the immediate post war dominance of US and British civil aircraft makers that seemed like the most sensible approach. And, once set, why change? Look up the "Gimli Glider" incident to see the problems you can get from changing measurement units!

I don't see where these are really much different from other types including the US plugs that are nearly identical other than the angle of the blades and the US lack of insulation on the active and neutral pins. We have mandated the shutters on the socket which is a PITA as they often don't work well making it hard to insert plugs.

One thing I noticed is there seems to be a switch requirement. That is not terribly useful as it depends on a user to turn the switch off when nothing is plugged in. However, there seems to be a version which only powers the contacts when a plug is inserted. Now that is a good idea.

Good greif! What have they ever done to you then?

I neither love them nor hate them. They are what they are. History that refuses to quite die, and I work in imperial and metric simultaneously.

I know exactly how many mm an inch is and how many grams a pound is.

That must be why we divide cups 8 ways and gallons 128 ways... oh, wait! They are only divisible by powers of 2. Heck, bakers are very generous giving 13 items when only 12 are required. But try dividing 13 between any group that's not 1 or 13.

How many cubic inches in a cubic yard? How much does a cubic yard of water weigh? How many teaspoons in a quarter cup?

I'll take metric any day of the week!

Yes, we have the same problem, but from going the other way. However, there are two mitigations:

- for starters, the variometer used to be a simple rate of climb indicator driven off a total energy compensated pressure probe. Now, with the addition of feeds from static pressure ports, pitot tube and a GPS, it shows us where we are on a moving map display relative to terrain and the task we've declared, predicts arrival height at the next turnpoint, and calculates windspeed and direction. IOW, it does almost all the calculations we used to do in our heads or with a whizz wheel calculator back in the day when a map was a large sheet of glossy paper with the task of the day drawn on it.

- Flying rules say that using oxygen is advisable above 10,000 ft AMSL and mandatory above 12,000, though in the US you're allowed up to 13,400 ft without oxygen provided you're not above 10,000 for more than 30 minutes.