# Metres or Miles .. who cares?

• Last night I was using the treadmill in the gym of the hotel I am staying in. It has a wonderful display that shows the total distance you have gone numerically, plus some spiffy graphics that show you how far you have gone incrementally around a virtual lap - split into 8 segments.

The total distance is shown in Miles .. but does not have any indicator as to what the units of length are. The incremental distance around the virtual lap is shown in by the arrow shaped icons along with a numerical value of 50M, 100M, 150M etc. So not only do they show distance in two different unit systems and only show the units for one of them, they even have the unit symbol wrong - it should be m not M

And as an added bonus WTF, I am doing an electrical safety course today which focuses on arc-flash safety - IE how to protect yourself from an arc-flash that could occur due to some sort of electrical failure. Lots of nice gruesome pics of people with burns etc all over their body. But the WTF is that the standard for determining the level of potential danger to a person is based on calculating the amount of energy that could be incident on your body in Cal/cm2 - yep thats right .. Calories per square centimetre.

• I see the first WTF, but not the second.

One calorie is the energy it takes to heat up a cubic centimeter of water by one degree (Celsius), in certain conditions surely to be mentioned by other pedantic forum members. So, considering we're mostly made of water, ten or twenty calories on a square centimeter of your skin should be enough for quite a lot of discomfort, whereas a few handful are sure to leave a mark.

• @OzPeter said:

And as an added bonus WTF, I am doing an electrical safety course today which focuses on arc-flash safety - IE how to protect yourself from an arc-flash that could occur due to some sort of electrical failure. Lots of nice gruesome pics of people with burns etc all over their body. But the WTF is that the standard for determining the level of potential danger to a person is based on calculating the amount of energy that could be incident on your body in Cal/cm2 - yep thats right .. Calories per square centimetre.

Note that a calorie is a unit of energy, which can be broken down into mass times square distance over square time. ( J = kg * m^2 / s^2 ) If you want to abuse SI, you could even measure the level of potential danger in Tesla-amps.

• The second WTF is probably meant in the sense that the calorie isn't an SI unit — it should be J * cm^−1 in that case.

• I assume the WTF in the bonus thingy is due to the difference between a calorie and a nutritional calorie (and the fact that they are using the nutritional one for the measurement).

•  If you get caught in an arc-flash, you're either dead or soon will be(and everyone else near you). Its question of how much body is left.

• @OzPeter said:

Cal/cm2

This is the standard SI unit of pizza.

• @zipfruder said:

If you get caught in an arc-flash, you're either dead or soon will be(and everyone else near you). Its question of how much body is left.

What? It's not an desintegration ray from War of the Worlds.

I routinely create arc flashes for my classes in Physics experiments. I strongly doubt that those are strong enough to make any part of my body disappear.
I mean, I sometimes even have problems igniting paper with those flashes (yes, it gets brown and carbonizes. But does not burn.)

It all depends on the voltage and the amount of electrical current you're feeding the system.

• Complaining about m vs M but you use "IE" instead of "i.e." hmm that was hard to type on swype.

• @Gurth said:

The second WTF is probably meant in the sense that the calorie isn't an SI unit — it should be J * cm^−1 in that case.
The bizarre thing is that you actually calculate the result as Joules per square cm and then convert that to calories in order to look up the result to see what level of protection is suggested.

• @zipfruder said:

If you get caught in an arc-flash, you're either dead or soon will be(and everyone else near you). Its question of how much body is left.

Umm .. no.

The amount damage sustained is related to the amount of energy released in the arc-flash, mitigated by the level of protective gear that you are wearing and the distance you are from the release [1]. If the maximum level of protective gear cannot protect you from a maximal (estimated arc-flash) then you shouldn't be in that location in the first place.

[1] The aim being to limit damage to no more than second degree burns across your body, as these are deemed as being able to be healed with no damage.

• @locallunatic said:

I assume the WTF in the bonus thingy is due to the difference between a calorie and a nutritional calorie (and the fact that they are using the nutritional one for the measurement).

They're basically the same thing, except the nutritional measurements are usually in kilo-Calories. You often find that on food packages the small-print actually states '1400 kCal per serving' or similar. So, one 'nutritional' kilo-Calorie is enough energy to heat a kilogram, rather than a gram, of water by one degree Celsius.

Andrew.

• @grkvlt said:

@locallunatic said:

I assume the WTF in the bonus thingy is due to the difference between a calorie and a nutritional calorie (and the fact that they are using the nutritional one for the measurement).

They're basically the same thing, except the nutritional measurements are usually in kilo-Calories. You often find that on food packages the small-print actually states '1400 kCal per serving' or similar. So, one 'nutritional' kilo-Calorie is enough energy to heat a kilogram, rather than a gram, of water by one degree Celsius.

Andrew.

Technically it's a kilo-calorie, small c. Calorie with a big C is the nutritional Calorie, which is equal to 1,000 thermodynamic calories, or one kilocalorie (kcal).

• @Zemm said:

Complaining about m vs M but you use "IE" instead of "i.e." hmm that was hard to type on swype.
Somethings are hard to type EG typing IE especially when you do mean i.e.

• I always thought miles were abbreviated neither "m" nor "M", but instead "mi".

• @MiffTheFox said:

If you want to abuse SI, you could even measure the level of potential danger in Tesla-amps.

My car, for example has a fuel consuption of 9m^-2.

• @OzPeter said:

Some things are hard to type. Ethylene Glycol: typing "Internet Exploder," especially when you do mean "intended example."

• @TwelveBaud said:

@OzPeter said:
Some things are hard to type. Ethylene Glycol: typing "Internet Exploder," especially when you do mean "intended example."

I usually mean id est when I type "i.e."

• @joe.edwards said:

@TwelveBaud said:
@OzPeter said:
Some things are hard to type. Ethylene Glycol: typing "Internet Exploder," especially when you do mean "intended example."

I usually mean id est when I type "i.e."

The example abbreviation is e.g. for exempli gratia.

• @joe.edwards said:

I usually mean id est when I type "i.e."

I prefer the common English equivalent that is to say, and its corresponding abbreviation.

• @OzPeter said:

The total distance is shown in Miles .. but does not have any indicator as to what the units of length are. The incremental distance around the virtual lap is shown in by the arrow shaped icons along with a numerical value of 50M, 100M, 150M etc. So not only do they show distance in two different unit systems and only show the units for one of them, they even have the unit symbol wrong - it should be m not M

Are you sure those weren't metric miles (1 mile = 1000 metres)

• @realist4ever said:

Are you sure those weren't metric miles (1 mile = 1000 metres)

No, that can't be, because metric miles are (logically enough) abbreviated mm.

• @realist4ever said:

@OzPeter said:

The total distance is shown in Miles .. but does not have any indicator as to what the units of length are. The incremental distance around the virtual lap is shown in by the arrow shaped icons along with a numerical value of 50M, 100M, 150M etc. So not only do they show distance in two different unit systems and only show the units for one of them, they even have the unit symbol wrong - it should be m not M

Are you sure those weren't metric miles (1 mile = 1000 metres)

more lightly it was a European made treadmill which allows the installer to setup the unit in miles instead of KM, however it is half arsed implemented.  Most gyms (that the manufacturer hears about) would set it up to KM.  Is it a Techno gym?

• @ekolis said:

@realist4ever said:
Are you sure those weren't metric miles (1 mile = 1000 metres)

No, that can't be, because metric miles are (logically enough) abbreviated mm.

"Give him an mm and he'll take a mm!"

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