Comment on 5 tomatoes
merc@sh.itjust.works 21 hours ago
My 2 main annoyances with the metric system:
First: The SI unit for mass is the kilogram. That’s fucking stupid. A kilogram is 1000 grams, the base unit for something can’t be “1000 of this other thing”
The second one isn’t really an issue with the metric system, it’s more when people are almost using the metric system then fuck it up, like the “Watt Hour” for measuring energy use. You know, there’s already a way of measuring energy use: the “Watt Second”, also known as “The Joule”
it’s more when people are almost using the metric system then fuck it up, like the “Watt Hour” for measuring energy use.
Energy is just so important to physics and engineering that it will be measured in whatever unit is most convenient to convert in that particular context: joules as the SI unit, watt hours for electricity usage, calories for certain types of heat or food energy calculations, electron volts in particle physics, equivalent tonnes of TNT for explosion energy, things like that.
I don’t believe that “watt hours” are more convenient than joules, especially when they’re not just watt hours but kilowatt hours or megawatt hours. At that point just use megajoules or gigajoules.
I can understand things like eV where the scale is so different that you’d have to constantly use tiny and unusual prefixes. But, for most other things like calories, it’s just tradition rather than a well thought out reason.
I don’t believe that “watt hours” are more convenient than joules
Clearly you’ve never had to do the calculations where these things come up, where hours are a much more common unit of measure for time than seconds, so that multiplying and dividing by time is easier when working with hours.
The real problem here is that there aren't 1000 seconds to the hour. Then this argument would be moot
foo@feddit.uk 17 hours ago
Image
I am glad someone else has noticed this. Why is my TV’s power consumption reported in kWh/1000 hours?
ricecake@sh.itjust.works 16 hours ago
Because your power is billed in kWh. Figuring out the kWh cost of a 77 watt TV is straight forward, but a lot of consumer labeling standards are about quick and easy side by side comparisons as opposed to perfect application of units. Easiest way to give a comparison that’s accurate enough and doesn’t involve odd numbers is to convert that way.
foo@feddit.uk 6 hours ago
Whilst this answer is correct, it’s not entirely accurate, because it is dismissive of the root cause. The logical follow-up question is: “Why is energy billed in kWh?”. If the question/cycle answer continues down this line there will probably be an answer like “because <some person> had to make a decision once, and they chose this because of <some reason>, and now we’re all stuck with it because of convention.”
Anyone who doesn’t understand what joules are probably doesn’t understand what kWh are either. If the billing convention (and every other power consumption label) used joules (of course MJ or GJ) instead, then most people would just accept that as the unit of billing and measurement, and those who understand what the units mean would have an easier time of it.
ricecake@sh.itjust.works 2 hours ago
Well, the follow up answer is pretty straightforward.
Selling power by the megajoule is silly. You want a unit that puts time in the name and the unit of power that’s on appliances. If I run a 35 watt fan for an hour I know I’ve used 35 watt hours of energy. Or I can say I’ve used 126 kilojoules.
It’s not highschool. You don’t lose points for not reducing your answer all the way. The goal is to describe reality clearly, not to use the most concise units of measurement.
If I’m running a powerplant I need to know how many joules I get from my fuel and what my customers need and what my generators can deliver. The customer needs to know the efficiency of their appliances, and how how much that costs them. These are the same thing, but life isn’t made simpler by having them be the same unit.
merc@sh.itjust.works 17 hours ago
Urgh. There’s a unit for that, it’s WATTS. That’s literally 77 Watts.
_stranger_@lemmy.world 16 hours ago
Honestly that’s the most aggravating part.
boonhet@sopuli.xyz 16 hours ago
Yea but people are idiots.