What are the reasons for KSP not using SI units?

[Hotblack Desiato]

some mods (started with KSPI) consider a EC to be 1 KW/s. That was in connection with their own reactors, which had a MW-value. the Near Future reactors and the USI-reactors are following this rule aswell. so it would be easy for squad to make it official.

one other thing that might be extremely nice: have a small readout of the total mass of a rocket/lander/other craft, and convert it into newtons for different objects in KSP. this way, a lander for duna has a certain weight and therefor a certain force in newton, and designing it in order to be capable to lift off (TWR > 1) becomes trivial.

[Fel]

some mods (started with KSPI) consider a EC to be 1 KW/s. That was in connection with their own reactors, which had a MW-value. the Near Future reactors and the USI-reactors are following this rule aswell. so it would be easy for squad to make it official.

EC is purely magic; claiming it is kW simply because "we can" (even though that unit makes as much sense as saying it's footpounds [you consume power, you generate power, but you cannot STORE power. Storage mechanisms have very different aspects and are measured in amp-hours for a reason.) doesn't fix the fact that it doesn't follow basic electrical principles.

Edited April 27, 2015 by Fel

[Borsek]

Ehm, my Li-ion power storing phone begs to differ.

[WWEdeadman]

Kilonewton and the metric tonne is thus not SI units.

a metric ton is literally 1000 kg. The use of it is simply to not get incredibly long and confusing numbers.

kilonewtons are the same deal. 1000 N. Again, we don't want long unreadable numbers.

[enneract]

You can't express the prefix "kilo" as a product of the SI base units. "Kilo" is a SI prefix, though.

Can you seriously get more pedantic? I'd really like to see you try. The real difference between 'kilo' and 'Kilo' in this context is negligible.

KSP uses SI units, period. Nobody in their right mind uses SI base units when dealing with numbers these large, because that is a great way to introduce accidental order-of-magnitude errors.

So bloody what if you calculate megajoules instead of joules - megajoules is likely to be the relevant unit size, anyway.

[Hotblack Desiato]

EC is purely magic; claiming it is kW simply because "we can" (even though that unit makes as much sense as saying it's footpounds [you consume power, you generate power, but you cannot STORE power. Storage mechanisms have very different aspects and are measured in amp-hours for a reason.) doesn't fix the fact that it doesn't follow basic electrical principles.

so if I can't store power, a simple capacitor wouldn't be possible? (the unit for capacitors is farad, which is Coulomb

/ Volt )

besides, I wrote KW/s, not KW. there is a difference.

but I know, batteries, capacitors or at least a bucket of fuel is pure magic

for the discussion whether KSP is metric or not: the whole discussion revolves around the idea that unit-prefixes like kilo are somehow not SI. and that's just not true, the SI-system even defines them.

one thing that needs to be done in KSP: the SI-units are defined through the some more or less obvious constants. the second was once defined through the length of the day, the meter was defined through the quarter of the length of the equator. those definitions need to be ported over to KSP with kerbin as the center of kerbalkind. maybe they defined the meter as the 600.000th part of the kerbin-radius (hinting that they once had a numbering system with the base 6... this would also explain, why a kerbin day has 6 hours )

mass can (analog to earth) then be defined by the density of water (1m³ of water = 1000 kg).

Edited April 27, 2015 by Hotblack Desiato

[FlipNascar]

feet of altitude, meters of visibility, nautical miles of distance... How did anyone let ICAO get away with this??? Three different units to measure lengths???

Nautical miles have some logic with regard to aviation... 1 nautical mile = 1 minute of latitude; 60nm = 1 degree. And for altitude in feet, that's just a throwback to the units in use when aviation was invented, and it's never really changed. Maybe it's because I had a license that it seems perfectly normal to me...

[sal_vager]

This thread has gone from KSP to complete disaster, to answer the OP, KSP uses the metric system and can be considered SI and derived SI units even if not explicitly stated in most areas of the game.

And if you divide a kilometre by 1000, you get one metre, I'm sure everyone can manage that.

Values are set with gameplay in mind, not real world accuracy, for a game set in a 1/10th sized star system with little green aliens this is perfectly acceptable.

I'm sure addons can change the names of the units to your liking, and can change densities, heat tolerance and other factors to be closer to a simulator which you obviously want instead of KSP, so I invite you to try Real Solar System and related addons.

Closing train wreck thread.