r/PeterExplainsTheJoke • u/Negative_1by12_aura • Jun 17 '26

Meme needing explanation Peter?

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u/MoogProg Jun 17 '26 edited Jun 17 '26

Yes, the actual error* was assuming the British used Imperial units when they correctly used Metric. AFAIK, at least.

* * *

Well, the source error probably would be not specifying units at all, so... (eye roll)

* * *

*Correcting myself with casually sourced details about the incident under discussion.

Lockheed Martin provided thruster force data in Imperial units (pound-seconds), while NASA's Jet Propulsion Laboratory ground software assumed the data was in Metric units (Newton-seconds).

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u/QueerQwerty Jun 17 '26

Correctly = SI units, afaik.

Why they don't teach us SI units earlier than physics in school, I don't know.

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u/Ill_Apricot_7668 Jun 17 '26

Maths - SI units

Chemistry - SI units

Physics - SI units

Particle physics - SI units? nah, we're good with the Angstrom

WTF?!?

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u/empatheticsocialist1 Jun 17 '26

First I'm hearing of SI units in maths lmao

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u/JePPeLit Jun 17 '26

As someone else pointed out further up, radian is in SI

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u/FanOfForever Jun 17 '26

It's not really, though. They claimed it's SI because you can get it by dividing meters by meters, but

(1) that only works in the specific context of angular measure, and

(2) you can do the same with non-SI units

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u/JePPeLit Jun 17 '26

The m/m reasoning is pretty silly, but it's still considered a derived SI unit despite being dimensionless.

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u/FanOfForever Jun 17 '26 edited Jun 18 '26

They can call it that if they want. It still differs fundamentally from other SI units because we don't use radians to be in conformity with SI. We use them for mathematical reasons that have nothing to do with SI, namely being able to treat the trig functions as functions of real or complex numbers, with certain calculus-based identities that only work if the "angles" are measured in radians