The languages of physics and maths
The languages that are viewed as the big scientific languages in mathematics are probably these;
1. English, it is the scientific lingua franca of the world
2. French, You must acknowledge the french of this, they are a very large "rationalistic" nation in terms of philosophy (they cared historically more about pure maths than industrial endeavors).
3-2. Russian, Because of the large amount of world class russian mathematicians in practice today.
3-2. German, Because the germans are a very large industrial and sceintific nation of import.
The languages in physics is a bit different.
1. English, same as above.
2-1. German, many good physicists historically, and many good still today, like in the frauenhofer-centers in germany (actually sweden got one too, in gothenburg).
2-2. French, Historically a very sharp scientific country. Still is today, almost on par with germany.
Any other languages?
Yes, but the cost-effective-value of learning said language is rather bleak, and that is japanese and/or mandarin chinese. Japanese I would understand if you learned, but then your speciality probably is reactor engineering, engineering physics, some parts of physics like condensed matter physics and/or particle physics, even a bit of mathematical physics I presume.
Take this at face value, I am not in the nobel committee. Just a rather interested undergrad in engineering chemistry with physics.

But I monitor all the big papers in science and economics. (not the american ones mind you

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