Translation:She was the first lady in physics.
Why would you say "Dame" here instead of "Frau"? In English "first woman" would mean perhaps the first woman to get a phd in physics. "first lady" would mean something like the most famous woman. Is that the distinction here?
As there is no such thing like the first "first lady in physics", the sentence is odd. The translation from lady to Dame is fine, but it doesn't explain what it meant to say. Anyway.
The meaning is most likely: "She was the first female scientist (in physics) who either discovered/invented something significant" and made history.
For Chemistry I would personally name Marie Curie as an example,
for Physics I have to "wiki" it.
Generally spoken the word: "Dame" is more respectful / honorable for someone who devotes his/her life to science for instance, but I personally would form the sentence as follows:
"Sie war die erste namhafte Frau auf dem Gebiet der Physik." Whoever she is, which doesn't matter to clear this up.
(to name her "Dame" is not necessary IMO)
Edit: correct myself. Marie Curie is widely known as: Mme Curie = Mademoiselle Curie. That translates to Dame, if I am not mistaken.
After I googled it I found that Marie Curie was into Physics and Chemistry and the first female Nobel price winner, so I stick to my assumption: "Marie" is the one and she deserves to be called a "Dame".
Actually, Chien-Shiung Wu was known as "the First Lady of Physics". She worked on the Manhattan project. Also nicknamed as "Queen of Nuclear Research".
Bear in mind that 'first lady' in the sense you're talking about is a US expression specifically, rather than one of the English language as a whole. To me, it simply means she was the first lady to get into physics or something to that effect.
The word "Physik" will always be definite? When is "Physik" used without der in front of it?
I think German doesn't have it like English rules that abstract things don't have articles in front of them.
@fbicknel That's exactly what I was driving at, but you stated it better.
@backtoschool Thanks for your explanation of the German First Lady
Yes, it's dative. ‘In’ in German is a dative preposition when it is used in the sense of the English ‘in’, as opposed to cases in which it's used in the sense of ‘into’, in which case it takes the accusative.