The amount of brainpower in that room is incredible. Now think about it this way: probably half of what was available at the time got lost somehow. Makes you wonder where we'd be technologically if we had not systematically repressed one half of the possible scientists. On the positive side: probably a lot of that research got done anyway, with some guy taking credit for it.

I may be going on a limb here, but I have a sense of the same broken logic here as the ubiquitous argument of lost revenue[1].

To be clear, I don't argue the point of suppression and cultural standards affecting the scientific (or, not specifically, any other) thought, but using such simplistic way to quantify that effect.

[1] https://en.wikipedia.org/wiki/Lost_sales

That is an absolute nonsense link that you are trying to make there. Lost sales are sales that make assumptions about every sale as though it is lost as a result of piracy, an alternative and often more convenient mode of delivery.

Denying half (or even more than half) of your citizens access to education and more prestigious stem jobs means you are tossing away an Einstein or a Bohr once every generation or so. The cumulative costs of that are enormous, and are compounding, compared to that a couple of $ of money that does not end up in the pockets of media moguls is very small potatoes.

It's way more than half. All those people are still white.

Well, they are all Europeans. I am not denying that racism existed at the time, but hardly any non-white person lived in Europe back then. (Even nowadays in most European countries the percentage of non-white people is so low that, in a group of 30, finding none is well within statistical error).

Interestingly, many (if not most) of people on that conference were Jews, which were often treated as second-class citizens even before Hitler.

Also, an additional testament how Marie Curie was exceptional was that she was an immigrant from Poland (which didn't even exist when she was born; her initial studies were in secret), and that she is still the only person ever to win two Nobel prizes for two separate fields (physics and chemistry).

If you want to go down that route - which is definitely your right - you could re-shoot a similar picture today and it probably would not show a major shift in demographics. Sad but true.