1. ### I Who defined the positive direction of the magnetic field?

This is about the history of electromagnetism. I already know about the convention that defined which electric charge is the "positive" one, which ended up making the electron a negative particle. But what about the "positive" direction of the magnetic field? Does anybody here know how it was...
2. ### I What false hints of new physics were most notable?

Sometimes experimental or observational evidence from credible physicists points to new physics and then turns out to be wrong due to statistical flukes, experimental error or a theoretical analysis mistake. What cases of this happening do you find most notable, what showed that the hints were...
3. ### B Origin and demonstration of Newton's second law

At highschool, we saw without demonstration the fundamental principle of dynamics (2th Newton's law), i.e : $$\sum \vec{F}=m \vec{a}\,\,\,\,\,\,\,\,\,eq(1)$$ after, at university, we saw another expression of this 2th Newton's law : \sum \vec{F}= \dfrac{d\vec{p}}{dt}\,\,\,\,\...
4. ### Historical paper dump sites?

I'm looking for sites with historical journal articles -- ideally in English, but if there's none available, I can settle for the original. Specifically, I'm looking for stuff by (in no particular order, and certainly not exclusively) e.g. Heisenberg, Pauli, Dirac, Schrodinger, Feynman...
5. ### Modeling the pre modern atom

In my studies, I find myself coming back to the same question.How do we know all these things about matter. Its quantized, it has mass and, charge and blah blah blah. I understand that these models of the building blocks of "physical things" are well tested mathematical models that attempt to...