What's a schwinger? No, not a bad joke from a Jewish parody of Austin Powers. (But probably, a bad joke from a Jewish parody of Austin Powers...)
A schwinger is somebody who participates in schwingen, also known as "hosenlupf", which is Swiss-German for "breeches-lifting". Hopefully, your imagination did not run wild there, for it's also known as Swiss wrestling, a sport that goes back to medieval times.
What makes schwingers unique? Well, they wear special breeches, or "schwingerhosen". Yes, schwingers basically wrestle in pants.
What does this have to do with Julian Schwinger, Nobel laureate in Physics in 1965? We would bet, absolutely nothing. Schwinger's family came to America from Poland. The last name probably originated in Germany, in either Schwinge in Pomerania or Schwingen in Bavaria.
That being said, the possibility of Jewish pants-wearing wrestlers is something to ponder... Perhaps in a bad Jewish parody of Austin Powers?