Erwin Schrödinger was highly regarded by students for the clarity of his lectures and his lack of formality, both in his teaching style and in his way of dressing.

 His informal attire sparked quite a bit of controversy at the fifth Solvay Congress in 1927.

Strengthened by the confidence he had gained from the success of his wave mechanics, Schrödinger did not feel the need to dress in a way that would make a good impression; he showed up at a refined hotel in Brussels, where the participants were staying, dressed in hiking gear and with a backpack on his shoulders.

In the official photo of the congress, Schrödinger poses with the greatest physicists of the time, wearing an informal light jacket and bow tie (though carefully placed at the bottom so as to hide it as much as possible).

The surprising thing is that the Austrian physicist did not worry about it at all.

In Berlin, where strict Prussian tradition required professors to wear a blue suit, white shirt, and tie, Schrödinger would wear a sweater, a bright bow tie, and an open-collared shirt in the winter, and a short-sleeved shirt in the summer.

On one famous occasion, when he was late for class, the students sent for him and discovered that the security guard had prevented the entry of this unkempt "imposter"; with considerable difficulty they managed to convince him that he was in fact Professor Schrödinger and that the students were waiting to attend his lecture.