The Schwarze Sonne or Black Sun shirt.
While most interpret this as a sun symbol, this image used by the N.S.D.A.P. had a much deeper meaning. This was chosen by Hitler as the symbol of the Nazi party, but while most assume it is a symbol for the sun, it was black and tipped on its side. The impression is of a spinning, vortex in motion. The Black Sun was believed by the Nazis to be at the center of the galaxy and while invisible to the naked eye, no less real and more powerful than our solar sun. This invisible sun was believed to be an all seeing eye in the minds of the SS, and while most thought of the SS as an abreviation for "Schutz Staffel" or body guard in English, to the initiated the SS meant Schwarze Sonne.
Today thanks to recent scientific discoveries we know that the Black Sun is no idle myth, at the heart of each galaxy there lies what we call a black hole which while consuming everything in its vortex, also emits massive amounts of energy.