Crookes Radiometer Blau

The way the blue glass catches the light is really striking, and I love watching the vanes spin as the sun hits it. It makes a great conversation piece on my desk while also showing how solar energy works.

I set this on my windowsill and the vanes started spinning within seconds of morning sun hitting it. The deep blue glass makes it look almost like a scientific artifact from an old lab, which fits my desk decor perfectly. It’s genuinely fascinating to watch the light push the paddles around.

Placed mine on the windowsill this morning, and the four vanes already spin smoothly even with just indirect light—the blue glass really catches the sun. It’s a simple, satisfying way to see solar energy at work.