Based on the Wikipedia explanation of Haidinger's brush I would expect it to remain oriented to the light polarization, no matter which way I rotate my head.

However that is not what I observe. When I rotate my head, the pattern tilts by about 20 degrees to the opposite direction. This is compared to the LCD monitor vertical direction, so total shift is around 40 degrees. I can also hold the pattern vertical by slight counter-rotation, but then it quickly disappears.

The tilt angle doesn't exceed about 20 degrees, no matter how far or fast I rotate. The tilt seems to reverse immediately when I reverse the direction of rotation, even if I haven't yet passed the original orientation. Thus it seems to be related to the rotational motion, rather than the angle itself.

I haven't found explanation for this effect, though I did find a description by Stephen James O'Meara where he observes the same tilting. I think it may be related to Troxler's fading because the pattern quickly disappears if I keep my head still.



You must log in to answer this question.

Browse other questions tagged .