The sensory world of polarization
How to navigate without the sun
In the Old Icelandic Saga by King Olav, it was told that a “Sunstone” could be used by the Viking King to tell the direction to the sun under completely overcast skies, when the eyes could not see any trace of the sunlight. In our work we have investigated this possibility by measuring the degree and direction of the pattern of skylight polarization under different cloud conditions and in fog, confirming the possibility and discussing the old navigation tools used by Vikings during their long sea-crossings.
Why the zebra got its stripes
I work in close collaboration with optical physicist Dr. Gabor Horváth and his research team at Eötvös University, Budapest. We study Viking navigation, but also host detection in horseflies and optical host protection in mammalian hosts like, horses, cows and zebras. Some of our work has received substantial media attention. We received the IgNobel Prize in Physics in 2016 for a study on why white horses are not attracting as many horseflies as black horses. We have also investigated why zebras have evolved a striped coat pattern, and propose it has to do with an evolutionary arms-race where zebras have evolved striped coats as optical protection against attacking bloodsucking Tabanide flies, that may irritate grazing mammals and spread lethal diseases.