Why does the shower curtain move toward the water? David Schmidt, an assistant professor at the University of Massachusetts Amherst, came up with an explanation.
Maybe it happened to you this morning: you entered the shower and the curtain moved in to engulf you. I have recently discovered a new explanation for this common phenomenon, thanks to modern fluid-simulation technology.
According to David, a low-pressure region –created as a result of a spray driven vortex– is what pulls the shower curtain in.
The best way to keep the curtain from sucking in is to sew weights in the bottom or use a thicker/heavier curtain (because the force is pretty weak it will hold the curtain in place).
Link via Kottke
Clive Thompson mentions a study in which Dutch scientists recorded and compared the song of the Great Tit in urban and rural areas.
The report, features in this month’s issue of Current Biology, finds that Cities change the songs of birds.
In the new work, the researchers studied songs of the great tit (Parus major), a successful urban-dwelling species, in the center of ten major European cities, including London, Prague, Paris, and Amsterdam. The researchers then compared these songs to those of great tits in nearby forest sites. The results of the comparison showed that for songs important for mate attractions and territory defense, the urban songs were shorter and sung faster than the forest songs. The urban songs also showed an upshift in frequency that is consistent with the need to compete with low-frequency environmental noise, such as traffic noise.
I enjoyed watching quite a few Great Tits and Blue Tits feeding on nuts and suet on my balcony last summer but I didn’t know their song was different from their friends in the forest.
Great Tits on my balcony: Feeding the baby
To read the full paper by Hans Slabbekoorn and Ardie den Boer-Visser you’ll have to pay (ScienceDirect), but you can check out some audio samples of the bird songs for free.