When large flocks of birds start flying around back and forth over a given area, they are called a murmuration. Murmurations of birds are an amazing sight. The birds seem to follow each other, and their random movements create areas of low and high density of birds. The overall effect to the observer is that the flock of birds resembles one giant shape-shifting organism. This type of group behavior is also found in other living things such as insects or fish.
Murmurations occur towards the end of the day when the birds are set to roost for the night, and they take place during the winter months. Although murmurations seem complex, the behavior that leads to the formation of a murmuration has been realistically recreated by computer simulations that follow simple rules. But why do murmurations happen?
There are several hypotheses that have been put forward to explain murmurations. One is that the birds fly around to attract nearby birds in order to form large groups that will make them safer from predators. Another hypothesis is that birds join these large groups to share information about food sources. Yet a third hypotheses posits that the birds join these large groups to stay warmer during the night.
The video shows a murmuration of starlings in Poolesville, Maryland.
The video shows a light bulb that not only seems to be levitating while rotating but is also on, although it does not seem to be connected to a source of electricity. In case you are wondering, this is not a trick. The levitation is achieved by magnets. Magnets on the periphery of the base attract the light bulb, while magnets in the center of the base repel the light bulb. The result is that the light bulb is locked in position in midair. Once set in motion by a twist, the light bulb can rotate for a very long time because it experiences little friction from the air.
As to how the light bulb is on, it is achieved by a phenomenon called “electromagnetic induction”, which was discovered by the English scientist Michael Faraday in 1831. Electromagnetic induction takes place when a moving magnetic field generates a current within a wire. In the case of the levitating light bulb, the base is connected to a power source that generates a moving magnetic field, which in turn induces the electric current inside the base of the light bulb. The principle of magnetic induction is behind electrical generators, and it powers all our electrical gadgets and appliances.