The photoelectric effect is the emission of electrons (called "photoelectrons") from a surface when light is shone on it. It was first observed by Alexandre Edmond Becquerel in 1839, although credit is usually reserved for Heinrich Hertz, who published the first thorough investigation in 1887. Another particularly thorough investigation was published by Philipp Lenard in 1902. Einstein's 1905 paper discussing the effect in terms of light quanta would earn him the Nobel Prize in 1921, when his predictions had been confirmed by the experimental work of Robert Andrews Millikan. The Nobel committee awarded the prize for his work on the photo-electric effect, rather than relativity, both because of a bias against purely theoretical physics not grounded in discovery or experiment, and dissent amongst its members as to the actual proof that relativity was real.
Who published the first thorough investigation of the photoelectric effect?
Heinrich Hertz

West is one of the best-selling artists of all time, having sold more than 32 million albums and 100 million digital downloads worldwide. He has won a total of 21 Grammy Awards, making him one of the most awarded artists of all time and the most Grammy-awarded artist of his age. Three of his albums rank on Rolling Stone's 2012 "500 Greatest Albums of All Time" list; two of his albums feature at first and eighth, respectively, in Pitchfork Media's The 100 Best Albums of 2010–2014. He has also been included in a number of Forbes annual lists. Time named him one of the 100 most influential people in the world in 2005 and 2015.
How many of Kanye West's albums were recognized by Rolling Stone Magazine?
3

Feathers being critical to the survival of a bird, require maintenance. Apart from physical wear and tear, feathers face the onslaught of fungi, ectoparasitic feather mites and birdlice. The physical condition of feathers are maintained by preening often with the application of secretions from the preen gland. Birds also bathe in water or dust themselves. While some birds dip into shallow water, more aerial species may make aerial dips into water and arboreal species often make use of dew or rain that collect on leaves. Birds of arid regions make use of loose soil to dust-bathe. A behaviour termed as anting in which the bird encourages ants to run through their plumage is also thought to help them reduce the ectoparasite load in feathers. Many species will spread out their wings and expose them to direct sunlight and this too is thought to help in reducing fungal and ectoparasitic activity that may lead to feather damage.
Birds preen often with the application of secretions from which gland?
preen gland