What has become an important alternative to piagetian approaches?

Due to the shortcomings in Piaget’s approach to cognitive development several other theories were put forward.

Explanation:

Jean Piaget is the psychologist that offered explanations about cognitive development in children. There were several shortcomings in his theories and thus alternative theories about cognitive development in children were developed.

Lev Vygotsky proposed another explanation to children’s cognitive development. He strongly emphasized on the influence of culture on children’s cognitive development. He believes that it is through socio-cultural interactions development progresses.

He believed that individualized thoughts begin after these interactions. He take on self-speech was different from Piaget. Vygotsky considered self-speech as a guide to thinking while Piaget thought self-speech  to be egocentric.

scattering of light by tiny particles in air to produce the colors we see on sky, is dependent on the following factors:

(i) wavelength of light

(ii) size of the scattering particle  

(iii) distance traveled by light through the atmosphere.

according to rayleigh's law of scattering, the amount of scattering is inversely proportional to the fourth power of its wavelength. shorter the wavelength, greater is its scattering. hence violet/blue light is scattered more than red.

sun's light is a composite light ( visible light) with wavelengths in the range 400 nm (violet) to 700 nm (red). as sunlight passes through our atmosphere, the molecules of air scatter light according to their wavelengths. during sunrise and sunset, the sun's position is below the horizon. hence light from the sun travels a greater distance in the atmosphere when compared to its position a noon.

as sunlight enters the earth's atmosphere, blue light is scattered away and at the end of its journey in the sky, only red and orange wavelengths remain in the beam.

hence at sunrise and sunset, the sky appears reddish orange.