[ou.04] the picture below shows two galaxies. what of these statements best describes a similarity between the two galaxies?

D.

Explanation: Both have shapes determined by gravitational forces.

Option (D)

Explanation: A galaxy is considered to be a large and extensive body comprised of the interstellar dust particles, dark matter and variable gases. The above mentioned particles are attached with one another forming variable shapes and are all held by the gravitational force. Gravity is the main factor responsible for the existence of this galaxies.

This is the reason, why the different shaped galaxies exist in the vast space, maintaining some similarity with one another.

Thus the correct answer is Option (D).

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.

where is the photo and the answer choices?