Compare and contrast how sound waves behave when they encounter solid (hard) surfaces
encounter soft surfaces
pass through an opening
encounter a barrier

Compare and contrast how light waves are

reflected from concave and convex mirrors
reflected/absorbed in black, red, blue and white paper
refracted in concave and convex lenses
transmitted in opaque, translucent, and transparent materials

Neptune is the eighth planet from the sun. it was the first planet to get its existence predicted by  mathematical calculations  before it was actually seen through a telescope on sept. 23, 1846. irregularities in the orbit of  uranus  led french astronomer alexis bouvard to suggest that the gravitational pull from another celestial body might be responsible. german astronomer johann galle then relied on subsequent calculations to   spot neptune via telescope. previously, astronomer galileo galilei sketched the planet, but he mistook it for a star due to its slow motion. in accordance with all the other planets seen in the sky, this new world was given a name from greek and roman mythology — neptune, the roman god of the sea.