1) The similarity is that in both the cases the light is deviated from its original path i.e. their angles change (even for a short while in a refraction) and the difference is in reflection the angle of incidence is equal to the angle of reflection whereas in refraction the angle of incidence is not equal to the angle of reflection.
2) A white t-shirt would feel cooler on a sunny day.
A black surface attracts heat and wearing a black t-shirt would attract the heat from the sun making us feel hotter.
3) There are three measurable properties
of wave motion: amplitude, wavelength,
and frequency. A definitive experiment was
Young's double slit experiment, which
demonstrated that light shined at two slits
in a screen show an interference pattern
characteristic of waves of light, rather than
particles.
