More About Light

• <S>:Light travels in a vacuum in straight lines at a constant speed.
• <A>:When light hits an object it can be reflected or absorbed by the surface of that object.
• Light travels at approximately 300,000 km/sec (186,000 miles per second).
• If we are looking directly towards the sun then all the sunlight will hit us head on so there will be no reflection.
• Reflection occurs when light bounces off a smooth surface such as water or glass.
• The angle between the incident ray and the normal is called the angle of incidence.
• The angle of incidence equals to the angle of reflection.
• The angle between the reflected ray and the normal is called the angle of reflection.
• The angle between the incident ray and normal is equal to the angle between the refracted ray and normal.
• Refraction is the change in direction of a wavefront as it passes from one medium into another.
• Total internal reflection occurs when light waves travel through a denser material and strike the boundary with less dense material at an angle greater than the critical angle.
• The law of reflection states that the angles of incidence and reflection are equal.
• Refraction is the change in direction of a wave as it passes from one medium to another.
• As light moves through different materials its speed changes which causes refraction.
• In general, light slows down as it enters a denser material and speeds up as it leaves a denser material.
• When light hits an object it can either be absorbed by the material or reflected from its surface.
• Refraction is the change in direction that happens when light passes from one medium into another.
• A mirror reflects almost all of the light that falls onto it.
• Objects that absorb most of the light appear darker than objects which reflect more of the light.
• When light travels through different materials, it changes speed and direction.
• When light travels from air (less dense) to glass (more dense), some of the light bends back towards the source, while other parts continue on their path.
• Light always slows down when passing from a faster material (air) to a slower material (glass).
• Light can be polarized by passing it through a filter that only allows certain orientations of electric field vectors to pass through.
• Light travels faster in air compared to glass, so there will be a bending or refraction of the path of light rays passing from air to glass.
• Light can be reflected off surfaces such as mirrors or shiny objects like ponds or glass windows.
• Transparent objects allow all wavelengths of visible light to pass through them.
• The angle between the incident ray (the incoming ray) and the normal line at the point where the ray strikes the mirror is called the angle of incidence.
• The angle between the reflected ray and the normal line at the point where the ray strikes the mirror is called the angle of reflection.
• If the refractive index of the second medium is greater than the first, then the light will bend towards the normal.