Bending & Bouncing
The imaginary line drawn perpendicular to a surface at the point where a light ray strikes it.
What is the normal?
This complete reflection of light happens inside a denser medium when the angle of incidence exceeds a specific limit.
What is total internal reflection (TIR)?
A piece of transparent material with curved sides that concentrates or disperses light rays by refraction.
What is a lens?
A dimensionless number that indicates how much a medium slows down light compared to a vacuum, calculated as n = c/v.
What is the refractive index (or index of refraction)?
The separation of white light into its component colors (wavelengths) when it passes through a prism.
What is dispersion?
This phenomenon occurs when a light ray hits a boundary and bounces back into the original medium.
What is reflection?
The specific angle of incidence in an optically denser medium that results in a refracted angle of exactly 90°.
What is the critical angle?
An optical element that is thinner in the middle than at the edges, causing parallel light rays to diverge.
What is a diverging (or concave) lens?
This law of refraction is mathematically expressed as $n_1 \sin(\theta_1) = n_2 \sin(\theta_2)$.
What is Snell's Law?
This type of image is formed where light rays physically intersect and can be projected onto a screen.
What is a real image?
The change in direction of a light ray as it changes speed when crossing a boundary between two different media.
What is refraction?
Flexible, transparent fibers used in communications technology that rely entirely on total internal reflection to transmit data.
What are optical fibers?
The precise point on the principal axis where light rays parallel to the axis converge after passing through a lens or reflecting off a mirror.
What is the focal point (or principal focus)?
The exact value of the refractive index of a vacuum (and approximately air).
What is 1 (or 1.0)?
This type of image is formed where light rays only appear to originate from, meaning it cannot be projected onto a screen.
What is a virtual image?
This law states that the angle of incidence is exactly equal to the angle of reflection.
What is the Law of Reflection?
To achieve total internal reflection, light must be traveling from a medium of [blank] refractive index to one of [blank] refractive index.
What are higher and lower?
This type of curved mirror curves inward like a cave and can produce both real and virtual images.
What is a concave mirror?
The universal constant representing the speed of light in a vacuum, roughly equal to $3 \times 10^8 \text{ m/s}$.
What is $c$?
This property explains why violet light bends more than red light during dispersion.
What is wavelength (or frequency, which changes the refractive index for different colors)?
The property of a medium that describes how difficult it is for an electromagnetic wave (like light) to propagate through it.
What is optical density?
This atmospheric optical phenomenon creates the illusion of water on a hot road, caused by light refracting through layers of air with different densities.
What is a mirage?
The distance from the center of a lens or mirror to its principal focus.
What is the focal length?
The formula used to calculate the critical angle ($\theta_c$) when light travels from a medium with index $n_1$ into air ($n_2 = 1$).
What is $\sin(\theta_c) = \frac{1}{n_1}$?
A triangular optical element made of glass or plastic used to demonstrate the dispersion of light.
What is a prism?