Light and Orbital Motion Study Guide

This flashcard set covers the vocabulary and core concepts from the lecture notes on light properties, the electromagnetic spectrum, gravity, orbital mechanics, and Earth's seasonal cycles.

Invisible Waves

Types of electromagnetic radiation that are not visible to humans, including Ultraviolet, Gamma Rays, Microwaves, and Infrared.

Red

The color in the visible spectrum that has the longest wavelength.

Violet

The color in the visible spectrum that has the shortest wavelength.

Light Medium Property

Light is unique because it does not need a medium to travel through.

Cones

Sensory cells in the back of the eye that detect color and detail.

Rods

Sensory cells in the back of the eye that detect brightness and contrast.

Matter and Light Brightness

As the amount of matter in the atmosphere increases, the brightness level of light becomes dimmer.

Electromagnetic Spectrum

A collection of different types of electromagnetic radiation.

Red Ball Reflection

An object looks red because it reflects red light waves and absorbs all others.

Refraction

The process that occurs when light changes speed as it encounters different materials.

Rainbows and the Horizon

Two phenomena that are similar because you can never reach either of them and neither of them is really there.

Newton $(N)$

The standard unit used to measure force and weight.

Kilogram $(kg)$

The standard unit used to measure mass.

$$m/s/s$$

The unit used for measuring gravity.

Gravity

A force that pulls matter together and acts on all matter in the universe; its strength depends on the masses of the objects and the distance between them.

Inertia

The factor that causes a soccer ball to continue moving across a field and is one of two factors keeping Earth and the moon in their orbits.

The Moon

The natural satellite of Earth.

Centripetal Force

A force that points in towards the center of a circle during circular motion.

Orbital Motion Factors

The two primary factors that keep celestial bodies in their orbits are gravity and inertia.

Black Hole

An object that would have the strongest gravitational pull compared to the Sun or a comet.

Ellipse

The shape that best matches Earth's orbit around the Sun.

Orbit

The path of Earth as it revolves around the Sun.

Axis

The imaginary line passing through Earth's center and poles.

Rotation

The movement of Earth around its own axis, which takes $1$ day.

Revolution

The movement of Earth around the Sun, which takes $1$ year.

Moon's Cycle

It takes approximately $1$ month for the Moon to revolve around the Earth and $1$ month to rotate on its own axis.

Tilt of the Earth's Axis

The main reason for the seasons on Earth.

Equinox

Occurring on the first day of Spring and Fall, this event features $12$ hours of day and $12$ hours of night.

Summer Solstice

The time of year in the Northern Hemisphere (usually June $20\text{th}$) with the most daytime, consisting of $15$ hours of day and $9$ hours of night.

Waxing

The term used when the moon is becoming more illuminated.

Waning

The term used when the moon is becoming less illuminated.

Reversed Seasons

The phenomenon where the Northern and Southern Hemispheres have opposite seasons because when one is angled toward the Sun, the other is angled away.