Albedo

The energy that warms Earth’s atmosphere comes from the Sun, but sunlight does not warm the atmosphere directly. The atmosphere warms from below. Most of the short wavelength, electromagnetic energy from the Sun passes through the atmosphere and is absorbed by the Earth. Absorbing this energy warms the Earth. As the Earth warms, energy re-radiates back into the atmosphere as heat. Eventually, this energy re-radiates from the atmosphere back out into space.

The Earth does not absorb all of the electromagnetic energy that hits it. Some reflects back out into space. This is important for the Earth’s energy balance because only absorbed energy contributes to the temperature of the Earth/atmosphere system. The amount of energy reflected by an object is its Albedo.
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Wave Interference

Anyone who as watched the surface of a swimming pool has observed wave interference. Wave interference occurs when two or more waves move through the same space at the same time. Unlike solid matter, waves move through each other. The principle of superposition describes the response of a medium being displaced by more than one wave.
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Pendulum Period

Clocks with quartz movements are more accurate at keeping time than those that use pendulums. Quartz has largely replaced pendulums in modern clocks. But, in their day, pendulum clocks were profoundly important due to their ability to measure time accurately over long periods. The first pendulum clocks were produced in the mid 17th century and their impact was dramatic. Their use ushered in a new era of accurate time keeping. The reliability of pendulum clocks is based on the predictable relationship between the length of a pendulum and the time it takes the pendulum to complete one full swing.
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Buoyancy II

If you wanted to move a heavy rock across the bottom of a shallow pool, would it be easier to move it if the pool was empty or full of water?

The rock would be easier to move if there was water in the pool. The reason, buoyancy force.
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Charles' Law

Three parameters used to describe the characteristics of gases are pressure, volume and temperature. The ideal gas laws describe the behavior of gases with respect to these parameters. Boyle’s Law describes the relationship between the volume and pressure of a gas when temperature is held constant. Charles' law describes the relationship between temperature and volume when pressure is held constant.

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Phase of the moon

The moon is second only to the sun as the most dynamic feature of our sky. It moves across the sky from east to west once every day and each month it goes from being invisible to the brightest object in the night sky and back to invisible again. These patterns result from the motions of the earth, moon and sun relative to each other.

Features of a wave

A standard set of terminology is used to describe the feature of waves.
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Boyle's Law

On Earth, naturally occurring matter exists in one of three phases: solid, liquid or gas. Matter in each phase exhibits distinct characteristics. Gases, for example, do not have a fixed volume or shape. As a result, gases respond to pressure changes by changing their volume. In other words, gases are compressible. In contrast, liquids and solids are not compressible. Their volume does not change in response to changing pressure. This is the reason air filled spaces in our ears “pop” during airplane takeoff and landings while the liquid filled spaces in our bodies do not. Boyle's Law describes this relationship between gas pressure and volume.

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Light reflection and refraction

Light is a complex phenomena. It exhibits both wave-like and particle-like properties and its exact nature is not completely understood. This complexity makes it difficult for one model to describe all of light’s properties. As a result, different models are used to describe different aspects of light’s behavior. The electromagnetic wave theory explains light’s ability to travel through a vacuum. The light ray model, on the other hand, can describe interactions between light and matter.
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Gravitational Acceleration

We all understand that if we hold something up in the air and then let go, it will fall to the ground. Things fall because of gravity. Gravity is an attractive force between all things that have mass.  It is one of the fundamental forces of nature. Gravity causes objects with mass to accelerate towards each other. The rate of acceleration depends on the mass of the objects and their proximity. The more mass an object contains, the more it will attract other objects. The closer an object is to another the greater the attraction between them will be.
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Buoyancy

Why do some things float and others sink? The first thing that comes to mind for many people is that it depends on how heavy an object is. While an object's weight, or more properly its mass^* does play a role, it is not the only factor. If it were, we could not explain how a giant ocean liner floats while a small pebble sinks. Mass matters, but there is more to it.
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Types of waves

Every sound we hear, every photon of light that hits our eyes, the movement of grass blown by the wind and the regular beat of the tides are all examples of waves. They are all around us.  Visible, physical waves such as those we see when a rock is thrown into water are what many people think about when they first began to think about waves. These waves have distinct properties specific to their type but also exhibit characteristics in common with more abstract waves such as sound waves and light (electromagnetic) waves.