Khan Academy: Scale of Earth, Sun, Galaxy and Universe: Scale of the Galaxy

It's hot today, but is that the weather or the climate? This colorful presentation isolates both concepts to allow for better understanding by covering the positioning of the planet, making comparisons of land versus water, and looking...

The concept of the universe can be incredibly complex on both physical and mathematical levels. Yet Salman Khan can explain concepts that lead to conclusions about the universe's size. He uses intriguing diagrams and presents information...

Sal explains the Big Bang and the spatial concepts of infinity versus a 'sphere' of expanding matter in detail.

Did you ever wonder which season is best for viewing the full moon? Find out why winter wins the honor, and why the tilt of Earth''s axis is the main contributor. 

An examination of a Hubble telescope image showing far away galaxies. [4:12]

A scale of Earth and Sun, the galaxy and the universe. [9:31]

Did you know it would take a jet plane 17 years to travel from the Earth to the Sun? This video lecture shows the scale of solar system by exploring the astronomical unit. Understand how the astronomical unit is used to measure the...

Using cabbage juice as a pH indicator, future scientists explore the effect of increasing carbon dioxide on the pH of the ocean and relate it to the health of coral reefs. Ideal for an earth or environmental sciences course, this lesson...

Here is an unusual comparison: the swimming conditions of a sperm cell and a sperm whale. Introduce your physics class to the Reynolds number by sharing this video comparison during your fluid mechanics unit. Afterward, teach them to...

Swirling and churning, the waters of the North Atlantic play a vital role in Earth's climate! Discover the many factors that produce circulation using a multimedia instructional activity from PBS's Weather and Climate series for high...