A theory of physics 100 years in the making.

In nature, most of our basic forces both attract and repel. In fact, gravity is the only exception. But, according to theorists, sound waves actually have negative gravity.

How did life on Earth get started? Did life on Earth originate on another planet? Either Mars, or in a distant solar system? Could Earth life have spread to have seeded life elsewhere? Let's see what modern science has to say about the...

In this video Paul Andersen explains how conservative forces can be used to store potential energy in an object or a system. The work done is equal to the amount of potential energy in the object. The following conservative forces are...

In this video Paul Andersen explains how a vector field shows the distribution of vector quantities. In AP Physics 1 student should be able to map and understand gravitational vector fields. In AP Physics 2 students should be able to...

In this video Paul Andersen explains how the gravitational field strength is directly related to the mass of the object and indirectly related to the square of the distance from the center of mass. The equation for gravitational field...

Why strings? What are they made of? How did physicists even come up with this bizarre idea? And what's all this nonsense of extra dimensions?

Are matter, mass, and time real?

Astronomers have announced the Juno space probe’s first findings from Jupiter!

New ReviewIn this lesson, we compare electric potential energy and gravitational potential energy for a proton moving between parallel plates in a uniform electric field, and we plug in realistic values to show just how small the gravitational...

New ReviewIn this lesson we derive the change in gravitational potential energy for an object moving in a uniform gravitational field and then use that result as a direct analogy to determine the change in electric potential energy for a charge...

Get ready to crush the AP Physics 1 exam with this complete 30-minute review of the entire course! This video covers every major topic from Units 1 through 8, including kinematics, dynamics, energy, momentum, rotation, harmonic motion,...

In the Copenhagen interpretation, which is what is typically taught to undergraduate students, particles are in superposition. What is superposition? In quantum mechanics, there is no equation that states...

SUMMARY

Albert Einstein was ridiculed when he first published his theory. People thought it was too weird and radical to be real. Einstein wasn’t satisfied with his theory either, because the theory did not...

Learn how to calculate gravitational force on a particle due to multiple masses using the principle of superposition. This lesson breaks down vector addition, force from extended bodies using integrals, and how to apply Newton’s law of...

Howcast - Initial searches for oil on land usually require the skills of geologists and geophysicists. These searches are often conducted by small exploration companies called wildcats.

On Sept. 10, 2011, NASA's GRAIL spacecraft launched on a mission to the moon! GRAIL, which stands for Gravity Recovery and Interior Laboratory, was sent to the moon to map its gravitational fields.



Scientists could study the...

Master Unit 7 Oscillations for AP Physics 1 with this comprehensive review! Dive into the concepts of periodic motion and simple harmonic motion (SHM) as we explore mass-spring systems, pendulums, and energy transformations in SHM....

This video discusses the concept of redshift and the expansion of the universe, starting with the discovery of the universe's expansion through the redshift of light from distant galaxies. It explains the three types of redshift: Doppler...

The field around a body of significant mass that exerts a gravitational pull on all other objects in that field.
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A Twig Science
Glossary Film.
Key scientific terms defined in just 60 seconds using stunning...

A measure of how much matter an object contains, in units of grams or kilograms.
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A Twig Science
Glossary Film.
Key scientific terms defined in just 60 seconds using stunning images and concise textual...

This review of the second half of Unit 2: Forces and Translational Dynamics for AP Physics 1, we cover key topics such as Newton’s Law of Universal Gravitation, spring force, and circular motion. We explain gravitational interactions...

Newton’s Third Law states that for every force exerted by one object on another, the second object exerts an equal and opposite force on the first. These forces act simultaneously and are external to the system, meaning they don't...

This review of circular motion explains key concepts such as tangential velocity, centripetal acceleration, and how objects move in circular paths. Tangential velocity is always perpendicular to the radius, while centripetal...