The idea that the Moon is a blown-off chunk of the Earth is known as the giant impact hypothesis - but the presence of carbon on the Moon throws this hypothesis into question.

Black holes are everywhere, including at the center of our galaxy. But because they’re invisible they’re quite difficult to study. Looking at the disks of material surrounding them, however, can give us tons of clues about how they...

In this video Paul Andersen explains how the linear momentum is equal to the product of the mass of an object and the velocity of the center of mass. He uses video analysis software to calculate the velocity of an object and therefore...

How Do Bikes Stay Up?

Hank explains absolute zero: -273.15 degrees Celsius - and the coldest place in the known universe may surprise you.

In the third act of "Swan Lake", the Black Swan pulls off a seemingly endless series of turns, bobbing up and down on one pointed foot and spinning around and around and around thirty-two times. How is this move - which is called a...

In this video Paul Andersen explains how classical waves (like light) can have particle properties. Albert Einsetein used the photoelectric effect to show how photons have particle properties.

In this video Paul Andersen explains how the energy, charge, and momentum in a system is conserved over time.

In this video Paul Andersen explains how a rotating system will have several quantities; including torque, angular velocity, angular acceleration and angular momentum. Each of these quantities have a vector property that can be...

e=mc2... it's a big deal, right? But why? And what about this grumpy cat in a box and probability? In this episode of Crash Course Physics, Shini attempts to explain a little more on the topic of Quantum Mechanics.

In this video Paul Andersen explains how the angular momentum of a system can be calculated by determining the angular momentum of all individual objects within the system. An inquiry activity using a gyroscope is also included.

COLLISIONS! A big part of physics is understanding collisions and how they're not all the same. Mass, momentum, and many other things dictate how collisions can be unique. In this episode of Crash Course Physics, Shini sits down to lead...

Every year the moon’s orbit gets a little bigger and it moves just a little farther away. Should we worry about the Moon breaking free?

In this video Paul Andersen explains rotating object have angular momentum. The angular momentum of a point object is the product of the distant from the center of rotation and the linear momentum. The angular momentum of an extended...

Scientists have known the outside of the sun spins slower than the inside for a while, but they didn't know why until recently.

The wave model of the electron can be used to explain the Bohr model. Electrons are found in certain orbits because they interfere with themselves and create standing waves. When the wavelengths don't match up with a whole integer they...

What IS Angular Momentum?

What if you were on a high floor of a skyscraper and the building started swaying? Today we’ll explore statics and dynamics, and what they mean for the structures we design. We look at the idea of static equilibrium, forces, and torques,...

Listen, we know you've thought about it, and we're here to give you THE DEFINITIVE ANSWER to one of the greatest science questions of all time. How long would it take to get to the MOON by farting? Join Gabe on PBS Space Time as we walk...

When scientists are planning missions, they sometimes have to take into account the fact that the light from the Sun pushes on the spacecraft. But with solar sails, they can also use that pressure to propel the craft along.

In this video Paul Andersen compares and contrasts elastic and inelastic collisions. In all collisions the linear momentum will be conserved. In an elastic collision the kinetic energy of the objects will also be maintained. Several...

In this video Paul Andersen defines impulse as the product of the force applied and the time over which the force is applied. The impulse of an object is equivalent to the change in momentum of the object. Several problems related to...

In this video Paul Andersen will first define momentum as the product of an objects mass and velocity. He will then demonstrate how a net force acting on an object will change the momentum in the direction of the force. Several...

In this video Paul Andersen explains how the boundary between the system and environment is chosen to simplify analysis of a physics problem.