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 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...

In this video Paul Andersen explores population dynamics of the human population. The population has show exponential growth since the industrial revolution and all countries will eventually move through the demographic transition. If...

Is the world overpopulated or underpopulated? While we worry about there being too many people for the planet to support, we can also worry about how fewer people in a given place may affect the economy, what may happen when there are...

Paul Andersen starts by defining transpiration as evaporation off of a leaf. He then describes how a potometer can be used to measure the rate of transpiration in different environments.

We've reached the grand finale of our four part series on human reproduction: BABIES! Today Hank walks you through the stages of pregnancy, beginning with how a zygote develops into blastomeres to a morula to a blastocyst and finally to...

How much should you get paid for your job? Well, that depends on a lot of factors. Your skill set, the demand for the skills you have, and what other people are getting paid around you all factor in. In a lot of ways, labor markets work...

Paul Andersen explains how natural selection is a major mechanism in evolution. The video begins with a discussion of Charles Darwin and the details of natural selection. The data of the peppered moth during the industrial revolution...

In this video Paul Andersen explains how covalent network solids form elementally (like graphite) or by combining multiple nonmetals (like quartz). Covalent network solids contain elements from the carbon group because they have four...

In this video Paul Andersen explains how covalent bonds form between atoms that are sharing electrons. Atoms that have the same electronegativity create nonpolar covalent bonds. The bond energy and bond length can be determined by...

In this video Paul Andersen shows how carbon dioxide in the atmosphere is causing a decrease in the pH of the oceans. The carbon dioxide combines with the water to create carbonic acid which dissociates into bicarbonate and carbonate...

Day to day, hospitals provide all kinds of services to help us get better and stay healthy, but during an outbreak, hospitals are the front line of the emergency. In this episode of Crash Course Outbreak Science, we'll look at how...

You're on YouTube right now, but you should probably be studying or writing that research paper. But as long as you're here, we're going to help you figure out how to get the better of your desire to procrastinate in the future. Just...

As the Earth's surface temperature gradually rises, it has become vital for us to predict the rate of this increase with as much precision as possible. In order to do that, scientists need to understand more about aerosols and clouds....

This week on Crash Course Economics, we're talking about monetary policy. The reality of the world is that the United States (and most of the world's economies) are, to varying degrees, Keynesian. When things go wrong, economically, the...

In this video Paul Andersen answers the very simple question: What is cancer? He explains how damage to the DNA can create uncontrolled cell growth. He explains how malignant tumors can spread the disease throughout the body and gives...

In this video Paul Andersen explains how water is unequally distributed around the globe through the hydrologic cycles. Seawater is everywhere but is not useful without costly desalination. Freshwater is divided between surface water...

If you lined up all the blood vessels in your body, they'd be 60 thousand miles long. And every day, they carry the equivalent of over two thousand gallons of blood to the body's tissues. What effect does this pressure have on the walls...

In this video Paul Andersen explains how biodiversity can be measured through genetic, species, or ecosystem variety on the planet. Species diversity is increased through speciation and decrease through extinction. The mechanism for...

As we keep pumping carbon dioxide into the atmosphere, more of it is dissolving in the oceans, leading to drastic changes in the water's chemistry. Triona McGrath researches this process, known as ocean acidification, and in this talk...

How can bottles and balloons help explain the different laws that govern gas? See how Boyle's Law, Charles' Law, and Avogadro's Law help us understand the laws that govern gas properties.

In this video Paul Andersen explains how engineers optimize the design solution. After a number of solutions have been identified engineers will test each of them against a given set of criteria. They will trade-off different...

Social distancing is a time-honored, low-tech tool for slowing the spread of contagious pathogens. But it can also take a toll psychologically. Luckily, there are ways to mitigate these harms, so you can protect yourself and your...

In this video Paul Andersen explains how natural disasters (like earthquakes, tsunamis, volcanoes and flooding) have affected and will continue to affect humans on the planet. Many of the natural hazards (like volcanoes and storms) can...