In this video Paul Andersen explains how energy flows in ecosystems. Energy enters via producers through photosynthesis or chemosynthesis. Producers and consumers release the energy from food through cellular respiration. An...

Down here, on Earth, if you look up at the night sky, it seems like all the stars up there look the same. Or maybe at least similar. But, it turns out that stars are very different and we shouldn't stereotype them. Some are bigger, some...

In this video Paul Andersen explains how energy can neither be created nor destroyed but may be transferred. Energy comes in many forms (including chemical, mechanical, light, electrical, and thermal). In AP Chemistry students must be...

In this video Paul Andersen explains how energy can be transferred from one system to another. In a closed system the energy can be transferred as either work or heat. Thermal energy transfer is know as energy transfer through heat. ...

In this video Paul Andersen explains how the resistivity of a material opposes the flow of charge. Conductors (like metal) will have a low resistivity and insulators will have a high resistivity. Semiconductors will have a moderate...

How does our knowledge grow? It turns out there are some different ideas about that. Schemas, Four-Stage Theory of Cognitive Development, and Vygotsky's Theory of Scaffolding all play different roles but the basic idea is...

Paul Andersen explains the structure, function and importance of adenosine triphosphate (ATP). He begins by describing the specific structure of the molecule and its three main parts: adenine, ribose sugar, and phosphate groups. He...

This video program compares mass and weight, while illustrating how these are measured. Metric units are used to measure these things using a scale or balance. The video correlates to the Next Generation Science Standard for Middle...

This program describes the force of gravity and its importance to us. Gravitational forces hold objects on Earth, as well as keep the planets in orbit. This video correlates to the Next Generation Science Standard for Middle School...

This engaging program helps students comprehend the concept of volume. Easy-to-understand examples illustrate how the volume of liquids are measured. Measuring solids is shown using a ruler, or through the process of water displacement.

This program helps students create an activity to make observations from data that relate the amount of daylight to the time of year. Students will also create graphs from the data to illustrate the difference in the amount of daylight...

The Chandra X-ray Observatory has discovered a black hole growing at a record pace. Credit: NASA/CXC/A. Hobart

CBD is so hot right now. The compound is being added to everything from gummies to lattes, attached to claims about how it can improve health in any number of ways. But what do we really know about the validity of those claims? And what...

While Thanksgiving is a time focused mainly on family, friends, and giving thanks, it's also the cause of a pervasive medical myth: that turkey makes you sleepy. Don't start with us about the tryptophan. Gah! We know about the...

How Would Republican Plans for Medicaid Block Grants Actually Work? That's the topic of this week's Healthcare Triage.

This week, in a special episode of Healthcare Triage, Aaron and John Green answer your questions! Learn answers to burning questions about handwashing, life expectancy, and stuff.

While we have long known about the existence of microbes - the tiny bacteria, fungi and archaea that live all around, on and in us - our full relationship has become one of the hottest topics for research only in recent years. That's the...

In this shorts video we will be writing a real world linear system. We will recognize that each equation in the given systems is written in slope-intercept form. We will understand that m represents the slope which is the unit rate in...

Discover how buoyancy and tension interact in this physics experiment! Learn why a wood sphere attached to a beaker changes the scale reading, even though it’s submerged like a steel sphere. Perfect for students exploring forces,...

Japan’s legal system is based mainly on the model of prewar German and Soviet legal theory. Thus, the system is grounded not in judicial precedent but in the laws of the constitution. Culturally, the Japanese aren’t very litigious; they...

In this lesson, we will understand the measures of spread or dispersion, which is the range, and we will look at the interquartile range in detail.

In this lesson, the author discusses his favorite job role in this industry, the penetration tester and what the job role entails.

Increase your system's performance by adding swap space, essential for managing memory efficiently.

In this video, you will learn how to create a billing alarm.