Hank explains the evolutionary basis for altruistic behavior in animals, including vampire bats!

In this video Paul Andersen explains how the perceived frequency of a source depends on the motion of both the source and the observer. As a source approaches an observer the frequency will increase and as it moves away it will...

Paul Andersen describes the important characteristics of viruses. He starts with a brief description of origin theories. He then describes the two characteristics of all viruses; genetic information and protein coats. He also...

In this video Paul Andersen discriminates between spontaneous (or thermodynamically favored) processes and those that are not spontaneous. A spontaneous process requires no external energy source. If the enthalpy change in a reaction...

Paul surveys the Kingdom Plantae. He begins with a brief description of the phylogeny of land plants. He then describes the defining characteristics of plants, including cell walls, embryophytes, alternation of generation and...

It snowed last night where Jessi and Squeaks live, so this morning they tried to go sledding, but they didn't end up going fast or very far. Can you help them figure out what they can do to get their sled zipping down the hill?

In this video Paul Andersen explains how the conservation of charge applies to objects in a system. When a charged object induces charge or conducts charge to a neutral object the net total of charge will not change. Grounding allows...

We all get a jittery after sitting still for too long. But some people experience an irresistible urge to move their legs, and it can seriously affect their daily lives.

Mr. Andersen gives a brief description of osmosis. He explains how water moves from a hypotonic to a hypertonic solution across a semipermeable membrane. The video ends with a time-lapse demon in class.

With the ambitious goal of becoming the first carbon-neutral continent by 2050, the European Union has committed to creating a greener world for future generations. In this bold talk, Ursula von der Leyen, President of the European...

"How fast are you moving?" seems like an easy question, but it's actually quite complicated -- and perhaps best answered by another question: "Relative to what?" Even when you think you're standing still, the Earth is moving relative to...

In this video Paul Andersen explains how the dimensions of space and time are combined in relativistic mechanics. Gravity and velocity can affect both space and time according to Albert Einstein's Special Law of Relativity.

Today we’ll explore how sociology defines family and the different terms used to describe specific types of family. We’ll look at marriage in different societies, as well as marital residential patterns and patterns of descent. And, of...

We need to figure out how we go into conversations not looking for the victory, but the progress, says world debate champion Julia Dhar. In this practical talk, she shares three essential features of productive disagreements grounded in...

Daniel Kish has been blind since he was 13 months old, but has learned to "see" using a form of echolocation. He clicks his tongue and sends out flashes of sound that bounce off surfaces in the environment and return to him, helping him...

Your cell phone is mainly made of plastics and metals. It's easy to appreciate the process by which those elements add up to something so useful. But there's another story we don't hear about -- how did we get our raw ingredients in the...

In this video Paul Andersen explains how biogeochemical cycles move required nutrients through the abiotic and biotic spheres on our planet. Matter on the Earth is conserved so producers must receive required nutrients through the water...

In this video Paul Andersen explains how Kirchhoff's Junction Rule can be applied to series and parallel circuits. Kirchhoff's Junction Rule is an application of the conservation of charge. The current into a junction will always equal...

The terminal velocity of an object is the speed at which the force of drag equals the force of gravity on that object.

In this video Paul Andersen explains how equipotential lines show equal electric potential in an electric field. Equipotential lines can be created from scalar values or by observing the electric field lines. An charged object can move...

Paul Andersen explains how epinephrine is responsible for changes in chemistry of our body associated with the fight or flight response. Epinephrine released by the adrenal medulla are received by a number of organs associated with the...

Is exercising indoors harder? #shorts #science #SciShow

In this video Paul Andersen explains how traveling waves move through space and time. The reflection and interference of traveling waves can create standing waves which appear motionless. Examples of traveling waves in one and two...

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...