Tumblr founder David Karp and Xbox program manager Jasmine Lawrence give a detailed description of how files and webpages are sent and received using HTTP and HTML.
Overview of this lesson.
Carbon dating is a real-life example of a first-order reaction. This video explains half-life in the context of radioactive decay. Created by Sal Khan.
Definition of half-life and graphing the decay of phosphorus-32. Calculating how much phosphorus-32 remains after 57.2 days. Created by Jay.
Engineering manager Erica Gomez, program manager Jerome Holman, and Microsoft founder Bill Gates explain how a computer's hardware and software work together.
This equation relates allele frequencies to genotype frequencies for populations in Hardy-Weinberg equilibrium. Created by Sal Khan.
The Hawaiian Islands formed primarily as a result of volcanic activity. While most islands form near tectonic plate boundaries, the Hawaiian Islands are nearly 2000 miles away from the nearest plate margin. Therefore, scientists believe that the islands formed due to the presence of the Hawaiian "hot spot," a region deep in the Earth's mantle from which heat rises. This heat produces melted rock (magma), which then pushes through the crust and solidifies. Created by Sal Khan.
Although mom controls the oxygen source, the fetus has a couple of clever tricks to get the most oxygen possible! Rishi is a pediatric infectious disease physician and works at Khan Academy.
Learn how the needs of the fetus are met by the placenta, which is a special organ that belongs to both the mother and the fetus! Rishi is a pediatric infectious disease physician and works at Khan Academy.
Using the stethoscope to check blood pressure is a technique thatŐs been used for >100 years! Blood pressure is one of the major vital signs frequently measured by health care workers, and it tells us a lot about our blood circulation. Learn what blood pressure is, how it relates to resistance in a tube, why it is necessary to get oxygen to your cells, and how it can change as you age. WeŐll finally put it all together by relating pressure, flow, and resistance in one awesome equation!
The human body enjoys stability. For example, if your blood pressure changes, the body puts a couple of brilliant systems into motion in order to respond and bring your blood pressure back to normal. There are some quick responses using nerves and some slower responses using hormones. The system using hormones is sometimes called the renin-angiotensin-aldosterone-system (RAAS), which is the main system in the body for controlling blood pressure. When your blood pressure drops too low or gets too high, your kidneys, liver, and pituitary gland (part of your brain) talk to each other to solve the problem. They do this without you even noticing! Learn how the body knows when the blood pressure has changed, and how hormones like angiotensin 2, aldosterone, and ADH help return blood pressure to back to normal.
The origin of letters. Created by Brit Cruise.
Ever wondered why your temperature stays at 98.6 degrees? Learn about homeostasis and how your body maintains a stable temperature. Created by MIT+K12.
How to solve for the horizontal displacement when the projectile starts with a horizontal initial velocity. We also explain common mistakes people make when doing horizontally launched projectile problems. Created by David SantoPietro.
In this video we're going to learn about how the concentration of hormones in our blood is regulated. By Ryan Patton.
How Earth's tilt causes seasons. Created by Sal Khan.
S-wave shadow and P-wave detection patterns give us information about the core. Created by Sal Khan.
A presentation of some Hubble Image of Galaxies. Created by Sal Khan.
Hubble's Law. Created by Sal Khan.
From the extinction of the dinosaurs to humanity. Created by Sal Khan.