Khan Academy

1–48 of 2,737 films, free to watch, from the world's open archives.

Where these films come from, and who sees what

Every film here plays from the archive that keeps it: the Internet Archive, Wikimedia Commons, the NASA Image and Video Library, the Library of Congress and Open Images (the Netherlands Institute for Sound and Vision). Nothing is copied to this site. Each film's page names its archive, links to its page there, and states its licence or status as the archive does.

Archive films carry no age ratings, so each is placed from the collections it sits in and the subjects the archive gives it, cautiously. Sexual content and nudity are left out altogether.

Little OnesFilms for young children by name: nursery rhymes, lullabies, preschool.
KidsCartoons and animation, children's and family films, and educational films, unless they deal with war, propaganda, crime, horror or drugs, or carry racial caricature.
TweensDocumentaries, science, nature and space, classic comedies, newsreels, commercials and lectures.
TeensEverything else, including anything we cannot tell about; war, crime, horror and westerns go no lower.
AdultSexual themes (such as the old "sex hygiene" films), gore, surgery, slaughter, atrocity footage.
Internet Archive The Kidney and Nephron Talk Overview of how the nephrons in the kidney filter blood and reabsorb water and other molecules. Internet Archive Liar Truthteller Brain Teaser Talk How to get correct advice when you can only ask one question from either a liar or a truthteller (when you don't know who is what) Internet Archive Elements and Atoms Talk How elements relate to atoms. The basics of how protons, electrons and neutrons make up an atom. Internet Archive Introduction to Programs Data Types and Variables Talk Writing a basic program. Basics of data types, variables and conditional statements Internet Archive Vietnam War Talk Overview of the Vietnam War Internet Archive Algebra: Linear Equations 4 Talk Solving linear equations with variable expressions in the denominators of fractions Internet Archive Introduction to Vectors and Scalars Talk Distance, displacement, speed and velocity. Difference between vectors and scalars Internet Archive Banking 1 Talk Introduction to how banks make money and the value they (potentially) add to society. Internet Archive French Revolution (Part 1) Talk Part 1 of the French Revolution. From the Convocation of the Estates General to the storming of the Bastille Internet Archive Calculus: Derivatives 1 (new HD version) Talk Calculus-Derivative: Understanding that the derivative is just the slope of a curve at a point (or the slope of the tangent line) Internet Archive Enthalpy Talk Understanding why enthalpy can be viewed as "heat content" in a constant pressure system. Internet Archive Simple Equations Talk Introduction to basic algebraic equations of the form Ax=B Internet Archive Statistics: The Average Talk Introduction to descriptive statistics and central tendency. Ways to measure the average of a set: median, mean, mode Internet Archive Heart Disease and Heart Attacks Talk Basics of heart disease, heart attacks, heart failure, angina, cardiac arrest. Special thanks to Edward J Perper, MD for help in clarifying certain aspects of… Internet Archive Parts of a cell Talk Parts of a cell: nucleus, ribosomes, endoplasmic reticulum, Golgi bodies, mitochondria, chloroplasts, vacuoles, and vesicles Internet Archive Greatest Common Divisor Talk 4 example problems of determining the greatest common factor of two numbers by factoring the 2 numbers first Internet Archive Basic Addition Talk Introduction to addition. Multiple visual ways to represent addition. Internet Archive Groups of the Periodic Table Talk Properties of alkali, alkaline earth and transition metals. Halogens and noble gases. Internet Archive Proof: lim (sin x)/x Talk Using the squeeze theorem to prove that the limit as x approaches 0 of (sin x)/x =1 Internet Archive Calculus: Derivatives 2 Talk More intuition of what a derivative is. Using the derivative to find the slope at any point along f(x)=x^2 Internet Archive Slope and Y-intercept Intuition Talk Using the "Graph of a line" module to understand how a line's graph changes when its slope or y-intercept is changed. Internet Archive Periodic Table Trends: Ionization Energy Talk What an ion is. Using the periodic table to understand how difficult it is to ionize an atom. Internet Archive Introduction to Cellular Respiration Talk Introduction to cellular respiration, glycolysis, the Kreb's Cycle, and the electron transport chain Internet Archive Chromosomes, Chromatids, Chromatin, etc. Talk The vocabulary of DNA: chromosomes, chromatids, chromatin, transcription, translation, and replication Internet Archive Brain Teaser: Blue Forehead Room Talk What happens when 100 perfect logicians have to figure out if they each have a blue forehead? Internet Archive Banking 2: A bank's income statement Talk Introduction to the income statement of a bank (and to income statements in general). Internet Archive Probability with Playing Cards and Venn Diagrams Talk Probability of compound events. The Addition Rule. Common Core Standard 457 S-CP.7 Internet Archive Complex Numbers (part 1) Talk Introduction to complex numbers. Adding, subtracting and multiplying complex numbers. Internet Archive Enterprise Value Talk Solving the P/E conundrum by looking at a different valuation metric (enterprise value) Internet Archive Precocious Puberty Talk At Stanford Medical School with Morgan Theis talking to Dr. Laura Bachrach talking about precocious puberty Internet Archive Cancer Talk An introduction to what cancer is and how it is the by-product of broken DNA replication Internet Archive Introduction to Heredity Talk Heredity and Classical Genetics. Dominant and recessive traits. Heterozygous and homozygous genotypes. Internet Archive Specific Heat, Heat of Fusion and Vaporization Talk Specifict heat and phase changes: Calculating how much heat is needed to convert 200g of ice at -10C to 110 degree steam. Internet Archive The housing price conundrum Talk Why did housing prices go up so much from 2000-2006 even though classical supply/demand would not have called for it Internet Archive Optimization with Calculus 1 Talk Find two numbers whose products is -16 and the sum of whose squares is a minimum. Internet Archive Economics of a Cupcake Factory Talk Economics of a simple business leading up to a discussion on inflation/deflation. Touching on income statements. Internet Archive US History Overview 3 - WWII to Vietnam Talk World War II, Hitler, Cold War, Bay of Pigs, Cuban Missile Crisis and the Space Race Internet Archive Mixed numbers and improper fractions Talk Converting mixed numbers to improper fractions and improper fractions to mixed numbers Internet Archive Limit Examples w/ brain malfunction on first prob (part 4) Talk 3 interesting limit examples (correct answer for problem 1 is 3/16 (6/(4*8) NOT 6/(4+8)) Internet Archive Electrostatics (part 1): Introduction to Charge and Coulomb's Law Talk Introduction to Charge and Coulomb's Law (video from May 2008 that I forgot to upload) Internet Archive Proof: A(log B) = log (B^A), log A - log B = log (A/B) Talk Proofs of the logarithm properties: A(log B) = log (B^A) and log A - log B = log (A/B) Internet Archive Why borrowing works Talk An explanation of why (not how) borrowing/regrouping works when subtracting numbers Internet Archive Blood Sugar Levels Talk Normal and elevated blood sugar levels before (preprandia) and after (postprandial) a meal Internet Archive Assessing Alignment of the Lateral Cervical Spine (neck) X-Ray Talk Dr. Mahadevan of Stanford Medical School shows Sal what misalignment in the neck could look like in an X-ray Internet Archive Banking 3: Fractional Reserve Banking Talk Fractional reserve banking and the multiplier effect. Introduction to the money supply. Internet Archive Calculus: Derivatives 1 Talk Finding the slope of a tangent line to a curve (the derivative). Introduction to Calculus. Internet Archive Renting vs. Buying a home Talk The math of renting vs. buying a home. Challenging the notion that it is always better to buy. Internet Archive Calculus: Derivatives 2 (new HD version) Talk Calculus-Derivative: Finding the slope (or derivative) of a curve at a particular point.