Reaching breaking point: Materials, Stresses, and Toughness: Crash Course Engineering #18

From Crash Course. Today we’re going to start thinking about materials that are used in engineering. We’ll look at mechanical properties of materials, stress-strain diagrams, elasticity and toughness, and describe other material properties like hardness, creep strength, and fatigue strength. Crash Course Engineering is produced in association with PBS Digital Studios: https://www.youtube.com/playlist?list=PL1mtdjDVOoOqJzeaJAV15Tq0tZ1vKj7ZV PBSDS wants to…

Mass Separation: Crash Course Engineering #17

From Crash Course. It can be really important to separate out chemicals for all kinds of reasons. Today we’re going over three different processes engineers use to achieve that separation: distillation, which separates substances based on their different boiling points; liquid-liquid extraction, which uses differences in solubility to transfer a contaminant into a solvent; and…

Earth Science: Crash Course History of Science #20

From Crash Course. It’s Earth Science time!!!! In this field, natural philosophers were asking questions like, what’s up with fossils? Are they the remains of extinct organisms? Or are they so-called “sports of nature”—rocks that just happen to look like living things but don’t /mean/ anything? And most importantly, how old is… everything? *** Crash…

The Rise of Melodrama: Crash Course Theater #28

From Crash Course. At the turn of the 18th century, audience were ready to go over the top, and get some really, really dramatic theater in their lives. Like, a dog dueling a man type of dramatic. In London, only two theaters were licensed, but entertainment entrepreneurs figured out that musical entertainments weren’t subject to…

P-Hacking: Crash Course Statistics #30

From Crash Course. Today we’re going to talk about p-hacking (also called data dredging or data fishing). P-hacking is when data is analyzed to find patterns that produce statistically significant results, even if there really isn’t an underlying effect, and it has become a huge problem in science since many scientific theories rely on p-values…

How Not to Set Your Pizza on Fire: Crash Course Engineering #15

From Crash Course. Today we’re going to explain how exchangers…exchange heat. We’ll look at concentric tubes, finned tubes, plate heat exchangers, and shell-and-tube heat exchangers. And we’ll look at some equations to help us sort through heat transfer and decide what heat exchangers are best suited for our designs. Crash Course Engineering is produced in…

Chi-Square Tests: Crash Course Statistics #29

From Crash Course. Today we’re going to talk about Chi-Square Tests – which allow us to measure differences in strictly categorical data like hair color, dog breed, or academic degree. We’ll cover the three main Chi-Square tests: goodness of fit test, test of independence, and test of homogeneity. And explain how we can use each…

Why So Angry, German Theater? Crash Course Theater #27

From Crash Course. Theater had a slow start in Germany, mainly because Germany wasn’t really a thing until *relatively* recent times. After Germany finally became a unified state, it had a couple of really important theatrical movements. Today we’ll talk about Sturm and Drang, as well as Weimar Classicism. We’ll also get into the work…

Heat Transfer: Crash Course Engineering #14

From Crash Course. Today we’re talking about heat transfer and the different mechanisms behind it. We’ll explore conduction, the thermal conductivity of materials, convection, boundary layers, and radiation. Crash Course Engineering is produced in association with PBS Digital Studios: https://www.youtube.com/playlist?list=PL1mtdjDVOoOqJzeaJAV15Tq0tZ1vKj7ZV *** RESOURCES: https://www.grc.nasa.gov/www/k-12/airplane/thermo1.html http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/firlaw.html http://coolcosmos.ipac.caltech.edu/cosmic_classroom/light_lessons/thermal/transfer.html http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/heatra.html https://spaceplace.nasa.gov/beat-the-heat/en/ http://www.weather.gov/jetstream/heat https://physics.info/conduction/ https://physics.info/convection/ https://physics.info/radiation/ http://thermopedia.com/content/781/ Çengel, Yunus A.,…

Degrees of Freedom & Effect Sizes: Crash Course Statistics #28

From Crash Course. Today we’re going to talk about degrees of freedom – which are the number of independent pieces of information that make up our models. More degrees of freedom typically mean more concrete results. But something that is statistically significant isn’t always practically significant. And to measure that, we’ll introduce another new concept…