The chemistry of cookies
AdultsFoodScienceCooking...You stick cookie dough into an oven, and magically, you get a plate of warm, gooey cookies. Except it's not magic; it's science. Stephanie Warren explains via basic chemistry principles how the dough spreads out, at what temperature we can kill salmonella, and why that intoxicating smell wafting from your oven indicates that the cookies are ready for eating.
The loathsome, lethal mosquito
AdultsAnimalsScienceEnvironment...Everyone hates mosquitos. Besides the annoying buzzing and biting, mosquito-borne diseases like malaria kill over a million people each year (plus horses, dogs and cats). And over the past 100 million years, they've gotten good at their job -- sucking up to three times their weight in blood, totally undetected. So shouldn't we just get rid of them? Rose Eveleth shares why scientists aren't sure.
How simple ideas lead to scientific discoveries
AdultsCreativityScienceEducation...Adam Savage walks through two spectacular examples of profound scientific discoveries that came from simple, creative methods anyone could have followed -- Eratosthenes' calculation of the Earth's circumference around 200 BC and Hippolyte Fizeau's measurement of the speed of light in 1849.
Anti-Gravity Wheel Explained
AdultsPhysicsScienceEngineering...It's a little shaky but if you average out the oscillations I think the result is clear. Again, huge thank you's to A/Prof Emeritus Rod Cross, Helen Georgiou, Alex Yeung, and Chris Stewart, the University of Sydney Mechanical Engineering shop, Duncan and co. Ralph and the School of Physics.
The Most Amazing Thing About Trees
AdultsEcologyNatureScience...Trees create immense negative pressures of 10's of atmospheres by evaporating water from nanoscale pores, sucking water up 100m in a state where it should be boiling but can't because the perfect xylem tubes contain no air bubbles, just so that most of it can evaporate in the process of absorbing a couple molecules of carbon dioxide. Now I didn't mention the cohesion of water (that it sticks to itself well) but this is implicit in the description of negative pressure, strong surface tension etc.
Why do we cry? The three types of tears
AdultsBiologyHumanScience...Whether we cry during a sad movie, while chopping onions, or completely involuntarily, our eyes are constantly producing tears. Alex Gendler tracks a particularly watery day in the life of Iris (the iris) as she cycles through basal, reflex and emotional tears.
Dead stuff: The secret ingredient in our food chain
AdultsEcologyFoodScience...When you picture the lowest levels of the food chain, you might imagine herbivores happily munching on lush, living green plants. But this idyllic image leaves out a huge (and slightly less appetizing) source of nourishment: dead stuff. John C. Moore details the "brown food chain," explaining how such unlikely delicacies as pond scum and animal poop contribute enormous amounts of energy to our ecosystems.
Anti-Gravity Wheel?
AdultsInternet CulturePhysicsExperiments...In this video I attempt to lift a 19kg (42 lbs) wheel over my head one-handed while it's spinning at a few thousand RPM. This replicates an earlier experiment by Professor Eric Laithwaite. He claimed the wheel was 'light as a feather' and could not be explained by Newton's Laws. I wanted to find out for myself what I really felt like.
Chris Hadfield: What I learned from going blind in space
AdultsLifeSpaceScienceThere's an astronaut saying: In space, "there is no problem so bad that you can't make it worse." So how do you deal with the complexity, the sheer pressure, of dealing with dangerous and scary situations? Retired colonel Chris Hadfield paints a vivid portrait of how to be prepared for the worst in space (and life) -- and it starts with walking into a spider's web. Watch for a special space-y performance.
When Water Flows Uphill
AdultsPhysicsScienceCooking...In the Leidenfrost Effect, a water droplet will float on a layer of its own vapor if heated to certain temperature. This common cooking phenomenon takes center stage in a series of playful experiments by physicists at the University of Bath, who discovered new and fun means to manipulate the movement of water.
Amazing Water & Sound Experiment
AdultsPhysicsScienceExperiments...The effect that you are seeing can't be seen with the naked eye. The effect only works through the camera. However, there is a version of the project you can do where the effect would be visible with the naked eye.
Coke Can Getting Swallowed By Lava
AdultsEnvironmentNatureScience...This is what happens when a coke can meets some flowing lava.
The mystery of motion sickness
AdultsHealthScienceBiologyAlthough one third of the population suffers from motion sickness, scientists aren't exactly sure what causes it. Like the common cold, it's a seemingly simple problem that's still without a cure. And if you think it's bad on a long family car ride, imagine being a motion sick astronaut! Rose Eveleth explains what's happening in our bodies when we get the car sick blues.
What Causes Traffic Jams?
AdultsScienceTransportationAutomotiveIt's happened to all of us: we're cruising down the freeway and suddenly find ourselves stuck in a thick jam of other cars. Where did they come from? What caused the traffic mess? Scientific American editor Larry Greenemeier explains.
The Invisible Universe Of The Human Microbiome
AdultsBiologyHumanScience...The next time you look in a mirror, think about this: In many ways you're more microbe than human. There are 10 times more cells from microorganisms like bacteria and fungi in and on our bodies than there are human cells. But these tiny compatriots are invisible to the naked eye. So we asked artist Ben Arthur to give us a guided tour of the rich universe of the human microbiome.
These Japanese Scientists Discovered A Way To Levitate Objects Using Sound
AdultsScienceTechnologyPhysics...Droplets, pellets, a stick of wood, nuts, screws, diodes, if the object in question is small enough, than this machine can not only lift them into the air and hold it in place, but move them around on all three axes
300 Years of Fossil Fuels in 300 Seconds
AdultsGlobal WarmingHistoryEnvironment...Fossil fuels have powered human growth and ingenuity for centuries. Now that we're reaching the end of cheap and abundant oil and coal supplies, we're in for an exciting ride. While there's a real risk that we'll fall off a cliff, there's still time to control our transition to a post-carbon future.
Sulfur Hexafluoride Gas
AdultsScienceTechnologyChemistry...A model boat floating on sulfur hexafluoride (gas significantly denser than air) at the Physikshow of the University of Bonn!