Physics-Minded Crows Bring Aesop’s Fable to Life

crow and archimedesEureka! Like Archimedes in his bath, crows know how to displace water, showing that Aesop’s fable The Crow and the Pitcher isn’t purely fictional.

To see if New Caledonian crows could handle some of the basic principles of volume displacement, Sarah Jelbert at the University of Auckland in New Zealand and her colleagues placed scraps of meat just out of a crow’s reach, floating in a series of tubes that were part-filled with water. Objects potentially useful for bringing up the water level, like stones or heavy rubber erasers, were left nearby.

Hair (dryer) Raising Experiences

Balloon

The following experiment will give you insight into the role air pressure plays on weather and help explain how airplane wings get ‘lift’. Have you ever put your hand outside the window of a moving vehicle? As you are doing this, hold the palm of your hand flat or parallel to the ground and slowly rotate your hand until it is perpendicular to the ground? Did you notice that with a slight rotation of your hand, as the wind hits your palm, your hand was forced up by the wind? This is what will happen to the balloon as the air from the hair dryer passes over the balloon’s surface. The balloon is hit by the flowing air, which flows around the outside surface of the balloon, pushing the balloon into the centre of the air column created by the hair dryer. The balloon with receive lift until gravity exceeds the force being applied by the air from the hair dryer.  As the balloon sits in this stream of air created by the balloon, a low-pressure area is created on the opposite side of the source of the air flow, leaving an ‘empty’ space behind the balloon. It is there because the wind is being blocked by the surface of the balloon. The air rushing over the balloon turns to fill up the low-pressure space, and then tries to keep on going—out the side of the main column. As the jet of air rushes ‘out’ over the surface of the balloon, it is pulled back onto the opposite side of the balloon, keeping the balloon inside the air column generated by the hair dryer.

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Which Grape is Heavier?

Floating grape

Students should already have had some previous experiences with solids and liquids.  This activity allows the students a chance to observe buoyancy and interactions of solids with liquids.  They can investigate and describe the properties of density, as well as adhesive/cohesive forces. The usage of common table foods creates high interest.

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Float or Sink – Cool Science Experiment

Scientists seem to be infatuated with objects that float and sink. Even non-scientists find great joy in dropping stuff in water to see if it floats or sinks. Fans of David Letterman are quick to point out one of Dave’s favorite segments called, “Will It Float?” Here’s the latest float or sink challenge: Why do lemons float in water but limes sink? Think you know the answer? Not so fast…

About Steve Spangler Science…

Steve Spangler is a celebrity teacher, science toy designer, speaker, author and an Emmy award-winning television personality. Spangler is probably best known for his Mentos and Diet Coke geyser experiment that went viral in 2005 and prompted more than 1,000 related YouTube videos. Spangler is the founder of http://www.SteveSpanglerScience.com, a Denver-based company specializing in the creation of science toys, classroom science demonstrations, teacher resources and home for Spangler’s popular science experiment archive and video collection. Spangler is a frequent guest on the Ellen DeGeneres Show where he takes classroom science experiments to the extreme. Check out his pool filled with 2,500 boxes of cornstarch!

Cool Science Toys – http://www.SteveSpanglerScience.com
Sign up for the Experiment of the Week – http://www.stevespanglerscience.com/e…
Watch Spangler’s Science Videos – http://www.stevespanglerscience.com/v…
Attend a Spangler Hands-on Science Workshop for Teachers – http://www.stevespanglerscience.com/t…
Visit Spangler’s YouTube Channel – http://www.youtube.com/stevespanglers…

Seven Layer Density Column

density column spanglerBy Steve Spangler

Stack seven different liquids in seven different layers. Anyone can stack blocks, boxes, or books, but only those with a steady hand and a little understanding of chemistry can stack liquids. What if you could stack seven different liquids in seven different layers? Think of it as a science burrito! Continue reading