Demystifying the Poly Density Bottle


Dr. Kenneth Lyle, Duke University Department of Chemistryby Dr. Kenneth Lyle

The demonstration

The Poly Density Bottle is a fascinating demonstration primarily due to the phenomena being counterintuitive to what one would expect.  The bottle containing white and blue beads suspended in a clear and colorless liquid is shaken vigorously, distributing the beads randomly throughout (bottle A).  Upon standing, the beads separate from one another (bottle B) with the white rising to the surface while the blue sink to the bottom (bottle C).  Then, the two sets of beads move towards one another (bottle D) meeting near the middle (bottle E).  This demonstration can be easily repeated again and again.  And, once prepared, it can be stored for subsequent use year after year.  No additional preparation is required. Read the rest of this entry »


The “Magic” of the Soother Ooze Tube


KenByrneBy Ken Byrne

Someone once told me that all magic is science, and all science is magic.  To me, a magic show is a series of puzzles for me to solve, trying to figure out just how they pulled off an illusion.  My favorite science demonstrations are much the same.  I love those demonstrations that make me scratch my head and ask, “Why?”

Here is one of my favorites that is easy and inexpensive.  It feels like a magic trick, but it is all science.  It simply involves rolling a cylinder down an inclined plane.  Sometimes the cylinder will roll down quickly.  Other times it will crawl down slowly. Read the rest of this entry »


Density in the News


Educational Innovations Newsletter - In the News

Density has been in the news since… well, since Archimedes shouted Eureka.  We have collected a sampling of news stories about density that you may want to use in your classroom as you open a discussion about this fascinating subject.

If you find a news article about density that you’d like to share, please let us know in the comments section.  Happy reading!

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EI TV – Density Videos!


Educational Innovations Newsletter - EI TVIt can be difficult for students to understand density.  It’s not as simple as saying that something is heavy or light…  Able to float or sink…  So how can we explain this to young minds?

No worries—we’ve collected some videos that will help you clarify some of the basics about density with your class.  If you know of a video we should include here, please let us know in the comments!

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Density Humor


Educational Innovations Newsletter - HumorWhen it comes to density humor—and laughter in general—the more, the merrier!  That’s why we decided to pack a whole bunch of laughs into our Density Humor corner.  If you have a favorite riddle, joke or cartoon related to density, let us know in the comments section below.

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