Jun 11 2015

Color-Changing Beads: Fluorescence from UV Light

Category: ScienceAdmin @ 11:27 am

The usual explanation for the behavior of color-changing beads is that they change color when they absorb ultraviolet light. True enough, but why? (Affiliate link to product at Amazon) The name for this process is “fluorescence.” Some pigments absorb light of one wavelength and quickly emit ‐ fluoresce ‐ light of another (or sometimes the same) wavelength. This is similar to the phosphorescence of glow-in-the-dark toys, clocks, etc., except that the light is emitted much more quickly in the case of fluorescence. At the… Read more

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Aug 04 2012

New Discoveries in Oobleck Science

Category: ScienceAdmin @ 9:51 am

If you have not ever seen anyone jog on a mixture of corn starch and water – “oobleck” – check out the video from the Spanish TV show, "El Hormiguero," included in Wired Magazine’s July 11, 2012 online article, "Defying Gravity: When Strange Liquids Act Like Solids." Water and cornstarch combine to form what in scientific circles is called a non-Newtonian fluid – a viscous fluid (sticky, slow-flowing) that doesn’t always act like we usually expect liquids to behave. When you apply sudden pressure to oobleck, the stuff… Read more

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