Burke.Word

In honor of this season of Festivals of Light – Bob Kulawiec, Chemistry teacher extraordinaire, offers the following Holiday Tale – On Strontium, on Lithium, on Copper, on Barium:

Most years, during the last class period of each section of chemistry before winter break, I share “celebratory holiday pyrotechnics” with my students.  The dishes contain metal salts dissolved in methanol, a highly flammable solvent.  When the methanol burns, the heat of combustion promotes the metal atoms to higher energy states.  When they fall back to their ground states, they emit the excess energy in the form of visible light.  Since each element has its own characteristic quantized energy states, each element emits light of different wavelengths, which we perceive as different colors.  The colors correspond to the classic “flame tests” used for centuries to identify elements.  They are, from left to right: lithium (bright scarlet), copper (green), strontium (reddish orange) and barium (green-tinged yellow).

Happy Holidays from the Edmund Burke School Chemistry Lab!

–Bob

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You may have already read that physicists at CERN, the world’s largest particle accelerator, claim to have found particles that may travel faster than the speed of light.  What is this – some kind of joke?

Cosmic Comedian

There is something funny about the finding though — it violates Einstein’s theory of special relativity, which has been our own “constant” of physics for the past 100 years.  This isn’t the first time people have come up with results that attempted to throw doubt on Einstein’s law. Physicists, the Nazi Party, even Einstein himself (!) have tried to cast doubt on good old E = mc².  To no avail… so far. (“A physicist, a nazi and Albert Einstein are on a train moving at the speed of light…”).

Neutrinos, the particle scofflaws attempting to break the speed of light limit, are a cosmic joke in their own right.  Ever coy, they are “virtually invisible and able to sail through walls and planets like wind through a screen door, but they are shape-shifters.”  They seem like an unsavory crew to bet your PhD on.

So, now to the punch line – if you’re having trouble understanding what all this means – here’s a (now) old bar joke that explains things from the excellent blog Sweetness & Light:

“We don’t allow faster than light neutrinos in here” said the bartender.

A neutrino walks into a bar.

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For our 7th grade inquiry lesson, we built bridges! First, we learned about cantilever, beam, arch, suspension and cable-stayed bridges. Then, students had to build their own bridges using the principles they had learned.  Students had to decide which type of bridge that they would construct, and were given only simple materials, such as popsicle sticks, duct tape, and styrofoam. The span of the bridge had to be a minimum of 50cms. Students had to decide whether they wanted to build a long bridge with less holding capacity, or a shorter, stronger span.  The Forceps team found a middle ground between these poles, and their 74 cm bridge, the second longest, could bear an amazing 60 pounds.   Several much shorter bridges held as much or more weight, but Forceps’ balancing of length and strength made their effort particularly impressive.  That said, every team completed the challenge, and each bridge held at least 30 pounds.  Here are the final results!

Teams:                                                    Weight:                 Length of Span:
Walking Popsicle Sticks                            30lbs                            84cms

Bridge of Doom                                          30lbs                            50cm

The Forceps                                                60lbs                             74cm

Taaki                                                            60lbs                             59cm

Build a Bridge Workshop                        70lbs                             50cm

Styrofoam Princesses                               70lbs                             58cm

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