Dec 03

Milli-Lincoln

Both classes zoomed in on pennies, wood grain, whiteboard eraser, and more.  Many US cents have President Lincoln on the front and his Washington DC Memorial on the back.  Microscopes reveal a faint outline of Lincoln sitting in the Memorial and a duck or goose climbing the stairs.  We used this activity to launch a mathematical problem: How many atoms thick would Lincoln’s hair be if the tiny image of him in the Memorial had hair?

We measured the Memorial columns, finding 1 millimeter horizontal centers, and approximating Lincoln’s shoulders spanning half that width.  We measured our own shoulder width, rounding up to 50 centimeters to keep the numbers easy.  The ratio of 0.5 millimeter to 50 centimeters (5*10e-5 : 5*10e-1) is 1:1000, making the image a “Milli-Lincoln”.  We computed using powers of ten because learning the power of exponents was my motivation for this exercise.

Students asked for information necessary to calculate the thickness of Lincoln’s hair in atoms: thickness of human hair, thickness of atoms.  We approximated human hair, which varies from 17 – 181 microns, as 100 microns or 1*10e-4.  We approximated the width of an atom as 1 angstrom or 1*10e-10, though atoms more massive than hydrogen have larger diameters and this also depends on their neighboring atoms.  By these numbers, human hair is 10e-4 / 10e-10 = 10e6 = a million atoms thick.  Milli-Lincoln’s hair would be 1/1000 as thick, or 1000 atoms.

We practiced multiplying and dividing exponents of ten. The afternoon class graphed the exponent against the value of the expression, watching the curve snuggle against the X-axis without reaching it.

The afternoon class also reviewed individual projects, with Max presenting on his energy-capture project that could be incorporated into a soccer ball.  Carlin outlined his tire pressure vs. traction measuring machine.  Jeanette explored lava lamps we could make with wax, crayons, or other materials.

The morning class researched specifications of infrared/non-contact thermometers, with Myles and Nathanael finding that the highest temperature that the best thermometer we have in class (900 C) is lower than the higher temperatures reached in a candle flame (1400 C).  Myles’ Grainger catalog offers a model that measures to 1550 C, but costs $335. The great 19th Century scientist Michael Faraday said that all science could be explained through a candle.  Even if only the science known then could be so explained, that’s still impressive.

Jeanette focuses microscope Lincoln in his Memorialfowl on steps of Memorialwood grain white board eraserwhite board Lincoln PM white board Lincoln AM 2 white board Lincoln AMCarlin and Max graph exponential curvecandle flame temperature

Nov 12

Newton’s Cradle big or bouncy

Jeanette planningbouncy with plans 2 bouncyJeanette designed and built a bouncy Newton’s Cradle.  She stapled dental floss to glow-in-the-dark bouncy balls and suspended five of them from a framework of skewers, coffee stirrers, and a paper towel tube.  Alignment of floss and stability of frame prevented the ideal bouncing of balls, we suspect. Click on the photo on the right to watch a short video showing the frame rocking and all the balls start moving together shortly after a promising first couple swings.  It was impressive how quickly she constructed this.

We all continued work on our giant Newton’s Cradle.  With bowling balls drilled last time, we constructed a saw horse, underneath which to hang them.  A photo shows Myles cutting one saw horse leg to length.  We discussed connection options from the balls and paracord to the horse: drill holes through the top beam of the horse or cut open a bicycle inner tube and lay this across the top beam so that the paracord does not shift.  Holes would commit us to certain ball spacing, but that spacing is crucial for long-lasting action (many impacts of balls), so a hybrid approach would be to start with just the rubber topper and, once we are confident we can position the bowling balls to very nearly touch each other (this is the ideal), use nails or staples to secure the paracord to the rubber covered saw horse.  We will also need guide-ropes, like at the ends of a tent, to prevent the saw horse from swaying lengthwise.

cutting leg for bigWe played a “Black Bag” game to illustrate what it’s like to infer structure that we cannot directly see: replicating Lego structures hidden inside black plastic bags that allow touch, but not sight.  The colors of the Lego bricks inside the bags are not possible to determine, but students found two approaches to determine which size bricks comprise the structure: (1) feeling with a fingernail for joints between bricks or (2) breaking one brick at a time off the structure, feeling its dimensions, and replacing it (both techniques worked through the plastic bag).  Our inability to replicate color is analogous to qualities that our best instrumentation of the day cannot determine.  There is always something unseen, always something further to characterize.

Although the activity is most pure when we do not open the bags, because in scientific exploration we infer structure when there is no bag to open, we could not resist.  Before opening the bags, though, we compared all the students’ replications and found one inconsistency.  We went back to the bags to see if 1 student was inaccurate, all but one student was inaccurate, or the bags contained different structures.  We found that 1 student had created a mirror image of the model and corrected it before opening the bags.  This reflects what scientists do when they compare their experimental results to those of others.

Finally, we discussed atomic structure, one reason that atoms are special (indestructible by chemical means), and radioactivity.  Each student summarized a page from the Encyclopedia of Science and walked us through it.

Nov 08

Nano-Link 2015 Day 2

The first day of the 2014 Nano-Link Conference in Minneapolis is blogged at http://nanoconnections.org/nano-link-conference-2015/. Here’s day 2:

Maya Blue is the name of the colorant  found in murals from Mesoamerica dating back many centuries. The remarkable thing about Maya Blue is that it lasts, it does not degrade with time, chemicals, or ultraviolet light. Thomas Higgins of Harold Washington College gave a fascinating presentation on Maya Blue and a variant called Maya Green, explaining how they’re made, their nano structure, and their cultural context. Natural colorants tend to be in the warmer part of the spectrum, orange to red. Because of that, blue green pigments were rare in preindustrial society. That makes Maya Blue stand out. Maya Blue is made from indigo, which gives its blue color, palygorskite, which is a clay that gives it its enduring nature, and copal, a tree sap that burns at just the right temperature to drive water from the clay channels and allow the indigo in. While Thomas is confident about the formulation for Maya Blue, he says that his creation of a green colorant by using copal not just as a fuel source but as an ingredient is speculative. Still, what he calls Maya Green does appear to match some areas of Mayan murals.

Both indigo and palygorskite can be used for health: indigo as a disinfectant, one reason bluejeans don’t smell, and palygorskite clay is used in Kaopectate (the Canadian version, not the US). Paul speculated that since Maya Blue uses no metals to achieve its color or durability, it might be useful in future healthier tattooing. What interested me most is the possibility of using the creation of Maya Blue as a high school student project, which would get them focused on something for which they would need to conduct experiments and use characterizing instruments such as an SEM.

Paul Wagner of Minnesota Wire (http://www.mnwire.com) opened with an admission that he knows little about carbon nanowire but a lot about funding and selling carbon nanowire. I was hesitant because I like technical talks, but his talk was energizing and refreshing. He told stories about forming DefenseAlliance.com to connect those in the military with needs (generals with defense budget) to businesses that could provide solutions. He focuses on finding new needs, something that needs a quick solution, that’s not a commodity. Start with the money, whether it’s an organization that has budget or a funding source like SBIR, Title 3, or RIF (rapid innovation funding).

The qualities that he looks for in new hires are attitude, communication skills, creativity, determination, dedication, motivation, being well-rounded, and the ability to get along. He recommends that students trying to find a job do not go through HR but find a company that has money, perhaps from a new investment or an award from the government. Use press releases to find out about this. In the press release look for a quote from an executive. Figure out the email address for that executive, then contact with “I’m a student, I’m interested in your key technology, I’m trained or experienced in a related area, and could you answer this technical question?” Paul said executive almost certainly pass it off to to a subordinate will understand the technical question (executive probably did not write the quote attributed). That subordinate will answer your question and my even hire you. It’s much better than cold calling HR departments, and much better than contacting businesses that may not have money.

When Paul retires, which does not seem soon, he said he like to teach. He would make an excellent teacher.

 

Nov 07

Nano-Link Conference 2015

The 2014 Nano-Link Conference in Minneapolis (http://www.nano-link.org) focused on nanoscience/ nanotechnology education. I Miguel) attended to learn about teaching nanotechnology in high school. Here is some of what interested me:

Karen Arnold of Nanocopoeia (http://www.nanocopoeia.com) said a great high school project would be anything that requires students to define a problem, design an experiment, execute it, and then prove their results. It would not have to be nano to be useful to her nano company. The qualities her company looks for in employees are technical skills, analytical skills, critical thinking, curiosity, teamwork, and fearlessness. Her company has an every Friday “lunch & learn” during which someone introduces a new idea, nano or not, and teaches everyone else about it.

Justin Patten of Hysitron (http://www.hysitron.com) looks for these key skills: instrumentation, statistics, technical knowledge, problem-solving, attention to details, precision, reliable, motivated, passionate, willing and able to learn, and be the master of something. He told stories about how applicants often think that they know how to be precise, but nano is a whole ‘nother level of precision. Justin recommended developing a diverse background. For instance learn tech and marketing or graphic arts, or information technology and nano. It will make you much more valuable.

Joseph Ward of RJA Dispersions (http://www.rjadispersions.com) looks for this in potential employees: math and chemistry labs, the ability to create formulas in spreadsheets, follow a recipe, get down and dirty (there’s no such thing as “it’s not my job”), learn new skills quickly, understand process, diagnose problems, propose solutions, be creative, get comfortable with trying out new things, identify needs and volunteer, understand company goals, be ready to grow, (always stretching), and have fun with it.

Vincent Ijioma of Boston Scientific (http://www.bostonscientific.com) described his career into and through nanotechnology. He provided many interesting examples of how the very definition of nanotechnology has been confused, and is even feared. By not advertising them as such, he has used his nanotechnology and nanoscience skills to create “miracles.” When asked how he would teach nano to high school students, he said to make nano instrumentation merely tools in the service of a greater project. Once the challenge is properly structured, instructors could shift from lecturing to facilitating students’ access of tools such as SEM or AFM.

The speakers have been skilled at using humor and stories to convey a great deal of technical and business information.

See Day 2 of the conference: http://nanoconnections.org/nano-link-2015-day-2/

Nov 04

Lava lamp and optic fiber

 

optic fibers 3optic fibers 1optic fibers 2 In Miguel’s Science Class we played with optic fibers and watched a documentary on the history of glass.lava lamp

We discussed plasma as a 4th state of matter, discovering through a bit of research that, like the gas state, it has no definite shape or volume.  Plasma does interact with electric and magnetic fields, unlike gas. We played with a plasma globe, noting heating when holding for a prolonged period.

Jeanette brought a lava lamp to fuel with Alka Seltzer tablets, which dissolve when dropped to the bottom of the bottle to release carbon dioxide, CO2.  Bubbles of CO2 attach to the colored water sitting at the bottom of the bottle (water is denser than this oil).  Combined, the gas and the water are less dense than the oil, buoying to the top, where the gas escapes and the water, abandoned, falls back to the depths.  Watch our video to see some gas-water pairings struggle to make it to the top by clicking on the bottle.

 

Oct 28

Plasma skull and bowling balls

skull glowing frontVideo of the skull encasing a plasma globe created in the last session of Miguel’s Science Class is on YouTube, linked from the skull image.

We discussed states of matter (who knew there was more than plasma?!?), identifying which states tend to persist in volume and shape with change of pressure.  Playing with a balloon, glass of water, and ice cube illustrated this pattern. We also applied the ideal gas law with simple numbers.

We discussed how we should drill holes in our 5 bowling balls for the Newton’s Cradle, and then drilled them.  One ball had a cut or crack between the 2 holes through which we wanted to loop our paracord, so we tapped a new hole and then tunneled from that one to one of the original holes.

 

states of matterbowling ball drilling considerations bowling ball tapping new hole bowling ball through hole drilling bowling ball

Oct 23

Halloween

skull glowing frontAnticipating Halloween, Miguel’s Science & Technology Class (2014 Oct  21) encased a plasma globe inside a foam skull.  Measuring the radius of the globe, we measured back from the eye sockets to determine where to slice the skull in half.  Then we carved out a spherical space inside the skull, repeatedly trying to seat the skull to determine what bits of foam impede it.

Carving the backs of the eye sockets reveals the plasma globe. From the front, one gets a deep, otherworldly view through the eyesockets to the dancing lightning within.

We also played with magnets called Buckyballs, which readily form strings and just as easily repel each other when trying to form cubes.  We combined small cubes into sheets into larger cubes, learning repeatedly which configurations are unstable and, therefore prone to collapsing into undesired shapes.

Our project is making a Newton’s Cradle with bowling balls.  We devised a threading pattern for the paracord that does not require cutting it and allows us to cinch it tighter if it stretches.  Each of the 5 bowling balls weighs 15 pounds and the paracord is rated for 550 pounds.  We will analyze how the paracord hangs off the eye-bolts to determine how much static weight it will have to support.  Then we will estimate dynamic loading when the balls are swinging and hitting.  The Pythagorean Theorem let us calculate the length of cord from each eye-bolt to each bowling ball.  We multiplied by 2 cords going to 5 balls and added the ball-length cord running between eye-bolts to estimate a need for 90 feet.  Yes, we are not using metric; the ball weights are imperial and our longest tape measure is, too.  The Pythagorean Theorem allowed us to review squares and square roots.

 

 

measuring skullincision markings on skull

sawing skull top

sawing skull bottomsaw and hacksawcarving out skull

skull glowing side

 

 

 

 

 

 

 

 

 

magnets in circle in square

magnets in cube Newtons Cradle broken Newtons Cradle fix Newtons Cradle plans

Jan 15

Lightning Experiments

 

Leaf before electrocution

Leaf after one electrocution

 

Leaf after 2 electrocutions

With two new students in class, we revived the Van de Graaff generator, because everyone wants to see and feel lightning. Students asked questions I thought would lead nowhere, like what happens to leaves near the base of a copper tube leaned against the generator? I guessed that the tube would ground itself and leave the leaf unaffected. No, the leaf, trapped under the edge of the tube danced violently. Then someone noticed very small gravel, not much larger than sand, hopping in the vicinity of the grounded end of the tube. Also, we electrocuted a leaf by putting it on top of the generator and then turning it on. Three photos show before and after 1 and 2 electrocutions. One student thought he could see differences, but I can’t tell. We’d need to do this more carefully to filter out expectations. Bouncing gravel led to a test of a pebble and leaf fragment to see how they jumped differently. Attracted to a hand connected to the copper tube, only the leaf fragment reacted. We recorded high-speed video, but it showed nothing, so I did not post it.

Feeling force of pie tins flying off Van de Graaff generator

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