This is a space gradually being developed for posting the results of original science research done by high school students at the Poughkeepsie Day School).

Spring 2008-2009

This site initially served as a place for the class I taught in 2008-09 in Wave Physics to collaborate in documenting their work on the sound made by running a finger around the rim of a wine glass. In the interest of time, I drafted the report and they made changes.

Here is the original draft of the report that I sketched out and Jasper W-B substantially revised.

Fall 2009-2010

A student worked independently to reproduce the results of the 08-09 wine glass experiment. She got different results.


Spring 2009-2010

In Spring 2010 this space was used by my chemistry students. Students each year measure the length of a molecule of oleic acid. The results are often off by a factor of 20 to 30 (not bad for measuring something a few ten-millionths of a centimeter long using a pie plate and graph paper). Suspicion arose among students in Fall 2010 that that the pie plate was too small to give good results, a prospect tested in the subsequent semester.

Refining Methods for Determining the Length of a Molecule of Oleic Acid

Spring 2010-2011

Physics
Two sections of the wave physics course were offered again. Students explored a wider range of phenomenon associated with the sound generated by running a finger around the rim of a wine glass. The focus of some groups shifted to include the sound generated by striking the glass. Preston P, Joe K and Cara I reran the original wine glass experiment, adding measurements of the depth of the water. Preston wrote up this account. Calle K, Riley, Anna, Sophie W and Emily J independently did the same as Preston, Joe and Cara. They collectively wrote a report.

Max H and Jake compared fundamental frequencies and overtones for the tapping and rubbing of a wine glass. Here is Jake's report of that work. Fatima and Alex ran a analysis of Tibetan Singing Bowls

Chemistry
The two chemistry sections were meeting that same semester as well. A question came to us from the middle school science class about three experiment to determine the oxygen content of air. The first uses the rusting of steel wool to consume oxygen in a closed environment. The essentials are described and illustrated here. In the second experiment, vinegar replaces the water to accelerate rusting time. In the third, a burning candle consumes the oxygen.

We ran several trials of the basic experiment, taking readings over five days. It produced reasonable estimates of the amount of oxygen in air. We considered that the analysis ignored the volume of the steel wool was negligible. Aidan and Sophie ran a calculation using the density of steel and the mass of the steel wool to show that the volume was indeed negligible.

We speculated that the addition of vinegar might produced something other than rust. Some online research led us to suspect iron (II) acetate would form as well as hydrogen gas. One group designed an experiment to explore this chemistry.

More experimental research was generated by the candle version of the experiment. We reasoned that, while the candle consumed oxygen, it also produced carbon dioxide and water vapor. Taking the candle wax to be C25H52, we wrote the balanced equation for the complete oxidation:

C25H52 + 38 O2 ---> 25 CO2 + 26 H2O

This indicates that more gas is produced than is consumed (51 molecules versus 38 molecules), which suggest the water level should go down in the graduated cylinder rather than rising.

We speculated about the resolution of the discrepancy. We thought the water might be condensing on the surface of the water. One group worked out a clever way to measure that, although their first attempt ran into trouble. Their method is documented here.

Joey suggested that we run the candle experiment using oil rather than water to see if a layer of water condense don the surface of the oil. We tried a few trials of that without evident condensation of water.

The middle school class supplied us with a link that argued the candle generates a carbon dioxide layer that builds down from the top of the container, such that the flame is smothered by carbon dioxide rather that by running out of oxygen. Reports from two groups who tested that prospect are here and here. Neither supported that contention. Ben, Alyssa and Emma ran one of those experiments and Emma wrote up this report. Alex, Andy, Ashton, Ella, Matt, Michael, Rosie and Peter conducted and reported the other experiment.

Spring 2011-2012

I asked students to work out a way to find how many calories are needed to melt one gram of ice (i.e., the thermal heat of fusion). One of the sections came up with an innovation: calibrate a hot plate, find out how many calories it put every second into a beaker resting on it. I think the initial idea came from Phil, who suggested using a match as the heat source. A collaborative effort by Chloe, Izzy L., Izzy L-S, Kelly, Lucas, Phil, Sabrina, Sophia, Talia and Usama then refined and executed the idea. Izzy L-S put in extra time to write the formal report.

The plan seemed excellent, but it gave results that ranged considerably. I hope a future chemistry class will take up the task of figuring out what went wrong.

Spring 2012-2013

One group in Wave Physics tried a novel approach to the wineglass investigation. There were three seniors (Joey, Kelton and Joyce) and one junior (Phil). They placed Vernier microphones in two sites around the wine glass as it sounded. This notably required reducing the sampling rate as the computers would not accept two sensors measuring 8000 times a second. They found that when the mikes were 90 degrees apart, one registered a compression while the other registered an expansion. This was consistent with an assumption the Day School researchers had held for several years: the sounding glass deforms from its resting circular shape, shifting between two oval that are oriented 90 degrees apart.

The group also tested the supposition that finger moving around the rim of the glass is pressing a node in the vibrating glass and pushes the node along. The researchers attached a Vernier accelerometer to moving hand and show that the finger is always in the same place relative to compression and expansions.

There results fell into place just before the seniors left for their senior internships, and the work was never written up.

Spring 2014-2015
Two groups of seniors in the wave physics course returned to the wine glass question, trying to reproduce the results of Spring 2012-2013. Jesse, Sarah, Simon and Joey D. used a larger wine glass and found compressions 120 degrees rather than 90 degrees apart. They interpreted this as as an extra wavelength being in the standing wave of the class. Chenlong, Lucy and Harry also found the extra wavelength, but directed more attention to measuring motions in the wall of the glass, not just the top rim. Their preliminary results support that walls move in two parts, with one pushing in while the other pushes out.

A third group of three juniors and one senior (Richard, Jayson, Calvin and Tianyi, respectively) took on a problem that has been dormant for about six years. The question is about the dynamics of bricks or blocks falling like dominoes in a line. Work done by Day School students in the past quantified the speed of the pulse that occurs when one block hits another and another. One set of experiments had previously shown that how hard the first block in the line was hit affected the speed of the pulse as long as no skidding or rotation about a vertical action resulted. Several careful run experiments showed that the spacing of the blocks did not affect the pulse speed, bit other experiments showed that it did. Around 2006 on student filmed actual dominoes toppling at 30 pframes per second. He showed that the pulse accelerated over the first seven or eight dominoes.

I think it was in 2007 that three students did preliminary work on a different approach. They let a wood block fall into a Vernier student force sensor, measuring the force the block applied to the sensor. Then they let a block fall into a second block, pushing it into the sensor. Next it was a block into a block into the sensor. They found that the force sensor recorded increasingly great force, but took the work no farther.

Richard, Jayson, Calvin and Tianyi took class time to try to reproduce and extend that result. They found that the force reading were not reproducible for a given set of blocks.