Thermal Protection- Science with Blowtorches!
Posted: Wednesday, December 10th, 2014
by Joanne Cozens Michael
STEM… the final frontier. Okay, not really, but it is our students’ future and it is up to us to get them as prepared as possible. One of the issues many educators face when teaching STEM is finding something that can cover multiple strands of the STEM “rope”. A few years ago, I attended Space Camp for Educators in Huntsville, Alabama, and was introduced to an amazing lesson sure to inspire engineering and creativity, get those STEM juices flowing, and captivate even the most reluctant of learners!
The lab is called “Thermal Protection”. The basic idea is to protect a screw that is hot-glued onto a wooden dowel from getting so hot that the glue melts, and the screw falls off. Protecting it from what? A blowtorch! I primarily do this with 5th grade students because my school goes up to 5th grade, but it can be done with students as young as 3rd grade. A colleague does this with his high school seniors- everyone loves it! It can also definitely be done as part of a family science night with parents helping.
Before the students arrive, you will need to prep the dowels. A dowel ½-inch in diameter works well, and only needs to be six inches long. Place a drop of hot glue on one end, and stick a screw, flat side-down, into the glue. The type of screw doesn’t really matter, but it shouldn’t be longer than two or three inches. You will also need to assemble some “protection materials”: non-insulated copper wire, aluminum foil, tin foil (if available), and any other metals that are (relatively) easy to shape or cut a hole into. I normally prep my aluminum foil for my students by cutting it into strips about four inches long by however wide the roll of foil is. The wire can be any length. You will also need to have some way to hold the dowel while the blowtorch is being used. A ring-stand from the high school chemistry department works beautifully, and most have a screw-clamp on them that will hold the dowel without issue. The clamp will need to be positioned about 2/3 of the way up the stand, and when the dowel is in place, the torch’s flame is about four inches from the screw – hot enough to cause the heat to radiate quickly from the flame to the screw, and melt the glue, but not so hot that it would cause injury or danger to anyone. I place newspapers down on the table that the stand is on and then a large piece of aluminum over them, to protect the table from melted glue or bits of metal that may fall off.
To introduce the lab, I show them footage of a NASA rocket launch and explain that in order to get the rocket up past Earth’s atmosphere, it obviously has to have an incredible amount of thrust that can only be attained by a chemical reaction producing insane amounts of heat as a by-product. The payload inside can have humans, food, various experiments, oxygen tanks, or other vital things that need to stay protected at a certain temperature, but the outside must be strong enough to withstand the launch, any meteorites or space debris that it may come into contact with, and be able to survive re-entry into Earth’s atmosphere. Metal has proven to be one of the best materials to use. From there, I bring out the ring stand, with a dowel/screw already attached, but no protection on the screw. I place the blowtorch in the correct spot, and have a student time how long it takes for the glue to get so hot that the screw falls off. That number is the benchmark for the class. The time is generally 30 seconds or so (not too long of a time!).
From that point, their mission is simple: using the various metals, create a “thermal shield” to protect the glue from heating up too quickly. This could very easily become a unit project in which students can research the heat conductivity of the various metals used, the best order of the metals to be placed on the screw, if certain metals should not be used at all, and/or the shape that best reflects the heat. They can weigh the materials, and use that data against the rest of the class’ data.
The highlight is obviously testing day. I set a time limit for how long the torch is on the dowel of three minutes, just to make sure we can get through all of the experiments in one session. The students that succeed over the baseline are deemed “thermal champions”, while the others can have a chance to improve their time. Depending on how your class/unit is structured you can have the students go back and reengineer their thermal protection. For example, they might alter the order of metals, shape of metals (was it better concave or convex? Folded over, or a single sheet? Crumpled up in a ball?).
One of the many reasons why I love this lesson is that it gives every single student the chance to be a star in front of their peers. It is generally pretty easy to reach the baseline time. The only exception I have experienced is when they’ve placed so much “protection” on their screw that it is too heavy, and just a little bit of heat is enough to pull the screw off – another engineering lesson in itself! I have had students that struggle to comprehend lessons on a daily basis just soar in this activity- to see their faces shine brighter and brighter as they see the seconds, and then minutes, tick by, and their screw holding steady under the intense heat of the blowtorch. It is these kinds of experiences that give students the encouragement they need to pursue other STEM activities, and possibly a future career. And all from using a blowtorch in class!
Posted: Wednesday, October 12th, 2016
by Jessica Sawko
In June 2016 California submitted a waiver application to discontinue using the old CST (based on 1998 standards) and conduct two years of pilot and field tests (in spring 2017 and 2018, respectively) of the new science assessment designed to support our state’s current science standards (California Next Generation Science Standards (CA-NGSS) adopted in 2013). The waiver was requested because no student scores will be provided as a part of the pilot and field tests. The CDE received a response from the U.S. Department of Education (ED) on September 30, 2016, which provides the CDE the opportunity to resubmit a revised waiver request within 60 days. The CDE will be revising the waiver request and resubmitting as ED suggested.
At its October 2016 North/South Assessment meetings CDE confirmed that there will be no administration of the old CST in the spring of 2017. (An archive of the meeting is available at http://www.cde.ca.gov/ta/tg/ai/infomeeting.asp.) Learn More…
Posted: Thursday, September 22nd, 2016
by Carol Peterson
1) To celebrate the 100th anniversary of the National Park Service, Google has put together a collection of virtual tours combining 360-degree video, panoramic photos and expert narration. It’s called “The Hidden Worlds of the National Parks” and is accessible right from the browser. You can choose from one of five different locales, including the Kenai Fjords in Alaska and Bryce Canyon in Utah, and get a guided “tour” from a local park ranger. Each one has a few virtual vistas to explore, with documentary-style voiceovers and extra media hidden behind clickable thumbnails. Ideas are included for use in classrooms. https://www.engadget.com/2016/08/25/google-offers-360-degree-tours-of-us-national-parks/. Learn More…
Posted: Thursday, September 22nd, 2016
CSTA is pleased to announce the winners of the 2016 CSTA Awards for Distinguished Contributions, Margaret Nicholson Distinguished Service Award, 2014 and 2015 PAEMST-Science recipients from California, and the 2016 California PAEMST Finalists. The following individuals and organizations will be honored during the 2016 California Science Education Conference on October 21- 23 in Palm Springs. This year’s group of awardees are truly outstanding. Please join us in congratulating them!
Margaret Nicholson Distinguished Service Award
The Margaret Nicholson Distinguished Service Award honors an individual who has made a significant contribution to science education in the state and who, through years of leadership and service, has truly made a positive impact on the quality of science teaching. This year’s recipient is John Keller, Ph.D. Dr. Keller is Associate Professor, Cal Poly San Luis Obispo and Co-Director, Center for Engineering, Science, and Mathematics Education, Cal Poly San Luis Obispo. In her letter of recommendation, SDSU science education faculty and former CSTA board member Donna Ross wrote: “He brings people together who share the desire to make a difference in the development and implementation of programs for science teaching. Examples of these projects include the Math and Science Teaching Initiative (MSTI), Noyce Scholars Program, Western Regional Noyce Initiative, and the Science Teacher and Researcher (STAR) program.” Through his work, he has had a dramatic impact on science teacher education, both preservice and in-service, in California, the region, and the country. He developed and implemented the STEM Teacher and Researcher Program which aims to produce excellent K-12 STEM teachers by providing aspiring teachers with opportunities to do authentic research while helping them translate their research experience into classroom practice. SFSU faculty member Larry Horvath said it best in his letter:“John Keller exemplifies the best aspects of a scientist, science educator, and mentor. His contributions to science education in the state of California are varied, significant, and I am sure will continue well into the future.” Learn More…
Posted: Tuesday, September 20th, 2016
by Peter A’hearn
NGSS is a big shift. Teachers need to learn new content, figure out how this whole engineering thing relates to science, and develop new unit and lesson plans. How could NGSS possibly make life easier?
The idea that NGSS could make our lives easier came to me during the California State NGSS Rollout #1 Classroom Example lesson on chromatography. I have since done this lesson with high school chemistry students and it made me think back to having my own students do chromatography. I spent lots of time preparing to make sure the experiment went well and achieved the “correct” result. I pre-prepared the solutions and organized and prepped the materials. I re-wrote and re-wrote again the procedure so there was no way a kid could get it wrong. I spent 20 minutes before the lab modeling all of the steps in class, so there was no way to do it wrong. Except that it turns out there were many. Learn More…
Posted: Tuesday, September 20th, 2016
by Robert C. Victor. Twilight sky maps by Robert D. Miller. Graph of evening planet setting times by Dr. Jeffrey L. Hunt
Our evening twilight chart for September, depicting the sky about 40 minutes after sunset from SoCal, shows brilliant Venus remaining low, creeping from W to WSW and gaining a little altitude as the month progresses. Its close encounter within 2.5° N of Spica on Sept. 18 is best seen with binoculars to catch the star low in bright twilight. The brightest stars in the evening sky are golden Arcturus descending in the west, and blue-white Vega passing just north of overhead. Look for Altair and Deneb completing the Summer Triangle with Vega. The triangle of Mars-Saturn-Antares expands as Mars seems to hold nearly stationary in SSW as the month progresses, while Saturn and Antares slink off to the SW. Learn More…