According to a recent article in Safety + Health magazine, Honeywell Safety Products had to recall about 9,700 bottles of Eyesaline emergency eyewash solution due to “a low risk of contamination” of bacteria that can cause eye infections (NSC 2016).

Science teachers need to see if they have this type of eyewash solution and also need to take care of the eyewash stations that have sat in their labs during the summer. Eyewash can mitigate eye injuries when there is exposure to physical and chemical irritants or biological agents.

An Infosheet by the Occupational Safety and Health Administration gives background information on the American National Standards Institute standard Z358.1-2014. The standard states that for plumbed systems, “the eyewash must deliver tepid flushing fluid (15.6–37.8°C or 60–100°F) to eyes not less than 1.5 liters per minute (0.4 gpm) for a minimum of 15 minutes” (OSHA 2015).

OSHA further notes, “Whether permanently connected to a potable water source (plumbed) or has self-contained flushing fluid, improper maintenance may present health hazards that can worsen or cause additional damage to a worker’s eye” (OSHA 2015).

If students or school employees use an eyewash that is not properly maintained, biological organisms can come in contact with the eye or skin, or may even be inhaled. Eyes also may be more susceptible to infection after being injured. Eyewashes not properly maintained may serve as a breeding ground for a host of organisms and present serious health hazards. OSHA mentions the following organisms as examples (OSHA 2015):

• Acanthamoeba—a microscopic single cell organism (amoeba) that may cause eye infections.
• Pseudomonas—infections typically caused by a common bacteria species.
• Legionella—bacteria that may cause Legionnaires’ disease, a serious lung infection.

Teachers need to check manufacturer’s instructions regarding how often and how long the eyewash needs to be flushed to reduce or eliminate biological contaminants, which often require a once-a-week flushing regimen. To maintain self-contained eyewash units, consult the manufacturer’s instructions for appropriate procedures.

It is important to first try working with your school administration to address your safety concerns. If your concern is not addressed, you have a right, as an employee, to file a complaint, under which OSHA will conduct an on-site inspection for potential hazards and determine whether your employer is following OSHA rules (OSHA 2014, p. 11).

Teachers or union representatives can call OSHA with questions or additional information at 1-800-321-OSHA. However, many states operate their own OSHA-approved safety and health program. Visit OSHA’s website to determine if your workplace is under Federal OSHA, a state OSHA plan, or other individual state department.

Submit questions regarding safety in K–12 to Ken Roy at safesci@sbcglobal.net, or leave him a comment below. Follow Ken Roy on Twitter: @drroysafersci.

References

National Safety Council. 2016. Safety + Health. Honeywell Issues Voluntary Recall of Eyesaline Eyewash. August 23. www.safetyandhealthmagazine.com/articles/14599-honeywell-issues-voluntary-recall-of-eyesaline-eyewash.

Occupational Safety and Health Administration (OSHA). 2015. Health effects from contaminated water in eyewash stations. www.osha.gov/Publications/OSHA3818.pdf.

Occupational Safety and Health Administration (OSHA). 2014. Workers’ rights. www.osha.gov/Publications/osha3021.pdf.

NSTA resources and safety issue papers

NSTA resources and safety issue papers

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With the fall harvest season coming up, planning begins for family and class fieldtrips to local farms and farm markets. People who live in farming communities have a much different understanding of what a farm can be than those who live in urban or suburban communities. The Maryland Agricultural Education Foundation, Inc. explains why we should teach about agriculture: “Incorporating agriculture into teaching and learning creates the foundation that students, as future citizens, need to make educated decisions regarding food choices and nutrition, community issues, land use planning, and natural resource conservation.” 

Getting to know where our food comes from is the first step and teachers want to plan meaningful, accurate experiences so young children can become familiar with food sources. We have tastings of different apple varieties, children graph their favorite flavor, and we read How to Make an Apple Pie and See the World by Marjorie Priceman (Dragonfly Books 1996).  My children enjoy seeing live farm animals at the Smithsonian Institution’s National Zoo where even the chickens have names. At Oxon Cove Park & Oxon Hill Farm, which replicates a historical farm, the Pre-k to 1st grade program on Animal Life on the Farm introduces children to the milking cows and chickens. (There is a PreK-1 teachers’ guide, Animal Life on the Farm to help teach about the animals and that they provide us with milk, eggs, wool and meat.)

We also visit the Claude Moore Colonial Farm in McLean, Virginia, “a living history museum that portrays family life on a small, low-income farm just prior to the Revolutionary War” where they raise tobacco, wheat, rye, corn, apples and vegetables, and heritage breeds that represent animals that were present in Virginia in the late 18th century.  The children delight in seeing live cattle, hogs and geese. Many children get their first experience with live farm animals at these museum farms. 

If we don’t live near farms of any kind, we can reach out to those who do for help in designing curriculum about food sources. National Science Teachers Association (NSTA) members have been answering one teacher’s request for help planning a social studies and science unit on farms for kindergarten students. The teacher’s planning began with activities such as, making homemade butter, milking a pretend cow, meeting and petting a real bunny, making a scarecrow, planting a vegetable garden, and meeting a real farmer.

Educators on the NSTA members’ listserv recommended first considering what the teacher wants children to learn about farms, and then prepare children ahead of time for a visit to a modern or historic farm. Here are some suggestions:

“Take it from someone who once took 20 (3) and (4) year olds from the inner city to a dairy farm. Singing Old MacDonald and doing cow puzzles had not in any way prepared them for the sight of those gigantic furry beasts lowing and breathing on them!”

“Everything we know about how young children learn tells us that REAL experiences (not one-shot activities and not worksheets) are what promote learning. Real experiences are even more critical when children are being introduced to concepts that they do not encounter in their everyday lives. My suggestion would be to provide as many authentic experiences about farms upfront and then have a fun farm day, having children help with planning and creating the activities.”

“Analyze and dissect ‘fruits’ to find seeds.”

“I highly advise “The Project Approach” by Judy Harris Helm. This helps teachers understand how to do in-depth investigations and learn the processes of engineering and science inquiry as well as develop understanding of the social world. As an Iowan growing up on a farm and now managing a farm for my mother, remember to consider female farmers as well as male.” Resources include: Young Investigators: The Project Approach in the Early Years (Teachers College Press 2010), Kohl Children’s Museum Projects of Chicagoland: Successful Implementation of the Project Approach 2009 (see pages 90-92), “Implementing the Project Approach in Part-time Early Childhood Education Programs” by Sallee Beneke (2000).

“If the class can’t get to a real farm, then providing kids with some real life experiences with the plants, animals, and activities found on a farm is the next best thing—having kids do some planting and growing of their own in a classroom garden, creating their own compost pile with worms; and hatching chicks and having other authentic experiences with farm animals. These types of activities extend way beyond one day and obviously require more time and commitment, however the pay-off in terms of what children will learn is well worth it. They will learn more about the characteristics, needs, and life cycles of living things and inter-dependency among living things.”

“And dig into soil!”

There are many books about farms, farm animals, and growing vegetables and fruit, but fewer about growing animals for meat. Adults can read or view media before choosing to share it with children. Farm animals may be discussed in great detail like in the delightful video, Come With Me Science, Farm Animals: Pigs by Pat Perea, which also lists products for human use from pigs. Lesson plans about farms often say “beef comes from,” and “chickens produce eggs and meat,” which could be misinterpreted by young children as unrelated to the animal’s death. The American Farm Bureau Foundation for Agriculture’s materials about beef begin at grade 3, and include book suggestions: Protein (Healthy Eating with My Plate) by Nancy Dickmann (Heinemann 2012) and Producing Meat (The Technology of Farming) by Rachel Lynette (Heinemann 2012). Children can read about a turkey farm in, My Family’s Farm, and a beef farm in My Family’s Beef Farm, both by Katie Olthoff.

The omission of butchering animals to produce meat reminds me of how the topic of death is avoided when teaching about life cycles—the animal or plant grows into an adult…and the story ends there. How do you include death of living organisms when you teach about a life cycle?

Books about animals eating other animals can be a stepping stone into the discussion of humans killing animals for food. Animals Eat Animals, a board book by Sarah Hutt and illustrated by Dave Ladd and Stephanie Anderson (Phaidon Press 2016), is a collection of three accordion-foldout volumes showing three food chains (humans not included). In What Do You Do When Something Wants To Eat You? Steve Jenkins’ always wonderful and realistic paper cutout illustrations depict many kinds of animals and what they do to avoid being eaten (HMH Books for Young Readers 1997). (See the teachers’ guide for Jenkins’ books.) The blog, The best children’s books.org lists additional books about food chains.

There are thoughtful discussions on talking about meat production with children—see “Kids and factory farming: Yes, tell them the truth” by Christina (Feb 27, 2012) and “Eating Reading Animals” by Jennifer Armstrong (May 1, 2010). That’s Why We Don’t Eat Animals by Ruby Roth (North Atlantic Books 2009) presents a vegan perspective where “We strive for a world where every earthling has the right to live and grow.”

What do you think young children need to know about how meat arrives at their table?

Using Web Tools to Support Learning

Standards play an important role in developing a strong curriculum and preparing students for the future. Science teachers are currently adjusting their curriculum to meet the Next Generation Science Standards, but other standards can also help us as the line between science and other subjects blurs.

The ISTE standards
The International Society for Technology in Education (ISTE) Standards for Students were originally published in 1998 under the name of the National Education Technology Standards. The standards emphasized technology as tools and required students to demonstrate proficiency with the tools.

Nine years later, in 2007, ISTE released an updated version of the standards that focused on how students use technology and moved away from simply learning about technology tools. They aspired to demonstrate such student behaviors as Creativity and Innovation, Communication and Collaboration, and Critical Thinking.

Now, ISTE has once again updated the Standards for Students. The new standards, released in June, look at how technology amplifies learning. They address the following student roles: Empowered Learner, Digital Citizen, Knowledge Constructor, Innovative Designer, Computational Thinker, Creative Communicator, and Global Collaborator.

Improved classroom activities
The 2007 revision of the ITSE standards made us rethink the skills students should be able to demonstrate upon graduation. We began to develop activities that combined one or more of the standard areas with curricular goals. At the time of their release, Ben Smith, co-author of this column, had an activity published by ISTE that required his physics students to make a video of some type of motion, analyze the motion with software, and publish their results on a website. Ben’s students learned how to use iMovie and VideoPoint and to create a website using Inspiration and Word. This multifaceted assignment was a great way to use standards to assess student skills.

Another assignment enhanced by the standards was Ben’s amusement park physics project. In earlier days, students simply took measurements while riding on amusement park rides and calculated experimental values. At the end of the day, they turned in a packet of papers to provide evidence for these calculations and perhaps performed some analysis.

In light of the evolving standards, students were next asked to become experts on just one ride and communicate how the ride works. They were assessed on creativity and ability to collaborate with peers and communicate their findings. This led to many different types of submissions. For instance, one group created a podcast while riding a roller coaster, explaining the physics behind the ride.

As technology developed, students created new formats for completing their work. Nowadays, they can even use apps for instant video analysis and for the collection of acceleration and motion data. Some use presentation tools while others make movies, websites, or other products with specific web 2.0 tools.

This year, students tweeted about physics experiences during the park visit. They used the hashtag #rlphun (RL for Red Lion and Phun for the class slogan “Physics is Phun”) as they gave a brief description of the activity and included a hashtag for the instructional unit (e.g., #momentum, #circular, and #newtons1st).

Conclusion
We are inspired by the actionable nature of the ISTE standards and the emphasis on student behaviors. These standards naturally fit with the NGSS as well as science, technology, engineering, and math (STEM) and science, technology, engineering, art, and math (STEAM) curricula. In coming issues, we will take a deeper dive into the tech standards and discuss what they may look like in a transformed science classroom.

Ben Smith is an educational technology program specialist, and Jared Mader is the director of technology, for the Lincoln Intermediate Unit in New Oxford, Pennsylvania. They conduct teacher workshops on technology in the classroom nationwide.

Editor’s Note

This article was originally published in the September 2016 issue of The Science Teacher journal from the National Science Teachers Association (NSTA).

Get Involved With NSTA!

Join NSTA today and receive The Science Teacher, the peer-reviewed journal just for high school teachers; to write for the journal, see our Author Guidelines and Call for Papers; connect on the high school level science teaching list (members can sign up on the list server); or consider joining your peers at future NSTA conferences.

The mission of NSTA is to promote excellence and innovation in science teaching and learning for all.

My principal asked me to be a mentor for a new science teacher. I received a checklist of high school policies to review, but how can I help him in other ways? – T., New Jersey

In my experience, a good mentor can be a role model, a good listener, a source of suggestions and resources, a critical friend, and a shoulder to cry on. New teachers are often overwhelmed, so it’s important to initially focus on a few essentials. Let him know that it’s okay to learn from mistakes (and we all make them).

You’ll want to be helpful, but not overbearing. For example, as a beginning teacher I struggled with classroom management and how to deal with difficult students. (I came to realize that the two were connected—establishing expectations and routines provided a structure that many students needed.). We did not have a formal mentoring program, but another teacher took me under her wing. One day, she mentioned she was having problems with students X and Y. I also had these students, and she asked if I had any suggestions. I was astounded! She (a legend in the community) was asking me for advice! Whether she really needed my advice or not, her approach made me feel like a colleague, not just a rookie. I also realized that veteran teachers also have challenges and student misbehavior was not necessarily a personal attack.

In addition to your checklist, discuss effective safety practices in science; the NSTA safety portal has many resources. New teachers should understand that if an activity or demonstration cannot be done safely, it should not be done at all, no matter how interesting or engaging or how mature students may seem.

NSTA’s position statement, Induction Programs for the Support and Development of Beginning Teachers of Science has a good description of the roles and responsibilities of mentors and mentees.

For more ideas, see

• Mentoring New Teachers
• Ideas for must-have strategies
• Mentoring a colleague
• Mentoring mentors

Science teachers are savvy users of instructional technology. They use a multitude of digital resources to help students explore and learn, to differentiate instruction, support collaborative classroom projects, and develop formative assessments. Science teachers also use technology (a lot) and rely on the Internet and webinars to help them increase their content knowledge, prepare for a lesson, or share ideas with others.

Earlier this year NSTA partnered with Project Tomorrow for the 2015 Speak Up survey of parents, students, and teachers to find out more about how technology supports student learning. Since 2003, Project Tomorrow has collected input from more than 30,000 schools and more than 4.5M responses have contributed to the national discussion on the use of instructional technology in the classroom. NSTA created a subset of targeted questions for teachers of science in light of A Framework for K-12 Science Education (National Research Council, 2012) and the Next Generation Science Standards (NGSS, 2013). More than 3,100 science teachers completed these targeted questions (33% indicated they were members of NSTA).

In addition to these key points, the survey tells us:

• When science teachers were asked what they would need to more efficiently and effectively integrate digital content, tools, and resources into their daily instruction, the number one answer was “Planning time to work with colleagues (63%),” followed by classroom access to technology, funding support, student safety, and professional development.
• Science teachers think these types of professional development formats are most effective to help teachers learn how to integrate technology within instruction in their classroom:
  • 49%: Observations of other teachers
  • 48%: In school peer coaching and mentoring
  • 47%: Teacher led trainings
  • 45%: In-service school or district training days
  • 44%: Face to face conferences with expert presenters

• Survey respondents said these student learning experiences are most effective in improving students’ engagement and achievement in science:
  • 81%: Learning from a teacher who is excited about science
  • 74%: Conducting real research on topics that students are interested in
  • 71%: Learning from a teacher who is well trained in science
  • 67%: Watching animations, videos, or movies about science topics
  • 64%: Taking field trips to places where science happens

Technology clearly supports student learning, and science teachers are quite adept at infusing technology into their classrooms.  But as states and districts turn to a new way of teaching and learning science, how can technology help to support and enhance teacher practice within the context of their schools and districts?

Supporting Teacher Learning with Technology

Teachers must see examples and gain practice in modeling new instructional strategies closely aligned with their curriculum, informed by student work samples and data, iterative over time, and part of geographically dispersed digital networks that may extend and enhance access to resources, experts and other professional colleagues.

With respect to the effective use of technology, science teacher professional learning should be ground in helping students explore locally relevant science phenomena and engineering solutions.

Students should generate their own questions for exploration, gathering data, designing investigations and solutions, and developing and using models to help them more deeply understand and communicate their level of applied knowledge and skill. This type of learning can be found in the Framework for K–12 Science Education (Council, 2012) and the Next Generation Science Standards (NGSS, 2013).  (In a February, 2016 blog post  I outlined some of the latest research-based strategies in designing professional development solutions that will be critical to the enactment and application of the three-dimensional teaching and learning espoused in the Framework and NGSS).

For example, augmenting a student’s reality can enhance learning as they investigate their local outdoor garden, pond, or school grounds, where thought provoking suggestions for exploration may be pushed to learners based on their location within their local environment, e.g., making observations of the flora and fauna, or collecting data in situ, perhaps using digital probes measuring the PH or O2 levels in a small stream or pond and exploring implications to sustain local ecosystems.

Similarly, platforms that seamlessly integrate virtual environments with the physical realm, situated within the authentic context of local community challenges, leverage the affordances of diverse educational technology in a coherent fashion.

Teacher professional learning and the infusion of technology to aid formative assessment also hold the potential to transform teacher practice. Differentiating learning based on student understanding as they engage in learning opportunities creates the opportunity for formative assessment and a feedback loop (for both students and teachers) that holds much promise. This resonates with the Speak Up survey data results on the top instructional strategies leveraged with technology (encouraging student self-monitoring of learning and providing feedback to students and examining student performance trends to enhance instructional plans and differentiate learning).

The 2016 survey data also shed light on the need for targeted professional learning for educators as we seek to equip them, and the students they serve, to use these tools and be critical consumers of data to inform not only their immediate teaching and learning goals, but also to guide their decisions throughout their life, as they make informed decisions and participate in a scientifically literate society.

 Creating Professional Learning that is Locally Sustained

It’s interesting to note that a vast majority of teachers (71% of science teachers and 65% of non-science teachers) use online video to enhance their personal learning. This data resonate with the notion of blending onsite and online teacher professional learning into coherent growth opportunities.

When teachers were asked what they would need to more efficiently and effectively integrate digital content, tools, and resources into their daily instruction, a whopping 63 percent said they needed “Planning time to work with colleagues.” This supports recommendations from the National Academies of Science, Engineering and Medicine, and Council of St
ate Science Supervisors, who call for support and delivery mechanisms that will “Enhance teacher practice through professional learning situated within the context of their schools and districts, where teachers must see examples and gain practice in modeling new instructional strategies.”

The survey also found that 81% of science teachers found information on the Internet to prepare/delivery a lesson, 58% watched Ted Talks or videos on a topic of interest, 46% attended a face-to-face conference, 31% pinned a classroom lesson plan idea to Pinterest, and 30% participated in a webinar or online conference.

Obviously the connectivity and connectedness provided via the Internet is a significantly critical support mechanism for educators. As stated in the 2016 National Education Technology Plan online learning provides immediacy, convenience, and access to other like-minded colleagues, experts, and resources that might not otherwise be available.

It is interesting to note the rise of mobile applications and social media sites like Pinterest for supporting teacher self-directed learning.  What is most important though is not what platform, app, or tool is the “flavor of the month” but in how the technology is used to enhance and personalize learning. What affordances increase connectedness, sharing promising strategies, and collegial discourse among educators? Teachers realize their passion for their subject matter, learning with like-minded colleagues, and facilitating research in topics their students are interested in energizes their students’ engagement and learning of science.

Professional Learning that Transforms Practice

Research suggests that educators are more effective and that greater student learning occurs when teachers have a deeper understanding of their subject matter, and how to teach it.

NSTA recognizes and integrates online teacher activity when collaborating face-to-face and vice versa to create a coherent experience, avoiding a bolt-on, separate and isolated, click-next, home alone activity. NSTA online networks provide immediacy, convenience, and access to colleagues, experts, and resources that may otherwise not be available.

Online personal learning and an abundance of rich content are the two cornerstones of the NSTA Learning Center. There teachers will find over 12,000 digital resources, web seminars and online virtual conferences, forums with like-minded colleagues sharing the latest practices, innovations and resources in science teaching and learning, and a suite of tools that allow them to create long term professional learning plans and document their growth over time.

NSTA formally collaborates with over 180 districts and universities across the country, helping them implement their strategic goals and course offerings in support of NGSS and STEM, both at the in-service and pre-service levels, respectively. Our NSTA Learning Center platform may be configured to enhance local onsite efforts with private cohorts and administrator dashboards to help document teacher growth as they create and complete long term professional growth plans catering to their unique needs and district and school strategic plans.

The NGSS@NSTA Hub, which is integrated with the Learning Center, contains over 300+ curated resources specifically aligned to the NGSS standards, including vetted lessons, activities, simulations, models, and other type of materials that might be used for instruction and meeting the new standards. The Hub has become a central source for science educators to locate professional learning, materials and resources to work towards the vision of the NGSS and Framework.

The NSTA Position Statements on a number of key issues including the role of technology in science education, NGSS, and inquiry support high impact and transformative instruction.

NSTA is now beginning to collaborate with districts to support  local efforts to build capacity by providing districts with targeted, face-to-face onsite programs (beyond our conferences), and with focused online webinars and moderated discussion on three dimensional learning through the NGSS@NSTA resource portal and NSTA Learning Center.

We are proud of the work NSTA does to combine online and onsite experiences that provide teachers of science with these multi-year, sequenced growth opportunities and we invite you to learn more at www.nsta.org.

Al Byers, Ph.D., NSTA Associate Executive Director, Strategic Development and Research

The mission of NSTA is to promote excellence and innovation in science teaching and learning for all.

Future NSTA Conferences

2016 Area Conferences

• Minneapolis, October 27–29
• Portland, November 10–12
• Columbus, December 1–3

2016 National Conference

• Nashville, March 31–April 3

Follow NSTA

Building an Understanding of Physical Principles

Our Earth is round, although it was not always thought to be that way. It looks flat. But if the Earth is viewed from a tall building, especially near the ocean when the horizon is clear, its curvature can be seen with the naked eye. This is helped with the aid of a straightedge held

Figure 1. From a high elevation, a straightedge held at arm’s length shows that the horizon is not quite level but curved.

at arm’s length aligned with the horizon (Figure 1), a popular activity of residents of tall high-rises near the seashore. 

Eratosthenes’ observations
The first person credited with measuring the roundness of Earth was the Greek scholar and geographer Eratosthenes of Cyrene in 235 BC. This man of learning was the chief librarian at the Library of Alexandria in Egypt. Just as the Sun and Moon are round, Eratosthenes assumed Earth was also round. He proceeded to measure “how round” and more.

From library information, Eratosthenes learned that the Sun is directly overhead at the summer solstice in the southern city of Syene (now called Aswan). At this special time in June, sunlight shining straight down a deep well in Syene was reflected up again—the only time the Sun’s reflection could be seen in the well. A nearby vertical stick in the ground at this time would cast no shadow, but farther north, in Alexandria, a vertical stick would cast a shadow.

This was evident to Eratosthenes, who noted the shadow cast by a tall, vertical pillar near his library during the summer solstice (Figure 2).

Figure 2. When the Sun is directly overhead in Syene, it is not directly overhead in Alexandria.

He measured the shadow, the shortest shadow of the year, to be 1/8 the height of the vertical pillar.

Eratosthenes’ calculations
Eratosthenes correctly assumed that rays from the faraway Sun are parallel. He then learned that while these parallel rays were vertical in Syene, they were nonvertical in Alexandria. Furthermore, he reasoned that if a line along the vertical well in Syene were extended into Earth, it would pass through Earth’s center. Likewise for a vertical line in Alexandria (or any point on the spherical Earth).

His knowledge of geometry told him that if the verticals at both locations were extended to the center of Earth, they would form the same angle that the Sun’s rays make with the pillar at Alexandria. Knowing the 8:1 ratio of the pillar’s height to the shadow length, Eratosthenes could calculate these angles to be 7.1° (Figure 3). Most

Figure 3. The 7.1° angle between the Sun’s rays and the pillar at Alexandria is the same 7.1° angle between the verticals from Alexandria and Syene.

importantly, 7.1° is about 1/50 of a circle (360 / 7.1 ≈ 50). Imagine Earth divided into 50 triangles, each with a 7.1° angle at Earth’s center and the angle’s opposite side equal to the distance between the two cities.

Aha! Eratosthenes reasoned that the distance between Alexandria and Syene must be 1/50 of Earth’s circumference! Thus the circumference of Earth becomes 50 times the distance between these two cities. This distance, quite flat and frequently traveled, was measured by surveyors to be about 5,000 stadia (800 kilometers today). Using this measurement, Earth’s circumference is 50 × 800 kilometers = 40,000 kilometers, which is very close to today’s accepted value.

Another line of reasoning that bypasses the 7.1° measurement is indicated by the nearly similar triangles in Figure 4. Just as the pillar is 8 times as high as the length of its shadow, the radius of Earth must

Figure 4. Similar triangles. Sides a and b have the same ratio as sides A and B. Just as the pillar’s height b is eight times the length of its shadow, Earth’s radius is eight times the distance between the two cities.

be 8 times the distance between the two cities. That is, Earth’s radius is 8 × 800 kilometers = 6,400 kilometers, very close to the currently accepted value. Once the value of the radius is known, the circumference is easily calculated (C = 2πr).

Eratosthenes’ legacy
Today, Eratosthenes is primarily remembered for his amazing calculation of Earth’s size, using only good thinking and a bit of geometry. Seventeen hundred years after Eratosthenes’ death, Christopher Columbus studied Eratosthenes’ findings before setting sail. Rather than heed them, however, Columbus chose to accept more up-to-date maps that indicated Earth’s circumference to be one-third smaller. If Columbus had accepted Eratosthenes’ larger circumference, then he would have known that the land he discovered was not the East Indies but rather a new world. ■

Paul G. Hewitt (pghewitt@aol.com) is the author of the popular textbook Conceptual Physics, 12th edition, and coauthor with his daughter Leslie and nephew John Suchocki of Conceptual Physical Science, 6th edition.

On the web
See complementary tutorial screencasts on physics by the author at www.HewittDrewit.com and on physical science and astronomy at www.ConceptualAcademy.com.

Editor’s Note

This article was originally published in the September 2016 issue of The Science Teacher journal from the National Science Teachers Association (NSTA).

Get Involved With NSTA!

Join NSTA today
and receive The Science Teacher, the peer-reviewed journal just for high school teachers; to write for the journal, see our Author Guidelines and Call for Papers; connect on the high school level science teaching list (members can sign up on the list server); or consider joining your peers at future NSTA conferences.

The mission of NSTA is to promote excellence and innovation in science teaching and learning for all.

Want to know how to maximize the products your elementary students make? What about getting fresh ideas for your middle school classroom? Looking for ideas on how to help your high school students understand the natural world through the construction of scientific models? Want to engage college students in meaningful outdoor learning experiences? The September K–College journals from the National Science Teachers Association (NSTA) have the answers you need. Written by science teachers for science teachers, these peer-reviewed journals are targeted to your teaching level and are packed with lesson plans, expert advice, and ideas for using whatever time/space you have available. Browse the September issues; they are online (see below), in members’ mailboxes, and ready to inspire teachers.

Science and Children 

When students create products to demonstrate learning, we need to think beyond how those products are used to guide assessment. In this issue, we also consider all of the experiences and skills students use and develop through the creation of their products.

Featured articles (please note, only those marked “free” are available to nonmembers without a fee):

• Free – Bringing the Maker Movement to School
• Celebrating Science With the Community
• Free – Editor’s Note: Creating Meaningful Products
• Firefly, Firefly
• Remaking Science Fairs
• Seeing Science in Haiku
• Table of Contents

Science Scope 

We’d like to welcome you to the new and improved Science Scope, which features an updated design, new content, and most importantly, a new editor—Patty McGinness (see “From the Editor’s Desk”). After you’ve had a chance to review all the changes we’ve made to your journal, please let us know what you think so we can continue to improve and better serve your needs.

Featured articles (please note, only those marked “free” are available to nonmembers without a fee):

• A Closer Look at Flowers: Exploring Structure and Function in Science and Art
• A Middle School Lake Study: Connecting Disciplines Through a Hands-On Experience
• Free – From the Editor’s Desk: A Welcome From the New Editor
• Free – Investigating Axial Seamount: Using Student-Generated Models to Understand Plate Tectonics
• Teacher to Teacher: Start the School Year With an Authentic Activity
• Science for All: Creating Student Buy-In on Day One
• Table of Contents

The Science Teacher 

In every scientific discipline, the most important overall goal is to develop understanding of how the natural world works through the construction of scientific models. This issue continues our look at systems and models that we started in the Summer issue. As you’ll see, scientific models come in many forms. In “Achieving Liftoff,” students must develop models to explain what happens during a rocket launch. In “Scaling Up,” students use plant growth to understand climate change. In “Separating a Mixture,” they build models to explain ionic interactions. As you work through this issue, think about how you can incorporate model building, a central science and engineering practice, in your own classroom.

Featured articles (please note, only those marked “free” are available to nonmembers without a fee):

• A Twist on Measuring Catalase
• Free – Achieving Liftoff
• Free – Editor’s Corner: Science Practice in the Post-Truth Era
• Find Your Center
• Focus on Physics: When Our Round Earth Was First Measured
• Scaling Up
• Table of Contents

Journal of College Science Teaching 

Looking to engage students in meaningful outdoor learning experiences? See the article about a pilot program in which preservice teachers partner with classroom teachers to provide students in grades 3 and 4 with Chesapeake Bay watershed educational experiences. Learn about a promising, active learning assignment in which students identify their own questions relevant to lecture content and provide logical answers. And don’t miss the article about the importance of teaching “work checking”—an essential component skill of monitoring and reflection during problem solving that may reveal errors or inconsistencies.

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Science cafés—events held in casual, social venues where attendees can listen to and interact with scientists—have become common worldwide. Many U.S. science cafés are modeled after Café Scientifique, a United Kingdom–based grassroots network of science cafés organized by Duncan Dallas in 1998. When Michelle Hall and Michael Mayhew heard Dallas speak about Café Scientifique at a 2006 American Association for the Advancement of Science meeting, they wondered if the same model could provide “a way to have high school students challenge themselves about what they believe [about science] and why, and how science and technology are changing their lives,” says Hall, a geophysicist, science educator, and president and chief executive officer of Science Education Solutions, a research and development company in Los Alamos, New Mexico.

Hall and Mayhew, a geophysicist who serves as senior research scientist for Science Education Solutions, also thought a Café Scientifique for teens would give them access to scientists and scientific research, help them see scientists as real human beings leading interesting lives, and encourage them to consider science, technology, engineering, and math (STEM) careers. In 2008, with National Science Foundation (NSF) funding, they established Café Scientifique New Mexico in four towns: Los Alamos, Albuquerque, Santa Fe, and Española. “These are very different communities, but the impact on the teens was the same in all of them: The teens enjoyed it,” Mayhew reports.

By 2012, other organizations expressed interest in starting teen science cafés (TSCs). After obtaining additional NSF funds, Hall and Mayhew established the Teen Science Café Network (TSCN) to spread the model nationwide. The network is active in 23 states, with 50 individual sites nationwide. TSCN offers free 

At the Open Minds Teen Science Café in Raleigh, North Carolina, David Roberts, assistant professor of computer science at North Carolina State University, and his dog Diesel demonstrate wearable technology that allows service dogs to communicate with their handlers. (photo courtesy of Open Minds Teen Science Cafe–Raleigh)

memberships to TSC coordinators, along with online training and a national on-site training event. New members can apply for a grant of up to $3,000 to help pay for food and materials for hands-on activities—essential elements of TSCs.

Though adults, including some teachers, establish TSCs at venues like science centers, zoos, museums, aquariums, and libraries, Teen Leadership Teams at each site—guided by adult coordinators—“recommend the topics they’re interested in, do the marketing, and coach the speakers,” explains Hall. Adult coordinators often ask science teachers to recommend students for teen leader positions.

“We really want it to be teen-driven; it gives kids a voice and helps them learn skills and get comfortable with adults outside their families and schools,” she maintains. “The scientists have to pitch their presentations to the teen leaders, and the teens give them feedback. This is a big role reversal for these kids, and the scientists take their words to heart.” Presenters are asked to keep their talks briefer than they would at an adult café “because teens have lots of questions,” she explains, adding that the program is intended to be a series of lively conversations among teens and presenters, not a lecture series.

The cafés allow students to learn more about concepts introduced in school. “What was abstract in school can become concrete,” says Hall. It’s also easier for scientists to attend an after-school or evening café than to visit schools during their workday, she points out.

“Once we get [scientists] to become adept at communicating with teens, they’re in a position to present effectively to other audiences [because] they get better at it,” Mayhew contends.

Generally, parents don’t attend TSCs because “teens might not ask questions with their parents there,” says Hall, especially when topics like the effects of alcohol and drugs are being discussed.

“And we want all kids to come, not just the ones who claim to be already interested in science. We’ve been successful in that,” observes Mayhew.

In North Carolina, Open Minds TSCs take place at the North Carolina Museum of Natural Sciences in Raleigh and at two other sites, funded by the Duke Energy Foundation. TSCs “are a way to connect teens to science careers,” says Lynn Cross, head of youth programs at the Raleigh site. “Teens can ask a presenter what he or she studied in college and what his or her workday is like.”

“Teens are typically not served in museums because it’s hard to attract them,” Kathryn Fromson, coordinator of youth programs in Raleigh, points out. “The café model is fun, relaxed, and social, and they like drop-in events [for which] you don’t have to register, just show up,” she reports.

Teens enjoy doing the hands-on activities, and “in this competitive setting, they enjoy being graded and winning prizes,” she contends.

Some teachers will give students extra credit for their participation. “We’re happy to have teachers use the café as a resource that way,” Cross observes. “We have supportive local teachers who bring their families.”

TSCs provide a way to “meet likeminded peers, people you don’t go to school with…It’s a free event that their parents approve of,” she notes.

Rockville Science Center in Rockville, Maryland, holds Young Adult Science Cafés with funding from the American Society for Biochemistry and Molecular Biology. Program coordinator Katherine Perez says, “The café started out as a place where middle school, high school, and college students could come together to discuss science events and issues…Later, we started inviting speakers, professionals in science and health who could talk to kids about careers, college, and graduate school.”

“Sometimes it’s challenging to have that wide of an age range,” she admits. “The middle school students tend to like doing the hands-on activities, but the older ones don’t…Some topics attract more of one [particular] age group; [a topic like] 3D printing is interesting to all ages.

“Many students attend the cafés as part of their grade,” she reports.

“We’d like to have more professionals in STEM fields giving talks adapted to younger kids. STEM fields can seem challenging to younger kids because there are not many mentorship opportunities, no push to join graduate programs, and many internships are unpaid…It’s hard to get jobs in STEM fields,” Perez contends.

“Presenters can serve as mentors or guide students to those who can help them,” she concludes.

The TSC at the Pacific Science Center in Seattle, Washington, “grew out of…Discovery Corps, a [teen] job training program,” says Tony Smith, program coordinator. “Discovery Corps teen members helped grow the program with guidance from adult staff.

“Our TSC Advisory Board has 20 to 25 teens,” Smith explains. One committee interviews scientists and serves as event moderators. “The food committee arranges for pizza and snacks,” he notes, while “the marketing committee does social media promotion.”

The Advisory Board created “a database of Seattle-area STEM teachers, and they e-mail fliers to them, encouraging them to give extra credit” to students who attend the cafés, says Smith. “We’ve had a very positive response from teachers.”

With speaker topics ranging from “health science to astrobiology to evolution and cooperation in species,” the events have also received high marks from teens. “‘I didn’t know this field even existed’ is what many of them say,” he reports. 

This article originally appeared in the September 2016 issue of NSTA Reports, the member newspaper of the National Science Teachers Association. Each month, NSTA members receive NSTA Reports, featuring news on science education, the association, and more. Not a member? Learn how NSTA can help you become the best science teacher you can be.

The mission of NSTA is to promote excellence and innovation in science teaching and learning for all.

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