Educator How-to: Tectonic Chocolate Bars

The earth is vast and its surface seems huge. However, the earth’s crust only makes up 1% of the earth’s mass — subsequent layers (the mantle and the core) make up the other 99%.

So, why do we care about the earth’s crust (besides the fact that we live there)? It consists of tectonic plates that move around, and where they hit, we get nature’s most impressive formations — Earthquakes and Volcanoes. Because the crust is so vast, it is hard to see the minor changes that occur daily. We tend to notice the big changes like mountains and effects from earthquakes.

In Houston, we don’t get to see either of those things! Luckily, the Houston Museum of Natural Science has Nature Unleashed: Inside Natural Disasters on exhibit right now. In Nature Unleashed you can see how the earth’s tectonic plates shift and learn about the earthquakes that can result, build your own volcano and watch as it explodes molten rock along the mountain side. You can even experience the inside of a tornado, and see some of the aftermath found in several cities.

Nature Unleashed: Inside natural DisastersIf you can’t make it to the museum, you can always show the effects of tension, compression and shifting on the earth’s crust using a simple chocolate bar!

Materials

  • Snack-sized chocolate bars (Milky Way and Snickers work best because of the caramel)
  • Wax paper or plates to place candy on while working

Procedure

  1. Tell the students that the earth’s surface is constantly changing. The crust is formed by tectonic plates which float on the plastic layer of the mantle called the asthenosphere. Where these plates interact, we notice changes on the earth’s crust. The chocolate on this candy bar is going to mimic some of those changes. This time I used Milky Way.

Structure of the Earth

  1. Have the students use their fingernail to make some cracks in the “crust” near the center of the candy bar. Ask them what they notice about the cracks in the crust?

Science Education

  1. Next, demonstrate tension by pulling the candy bar apart slowly. Notice how the crust shifts on top of the caramel layer. The caramel is the exposed upper mantle also known as the asthenosphere. It is this layer that allows the tectonic plates to move around. Sometimes this tension between plates can form basins or underwater ocean trenches.

Science Education

  1. The students should then place their chocolate bar back together gently. To demonstrate another way the earth’s crust moves, ask the students to move one half of the candy bar forward and pull the other half backwards. This is an example of a strike-slip fault. Notice how the chocolate changes at the fault line. This mimics the bending, twisting and pulling of the rocks that can occur at a fault.

Science Education

  1. Lastly, ask the students to push the two ends of the candy bar together. Notice how some of the chocolate pushes up and some even slides on top of another piece, showing how mountains can be created on the earth’s crust.

Science Education

  1. Now that you’ve seen what the earth’s crust can do, feel free to allow your students to eat their new landform creations! 

And don’t forget to come check out Nature Unleashed: Inside Natural Disasters showing now through September 14!

Shark Week: Of Fins and Fiction

At the risk of sounding obvious — it’s Shark Week, the Discovery Channel’s annual plug for the much maligned (but secretly awesome) top predators of the deep!

Started in 1988, as a way for the station to capitalize on the lack of summer competition for programming while aiding conservation efforts for the infamously finned and fanged fellows, the sharks and Discovery Channel have had what you may call a symbiotic relationship. Sharks get the station viewers and the viewers provide better ratings for the station while becoming better educated about sharks and the need for strong conservation efforts. Win/win/win.

Well, at least that’s how Shark Week started…

Lately, Shark Week has, well, it’s been a little disappointing — at least from a scientific standpoint. 

Most of the programming is seemingly centered on making the public at large even more afraid of sharks than they already are (even while these fears are generally not grounded in fact). They’re hyping up fears of getting eaten by one while making the shark from Jaws look comparable to a goldfish you’d take home in a plastic bag.

Here I’m talking about the megalodon, or Carcharodon megalodon

While it’s incredible that this positively massive species of shark ever existed (let alone that we now have the capabilities to find and date their fossils to between 28 and 2 million years ago) the folks with Shark Week have decided that the species wasn’t interesting enough on its own merit. Instead, they’ve now made two completely un-scientific “documentaries” about “scientists” “searching” for it (Click here for an in depth review of actual scientific theories surrounding megalodon).

You may also have heard that some restaurants have tried to capitalize on Shark week this year by serving shark meat on their menus. Really.It’s getting pretty clear at this point that the programming is seriously diluting the conservation message that Shark Week was originally meant to convey.

In a conversation on all things Shark Week with the International Business Times, Sonja Fordham, a marine biologist and founder of Shark Advocates International was asked about the positive and negative effects of Shark Week on the public’s perception of sharks. On this point she said:

“Well, it’s really hard to tell. There’s good things and bad things,Talking about sharks, providing all types of people and interest groups to get out their messages tied to this global event — one time a year we’re all focused on sharks — so that can be very positive if we capitalize on that. But then of course the negative image, the perpetuation of the fear of sharks, does not help shark conservation. It’s a pretty outdated view to see sharks as killing machines or serious threats to beach goers. That negative imagery doesn’t help in help of advancing shark conservation policies.” 

So it’s a mixed bag. But we can use the hype of Shark Week to start conversations about conservation, the need to protect sharks and ways change our perceptions of them.

It might be an uphill battle, but we’re still making progress.

If you have the desire to learn more about sharks (including the extinct megalodon) make sure you come to HMNS for our SHARK! exhibit, opening August 29.

Off With Its Head! The “De-restoration” of the MCCM Coffin Lid

Greetings, and welcome to my second post on the conservation of a Third-Intermediate-Period coffin lid at the Michael C. Carlos Museum. If you missed the first installment, you can hop over here to catch up.

Cut-away diagram of restoration over

Cut-away diagram of restoration over

After the documentation, research and planning stage, the treatment of the Third-Intermediate Period Coffin Lid is well underway. Solvent tests, chemical spot tests, and pre-restoration photographs helped us to design the treatment. The goal is to reverse all but the most necessary, stabilizing additions to the object.

It is clear that this object has, like other fragile polychromed wooden objects from ancient Egypt, suffered from flaking and powdering of its painted decoration. Indeed Egyptian funerary furniture, if not recently excavated, is likely to have been treated for one of these conditions during its lifetime.

Graphic by Kate Brugioni.

Before-treatment photograph of Coffin Lid (left) and condition-map overlay (right).

However, this particular object was restored with an excessively heavy hand, as is visible in the orange-and-blue head piece. Constructed in modern materials around the ancient head, the tripartite-wig form was glued tightly (and messily) to the ancient wood. On top of the wood, a composite material made of saw dust and wood glue was smeared over the top portions of the object. Where it was pealing away, it was taking ancient painted surface with it!

Photograph by Kate Brugioni.

From the reverse the lighter modern wood at the head contrasts with the darker ancient planks.

 

Photograph by Kate Brugioni.

Detail view of the reverse of the coffin lid, showing the excess of yellow wood glue attaching the modern construction to the ancient wood.

Not only was this “restoration” causing damage, but it also impaired a visual appreciation of the object.The modern paint looked incongruously plastic-like and the combination of orange, pink, and blue colors were unsuited to an Ancient Egyptian object.

It was easy enough to call for the removal of the headpiece, but the actual procedure would be challenging and time-consuming.

First, I undertook a micro-excavation to uncover the joint between the modern and ancient structures.

A view of the modern headpiece after partial clearing of the top layers of paint and saw-dust fill.

A view of the modern headpiece after partial clearing of the top layers of paint and saw-dust fill.

 

Photograph by Kate Brugioni.

A section through the top of the modern headpiece construction, showing acrylic filler (white), wood glue and wood-flour (dark brown), wood glue and saw-dust (pink and light brown), and paint (orange and blue).

After establishing the stratigraphy and working through a few (hard!) layers with a scalpel, I established the boundary between ancient and modern. Many of the joints were still inaccessible, however, and to reverse them we reached for a saw.

Face and lapet stratigraphy diagram_w KEY

 

Kate using a coping saw to free the ancient from the modern wood.

Kate using a coping saw to free the ancient from the modern wood.

 

Detail of proper-left shoulder of coffin. As the modern (lighter) wood is being sliced away, the ancient surface is revealed.

Detail of proper-left shoulder of coffin. As the modern (lighter) wood is being sliced away, the ancient surface is revealed.

 

Detail of proper-right shoulder of coffin. By slightly off-setting the kerf (width of saw cut) from the ancient wood, the bulk of the modern (lighter) wood can be removed.

Detail of proper-right shoulder of coffin. By slightly off-setting the kerf (width of saw cut) from the ancient wood, the bulk of the modern (lighter) wood can be removed.

We first tried a coping saw, and then we graduated to a shiny, new Japanese double-blade hand saw. Although versatile enough for most applications, it was difficult to maneuver into tight spaces. Furthermore, using the hand saws was very time consuming.

Renée Stein maneuvering the

Renée Stein maneuvering the hand saw

Finally, after carefully excavating all of the tracts to be cut, we unveiled the one tool to rule them all… the Fein Multitasker FMM 250Q, a variable speed tool for sanding, scraping and cutting. 

IMG_0964_1

Photograph by Kate Brugioni.

Tracts cut around the ancient material, as viewed from the proper-right side of the coffin lid.

 Tune in next time to see our continued progress with the MCCM Coffin Lid!

Sharing The Love: HMNS Outreach fan mail shows kids and teachers agree, hands-on science is FUNdamental

Editor’s Note: This post was written by HMNS Outreach Presenter Sahil Patel.

Even with a brand new school year just around the corner, students, teachers, and parents alike are still raving about last year’s HMNS Outreach programs. During the 2013-14 school calendar, HMNS Outreach conducted about 500 presentations, helping foster a love of learning and science in thousands of children. But you don’t have to take our word for it; check out these comments, pictures and thank you notes, all from satisfied customers from around the Houston area and beyond!

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The cards, letters, comments, and notes posted below were sent to the Museum following Outreach presentations:


Our ever-popular Outreach programs have gotten some fantastic thank you cards over the years, featuring adorable artwork like the Triceratops below.

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Our programs get kids on the edge of their seats in excitement! It isn’t often real prehistoric fossils come to school…

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“My students thought the fossils were cool. I have one student that is a dinosaur “nut” and he was so excited!” wrote a teacher following a Chevron Earth Science on Wheels program. From dinosaur fossils to shark teeth, this program has something of interest for everybody.

 

…and the requests to return are endless once we leave!

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HMNS Outreach Programs have been fostering a love of science in children for years…

Outreach IMG 04“All of our students, parents, faculty and staff were highly impressed and appreciative to the docents’ time, knowledge and friendliness” wrote a supervisor following a Docents To Go program. Extensively trained Museum volunteers present on any of eight different topics in our lowest-price Outreach program. 


…for kids of all ages and backgrounds from all over Southeast Texas…

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“I enjoyed the fact that our students were able to see and ‘pet’ the insects. Also, the presenter introduced, treated and spoke about the insects like they were her own pets. She has deep passion for her work and it showed!” wrote a teacher about LyondellBasell Bugs On Wheels. Staff from the renowned Cockrell Butterfly Center will present bugs of all kinds, shapes, and sizes in a program sure to please even the entomophobic!

 

…leading to even the most unlikely of friendships!

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It’s great when kids think we’re super smart…

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…because that tells us they learned something.

Outreach IMG 08 

While we love hearing that kids enjoyed our programs…

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“The response was very enthusiastic. Numerous parents commented that they appreciated having the opportunity to let their children experience something that was both educational and fun,” a teacher wrote about Discovery Dome. The Museum’s most popular outreach program takes viewers on a voyage to outer space, a trip back in time, and more, with shows appealing for all ages.

 

…we are just as happy to hear that the students enjoyed being taught…

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“I have so many favorites from this presentation! Honestly, I think my teachers and I learned along with the students with this one!” wrote one teacher about our ConocoPhillips Science On Stage show. 2012 Educator of the Year Carolyn Leap leads the way as children and adults alike explore topics in chemistry and physics.

 

…and even happier to hear that it has spawned a love of science and learning!

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“Please have more programs like this one coming to school. It’s always fascinating for children to see live animals and not just pictures!” wrote a parent to a teacher following a TOTAL Wildlife On Wheels program. From salamanders and snakes to alligators and ferrets, kids get an up close and personal encounter with some of the museum’s exotic animals.

 

Inspiring children to consider STEM careers? We love that, too.

Outreach IMG 12

 

And it’s always nice to know the teachers are pleased with us as well.

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“Love them all…you are a standard every year” another teacher wrote. Over 550 programs have already been booked for 2014, and spaces for 2015 and 2016 are already being filled!

 

The feelings are mutual. Our presenters love teaching and working with kids, and cards like these are why we love our jobs.

 Outreach IMG 14

All of the Outreach programs featured above are bookable for visits; we like to say we’re bringing the Museum to you. Bookings are already underway for the 2014-2015 school year, and programs are filling fast, so get in on the action today! For more information, please visit our HMNS Outreach website or send us an email at outreach@hmns.org!

About the author of this post:
Sahil has worked for HMNS in some capacity each summer since 2007 with the Moran Ecoteen Program and Xplorations Summer Camps. He quite literally grew up at the Museum; Sahil and his mom made biweekly trips at lunchtime until he started school at age 5, and he was a regular camper in Xplorations from ages 6-13. In 2014, he was hired full-time as Outreach Presenter, a job where his friends think he spends all day playing with alligators, tarantulas, and dinosaur fossils. He doesn’t like to contradict them.