Educator How-To: Crystals, Geometry and Chemistry

Math is beautiful and inescapable. Especially in nature, patterns and equations just keep showing up.  The path of an orbiting planet, the growth of a nautilus, arrangements of leaves on a stem, the efficient packing of a honeycomb; we can find rules and algorithms and make predictions from them.

Crystals, with their obediently repeating structure, are an elegant manifestation of the ‘rules.’  To be a crystal, your building blocks (atoms, molecules, or ions) must follow patterns over and over and over and over and over.  Atoms, being predictable, simply do what their chemical properties and the conditions (temperature, pressure, etc.) indicate.  So what exactly does it take to go from a mess of elements and compounds to this[picture of green “Crystals of India” crystal specimen] example from the Crystals of India exhibit at HMNS Sugar Land?

If you’ve ever tried making rock candy from sugar water or ornaments from borax solution, then you have some idea what it entails: something dissolved that is capable of making crystals has to slowly come out of solution – usually the longer you give it, the bigger it can grow and the slower it grows, the more perfect the crystals.

Freezing water into ice also gives you crystals; they just don’t stick around and let you handle them conveniently at room temperature. Water and solutions in water aren’t the only way to get crystals; molten rock cooling (slowly) can also give crystals, but that’s a little tricky for home experimentation.

So time is your friend for crystal growth, pressure is a factor, and it needs to be easier for atoms to attach to the forming crystal than to stay in solution.  Having a solution that is saturated or supersaturated so it can barely hold all of the dissolved material helps. It also helps to have places for the crystals to start forming; a tiny ‘seed’ crystal or sometimes even just a rough spot on a surface can provide the nucleation sites to kick off crystal growth. Are there other ways crystals and the things we consider ‘gems’ can form? Yes!

For those of us with shorter attention spans, a cool way so see the process is with crystallizing hand warmers – a pouch holds a saturated solution of sodium acetate. When you flex a metal disk inside the pouch, you kick off a chain of crystallization and end up with solid material (and released heat energy).  Because the process is so fast in the hand warmer, the individual crystals are very small and jumbled up (polycrystalline); oriented in all different directions, and as a mass they are opaque (light is refracting all over the place) and relatively dull rather than shiny and smooth as slower-forming large crystal faces can be.  The structure of most metals is also polycrystalline, and things like plastic and glass (even the kinds misleadingly labeled “crystal!”) are amorphous.

The external crystal shapes we see are related to the internal structure – there are a lot of different ways atoms can pack together.

Practically, there will always be some disruption in a crystal structure, no matter how perfect it may appear, which allows for some very cool effects – crystals “twinning,” impurities that alter the color; the reason ruby and sapphire (both corundum crystals) appear different.

Crystals aren’t always pretty! Sometimes we want to prevent crystallization to avoid things like kidney stones, but crystals are useful for all kinds of things; optical equipment and lasers, X-ray crystallography to figure out structures of proteins (and once upon a time, DNA), and silicon chips used in electronic devices. 

Whether you prefer your crystals practical or decorative (photo of white spikey crystal from Crystals of India), they are amazing!

Can’t get enough crystals? Check out the Crystals of India exhibit at HMNS Sugar Land (free for members!)

 

 

What has eight legs and is coming to a school near you? “Awesome Arachnids” from HMNS!

In 2015, The Cockrell Butterfly Center will be making a couple of new outreach programs available to classrooms all over the Houston area. One of which was given to kindergarten students at St. Francis Episcopal School in December, and it was a hit, Awesome Arachnids!

For almost 10 years, we have been fascinating kids with “Amazing Arthropods”, a program that introduces students to members of the major classes of arthropods, mostly insects. We always include a tarantula to represent arachnids and can get quite carried away with talking about them. Unfortunately, we are only afforded about 5 minutes per presentation to do this. This frustrated me, as arachnids are one of the most feared and misunderstood classes of arthropods, but they are also SO COOL! So, the idea of Awesome Arachnids was born!

In this presentation, Entomologists from the Cockrell Butterfly Center will introduce you to some of our most interesting eight-legged creatures and explain the features that make them different from their six-legged cousins and other relatives.

Have you ever wondered what a tarantula feels like? Have you ever seen a scorpion change color right before your eyes? Can you even name any other types of arachnids? Don’t worry, that’s what we’re here for!

Here is a sneak peek at some of the stars of our show…

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Rosie, a Chilean Rose Hair Tarantula, is one of two terrific tarantulas you can meet during the Awesome Arachnids program!

Rosie and Peanut, 20 and 10 years old, respectively, are two of our special tarantula ambassadors! They will help ease you into the world of spiders – one of the most feared types of animals on the planet. As many as 55% of females and 18% of males in Western society are estimated to have arachnophobia – a fear of spiders and other arachnids. Although spiders are venomous, and venom CAN cause people harm, more often than not, a spider is harmless to us. No one helps illustrate that point better than Peanut and Rosie, with their furry appearance and docile nature. We will teach you all about spiders; which ones are ok, which ones to avoid, and how they help us way more than they could ever harm us.

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Vinny the Vinegaroon may look scary, but he’s really a shy guy with a very unique defense mechanism!

Vinny is a bizarre looking creature, one that most people have never come across before! Vinegaroons, also known as whip scorpions, inhabit tropical and sub-tropical areas all over the world. They have no venom glands, so cannot bite or sting. They are very shy, spending most of their time underneath rotten logs or rocks. At night, they hunt for insects, worms, and slugs. They help us control cockroach and cricket populations. Why are they called vinegaroons? Well, you’ll have to meet Vinny to find out. Once you meet him, you’ll want to meet more bizarre looking creatures like him!

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Pinchy the Emperor Scorpion is one of the largest scorpions in the world!

Scorpions are another arachnid that most people fear, and for good reason! That intimidating looking stinger can pack quite a punch! Fortunately, the venom in their sting is formulated to act on other invertebrates, so it is USUALLY not dangerous to us, but can be quite painful! Emperor scorpions, like Pinchy, have very mild venom, no more severe than a bee sting. They are also more likely to pinch with their large, strong claws than sting, hence the name! Scorpions are incredible animals and have many characteristics that set them apart from other arachnids. Want to know more? We’ll be happy to share with you!

Children will be allowed to gently pet arachnids which pose no threat to their safety, such as the tarantulas. Necessary precautions are taken by the presenters to ensure the safety of the children and the animals at all times.

So there you have it! Hopefully we’ve whet your appetite for more fun facts and stories about these fantastic creepy crawlies! If you’re interested in bringing Awesome Arachnids to your school – just email us at outreach@hmns.org, or give us a call at 713-639-4758!

These students are real GEMS: Girls Exploring Math and Science

On February 21, 2015, The Houston Museum of Natural Science will celebrate our tenth year hosting Girls Exploring Math and Science (GEMS)!

GEMS highlights student projects covering science, technology, engineering and math. It aims to increase interest in STEM through student presented projects, and highlight possible STEM careers as represented by our Community Booths.

We had quite a turn out last year, and we are lucky enough to offer awards to the top student projects as selected by STEM professionals. Here’s a story from two groups that won prizes at GEMS 2014!

GEMS winners 3Girl Scout Troop 21318 represented two booths in GEMS – “Any way the wind blows” and “A look into Optics.” The girls were excellent at explaining their projects to both young visitors as well as professionals visiting their booths. “Any way the wind blows” was presented by Josie Blackburn and Tiffany Bridges, and they took a look at wind energy and its effects on the environment. They discussed the many ways that wind energy is used from wind mills to paragliding, and they even had a windmill generator to demonstrate wind power in action! Hannah Cox, Hanna Gano and Qiwei Li also presented at GEMS last year, but their project took on a different focus! In their project, “A look into Optics,” the girls used a laser to show how different lenses affect the focus on the retina of the eye. The girls showed other ways lenses are used outside of our eye, like with telescopes and binoculars. It was a really eye-opening project!

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Both groups from Girl Scout Troop 21318 won prizes for their STEM projects! We caught up with them a few months after GEMS to see how they used their winnings. Blackburn, Bridges, Li, Gano and Cox chose to give half of their winnings back to their school, Glenda Dawson High School. They wanted to give back to the people who had helped them with ideas and supplies – a great way to continue STEM education!

They used the rest of their winnings to take an educational trip to HMNS! They went on a docent tour of the Magna Carta Exhibit to see the infamous document on its only journey outside of the United Kingdom. The rest of the day was spent visiting the special exhibition Bulgari: 130 Years of Masterpieces, the Cockrell Butterfly Center and watching a film in our Giant Screen Theater. Of course a trip to the museum wouldn’t be complete without visiting the Moran Hall of Paleontology! All in all, it was a fun-filled day of Science!

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Troop 21318 has participated in GEMS for many years, and we wish them all luck as they graduate and go on to their next STEM adventures! We hope to have more projects like these at GEMS 2015!

You have the opportunity to win prize money just like these girls! If you would like to participate in GEMS 2015, you can apply here. All it takes is a group of enthusiastic students, an adult chaperone and a project exploring science, technology, engineering or math. For more information, check out our GEMS page and download the application!

Mark Your Calendars for these events happening this week (12/8-12/14) at HMNS

R_rating_WBust out your planners, calendars, and PDAs (if you are throwback like that), it’s time to mark your calendars for the HMNS events of this week!

Film Screening & Lecture
Dinosaur 13
Tuesday, December 9
6:00 p.m.

Join paleontologists Peter Larson and Dr. Robert T. Bakker for a candid discussion on the discovery of Sue—the largest, most complete T. rex ever found—and the ensuing battles that Larson and his crew faced after their monumental find. This talk will be followed by a screening of Dinosaur 13—the new film from Lionsgate and CNN Films that tells this riveting story, and features Larson and Bakker. Click here for more info.

Opening of Special Exhibition: Crystals of India at HMNS Sugar Land
Friday, December 12
Discover the Crystals of India at HMNS at Sugar Land. Originating from India’s Deccan Plateau, a large geologic formation that comprises most of the southern part of the country, the exhibition features a never-before-seen collection of almost 50 of the most beautiful and most perfectly formed natural mineral crystals ever found anywhere in the world.
For this exclusive engagement, the temporary exhibition hall at the HMNS at Sugar Land will be transformed into a jewel box that will highlight these exquisite mineral masterpieces in a setting more befitting an installation of the crown jewels—made complete with dramatic lighting and custom display cases.

Crystals of India is organized by the Houston Museum of Natural Science. Local support is provided by the City of Sugar Land, Frost Bank, and Sudha Chittaluru, M.D (Internal Medicine) – First Colony Primary Care.

Frozen
Saturday, December 13 & Sunday, December 14
10:00 a.m. & 4:00 p.m.
Fearless optimist Anna sets off on an epic journey-teaming up with rugged mountain man Kristoff and his loyal reindeer Sven-to find her sister Elsa, whose icy powers have trapped the kingdom of Arendelle in eternal winter. Encountering Everest-like conditions, mystical trolls and a hilarious snowman named Olaf, Anna and Kristoff battle the elements in a race to save the kingdom. Arts and crafts will follow this showing of the movie. Costumes are encouraged! Click here to purchase tickets.

Holiday Trunk Show – Mirta Tummino and Sarah Stewart
Saturday, December 13
12:00 p.m. – 4:00 p.m.
Two Houston designers are teaming for this special trunk show. Mirta Tummino’s delicate wirework showcases colorful gemstones. Sarah Stewart designs beautiful silk and wool scarves that are batiked and woven in Indonesian by master textile artists.

Geminid Meteor Shower
George Observatory
Saturday, December 13
Open until Midnight
Enjoy the annual Geminid Meteor Shower at the George Observatory. Not rising until past midnight, the Moon will be favorable this year. The peak of the shower will be 9:00 p.m. to midnight. Dress warmly and bring lawn chairs. Telescope viewing will be open until 10:00 p.m. Cloudy skies will prevent viewing of meteors.