Ever wonder how fireworks… work wonders?

The Fourth of July just isn’t the same without pyrotechnics. And while the inevitable giant fireball from Dad lighting up the grill may be exciting in the moment, I’m actually referring to the giant chemistry demonstration we watch at night.

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Fireworks are basically a bunch of combustion reactions, which are rapid chemical reactions involving oxygen gas (O2) combining with another substance. These combustion reactions are exothermic, which means energy is released during the reaction in the form of heat, light, and sound.

A firecracker explosion is essentially one large combustion reaction involving black powder or gunpowder, which is made up of potassium nitrate (KNO3), charcoal, and sulfur. Potassium nitrate will provide oxygen to the reaction, while charcoal and sulfur will act as fuel. This reaction produces a lot of gas and heat in very little time, and all of that gas produced needs a place to go. When too much of it builds up in an enclosed space and the pressure becomes too great, you get an explosion.

The basic components of a firework are a fuse, tiny explosives called stars, and a burst charge that triggers the explosion. Precise timing is also helpful.

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First, you need an entirely separate explosion to get the firecracker up into the air. Typically to get the whole package airborne, you need what’s called a mortar, a long tube that directs the firecracker onward and upward away from bystanders. This explosion needs to be very controlled so you don’t set off the second firecracker inside, yet strong enough to get the whole package off the ground. A malfunction can have disastrous consequences. You can search for “fireworks fails” on YouTube for some disaster action.

When you light a firework, it’s not just one fuse; it’s two: the fuse that sends the firework up, and a time-delay fuse that is longer and burns more slowly, allowing the firecracker to gain some altitude before the second reaction begins. If the fuse is too short and the firecracker doesn’t fly high enough before exploding, it can get noisy (not to mention dangerous.)

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Once the time-delay fuse expires, the stars begin to explode. A burst charge will explode and expel the stars, spreading them out. The stars themselves may have different chemical components within, but the basic idea is still a combustion reaction. There is some sort of fuel reacting with oxygen and producing a lot of gas and heat.

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All those colors you see come from burning metals, which produce different wavelengths of light when heated. I don’t know how many of you have tried to burn metal before, but I can tell you from experience, it’s not easy.

We model this particular combustion reaction in one of our ConocoPhillips Science On Stage Outreach programs! Since lighting a firecracker in a school is a terrible idea, in Cool Chemistry, we use a fuel and some granular chloride salts in a beaker. When I light the fuel, I am beginning a combustion reaction that releases a lot of heat and will burn the metal salts.

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The red/pink flame is from the metal lithium, sometimes used in batteries. You’ll notice that in this photo, there is a large Nalgene beaker covering the beaker that used to be full of green flames. That Nalgene beaker is airtight and cuts off the flow of air in and out of the beaker. When this happens, no new oxygen is allowed to enter; once the combustion reaction has used all of the oxygen inside the beaker, the flame will be put out.

Our beaker simulation doesn’t produce the loud bang we often associate with fireworks because it is open to the air around it. The boom heard is actually all of the gas building up inside of the firecracker being expelled all at once, moving faster than the speed of sound, just like the pop heard when a balloon bursts.

One prevalent legend says fireworks were invented accidentally by a Chinese cook some 2,000 years ago, and the basic concept has remained the same over the years. If anything, precise timing of explosions in fireworks shows has made the spectacle all the more enjoyable.

So grab some apple pie, pull out a lawn chair, relax and enjoy the world’s most famous combustion reaction, celebrating America’s birthday in style!

Bring the wonders of the Houston Museum of Natural Science straight to you with HMNS Outreach! To book a presentation of Cool Chemistry, email outreach@hmns.org or call (713) 639-4758!

Hey, Texas! Get outside and visit your wild neighbors.

by Melissa Hudnall

Texans! Want to see exotic birds? Look out the window! Want to see 250,000 bats? Just go outside tonight and look up! As a wildlife teacher and outreach presenter for the museum, I’ve had a chance to talk with future generations about the amazing wildlife found in Texas. Usually students think you have to travel to exotic lands to see the really cool animals, and they’re shocked to hear about all of the incredible animals they’ve been living right next to in Texas.

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Texas wildlife artifacts for the mobile classroom. Sahil Patel

That’s why I was excited to see the new HMNS at Sugar Land exhibit Treehouses: Look Who’s Living in the Trees!, because it makes these critters more accessible and feeds a natural curiosity that most children already seem to have about wildlife. After visiting this exhibit, young naturalists may start asking questions like, “Who made those track marks?” and exclaiming things like, “I know what that scat came from!”, which would make any parent’s heart swell with pride. Luckily, Texas is the perfect place to raise a young naturalist.

Look in our trees and under our bridges, and you might have a chance to see the only true flying mammal: bats! (Sorry, “flying” squirrels. Gliding doesn’t count.) Texas has tons of bats. In fact, we have so many that they are often picked up on radar used for weather reports.

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Radar around the Bracken Cave in San Antonio shows a cloud of bats. Every blue dot is one in flight.

Everyone’s heard about the Ann W. Richards Congress Avenue Bridge in Austin and the Bracken Bat Cave in San Antonio, but visit these locations in the winter and you might be disappointed to find they have migrated for the season. Drive just 15 minutes away from the Houston Museum of Natural Science, and you can see bats year round at Waugh Bridge. This bridge has roughly 250,000 Mexican free tailed bats who would love to meet you. Before you go, be sure to get them a Thank You card, because the bats under this one bridge in Houston eat up to 2.5 tons of insects each night!

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This Mexican free-tailed bat might look cute and cuddly, but don’t pick them up like you see in this picture. Being mammals, they can carry rabies. Report any bats that you find on the ground in the day time or behaving strangely. They could be sick.

This is the perfect season to visit Waugh Bridge, as baby Mexican free tail bats test out their flying skills for the first time in early July. Just be sure to watch nearby towers for local birds of prey, such as red-tailed hawks and peregrine falcons, who are keeping a watchful eye on these bats as a source of food.

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This peregrine falcon can reach speeds of 200 mph diving to catch its prey. This is a preserved specimen that travels to school with our Wildlife on Wheels program. Sahil Patel

In fact, Texas is a huge birding state. Individuals travel from all over the United States just to see the colorful migrants that pass through here, like Cerulean Warblers, Golden-cheeked Warblers, and Vermillion Flycatcher. Our Farish Hall of Texas Wildlife does a really nice job of highlighting some of the phenomenal birds that pay us a visit, for those of us (me) who do not have the patience for actual birding.

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Vermillion Flycatcher

Another adorable, and partially arboreal animal is the North American Porcupine.

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North American Porcupine

Looking for a kiss under the mistletoe this winter? This rodent is happy to oblige. Porcupines have been known to slowly amble up trees in search of mistletoe and pine needles when their preferred shrubbery is coated with snow. However, you may wish to rethink this close encounter, not only because of their dangerous defensive quills, but also because of their orange teeth.

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The orange coloration of the North American porcupine’s incisors is due to the high amount of iron in their enamel.

These teeth are not orange due to poor hygiene, but rather because of iron found in the enamel. This iron oxidizes, forming a rusty color. It’s the same reason your blood is red.

So Texans, get your wildlife education with HMNS and HMNS Sugar Land, then go out and explore! After all, now that you know their home address, it would be rude to ignore your neighbors…

Sahil Patel: Legacy Camper

Once in a while, the Houston Museum of Natural Science Xplorations program gives children so much enthusiasm about science that they never really leave the museum. Sahil Patel discovered the museum as a child with the Xplorations program, and moved on to become an Ecoteen as he grew older. Now, he is an HMNS Outreach Presenter and a writer for the BEYONDbones blog.

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Patel teaches a children’s class about the density of various items for the Science Start Outreach Program. Interested in the Houston Museum of Natural Science since age 6, Patel hopes to share his excitement with other kids, cultivating their education through HMNS.

HMNS: When did you start attending summer camp here? And why?

SP: I started attending camp when I was six years old. I didn’t start going to school until Kindergarten, but I would go to work with my mom every day. Every day at lunch time, we would go to either the zoo or the museum, depending on weather, and I was hooked. The real reason I came to camp is probably so my mom could get me out of her office, but I kept coming back because I just never had a bad time. There wasn’t a single class I didn’t enjoy.

HMNS: What was your favorite class? What made it your favorite? Any stories from that class?

SP: Every summer, I had to take the Space Commander class; I must have taken it at least four times. My favorite part was the Expedition Center mission to Mars or the Moon on Friday afternoon. I loved it so much that I had a birthday party mission one year! Every time, I tried to be on a different team inside and was mostly successful. My favorite of those had to be the CIMCOM team, which got to talk to mission control. Years later, when I was a Moran Ecoteen, I got to be a part of mission control for a summer camp mission and loved every second of that, too!

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As an Ecoteen in 2010, Patel interned with Paleontology Curator David Temple.

HMNS: What is your favorite memory from summer camp?

SP: I enjoyed the camps that used to take field trips; one of my favorites was called Thrills and Chills, and the physics-based camp ended with a trip to Astroworld on Friday! Sadly, neither Thrills and Chills nor Astroworld still exist. I also enjoyed the Senior Coastal Ecology class that would take daytrips to Galveston to study wildlife and various aspects of the gulf coast, but this camp was discontinued in the late 2000’s. But I’d say my favorite memory was from when I took Crime Scene Investigators one year. Friday afternoon of Crime Scene Investigators involves a crime scene that the Xplorations staff and Moran Ecoteens set up, and our class went about examining evidence and following clues to try and figure out who committed the crime. Low and behold, it was our TA, who took off out the door and down the hall before he was captured and brought back to the classroom to explain himself.

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HMNS: If you could go back to Xplorations Summer Camp for one week this summer, what class would you take and why?

SP: I’ve taken quite a few of the camps that are still offered today, but one that I didn’t get to that I always wanted to take was Wizard Science Academy. Harry Potter and the Sorcerer’s Stone was released on my tenth birthday, and I was obsessed from the opening chorus. The Potter-themed summer camps weren’t created until I was too old to go to camp, and I always felt like I missed out on something amazing. That was confirmed for me when my brother took Wizard Science Academy four years ago and came home with a wand, a broomstick, and a Triwizard Tournament championship.

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As an Ecoteen, Patel was present for the blooming of Lois the Corpse Flower in 2010.

HMNS: What made you decide to come back and work at HMNS?

SP: I guess you could say that I never left. Since I started summer camp at age 6, the only summer I did not work at the museum was when I was 14, because I thought I was ineligible for the Moran Ecoteen Program at that age. HMNS has always held a special place in my heart, from the moment I saw the massive T. rex in the old Glassell Hall. The museum has always made me question what I know, motivated me to learn further, and inspired me to pursue a career in science. Over the years, I fell in love with this place as I learned more and more about it. I got to a point where a summer without HMNS was a summer wasted. I wanted to show others why I was so passionate about this place and what made HMNS so special to me. Coming to work here was a no-brainer.

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With HMNS Outreach, Patel teaches children TEKS-based science skills with the Chevron Earth Science on Wheels: Dinosaur Discovery program.

HMNS: How did the Xplorations Summer Camp influence your life?

SP: Xplorations Summer Camp has had nothing but a positive impact on my life and thousands of others. The museum set me up for success by instilling in me a love of learning at a young age; Xplorations made science fun! With a summer’s worth of learning at camp, I was ready to go when school started up again in August, and I had all kinds of new, useful knowledge to impress my classmates. But most importantly, the summers I spent at Xplorations opened a door for me to a true passion: teaching. Xplorations led me to a career at HMNS. I wouldn’t be here today without it.

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Even hard at work at his desk in the outreach office, scheduling educational programs, Patel has a good time. He can’t imagine working anywhere else.

 

Take It: HMNS shopping trips rival Liam Neeson’s shakedown

May is upon us, which means it is time for stocking up on mosquito repellent and sunscreen, flip flops and floppy hats, bathing suits and beach towels. For the education staff at the Houston Museum of Natural Science, it also meanstake it heavy lifting and preparing for the emotional gauntlet that is summer camp shopping. Julia does the bulk of the mass ordering, but there are some things we just have to go to a brick-and-mortar store to get. So off to the store we go! Usually three or four hours at a time.

Generally, when we get to the store we take it. We take it all. Just like Liam Neeson.

The most common quantity on a shopping list is “all of them.”shopping list

We are like a plague of locusts, actively demolishing orderly displays of stock, leaving only a husk behind. If you are the unfortunate person who comes behind us looking for just one single solitary bottle of green food coloring, I’m sorry. Because I took them all.

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Inventory before HMNS hits…

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…and after.

On this particular trip, we start in what we affectionately refer to as, “bathroom.”  This is all the stuff that you might keep in your medicine cabinet, make-up drawer or shower. It’s a fairly small section in our shopping adventures, but it almost fills a basket by itself. “Bathroom” is a weird mixture of heavy items and small items. They have a tendency to sneak out through the holes in the bottom of the basket if you aren’t keeping an eye on them.

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We need all the cotton balls!

That white box? It’s an entire container of cotton balls. Why? Because we need them all.

After about an hour, in which Julia and I cover “bathroom,” “appliances,” and “party” (and I’d like to point out that it’s always a party in our department), we take a short break and check the list before heading to “craft” and “office.” There is no lunch break until the basket is full. Once we reach the point of having to carefully place items so they won’t fall out of the basket, trailing behind us like breadcrumbs, we decide it’s time to stop for lunch.

With special permission from Josh, the assistant manager, and promises from the clerks that no one will try to put our treasures away, we drop our first basket near the front and head for a quick “strategy meeting” (which is actually code for lunch), which allows Julia to double-check the list. Again. For the fourth time.

“I don’t know who you are.  I don’t know what you want. But if you are looking for Raisinets, I can tell you they don’t have any.”

Our summer camp uniform shirts are navy blue. This also happens to be the uniform shirt color for employees at one of our frequented summer camp shopping spots. This coincidence combined with the fact that our shopping basket is always filled with nonsense, and plenty of it, ensures that we will be confused with store employees at least once during any excursion. I have discovered that it is often easier for everyone if I can just tell the confused shopper where the item they are looking for is located. Due to the fact that we often need so very many weird things of specific shapes and sizes, I can almost always tell them if the store has it in stock and where to find it.

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When customers come up to me asking where they can find an item, I just tell them; I know where almost all of it is, anyway.

On this trip, we are asked twice to lend a helping hand. The first time, it’s a guy looking for reading glasses (usually across from the pharmacy window), and the second is a corporate stocker looking for her product placement (Swedish Fish and Sour Patch Kids – on the bottom shelf next to gum). We have been asked to locate anything and everything including, but not limited to, powdered sugar, colored ping pong balls, decorative masking tape, Abuelita chocolate, and picture-hanging supplies. (In this particular instance I recommend 3M Velcro strips, at the very end of the hardware aisle.)

My favorite case of mistaken identity happens while shopping with Sahil. He and I have spent many a summer’s day at the store shopping for 12-inch yellow balloons (with birthday party supplies) and Cheez Whiz (usually in the cold cheese section, which is weird because it doesn’t actually need to be refrigerated). Usually when shopping, we make a list by section – garage, craft, clothing, etc. – and then divide and conquer with one of us on aisle 10 and the other on aisle 11. Because Sahil is so very nice and polite, I have come around the corner more than once, turning slowly because my basket is so full, and see him helping a customer reach an item on the top shelf or discussing the merits of the three coolers in front of them.

On one particular occasion, we’re short on time, so Sahil‘s concentrating on the list in front of him, determining what we have left to find, when a customer comes up and asks him for the location of the honey, which stumps him. Honey isn’t something we’ve purchased before, so Sahil politely tells the customer that he doesn’t actually know where the honey is located. He apologizes and goes back to his list. The customer insists he help her, but he again tells her he doesn’t know where the honey is. He suggests it might be in the breakfast aisle, maybe with syrup, and again goes back to his list. The customer, feeling she’s been ignored, reports him to the store manager who then comes to chew Sahil out, the “unhelpful store employee.”

Oh, summer camp

“But what I do have is a very particular set of skills… Skills I have acquired over a very long career. Skills that make me a nightmare to people like you.”

dr mariotetrisWhen I was a child, my mom and dad purchased Nintendo Game Boys for my brother and I from a neighbor at a garage sale. I had two games I played regularly, Dr. Mario and Tetris. I was super good at both. We weren’t allowed to play our Game Boys a lot, but they were encouraged on road trips. I would play one of those two games for miles and miles, laying on the floorboard in the back of the sedan so my older brother could have the bench seat. Despite what my mom said, playing these games did not rot my brains out, though I do remember on more than one occasion, at the end of a long day of driving, dreaming of dropping pills and “tetrominoes.”

What seemed a pointless game for children has turned into a useful and particular skill as an adult.

I don’t love shopping. Never have. This combined with my Type A personality traits and the fact that shopping carts can only hold so much means that I have turned camp shopping into a game of sorts: Tetris – Museum Edition.

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Tetris: Museum Edition

When filling a cart, one should start with heavy and square items on the bottom, filling the gaps as the occasion arises. Hydrogen peroxide, for example, leaves just enough of a gap in the basket that you can tuck in your petroleum jelly to fill the space. When you have established a base layer, it’s time to start building side walls. These are the ramparts, allowing you to generate volume in the basket without an avalanche of Q-tips. Finally, top off your basket with bags of things to cement all the layers together. Generally, heavy bags work best, such as bags of candy, but use what you can. Once your basket can’t safely hold another item, it’s time to head to the check-out.

I’d just like to apologize to any check-out clerk that has ever helped me during summer camp shopping. They see us coming, with our two or three carts packed to the rafters, and the audible sigh can be heard three lanes over. We try not to be too irritating, but we know we are. The standard speech to the clerk goes something like this, “Hello (insert name here). We are making a tax-exempt purchase today. Whenever possible, we will put like items together for ease of counting. My colleague has gone to get an empty basket to help you out.”

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Car Tetris…

Inevitably when we check out, we end up with way more output than we had input due to my mad Tetris skills. On this particular trip, we have a one-to-two ratio of pre-check out baskets to post-checkout baskets, which I kind of consider a failure on my part. I think I could’ve done better. In my defense, this is just the first shopping trip of the season, and I haven’t stretched.

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…showing my particular set of skills.

Next comes car Tetris, where you take all of your goodies out to your vehicle of choice and build a mountain of things. As with the cart, you must start with the square and heavy items, then slowly build up to the items that can be crushed or smashed. On more than one occasion, I set my heights a little too high and have to pack stuff around my shopping companion. Today, the four baskets of treasure fit quite nicely into Julia’s back seat.  According to Julia’s Instagram, #wehadmoreroom.

The final stretch of any shopping trip is reverse Tetris, where the supply vehicle is met at the loading dock by all the worker bees, and we unload and sort the treasure. Depending on the trip, this could go a number of ways. We could sort by camp requests, by storage area, by weight, by refrigeration needs, and so on. Today’s trip?  We sort by storage location because, starting next week, we have INTERNS coming and we don’t want to deprive them of the opportunity to figure out where all this stuff goes!

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Reverse Tetris begins…

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…and game over. Now time to let the interns sort it out.

“If you have a case of glow-in-the-dark paint in the back, that’ll be the end of it. I will not look for you. I will not pursue you. But if you don’t, I will look for you. I will find you and I will bother you repeatedly.”

One of the trickier parts of camp shopping is when we need it, we need it now. If the store is out of stock, you go to another store. If that store doesn’t have it, you try at another place. On the hard-to-find items, we try to buy ahead or find a place we can order them, but that doesn’t always work, particularly if we are looking for a specific item for a specific purpose. Occasionally, even when there is a source for an item, we will run short and it becomes an emergency thereby causing us to hoard said item for years. I remember with dismay the Button Magnet Shortage of 2010 and the Silver Tinsel Crisis of 2008. Those were dark times… Dark times indeed.

Because there is a limited amount of time and a limited number of places, we have learned to be persistent. We ask questions. We know you have it in stock in the back… Please go look… And the poor clerk that runs into our brand of crazy, usually doesn’t understand our request.

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HMNS camp shopping isn’t for the faint of heart.

“How many do you want?”

All of them.

“But there’s like 50.”

Yes. All of them.

This style of shopping takes a minute to get used to and isn’t for the faint of heart or weak of muscle. And, once the summer has ended, you have to transition back to your normal life. Sahil, former shopping partner and current Outreach presenter, has fallen victim to this trap more than once. While at the store with his mom shopping for a big family dinner, he was sent off to get enough refried beans to feed 12 people. He returned with 12 cans.  His mother was not amused.

Our persistence usually pays off and, at the end of the day, we return victorious with the last carnivorous plant in town (or whatever the item might be).