Category: E-News HTHT

Slip and Slide

Slip and Slide: Ice, the Winter Olympics, and Animal Adaptations.

Ice ice baby! One of the most fun memories I have of winter is pretending to ice skate by sliding on the ice in my shoes. If you were careful and kept your balance you could zoom down the street like magic! Other times, I would slip and fall right into the snow!  Have you ever wondered about the slipperiness of ice? Other solid things don’t have this slick property, so how come ice does?  With the Winter Olympics coming up it is fun to explore the world of ice both through sport and through animal adaptations!

Turns out that ice is very special because of the molecular properties of water.  Remember that solid water (ice) is one of the few solids that is less dense than its liquid state.  Also, water’s freezing point is very close to what is known in chemistry as the triple point.  The triple point is a where a substance exists in multiple phases at once.  So, if you take your foot and apply pressure to the ice it may melt ever so slightly creating a liquid layer on top.  This means that ice has little friction, so sports on the ice and snow must compensate.  In some cases, such as downhill skiing, they reduce friction even further, but in others such as cross-country skiing, you add friction to create propulsion.  Even more interesting are sports such as curling that manipulates friction in many ways to send a rock down the ice to hit a target.  Many different animals have also adapted to slipping and sliding along the ice!

Sliding on Ice: Curling

One of the sports in the Winter Olympics I’m most intrigued by is curling.  It looks simple and yet the physics of this sport is both complex and fascinating.  Each team member, from the skip to the sweepers plays a role in guiding this big rock down the ice to the house where the target is.

Curling has been around since 16th century Scotland and gets its name from the slow gentle curve the stone makes as it slides down the ice.  It became an official Olympic sport in 2002 and consists of 2 teams of 4 throwing 8 stones each.  They go 8-10 rounds and compete for points.  Curling stones are made of granite, which is hydrophobic, and come from a quarry in Scotland.

Beyond the handle, the curling stone has two important features: the running band and the striking band.  The running band is a sharpened ring on the bottom of the stone, which reduces contact with the surface. It is the rotation and pressure from this running band that manipulates the friction under the stone and helps it glide down the ice. The striking band is the smooth outer edge of the stone and its purpose is to allow for transfer of energy from one stone to the next, so you can knock your opponent off target!

I honestly always thought the sweepers were adding friction, so the stone didn’t soar past the target, BUT it is actually the opposite.  Also, curling ice is different in that it is pebbled.  Tiny droplets of water are sprayed onto the surface where they freeze to create a textured surface.  They slice the tops off each tiny ice bump and ta da you’ve got perfect curling ice. This results in less friction because less of the rock is touching the ice.  The purpose of sweeping, as I discovered, is to further reduce the friction by creating tiny scratches in the pebbled ice.  This decreases the amount of ice sliding under the running band even more. Sweeping helps the rock go straighter and further.  It is one of the few sports where once thrown the team can adjust and manipulate the trajectory of their object.

Tobogganing Emperor Penguins:

In the animal kingdom sliding on ice immediately makes me think of penguins sliding around on their bellies. The emperor penguin is both the tallest and heaviest species of penguin and has several adaptations that help it survive the harsh weather of Antarctica.  They have a lot of blubber to stay warm especially during the long winter, but one of the drawbacks to this adaptation is that it makes them very unbalanced and gives them a lumbering waddle.  So, what do they do if they have to move quickly while on the ice? They toboggan!

Tobogganing is when the penguin slides on his stomach.  His slick waxy feathers offer little friction against the ice and the penguin can slide off and away if a sea leopard comes up on the ice.  Their target when trying to escape is almost always the ocean.  Once in the ocean emperor penguins can go nearly 8 mph and can stay underwater for around 20 minutes.  They can also compress air in their feathers and use it to propel themselves twice their speed, so they can shoot out of the water and up onto the ice.

Speeding over the snow: Cross Country skiing

So, what about snow?  Snow is made up of tiny ice crystals but is fluffier – you can slip on it, but mostly you just get stuck in it – unless you have the right equipment! Cross country skiing is the oldest form of skiing and emerged from a need to travel over snowy terrain.  It was developed into a sport at the end of the 19th century and was added to the Olympics in 1924 (men) and 1952 (women). Traditionally this Olympic sport is dominated by the Nordic countries.

In cross country skiing you rely on your own locomotion for propulsion versus using gravity to zip down a mountain like in downhill skiing. The motion of cross country skiing is very different from downhill.  The boot is attached only at the toe, so the heel goes up and down as the skier strategically uses friction to glide forward.  As you put pressure down on one ski you gain traction from the grip zone and can glide forward on your other ski.

The classic stride is alternating pressure on your skis like this on prepared parallel tracks.  There is also the skating stride, which is shorter, and faster.   The skier is propelled on a smooth, firm snow surface by pushing your skis alternately away from one another at an angle, in a manner similar to ice skating.  As you can imagine the skating stride looks a little crazy, but is super effective in a race.  Look for this when you watch the Olympics!

Both strides take advantage of the increased surface area of the skis to prevent the skier from sinking in the snow.  Well before humans strapped on skis, animals adapted to run on and over the snow.

Predator and Prey: Snowshoe Hare versus Canada Lynx

The snowshoe hare and Canada lynx both have adaptations that allow them to move quickly over snow.  As with most predator prey relationship their survivals are interwoven.  The Canada lynx’s population parallels that of the snowshoe hare since it is its primary source of food.  So how do they match up in the snow?

Snowshoe hares have larger hind feet and lots of fur between its toes compared to other hares.  This means its hind feet act like snow shoes allowing it to quickly move over the snow.  A snowshoe hare can run nearly 30 mph over the snow and can jump 10 ft in a single bound.  This is helpful as it escapes its main predator the Canada lynx.

Snowshoe hares are the main prey of this small cat, which also has special snow adaptations.  Their feet are oversized with extra fur, which gives the Lynx its own pair of snowshoes!  Since the hare is faster than the lynx, the lynx relies on ambush for success and can silently stalk prey in the snow thanks to its snowshoe feet.

It is amazing how both humans and animals have adjusted to getting around in the ice and snow.  From sliding rocks and penguin bellies to skis and “snowshoe” feet, the ice and snow is a fun arena in which to compete.  I don’t know about you, but I cannot wait to watch the Winter Olympics this year – especially curling!

Turning up the Heat!

As the temperature drops, the coats and scarves come out and you probably barely think about heat -unless you leave your coat behind!  Have you ever wondered about how we keep the heat or why we need it? Or how animals and humans differ? What would you need to survive in the extreme cold?

All creatures have an optimal temperature their body needs to achieve proper function.  Warm-blooded creatures (endotherms) can regulate their body so it stays at a constant temperature.  So naturally if you were in an extremely cold environment your body will have to work overtime to stay warm! How is the heat escaping?

On the Move

Heat radiates out and diffuses from an area of high concentration (your body) to areas of lower concentration (everywhere else) through either conduction or convection.  Conduction is transfer of heat between two solid surfaces.  So, if you sit in the snow heat will escape via your direct contact with the snow.  Convection is the transfer of heat between a mass (i.e. you) and a moving fluid or gas. So, if you are standing outside and an icy wind blows past you, it is pulling heat away from you.  Same thing is true if you jumped in the Arctic Ocean.  Your heat will escape in the passing chilly water.

The heat from a warm-blooded human or polar bear in the Arctic is constantly trying to escape and move away from the body through these two mechanisms.  The goal in these extreme environments is to either contain your body heat and stop its movement, or at least slow it down so the internal body mechanisms can keep up with production.

Capture the Heat

What are some ways your body stays warm and what are some things you can do?

  • Fuel your fire – make sure you are well fed and hydrated so your body can burn extra calories to maintain your core temperature.
  • Shivering – This is actually a warning that you are too cold. Your muscles spontaneously contract to burn calories and generate heat to increase or maintain your core temperature.  If you are shivering, you should get somewhere warm or put on more layers.  It is one of the last lines of defense your body has to prevent hypothermia.
  • Layer up – Adding clothing layers traps air and slows the transfer of heat. This insulation, especially if your coat is waterproof, is a powerful way to keep the heat in.
  • Shelters – such as igloos in the artic, or your own house are designed to trap heat and keep you and your environment warm.

Animals versus Humans – how do they capture the heat? What do you think makes animals and humans different when it comes to the cold? Animals have evolved many different adaptations to allow them to cope with extreme cold.

Polar bears have both an extra layer of fat and special fur. Their special coat features two types of fur: long oily guard hairs and short insulating hairs. Together these different types of hair help the polar bear stay warm. The oily guard hairs are hollow allowing them to trap warmth and bring it close to the skin.  They also provide an oily outer layer which prevents the polar bear from getting wet and losing heat via convection. The shorter insulating hairs help polar bears stay warm by trapping heat close to the skin. Under their fur, polar bears have black skin which is good for absorbing the rays of the arctic sun. Plus, their coat is white, which is helpful for camouflage, and reflects light making it a poor conductor of heat.

Whales, seals, walruses are all examples of marine mammals that use blubber to stay warm.  Blubber is just an extra layer of insulating fat, which keeps their internal heat from escaping. Having blubber means those animals can swim in the cold arctic ocean without getting a cold or hypothermia.

Otters are an interesting marine mammal that can survive in the icy ocean, but don’t have blubber.  Otters have a super dense, double-layered coat of up to a million hairs per square inch!  That fur is designed to be water-proof and capture pockets of air.  All that air makes them float and works just as well as a layer of blubber.

Humans on the other hand must add something to their body to stay warm.  The simplest solution for early humans was to wear the skins and pelts of these animals. We basically borrowed the animal adaptations by making clothes out of animal skin – everything from seal and caribou to rabbit and bear. Eskimos even make waterproof parkas from the skins of marine mammals.

Modern fabric technology:

Scientists and engineers have been able to replicate these animal adaptations in a variety of ways.

  • Fleece is similar to wool and very efficient at keeping you warm by trapping air and adding insulation to your layers. Guess what – it’s made of plastic polymer! Its polyester fiber can even be made from recycled bottles.
  • Nanowire tech – a newer technology that features special metallic fibers that trap air and can even be used to generate heat when a charge is run through them.
  • Adaptable smart fabric –Astronauts wear a temperature regulating suit under their space suit that circulates liquids and helps them maintain a constant temperature. Scientists have been studying a way to create something similar to this for everyday use.  Imagine wearing a light weight shirt that adjusts to the temperature no matter where you are. Almost like having a central air system right next to your skin.
  • Synthetic furs and fabrics- Also we can spare the rabbits and other animals and manufacture faux fur and other coverings that keep the adaptation and hold the slaughter.

Bundle up your layers and stay warm this winter just like a polar bear!

Fall into Hibernation With Fun Science!

Beautiful leaves, fruitful harvests, and cooler weather are all things we think of when we picture fall.  It is a transitional time from the sweltering summer months to the frigid winter months.  For many creatures, fall is also a transitional time when they prep for hibernation.

What exactly is hibernation?

Bears snoozing in a den is what many of us probably imagine when we think hibernation, but a lot of different types of animals hibernate and experience similar processes.  Hibernation is a state of inactivity and metabolic slowdown in endotherms i.e. warm-blooded organisms. It is characterized by low body temperature, slow breathing and heart rate, and low metabolic rate.

Many ectotherms (i.e. cold-blooded organisms) seem to hibernate via a similar process called brumation.  Remember that the main thing that differentiates warm-blooded and cold-blooded creatures is that warm-blooded organisms can self-regulate their temperature and metabolic responses.  Whereas cold-blooded organisms’ metabolism reacts in response to their environment.  So cold environment = slower metabolisms for all ectotherms versus cold-environment = hibernation for some endotherms but not all.  Fish seem to hibernate but are an example of an ectotherm slowing down in response to the cold.

Hibernation is a considered a period of energy-saving torpor.  Torpor is a state of decreased physiological activity in an animal and includes a lower body temperature and metabolic rate.  Some animals experience what is called daily torpor, which refers to a period of low body temperature and metabolism lasting less than 24 hours.  For instance, hummingbirds experience a state of torpor just at night and have been known to hang upside down from their perch while in this state.

Hibernation in general occurs in winter and the opposite of hibernation is called aestivation, which occurs in the summer months.  Many invertebrates and amphibians have an aestivation cycle that helps them survive hot, arid seasons.

Why hibernate?

Whether it is hibernation or aestivation it is all about surviving extremes.  It is a way for animals to survive difficult conditions.  For instance, winter for a bear or squirrel means cold temperatures, not a lot of food, very little camouflage cover.  Despite being in a vulnerable torpor state, being out in those conditions seem way riskier. The risk of vulnerability must have been outweighed by the benefits of hibernation for bears and other creatures to evolve this unique mechanism.

Prep for hibernation

Bears, for instance, have a period prior to hibernation where they eat and drink in excess to build up their fat stores for hibernation.  Gorging themselves on nuts, berries and other food sources while they are around help them survive once they go into torpor and hibernate for several months.  They also have a transition period where they aren’t hibernating but their metabolism is beginning to slow so they start to eat less and sleep more.   The creation of a cozy den or nest is also essential for hibernation. This keeps body heat contained, protects from the elements, and conceals the hibernating animals.

Can humans hibernate?

You might feel sleepier in the winter months, but humans never evolved to hibernate.  Part of that reasoning is that since we evolved in equatorial, tropical Africa where there is a consistent food supply we would not have needed to hibernate to escape harsh conditions.  We also would have been a top predator, so less likely to need hibernation to avoid predators.  We are also bigger and most hibernators are small with the obvious exceptions here and there (bears).

Our hearts are also different from other mammals that hibernate.  Our hearts contract in response to calcium. So, if our heart gets too cold, there is a buildup of calcium and we go into cardiac arrest.  Mammals that hibernate have a special pump that gets rid of excess calcium, which means their hearts continue to beat at much lower temperatures.

Scientists are interested in engineering ways for humans to hibernate because it would aid in long-term space travel.  Astronauts must exercise 6 hours a day in space to prevent muscle and bone atrophy, which might be avoided if they could hibernate.  Hibernation obviously would reduce the amount of supplies they would need, and could protect from radiation.  A year in space right now is the max an astronaut can do without significantly increasing the odds that they’ll get cancer and other side effects due to radiation.

Engineering and Roller coasters!

Image Source: Pixabay.com

Pupils dilate, heart rate soars, you feel like you’re flying!  Somehow you feel weightless and then twice as heavy all in a matter of minutes.  You are experiencing the euphoria of riding on a roller coaster!  Ever wonder why you feel all these different things?  Or how roller coasters came to be?

When did people start riding roller coasters?

Historians trace the first roller coasters back to Russia in the 16th century. They designed and constructed wood-framed sleds to go down Ice Slides. They would find ice slopes reaching 70 feet high, sit on the wooden sleds, and slide down the ice. As this activity gained popularity, Russians rolled down the slopes in wooden carts during the summer. These wooden rolling carts were the first designs for roller coaster cars!

Leap the Dips Coaster - By Bhakta Dano. Public Domain, https://commons.wikimedia.org/w/index.php?curid=5166801

The earliest coasters were wooden with huge lattice structures and resembled railroad tracks. The oldest coaster in America still in operation is Leap the Dips at Lakemont park in Altoona, PA.  Built in 1902, Leap the Dips is registered as a Historical Landmark.  It boasts a 9ft drop and can reach speeds of 10mph.  Coasters have certainly come a long way.

In present day, the fastest coasters can go up to around 150 miles per hour and have drops between 400-450 ft.  You could find yourself dangling from a suspended car, twisting in a spiral, going through a loop, and even going backwards.  There are still wooden coasters, but to achieve the newest thrilling elements a lot of coasters are made of tubular steel. Currently, the fastest coaster in the world is the Formula Rossa at Ferrari World in Abu Dhabi, United Arab Emirates where it reaches 150mph!

Image Source: Stdragon04 - Own work, CC BY-SA 3.0, Wikimedia Commons

The physics behind roller coasters involve gravitational potential energy, and Newton’s laws of motion.

Firstly, to understand roller coasters you need to understand potential energy.  Potential or stored energy is the energy an object possesses based on its position rather than its motion. When you ride a bike, and reach the top of the hill that is potential energy. If I hold a pencil above my head, it contains potential energy. If I drop this pencil, what happens? The potential energy is converted to kinetic energy as it falls to the ground.

What is pulling the pencil to the ground? Gravity! What is gravity? It is a force that attracts or pulls an object towards the Earth. We can stand on the ground because of gravity. The things in this room are not floating around because gravity pulls them towards the Earth.

As our roller coaster climbs the hill, its gravitational potential energy increases. The higher the car is from the ground, the more gravitational potential energy it possesses. When the car peaks at the top of the hill and starts to go down, the energy converts into kinetic energy. The car possesses kinetic energy due to gravity. As the car goes down the hill, the kinetic energy increases.

When the drop is very high, you get that feeling of weightlessness as you go down.  As you plummet, gravity pulls you down while the acceleration pulls you forward.  If you are going fast enough the forces balance each other out making it feel as if you are in free fall!

Newton’s first law is also in play on a roller coaster.  The first law is all about inertia; an object at rest will want to stay at rest and vice versa.  As you navigate the twists and turns, you get jerked around because of your body’s resistance to the change in direction, momentum, or acceleration.  You might also feel plastered to your seat as you zoom down a hill – it’s all about inertia!

What about the loops?  How come you don’t fall out? Centripetal Force!

Image Source: Pixabay.com

As you go through the loop, the forces on your body vary as you go up and around.  Besides gravity pulling down, the one thing that remains constant is a force pulling towards the center of the loop; that’s centripetal force!  Even if your straps weren’t there you’d still stay in the car because of inertia.

Initial loops were circular meaning the angle of turn was constant all the way round.  The downside of the circular loop was that the cars had to enter the loop at an immense speed making it uncomfortable for riders.  Engineers switched to a teardrop loop design, which has a sharper turn at the top.  The new shape allows the car to have the right amount of acceleration to get up and through the loop with more fun!

Engineers can do amazing things! Next time you are on a roller coaster, pay attention to how your body feels as it moves through the twists and turns.  That came straight from the imaginative mind of a roller coaster engineer.

For more roller coaster information please visit the links below:

http://www.physicsclassroom.com/mmedia/circmot/rcd.cfm

http://science.howstuffworks.com/engineering/structural/roller-coaster5.htm

May 2017 E-News: Bird Migration & Climate Changes Affecting Migration Patterns

With International Migratory Birds Day approaching on May 13th, we wanted to dedicate our feature article of the May 2017 e-newsletter to be all about bird migrations and factors that affect it.

One of my favorite past times is feeding and watching the birds in my backyard!  I have different visitors, such as the goldfinch, throughout the year depending on the season, and it is always exciting when they arrive.  Do you ever wonder about that?  Some birds are always around and others are just there in the summer because some birds migrate and others do not.  It is all about migration! Let’s be ornithologists and take a peek at different birds that migrate.

Migration is the regular seasonal movement between breeding and winter grounds. Many types of animals and even butterflies migrate, but what comes to mind for most is geese flying in a V headed south for winter.  All birds have an expected range where they might be found, but birds that migrate have seasonal ranges.  Meaning in summer you might find them in one area, and in winter another.  The main thing to remember is that it is a predictable pattern.

Reasons Why Birds Migrate

The reason that birds migrate can be anything from food accessibility, weather, to availability of breeding grounds.  Yet food appears to be the most prominent reason for migration because everything is connected to food.  Change in weather can affect food supply and lead to less successful breeding.  So many birds leave their home to breed where the weather permits greater food access.  Basically more food equals more baby chicks!  Yet migration is risky because of hunting, increased predation and getting blown off course among other things.  Not all birds migrate, but those that do migrate evolved to do so simply because the food and reproductive payoff outweighed the risks.

How do they do it and how do they know when to go?

Migration is thought to be cued by changes in day length. Migrating birds navigate using the sun as a compass, stars, the Earth’s magnetic field, and possibly mental maps and olfactory senses.  Birds seem to use a combination of evolutionary adaptations as well as experience for successful migration.  For instance a young bird on its first migration might know which way to go because it can read the Earth’s magnetic field but it doesn’t know how long the journey is or which nesting site is the best yet.

Here are some cool examples of birds that migrate and even one that seems like it does, but actually experiences something unique called irruption:

Tree Swallow - Image Source: Pixabay.com

Swallows:  There are different types of swallows on every continent but Antarctica. Some migrate while others don’t.  The tree swallow is a migratory bird that breeds in North America and winters in Mexico and Central America. You might observe their unique silhouette as they swoop through the air catching insects.

Canada Goose - Image Source: Pixabay.com

Canada Goose – They travel from Canada to the northern USA in a distinctive “V” formation between September and November every year.  By using this formation the geese work together to conserve energy during their trip.  Some geese migrate to the same area to nest each year!

Snowy Owl - Image Source - Pixabay.com

Snowy Owl – They are unique in that their movements don’t really follow a predictable pattern and therefore aren’t considered migratory.  It might be more accurate to describe them as nomadic.  Some owls travel south every year; others stay put or even go further north.  Snowy owls do experience a unique phenomenon called irruption.  During an irruption snowy owls come flooding out of the north and one year were found as far south as Florida.  Scientists are still trying to understand irruptions but they typically occur after an abundance of food leads to an overly abundant breeding season.  In other words, A LOT of juvenile snowy owls decide to travel abroad to discover themselves (that was a joke).

Arctic Tern - Image Source: Pixabay.com

Arctic Tern – The longest migration belongs to the arctic tern, which has a continuous worldwide circumpolar breeding distribution and makes the trip from pole to pole each year.  They get to experience two summers and more daylight than any other creature!  One study that tracked terns found that the annual trip can be an average of 56,000 miles and that the average tern with a lifetime of 30 years can travel 1.5 million miles over the course of its life.  That is the equivalent of more than three round trips between the Earth and the Moon!

Each bird has a unique life history and depending on where you live you can experience different bird visitors throughout the year.  Put on your ornithologist hat and create a habitat for birds in your own backyard.

What birds need:

–          Food – birdseed or suet in a feeder, or even nectar, berry, or seed producing plants.

–          A place to nest –a bird box, or a tree or shrub you can plant

–          Water – a bird bath or shallow tray of water  that you keep fresh year round

You can keep a journal and track which birds visit your habitat throughout the year and research their life histories.  If you have a friend that lives in another part of the country you could even compare and contrast the different birds that live nearby.  You can determine if they migrate, what food they like, and also what type of nest they might build all in your own backyard!

Download our HTHT Bird Observation Sheet here: http://sciencemadefunwnc.net/downloads/bird_migration.pdf

Image Source: Pixabay.com

Effects of Climate Change on birds

Many scientists and bird enthusiasts might wonder what effect climate change has had or may have on their favorite birds.  First of all there is a definitive difference between weather and climate; weather refers to changes we see and feel outside from day to day whereas climate is the long term weather pattern of a specific region.  For instance it might be sunny and 70 degrees in both Arizona and North Carolina (i.e. the weather is the same that day), but the overall climate of those two regions is completely different.

Climate change can have profound influences on our weather.  Most scientists predict that we can expect an increase in extreme weather patterns, rising sea levels, melting glaciers, and changes in wind and sea patterns as a long-term result of unchecked climate change. Some other effects we see from climate change are ocean acidification, a large reduction in the diversity of species, a drop in total fish population, loss of coral reefs and a weakening of the Gulf Stream.

Now imagine you are the globally travelling Artic Tern – a bird that relies on wind currents, fish populations, and also certain seasonal weather patterns to migrate, survive, and breed.  What would happen if it’s nesting grounds and/or food supply was to disappear?  No more Artic Tern.  This is just a hypothetical example, but the key thing to remember is that small changes can have a compounding effect on our environment and the creatures that live there.  A rapid change in planetary conditions could also outpace evolutionary adaptations and lead to a mass extinction event and the loss of the majority of the world’s species.  Unfortunately we probably won’t see the effects of OUR impact until it is too late.

Ornithologists are continually studying this topic and they’ve found that overall climate change can affect the timing of events like migration or breeding. It can also affect birds directly, through changes in temperature or rainfall.  Combine all that with other major threats like habitat loss and alien invasive species and the impact gets worse.

Bottom line is the vast majority of scientists agree that humans have and continue to have a negative influence on our climate.  Our cars, and homes all require energy and the main way right now we get energy is by burning coal, oil and gas. Burning these sources release carbon dioxide into the air, increasing the greenhouse effect and is leading to a change in our planet’s climate.  Scientists have measured an exponential increase in carbon dioxide in our atmosphere since the industrial revolution and have studied the effects it has on climate since 1960. So it is up to us to make a change in our carbon habits – the birds can’t do it for us.

Sources:

http://www.ibiologia.unam.mx/directorio/r/d_renton/pdf/Crick_2004.pdf

http://awaytogarden.com/i-know-what-birds-like-11-backyard-habitat-tips/

http://www.projectsnowstorm.org/what-is-an-irruption/

The Science of Basketball

Pass, dribble and shoot! It is time for March Mania basketball – one of the most famous annual sporting events in the US. Whether you are watching college teams on TV or playing in the backyard, basketball is fun because of Science! I betcha’ didn’t know there was science involved in the sport of basketball!

Bouncing the ball on the ground, passing to your teammate, and shooting at the goal all depend on physics, math and the laws of motion.

Origins of Basketball

By Evdcoldeportes via Wikimedia Commons

Basketball is considered the first sport that completely originated in the United States.  It was invented in December of 1891 when Dr. James Naismith nailed up some peach baskets in a gym.  Basketballs today are designed to bounce around the court and soar in an orange arc from your hands into the basket.  But were they always like this?  Why do they have those bumps on them?

When the sport was first invented soccer balls were used and players had a harder time holding on to and dribbling the ball than they did shooting a basket.  The orange, bumpy ball we know today was developed as a result of problems players were having trying to play this brand new game.

Changes they made to the ball included making them bigger and adding bumps to the leather surface.  This added bounce and friction to the equation.  Modern basketballs are hollow with an inflatable inner rubber bladder and have a small opening that lets you control the air pressure.  This hollow center is generally wrapped in layers of fiber and finally covered with leather, which is usually bright orange so players can easily see them.  They took a problem – slippery, not so bouncy ball – and engineered a solution!

Why do they bounce?

Evdcoldeportes - https://commons.wikimedia.org/w/index.php?curid=10785157

Basketballs bounce because of the pressurized air inside of them, gravity and Newton’s Laws of Motion.

When you dribble a basketball, your hand and gravity both push the ball towards the ground (Law #1).  As it drops, the ball accelerates and speeds up (Law #2).  It wants to stay in motion so the ball pushes into the ground when it hits, compressing the air inside.  The ground pushes up with an equal, but opposite amount of force resulting in the ball bouncing back up in to your hand (Law #3).  The energy in the compressed air is transferred back to the ball pushing it back into motion.  If you were to take your hand away and stop dribbling, the ball would continue to bounce due to Newton’s first law, but would slow down and eventually stop due to friction. 

The more air pressure inside, the harder it will push on the sides of the ball and the more bounce you’ll get.  This is why an under inflated ball won’t bounce very well because there is not enough air pressure inside to maintain the forces necessary for bounce. 

Why the bumps?

Image Source: Pixabay.com

So the last detail they added to their new ball was little bumps on the surface of the leather called pebbling. Adding these bumps was all about friction.  When forces collide, friction naturally slows things down over time and the more points of contact an object has with another surface the more friction comes into play.  So the bumps on the basketball basically increase the surface area of the ball and the amount of friction acting on it.  This makes the pebbled ball ideal for a player to grip, pass quickly, and dribble without fear that the ball will slip away in a random direction. 

Next time you shoot some hoops, observe all the features of the basketball that make it special.  It’s a great example of engineering and American innovation in action!   

Try this fun, at-home STEM basketball activity: http://sciencemadefunwnc.net/downloads/basketball_STEM.pdf

S.T.E.A.M & Engineering with Gumdrops

S.T.E.A.M. has become a hot topic in the world of education. It is an educational approach to learning that uses Science, Technology, Engineering, Arts & Mathematics for guiding student inquiry, discussion, creativity, and critical thinking skills.

Today we are going to focus on the Engineering side of S.T.E.A.M. What is engineering? Basically, anything that is built must first be engineered, or in other words, planned out. An engineer is a person who designs and builds complex products, machines, systems, or structures.

Engineering combines science and mathematics to create structures and devices to solve problems.
-Need a bridge? Ask an engineer.
-Need to keep food cold? Ask an engineer.
-Need to keep your house from falling? Ask an engineer!

The engineering process involves these 5 Steps:  ABDCE: Ask/Problem, Brainstorm, Design, Create, Evaluate/Test. Encourage your junior scientists’, and teach them about the engineering process with our super-fun gumdrop challenge below.

Gumdrop Challenge
Engineering always starts with a problem to solve.  For the gumdrop challenge the problem is: how can you build a structure with just 10 gumdrops and 20 toothpicks that can hold up a textbook?

Strength in Triangles
Let’s brainstorm! What shapes are super strong?  Should your structure be skinny or have a wider base?  What will it look like – a house, a dome, a teepee?

Some shapes are stronger than others.  Triangles for instance are super stable and can be found in many bridge and house designs where extra strength is needed. Even in nature you find the triangle.  Pine trees generally have a triangle-like shape so that they don’t topple over when heavy snow falls.  You tend to find a lot of pine trees in colder climates for this reason.

What makes the triangle so strong? The triangle can hold large loads without collapsing because of its inherent structural qualities and it is the only shape that has this level of stability and rigidity. For instance, triangles have three hinged connections, while squares have four right-angle connections.  The acute angles of the hinged connections help fix the triangle’s shape, even when a force is applied, because the edges are compressing against each other providing support. When forces are applied to a square, it easily loses its shape and becomes a parallelogram because its connections lack that angled compression unique to triangles. Engineers often add a diagonal through the middle of a square, basically turning it into two triangles and making it stronger. Even hexagons have hidden triangles within their shape that add stability!

Gumdrop Design Time:
Draw out your gumdrop structure. What will it look like?  How will you incorporate triangles? Can you do it without triangles?

Many structures look like one shape but are made up of several connected triangles.

-Truss bridges are used to span greater distances than your basic beam bridge.  They tend to look like trapezoids but are made of chains of alternating triangles.

Build and Test your Structure:
The next step in the engineering process is to build your gumdrop structure.  Try a bunch of different designs:  with or without triangles, skinny and tall, squat and low, dome shaped. Try to guess which will do best!

For the final step, test your structures by placing a book on top of each one.  Which structure holds the book best?  What improvements can you make to achieve your goal?

Reflect and Rebuild:
Like any good scientist, you’ll test your structure, assess its effectiveness, and then go back to the design step to improve it! Science is all about experimenting, adjusting, and repeating your efforts until you reach your desired outcome. Plus, when you’re done you get to eat some delicious gumdrops.

Join our HTHT @ Home Science Experiment to make your own Truss Bridge:
https://sciencemadefun.net/downloads/Truss%20Bridge_EOTD_May%205th.pdf

September 2016 E-News: STEM Careers Pertaining to the study of the Ozone Layer

The International Day for the Preservation of the Ozone Layer

On September 16, 2004, it was announced by the United Nations General Assembly to proclaim the day as the International Day for the Preservation of the Ozone Layer which also commemorates the date of the signing, in 1987, of the Montreal Protocol on Substances that Deplete the Ozone Layer.

What is the Ozone Layer?

The ozone layer is one layer of the stratosphere which makes up the second layer of the Earth’s atmosphere. The stratosphere is comprised of protective gases including ozone and oxygen molecules that cling to our planet. The ozone layer is very important as it absorbs intense ultraviolet radiation from the sun and blocks the UV rays from reaching the Earth’s surface.

STEM Careers Pertaining to the study of the Ozone Layer

As STEM (Science, Technology, Engineering and Mathematics) education becomes ever more popular in today’s academics, we wanted to talk a little about STEM careers pertaining to the study of the Ozone Layer. The type of scientist who studies the ozone layer can be called a Meteorologist or Climatologist. Over the year’s these types of scientists noticed that the ozone layer was thinning out. With no ozone layer, there would be no protection from the Sun’s harmful UVA & UVB rays.

What Have We Done About Ozone Depletion?

So as a way to help strengthen the ozone layer, officials banned the use of chlorofluorocarbons or CFC’s. A CFC is a molecule that contains the elements carbon, chlorine, and fluorine. CFC’s are everywhere, but are mostly found in aerosol sprays, refrigerants and plastic products. CFC’s released on the surface of the Earth diffuse upward through the lowest layer of the atmosphere, called the troposphere. The vertical air current of tropospheric weather help push CFC’s up to the stratosphere. Once the CFC’s get into the stratosphere the UV rays from the sun break them down which releases chlorine. The chlorine will actually destroy the ozone molecules and more reactions will cause more ozone depletion.
From the efforts of climatologists, meteorologists, governments and businesses to control aerosol can and CFC production the ozone layer has slowly been recovering. The work of atmospheric scientists and environmental researchers continues to play a paramount role in policymaking under the Montreal Protocol to protect the ozone layer.

It is important for us to highlight this STEM career this month as climatologists and atmospheric scientists do such valuable work in protecting our human lives on Planet Earth from the Sun’s harmful rays.

Please show this catchy tune and video to your students/children to help them fully understand the ozone layer!

Ozone Song

Sources: http://ozone.unep.org/es/precious-ozone

https://en.wikipedia.org/wiki/Ozone_layer

http://www.ozonelayer.noaa.gov/science/basics.htm

The Science of Moonbows

Dumgoyach, via Wikimedia Commons

With National Moon Day approaching on July 20th and the Anniversary of the Apollo 11’s first landing on the Moon, we felt it appropriate to feature the science of moonbows in this month’s newsletter.

A moonbow is also commonly referred to as a lunar rainbow. A moonbow is a rare natural atmospheric phenomena that occurs when the Moon’s light is reflected and refracted off water droplets in the air.

Moonbows are much fainter than rainbows made by the sun and often appear to be white. This is due to the smaller amount of light reflected from the surface of the moon. The light from the moon is usually too faint to be perceived by the receptors in the human eye, it is difficult for the human eye to discern colors in a moonbow. However, the colors in a moonbow do appear in long exposure photographs.

A bright moon near to its brightest phase known as a full moon is needed in order to have a chance at seeing a moonbow. It must be also be raining opposite the moon, the sky must be dark and the moon must be very low in the sky (about 42º above the horizon). All these put together makes seeing a moonbow very special and rare!

There are some locations around the world where moonbows occur more frequently. Most of these locations tend to have waterfalls, which create layers of mist in the air. Some of these locations include Yosemite National Park in California and Cumberland Falls State Resort Park in Kentucky. Victoria Falls on the border of Zambia and Zimbabwe and Waimea in Hawaii.

Moonbow at Victoria Falls; By Scolopendra33 via Wikimedia Commons

Moonbow at Lower Yosemite Falls; By Brocken Inaglory via Wikimedia Commons

Moonbow over Kula, Hawaii; By Arne-kaiser via Wikimedia Commons

 

Sources:

http://www.timeanddate.com/astronomy/moonbows.html

https://en.wikipedia.org/wiki/Moonbow

http://www.atlasobscura.com/articles/where-to-catch-a-moonbow

http://fullmoonphases.com/moonbow/

May is National BBQ Month – Grilling Around the World

National BBQ Month is an unofficial holiday and an exciting way to kick off the start to summer! In this article we will take a look at some of the ways American’s celebrate during the warm summer months. We will also look at some of the ways cultures from around the world use grills and the different foods they use to barbecue!

Barbecuing in the United States is national past time during those hot summer months! In a 2013 study conducted by the Hearth, Patio & Barbecue Association (HPBA) showed that 80 percent of all U.S. households own a grill. Families in the United States, fire up their grills for all sorts of foods, but mostly for hot dogs, hamburgers, and chicken.

Satay - Image Source: Pixabay.com

In a recent info graphic by Kalamazoo Gourmet, they set out a list of 15 countries and their grilling habits. The huge variety in grilled foods around the world means that what we eat is all about where we live. Even grills in other countries look quite different from our charcoal or propane powered grills in the U.S.

Turkey is the birthplace of the shish kebob! In Turkish “shish” means “the skewer”. Typically, the shish kebob will have lamb, beef, poultry or fish. Unlike how kebobs are usually made in the United States, with vegetables placed between the meat on the same skewer. In Turkey the vegetables are grilled separately, normally not on the same skewer.

Grilling in Southeast Asia and Indonesia is very similar to grilling in the United States and Turkey. They use small portable charcoal grills to make a dish called “satay”. Satay is a dish of seasoned, skewered and grilled meat, served with a sauce.

Asado - Image Source: Wikimedia Commons

Much like the Turkish shish kebob and the Indonesian satay, the Japanese prepare their own type of skewered grilled meat called Yakitori. Traditional Japanese yakitori is skewered chicken that is typically seasoned with tare sauce (a sweetened, thickened soy sauce) and grilled on a tabletop grill called a hibachi.

The way of grilling in South America is quite a bit different in style then the traditional barbecue. A fire is made on the ground or in a fire pit and surrounded by metal crosses (asadores) that hold the entire carcass of an animal splayed open to receive the heat from the fire. This way of grilling in South American countries is called Asado, the standard word for “barbecue”.

Tandoor - Image Source: Wikimedia Commons

In India, grilling is done by using a Tandoor which is a 5-foot-high round sided clay oven. Typically, naan bread is grilled by pressing the dough against the side of the tandoor. Tandoori chicken and grilled pineapples are also popular items to be grilled in this method

 

 

 

 

What you may not know is that there are even more distinct — and delicious! — grilling styles all over the world! Check out the info graphic below from Kalamazoo Gourmet to see other types of grilling in other countries from around the world! Let us know which style is most intriguing to you!

Image Source: https://kalamazoogourmet.com/

 

Sources:

https://pixabay.com/

https://kalamazoogourmet.com/

https://www.finedininglovers.com/blog/food-drinks/bbq-habits-around-the-world/

http://www.usfoods.com/food/operator-insights/archive/grill-your-way-around-the-world.html

http://www.bonappetit.com/test-kitchen/cooking-tips/article/grilling-traditions-around-the-world-from-argentina-to-south-africa-to-china