Ocean Acidification & Its Impacts

Beach in Oahu, Hawaii

Beach in Oahu, Hawaii

With warm weather and summer vacation just around the corner, it is difficult to escape the draw of our oceans and beaches. Almost all of us, especially here in San Diego and other beachside cities, have stories to tell about our oceans, whether it is a fond memory from a family trip to the beach, a fishing voyage with friends, or a solo surf session by a pier at sunset. However, the oceans also tell us stories, and the narrative becoming clearer and more imminent is that of the declining health of our oceans.

A factory in China. The Industrial Revolution brought about a reliance on burning fossil fuels for energy, which pumps large amounts of carbon dioxide and pollutants into our environment.

A factory in China. The Industrial Revolution brought about a reliance on burning fossil fuels for energy, which pumps large amounts of carbon dioxide and pollutants into our environment.

Since the Industrial Revolution, the use of fossil fuel-powered machinery has emitted billions of tons of carbon dioxide along with other gases into our atmosphere. Today, it is estimated that one million tons of carbon dioxide are emitted every hour – that’s a faster rate than has existed on our planet in tens of millions of years. Our oceans and seas absorb up to one-third of these gas emissions. This helps all of us on land because these greenhouse gases are taken out of the atmosphere, slowing down climate change. But, still, this comes at a cost.  

All solutions are acids or bases, and the acidity or basicity of a solution is defined by its pH value. A pH of 7 is neutral - the pH of pure water. Above pH 7 is basic, and below pH 7 is acidic. The surfaces of our oceans are healthiest when they are slightly basic with a pH of 8.2. Because of the large amounts of carbon dioxide entering our atmosphere, the pH of our oceans is decreasing, which is a process called ocean acidification.

A scientist in Svalbard, Norway studying the effects of climate change on the oceans' chemistry. 

A scientist in Svalbard, Norway studying the effects of climate change on the oceans' chemistry. 

Because of ocean acidifications, our oceans are now at pH 8.1, and at the current rate, the ocean’s pH is predicted to drop about 0.5 pH units before the end of the century! At a glance, this may seem like a small or insignificant change, but it is enough to cause very serious problems in biological systems. For example, human blood is normally between a pH of 7.35 and 7.45. A drop in pH of 0.2-0.3 can cause seizures, comas, and death. You can imagine the large impact such a change can have on an ecosystem that takes up over 70% of our planet! About 250 million years ago, large levels of volcanic activity caused a similar level of ocean acidification, and this change contributed to the death of 90% of marine species.

So, how does ocean acidification occur? Carbon dioxide in our atmosphere dissolves in water to make a molecule called carbonic acid, so as our oceans continue to absorb carbon dioxide, the waters become increasingly acidic. In the past, basic molecules created by weathering rocks and sediments were enough to balance the carbonic acid and keep the oceans at their ideal 8.2 pH. However, rock erosion is not fast enough to keep up with acidification caused by an increasing excess of carbon dioxide released into our atmosphere.

An experiment showing how acidic waters dissolve marine organisms' shells.

An experiment showing how acidic waters dissolve marine organisms' shells.

Such a rapid change in our oceans’ chemistry is not compatible with our marine organisms, which have evolved over millions of years in an ocean with a stable pH of 8.2. Ocean acidification affects marine organisms’ ability to communicate, reproduce, and grow. For example, at a healthy pH, about 10% of the carbon dioxide dissolved in the water exists as a molecule called carbonate. To make their shells, marine organisms like corals, clams, mussels, and oysters combine calcium with carbonate. Acidic waters have less carbonate, making it difficult for these animals to survive. Furthermore, acidic waters can chemically change the carbonate in the organisms’ shells to slowly dissolve them.

Acidic waters also lower the pH of the body fluids in all marine life, such as fishes, making it difficult for them to breathe and for their brains to function. It’s similar to if the air we breathe changed. If you have ever been at high elevation in the mountains where there is less oxygen in the air, you might have had a similar experience with difficulties breathing or headaches.

Coral reefs in the Red Sea

Coral reefs in the Red Sea

In addition to harming marine life, ocean acidification is hurting certain industries, creating economic stress. There is a decline in commercial fisheries, especially those that trade in lobster, scallops, and other shellfish. California, which is home to 31 different kinds of salmon and trout, is predicted to lose 23 of these species within the next century. More gravely, in many fishing villages in Indonesia, The Philippines, and Malaysia, fishing is necessary for survival. Hundreds of communities like these around the world must fish to feed themselves, so the depletion of their food source is a serious issue.

Fortunately, ocean acidification is a somewhat gradual process, giving us time to recognize the impact of human activity and change our behaviors to lessen harmful disruption to our oceans. To lower your own individual carbon dioxide emissions (or “carbon footprint”), you can use less electricity, recycle, and reducing use of your car by biking, walking, or using public transportation instead. If you want to find out your carbon footprint, you can visit The Nature Conservancy’s calculator here. More powerful ways to help the oceans are to support political measures that combat increasing carbon emissions and to donate to or volunteer with local organizations that champion environmental causes. One example is the Surfrider Foundation - an international organization that promotes the health of our oceans and beaches. 

Fishermen in Pangadaran, Indonesia

Fishermen in Pangadaran, Indonesia

Carbon dioxide is estimated to exist in the atmosphere for hundreds of years, so even if we cut off all carbon emissions today, we will not see a reversal of ocean acidification immediately. By teaching all of our friends and family about how we affect our environment, and by encouraging everyone to reduce our carbon footprints, we can thank our oceans for all that they give to us and ensure that our beautiful oceans and all of its organisms will exist in the future.

 

 

References

·      Bland, Alistair. “Many Of California’s Salmon Populations Unlikely To Survive The Century.”  The Salt. NPR, 17 May 2017. http://www.npr.org/sections/thesalt/2017/05/17/528826774/many-of-california-s-salmon-populations-unlikely-to-survive-the-century. 19 May 2017.

·      Brewer, Peter G. and James Barry. “Rising Acidity in the Ocean: The Other CO2 Problem.” Sustainability. Scientific American, 1 September 2008. https://www.scientificamerican.com/article/rising-acidity-in-the-ocean/. 17 May 2017.

·       “Ocean Acidification.” Pristine Seas. National Geographic. http://ocean.nationalgeographic.com/ocean/explore/pristine-seas/critical-issues-ocean-acidification/. 18 May 2017.

·      “Ocean Acidification.” The Ocean Portal Team and Jennifer Bennett. Ocean Portal. Smithsonian National Museum of Natural History. http://ocean.si.edu/ocean-acidification. 18 May 2017.

·       “Ocean Acidification.” Know Your Ocean. Woods Hole Oceanographic Institute. http://www.whoi.edu/ocean-acidification/. 16 May 2017.

Images:
All images used were found on Wikimedia Commons and are Public Domain

The Extraordinary Life and Work of George Washington Carver

This post is the first installment of our "Meet a Scientist" Series

George Washington Carver in 1910

George Washington Carver in 1910

Meet George Washington Carver – scientist, agriculturist, scholar, inventor, but, contrary to popular belief, not the inventor of peanut butter.  Although none of his hundreds of peanut products achieved commercial success, Carver’s accomplishments have landed him an irreplaceable part in history for revolutionizing agriculture in the United States and overcoming seemingly insurmountable obstacles to become a highly esteemed, African-American faculty member of the Tuskegee Institute in a time of extreme racial tensions.

George Washington Carver was born into slavery in Missouri to Mary and Giles, a slave couple owned by Moses and Susan Carver. The exact date of his birth is unknown, but it is estimated to be in the mid-1860s. Sadly, at approximately one-week old, George, his mother, and sister were kidnapped by farm raiders to be sold in Kentucky. George was located and returned to Moses Carver’s farm, but his mother and sister were not found.

George Washington Carver at work

George Washington Carver at work

Moses and Susan Carver decided to keep and raise George and his brother. Because no schools accepted black students, Susan taught them to read and write at home. George valued learning from a young age, and enrolled in a school for black children about ten miles from the Carver Farm. When he enrolled, instead of continuing to be referred to as “Carver’s George,” he adopted the name “George Carver.” George pursued his education and graduated from high school in Kansas, but was denied admission to Highland College because of his race.

George enrolled in the botany program at the Iowa State Agricultural College as the first black student at the school. He graduated with a Bachelor of Science degree and, in 1896, a master’s degree, establishing himself as an exceptional botanist in the process. In 1896, Booker T. Washington, president of the Tuskegee Institute in Alabama, took notice of George Carver’s outstanding accomplishments and hired him as the head of the institute’s agricultural department. Carver’s research and work focused heavily on creating alternative uses of common crops, especially the peanut and sweet potato. He developed products from these plants for a myriad of purposes (over 300 products from peanuts and over 100 products from sweet potatoes!), such as paints, plastics, flours, shaving cream, glue, and even a form of gasoline. He is mistakenly commonly credited with the invention of peanut butter, but in reality, peanut butter made from ground peanuts date as far back as the 15th century by the Aztecs and Incas – centuries before Carver was even born.

George Washington Carver Museum

George Washington Carver Museum

Carver remained adamantly passionate about education. Due to his very humble beginnings, he spent his entire life helping poor farmers, especially African-Americans, improve their crops and get out of poverty, always refusing compensation for his advice. Carver promoted various methods of crop rotation, which is a large part of why peanuts became a large source of his innovations. He promoted the growing of crops that fixed nitrogen, promoting sustainability of nutritious soil and, therefore, healthy crops. Carver lived frugally and used his fame to promote scientific causes. He also started a mobile classroom known as the “Jesup wagon” that visited various farms to educate the farmers about agricultural techniques. He wrote for a newspaper column and traveled around the country, speaking about the importance of agricultural research and innovation. For ten years in 1923-1933, he spoke in support of racial harmony when he visited white colleges in the South for the Commission on Interracial Cooperation and the YMCA. Although he never spoke out directly against racist social and economic injustices of the time, his scientific success and open-minded demeanor still earned him great respect and admiration from both African-American and Caucasian people.

George Carver became so well-known for his work that president Franklin Delano Roosevelt looked to him for advice on agricultural matters. In 1916, Carver became a member of the British Royal Society of Arts, which is a very rare honor given to Americans.

1942

1942

George Washington Carver passed away in 1943 at the age of 78. He is buried next to his friend and colleague Booker T. Washington. President Franklin D. Roosevelt dedicated $30,000 for a monument to be constructed in Carver’s honor, located west of his hometown of Diamond, Missouri. This is the first national monument dedicated to an African-American. Carver’s epitaph summarizes his beliefs and the humble philosophy by which he lived his life: “He could have added fortune to the fame, but caring for neither, he found happiness and honor in being helpful to the world.” To this day, he remains an icon of African-American achievement, scientific achievement, and the transformative power of education.

 

 

Sources:

“George Washington Carver Biography.com.” Biography.com Editors. The Biography.com website. http://www.biography.com/people/george-washington-carver-9240299. September 28, 2016. A&E Television Networks. April 26, 2017.

“Who Invented Peanut Butter?” National Peanut Board. http://nationalpeanutboard.org/peanut-info/who-invented-peanut-butter.htm. April 26, 2017.

“Major Contributions – George Washington Carver.” https://sites.google.com/site/georgewashingtoncarverbiotech/.  George Washington Carver Biotech. April 25, 2017.

“George Washington Carver.” Linda O. McMurry. The Reader’s Companion to American History. 1991. http://www.history.com/topics/black-history/george-washington-carver. April 25, 2017.

Images:
All images used were found on Wikimedia Commons and are Public Domain

The Colorful Chemistry Behind an Eggscellent Easter

It’s that time of year when we can’t walk into a store without seeing displays of chocolate bunnies, marshmallow chicks, and vibrant bouquets of flowers. Along with all these springtime treats, perhaps the most memorable and engaging tradition (and my personal favorite) is the dyeing of Easter eggs.

By Superbass - Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=31904555

Decorating eggs is a deeply rooted, international tradition. The oldest examples of this activity are the engraved ostrich eggs found in Africa 60,000 years ago. Eggs across many countries and cultures are celebrated, and whether these activities are based on religion or the coming of spring, eggs represent rebirth and life.

For those who have participated in egg dyeing, you may have wondered: Why is vinegar added to the dye solution? This can be explained through simple chemistry. You've probably heard of acids and bases - it turns out that all solutions have a degree of acidity or basicity. Acids chemically react with bases to create solutions that are more neutral – that is, closer to pure water.

lkonact via wikimedia commons

lkonact via wikimedia commons

So, back to the initial question – why is vinegar needed to dye an egg? The answer is that most egg dyes need acid to bind the dye to the eggshell.* Vinegar is an acid, and eggshells are bound together by a basic molecule called calcium carbonate. The eggshells base molecules assure that neutral and basic solutions will not change the eggshell. However, vinegar will react with the calcium carbonate shell to dissolve it slightly, allowing the dye molecules to stick to the eggshell, giving you vibrantly colored eggs.* Without adding vinegar to your dye solution, you will likely get very faint coloring.

Egg in vinegar. The bubbles on the shell are from gas released when the vinegar reacts with the calcium carbonate. Leave this overnight and the eggshell will dissolve! Image by Yat-Long Poon, from Experimenting with Science, published by Wiley

Egg in vinegar. The bubbles on the shell are from gas released when the vinegar reacts with the calcium carbonate. Leave this overnight and the eggshell will dissolve! Image by Yat-Long Poon, from Experimenting with Science, published by Wiley

Have you ever tried changing the amount of vinegar added to your dye solution? Because acid is needed for the dye molecule to stick to the egg, you might predict that adding more vinegar to the solution will give you more colorful eggs. This may be true to an extent, but be careful! The acid reacts with calcium carbonate to produce carbon dioxide gas, which will float out of the solution, like carbonation in soda. This gas forming on the surface of the eggshell can leave behind streaks, causing a blotchy dye job. That is why there is an optimal amount of vinegar recommended for the dye solution. Too much vinegar or leaving the egg in the solution too long will eventually dissolve the eggshell. For a neat science experiment exploring this, click here ; you can also find this experiment in Dr. Olivia Mullins' book here!

Have you ever seen someone dye eggs with a silk tie? (If not, watch this clip from Martha Stewart!) The patterns on a silk tie can be transferred from the tie onto the egg by wrapping the egg in the tie and submerging it in water with vinegar. Eventually, some of the dye from the tie will be transferred to the eggshell. This is because silk ties are usually dyed using dyes that require an acid to bind – the same reason that dyeing eggs requires vinegar. By adding vinegar to the water, the tie’s dye molecules can be transferred over to the eggshell.

Now that you know the chemical principles behind this tradition in addition to some tips and tricks for optimal coloring, there is no reason for not making this Easter your most colorful yet.

*Going further: Egg dye molecules are typically sodium salts of a negatively charged molecule called a phenolic acid. In an acidic solution, it gains a H+, allowing it to interact with the surface of the eggshell. In particular, dye molecules interact with slightly negative parts of the eggshell, including the calcium carbonate and some parts of proteins.

Other fun egg experiments

Grow Egg Geodes
Suck an egg into a bottle
Make "Mood" Easter Eggs
Walk on Eggs
Make Water Marble Easter Eggs
 

References
·         “Silky Science: Tie-Dyeing Eggs.” Scientific American. 21 March 2013. https://www.scientificamerican.com/article/bring-science-home-silk-egg-dyeing/. 26 March 2017.
·         Stewart, Brian. “Egg Cetera #6: Hunting for the world’s oldest decorated eggs.” University of Cambridge. 10 April 2010. http://www.cam.ac.uk/research/news/egg-cetera-6-hunting-for-the-worlds-oldest-decorated-eggs . 26 March 2017.

 

Picture Credits:
Bunny and eggs: Superbass, CC BY-SA 4.0, via wikimedia commons
Basket of Bulgarian Orthodox Easter Eggs: lkonact via wikimedia commons
Egg in Vinegar: Yat-Long Poon, in Experimenting with Science, Wiley Publishing

 

The Genetics of the Luck o’ the Irish

by Ana Wang, Graduate Student at The Scripps Research Institute

With St. Patrick’s Day around the corner and a tumultuous start to 2017, most of us probably hope for a little of that fabled Luck o’ the Irish, and what’s more hopeful this time of year than finding a four-leaf clover? The myth of the four-leaf clover bringing good fortune has cultural origins that may be as simple as the fact that these clovers are rare, so finding one can make you feel special – or lucky. And they are pretty uncommon – on average, you’d have to search through 10,000 clovers to find one four-leaf clover! More rare still are clovers with five, six, seven, or more leaves – but they do exist. Currently, the world record is at 56 leaves on a clover found in Japan!

Four-leaf clover

Four-leaf clover

Have you ever wondered why some clovers have four (or more) leaves? Or maybe you’ve wondered why more clovers don’t have four leaves. Well, look no further as we are going to delve into the science behind this lucky charm.

Whether or not a clover has the fortuitous fourth leaf – (or, more accurately leaflet) – is largely based on the code in the clover’s genetic material.  That being said, the exact cause of the fourth leaflet is hard to study and largely unknown, due to some quirks of the clover’s DNA. The common clover in North America is the white clover* which has four copies of each gene.** For reference, humans and most other organisms only have two copies of each gene. To add to the white clover’s genetic complexity, each chromosome (which contains the genes) in an individual clover often comes from a different species. You can imagine how hard it is to study lineage and inheritance with essentially four different parents!

Five-leaf clover

Five-leaf clover

It is hypothesized that many genes, rather than a single gene, contribute to the determination of whether a clover is a trifoliate (three leaflets) or multifoliate (more than three leaflets). The Parrott Lab at the University of Georgia shed some light on this issue by studying three-leaf and four-or-more-leaf clovers in separate, but identical, surroundings. This set-up allowed the researchers to zero in on differences that stemmed from only genetics, as it kept the environmental influences of the two groups the same. Studying the DNA from the clovers showed that the multifoliate trait is recessive to the trifoliate trait. This means that even when a clover contains genes for both traits, it will have a trifoliate morphology. This is predominantly why the multifoliate variants are much more rare than the traditional three-leaf shamrock.

Genes are not the end of the four-leaf-clover story, however. The Parrott Lab also did some work on environmental influences. They ran their studies in both summer and winter and found more four-leaf clovers grew in the summertime, showing that genes AND the environment influence the number of leaves on a clover. Many suspect that chemicals and radiation may also increase the occurrence of four-or-more leaf clovers – but that has yet to be proven.

Three-leaf shamrock  

Three-leaf shamrock

 

The four-leaf clover has become an international symbol of good luck. It is said that St. Patrick used the shamrock – the clover symbol of Ireland - to explain the Holy Trinity, with each leaflet representing one hypostasis . It is also said that the three leaflets represent hope, faith, and love. To many today, the fourth leaflet on a four-leaf-clover represents luck. To many in the Middle Ages, it was believed to bestow the carrier with the magical power to see fairies. To  plant biologists, though, it can represent the amazing complexity and infinite possibilities that lie within even a seemingly simple and common weed.

 

*The scientific name for the white clover is Trifolium repens, where trifolium refers to three leaves.

**Organisms with four copies of each gene are called allotetrapoloids.

 

References:
·         “Most Leaves on a clover.” Guinness World Records. Web. 15 March, 2017.
·         Tashiro, Rebecca M., et al. Leaf Trait Coloration in White Clover and Molecular Mapping of the Red Midrib and Leaflet Number Traits. Crop Science 50, 1260-1268 (2010).

 

Images:
Many clovers: By JPS68via Wikimedia Commons
Four-leaf clover: By Calignano via Wikimedia Commons                                            
Five-leaf clover: By 本人 - 本人, via Wikimedia Commons
Three-leaf Shamrock: via Wikimedia Commons

 

 

Science Delivered on The Radio Show Esoterica!

Did you know Marie Curie had a daughter, Irene Joliot-Curie who won a Noble Prize in Chemistry? Get a run down of some of the early women pioneers in STEM in this Esoterica podcast! We are happy to say that Science Delivered gets a shout-out at the end. It's a short program so we highly recommend listening to the whole thing, but if you MUST skip ahead our piece starts around 2:47.

Thanks to Chris Kenna and Esoterica for this great piece!

*Esoterica is weekly radio program in Maine.

Book Announcement: "Experimenting with Science" is published!

Science Delivered founder "Dr. Olivia" has authored her first book! "Experimenting with Science" is published by Wiley and the For Dummies people. It's part of a new Dummies series for kids, aimed at ages 7-11, but we think grown-ups can enjoy it too.

Inside you'll find some of our favorite experiments! All experiments are done with simple and mostly household materials. We take on: Forces, Air Pressure, Sound, Chemistry, Plants and Animals, Perception and Art and Science. Check out the bonus material too!

Time for Credits! Our models were Teke Helms and Annika and Avery Pitts. Sam Poon did much of the photography work. Cynthia Mullins did several of the art and science experiments and inspiration for using recycled materials for Magnet Monsters can from Erin Pennell from ArtFORM. Paul Bonthius and Charles Toth did the technical editing, and Oliver Mullins helped with some Chemistry. Stephanie Mullins helped edit some of the "layman" pictures we had. Thanks everybody for your great efforts!

14 Definitions of Critical Thinking

Here at Science Delivered an important part of our mission is promoting confidence and critical thinking. Kids and adults possessing these attributes are well prepared to pursue their goals and navigate life’s obstacles. But while the words ‘critical thinking” gets thrown around quite a bit, we rarely see a critical analysis of the term itself. So what does 'critical thinking' really mean?

The dictionary definition is:

"The objective analysis and evaluation of an issue in order to form a judgment.”

But this definition isn’t overly helpful. So, in order to define this skill that we aim to cultivate, we’ve come up with 14 of our own definitions. Here it goes!

What does 'critical thinking' really mean?

  1. Critical thinking means being willing to change your position or beliefs as you collect more data.

  2. Critical thinking means being open to (quality) data that contradicts your previous beliefs.

  3. Critical thinking can mean ignoring an emotional or “gut” reaction to new information; our guts can make mistakes!

  4. Critical thinking means taking into account the source of the information.

  5. BUT critical thinking also means never (or rarely) dismissing information out of hand simply because of the source.

  6. Critical thinking means understanding that presented facts can be technically true but the manner in which they are presented can be skewed or misleading.

  7. Critical thinking means understanding that people, companies, ads and politicians often rely on authoritative sounding “science” and “statistics” to change your beliefs or behavior. Sometimes the facts they present are legitimate, but often they are not. Learning how to tell the difference makes navigating the world easier.

  8. Critical thinking means viscerally understanding that you don’t know everything.

  9. Critical thinking means resisting believing things solely because they fit in with your worldview.

  10. Critical thinking means understanding that others have had truly different experiences than you and may have different values and expectations of the world. This doesn’t (usually) mean one person’s values are right and another’s are wrong.

  11. We can’t be experts on everything, so we have to trust experts to inform our beliefs and ideas. But experts are not infallible – they can be wrong! In our opinion critical thinking means trusting the experts around 80-85% of the time.

  12. Critical thinking means being skeptical, especially when things seem somewhat unbelievable, but not being dismissive out of hand of new ideas.

  13. Critical thinking is often described as removing emotion from your ideas and decisions, but we only partially agree with that. Sometimes emotions and empathy are needed for sound critical thinking.

  14. Critical thinking means knowing that just because you have believed something all your life, doesn’t necessarily mean it’s true! Sometimes beliefs and ideas need to be reevaluated as we grow.

 

Teaching and engaging in critical thinking is helpful for the individual student and helpful for society. Critical thinking helps counteract bias and lets us evaluate what our biggest needs are and where our energy is best spent. We hope we can help our students obtain these lofty goals!

We’d love to hear from you – is there a definition of critical thinking that you'd like to add to our list?

 

Oobleck and Non-Newtonian Fluids

Move like crazy - or sink!

Recently at Science Delivered, we created an Oobleck Pool. Never heard of this before? Watch the video below and see if you see anything unexpected.

 

wHAT'S GOING ON?

"Oobleck" is the popular name given to a corn starch and water mixture. This mixture has the fascinating property of being a solid or a liquid depending on the pressure, or shearing force, exerted upon it. More on this down below, but in practical terms, it means that smacking the Oobleck Pool with your feet temporarily turns the surface into solid. But if you place you feet (or hands, or elbow etc) into the Oobleck slowly, you'll get sucked right in.

 

Where does the name "Oobleck" come from?

          The original Oobleck from Dr. Seuss

          The original Oobleck from Dr. Seuss

The term "Oobleck" comes from an early work of Dr. Seuss, Bartholomew and the Oobleck. Magicians make a green gooey substance come down from the sky; it creates havoc in the land and look quite similar to the cornstarch and water mixture when you play with small amounts of it and let it drip. Our Oobleck can create havoc too - if you get stuck in it!

 

What is a non-Newtonian Fluid?

This might be best answered by defining a "Newtonian" fluid, which is an ideal liquid. In lay terms, the flow of a Newtonian fluid will not change no matter what you do (assuming constant temperature). If you consider water, you can pour water our slowly, or stir it really fast, or shake it up in a bottle and flows remains the same in all conditions. The viscosity does not change.

In contrast, consider trying to get ketchup out of a glass bottle. The ketchup will sit, clumped, requiring you to bang the bottle to get it out . . . at which point it would all come out at once. The applied force (hitting the bottle) causes the viscosity of the ketchup to change. The Oobleck is a mixture of corn starch and water. When you apply force to this mixture, the mixture hardens, enough so that you can walk on a pool of it. But if the force is too weak, the substance will act as a liquid and you will sink right in.

 

Are all non-newtonian fluids the same?

No! Non-Newtonian fluids can be classified as shear-thinning or shear-thickening. Meaning, fluids can either decrease or increase their viscosity in response to force. Remember how the ketchup flowed quickly out of the bottle once you hit it? That means it is sheer-thinning, it flows more easily in response to force. Other shear-thinning fluids are paint, blood, whipped cream and lava. The Oobleck corn starch and water mixture, on the other hand, is shear-thickening. This mixture becomes a solid with increased force, and acts as a liquid otherwise, as you can see from the video above and this one here.

 

It is interesting to note that the Oobleck is often compared to quicksand, however, according to this article, quicksand is shear thinning, and therefore behaves in an opposing manner to the Oobleck. In quicksand, it is the force of walking on it that liquifies the substance, which is why frantic struggling will only get you deeper. See the powerful effects of quicksand, and how to escape here.

 

So How do you make an oobleck pool?

Oobleck is easy to make in small quantities - just add a cup of water to ~ 3/4 cups of cornstarch and kneading it with your hands until the cornstarch is mixed in and not clumpy. More detailed instructions can be found here or here.

Making a pool is a whole other story. It's messy and expensive, and a difficult clean up, but if you are really hankering to do it we will give you instructions!

You will need:

200 pounds corn starch (can be modified for different size pools)

20 gallons of water

Kiddie pool

Cement mixture

Tarp to protect the ground

~15 heavy duty trashbags for disposal.

We started by using this kiddie pool and finding a wholesale food company who generously allowed us to open an account even though we wouldn't be making regular purchases. 500 pounds of cornstarch delivery later and we were ready to go! You can order large quantities of corn starch off Amazon, although it's not cheap.

We then rented a cement mixer. Do not even attempt to mix this by hand! Ours fit one 50 pound bag of cornstarch at a time. We used roughly 5 gallons of water for every 50 pound bag. Even with the cement mixture we would get clumps of unmixed cornstarch stuck to the sides and have to scrape them off. Test the mixture with your hands, if you move your hand slowly through the material (with the mixer off of course) it should be relatively clump free.

We ended up getting a pretty decent pool with "only" 200 pounds of cornstarch, so it took four cycles in the cement mixture. I'd recommend leaving at least an hour for set up assuming you have several strong adults.

If the pool is left untouched for a few hours the cornstarch will separate from the water and settle at the bottom - this pool is good for one-day use only.

Put down a tarp! This is an extremely messy project. The cornstarch billows everywhere and it does not come off the ground easily. The ground protection we used was inadequate and after several sweeping and hitting our patio with a hose there is still cornstarch stuck in cervices.

Disposal is another issue. We let the cornstarch sit for a couple days in an attempt to let it dry out, but it will start to rot so you can't let this go on for too long. We then double bagged heavy duty trash bags and picked it up in clumps into the bag. The trash can was extremely heavy but luckily the city still took it away.

There you have it! Everything you wanted to know about Oobleck Pools. For the unique chance to try this yourself, come to Science Fest 5K. [edit: Science Fest 5K has passed]

 

The Science of Kindness

We talked to Kaitlin Roig-DeBellis, founder of a like-minded non-profit Classes 4 Classes, about empathy and compassion. We loved what she had to say! (Scroll down for interview). You can read our interview by Classes 4 Classes here.

What is Classes 4 Classes?

The beautiful thing about our world is that there are often infinite ways to tackle a problem. While Science Delivered is, of course, science focused, our ultimate goal is to promote positive outcomes to our students. That’s why many of our programs incorporate lessons about being good citizens. Our psychology and critical-thinking courses especially are designed to help students understand that those different from them also deserve respect and compassion. But children need to hear this message again and again and in multiple ways. A task bigger than any one company!

That’s why we were so excited to learn more about the non-profit organization Classes 4 Classes. Classes 4 Classes (C4C) has an awesome yet simple mission and that is to teach children the power of kindness, and that through compassion they have the power to enact positive change. They also teach about how we are all inter-connected. Should kids be learning this at home? Yes, of course, but recent research suggests that even in many well-meaning households the ideas of fairness and compassion are treated as less important than other qualities. And there is hard science to support the rather intuitive idea that compassion can be taught! While on the face of it C4C's goals are very different Science Delivered's, we found, at the core, there is actually a lot of overlap in our missions.

A class "Kindness Corner" listed on a C4C project page

A class "Kindness Corner" listed on a C4C project page

Kids need more than to be told to “be kind” they need chances to practice kindness and altruism. That’s where C4C comes in. Their free program is based on giving without the expectation of getting something back, a “pay it forward” model. After a classroom, say ‘Classroom A’, signs up to participate, their next step is to choose a recipient class, say ‘Classroom B’. Classroom A now takes the time to learn about ‘Classroom B’ and what this classroom needs. Once they find out what item (within reason) will help ‘Classroom B’ the most, ‘Classroom A’ chooses this as a gift and posts it online. Donors can now help fund the gift and ‘Classroom A’ gets to experience the joy of giving.

The fun part is that once ‘Classroom B’ receives a gift, they now pay it forward by choosing another class to research and pick out a gift for!

Classes 4 Classes started in Connecticut but has spread as far as Arizona and has been nationally recognized. You can read more about the organization at their website as well as news stories and accolades here, here, here and here. We talked to C4C founder Kaitlin Roig-DeBellis to find out more about her thoughts on C4C and its mission!

 

Interview

Q: We know that the mission of Classes 4 Classes is to increase empathy – what does empathy mean to you? Why is it important?
Teaching empathy is crucial because we can’t assume that our students come to school already aware of how to be empathetic towards others - they need the chance to have tangible experiences with it

Kaitlin: Empathy to me is the ability to relate to and put yourself in the position of someone else, whether they are similar to or very different from yourself. It’s the ability to understand someone else's feelings and relate to what they are feeling on a personal level.

Teaching children empathy assures that they are aware of what makes us each different, as well as what unites us as one - and being accepting of both. Teaching empathy is crucial because we can't assume that our students come to school already aware of how to be empathetic towards others  - they need the chance to have tangible experiences with it.

 

Q: How did you decide on the structure of C4C?

Kaitlin: When planning the structure of C4C, it was crucial that students would have an active role and actually be engaged in giving the gift to another class and ultimately in being kind, caring, compassionate and empathetic. I knew they had to be active in the process in order to learn these lessons. That's where the format for the individual project pages came from - a place to showcase the students' work [ed note: see here].

I also knew that funding the projects had to be crowd sourced because I didn't want any financial responsibility to fall on schools, teachers or students. I wanted to make sure that all students in all schools would be able to participate.

Lastly, I knew that it had to be a pay it 4ward model, because if the core of what we teach is giving back and connectedness (which it is) then we need to follow that model and encourage all students to give back!

 

Q: What’s one favorite story that has come out of a Classes 4 Classes event or classroom?

Kaitlin: There are so many! I think one that truly illustrates what we at C4C aim to inspire in students, is the story of two 4th grade classes who participated in C4C. The students had posted a project for another class to get iPads. Then those students did something truly amazing. They decided it wasn't enough to just wait for outside donors to fund their project. They wanted to do more! They asked their teachers if they could host a tag sale, where students who wanted to participate could bring in an item that they no longer used to sell. This was completely their idea. They spent all day on a Saturday hosting and working at their tag sale. They raised over $700 for their project! To me this illustrates exactly what C4C is working to engage students in-actively caring, being kind, compassionate and empathetic. Those students' actions illustrate all of these! I can't think of a better way to demonstrate empathy for others-than selling your own possessions to give a gift to someone else.

 
Q: What’s been your favorite part of your C4C journey?

Kaitlin: There have been so many favorite parts! I could never choose just one. It has been the journey, the daily ins and outs, the connections and spreading our mission. It's the teachers and students I've met with and interacted with. It's been watching the growth, how far we've come since February 2013. It's seeing the vision for our mission come to fruition. It's changing the way kindness and empathy are taught to students. It's all of the people and organizations who have supported and continue to support us. It's working with our incredible board on a day to day basis to spread our mission. It's been realizing that if you believe in something, in your vision for it, you can make it a reality. 

 

Q: If someone wants to support C4C how can they get involved?

Kaitlin: Anyone can get involved! Simply visit http://www.classes4classes.org and click on 'Get Involved' there are lots of ideas whether you are a parent, teacher or potential supporter. There are also downloadable documents that you can use to share our mission with others. Our supporters can support our class projects, our mission directly or both! If you have specific questions you can email: info@classes4classes.org

 

 

In the News: What if an asteroid were headed toward earth?

Asteroid 2004 BL86 (large object) has a small moon (top, small bright object)

Asteroid 2004 BL86 (large object) has a small moon (top, small bright object)

On Monday January 26, an asteroid, 2004 BL86, came close enough to earth for us to see. To add to the excitement, this asteroid has its own moon. (NASA reports that they have found 150 asteroids with moons, or even double moons.)

Now, at 745,000 miles away, 3.1 times the distance to the moon, 2004 BL86 is not dangerously close. However, it got us curious about NASA’s Near Earth program, which closely tracks asteroids that enter Earth's "neighborhood" and can predict their path years in advance.

Perhaps some readers remember that in 2004 an asteroid named 99942 Apophis was evaluated as having a 2.7% chance of hitting earth in the year 2029. Refined measurements of it's movements showed that we were in the clear for 2029, but that a very small chance of impact remained for the year 2036. A 1 in 45,000 chance to be precise. Even with a 0.0022% chance of an asteroid hitting the earth, there was serious discussion about how to deal with this risk, which shows us that NASA takes it's job seriously. Then in 2013, it was announced that the chance of the asteroid hitting the earth in 2036 was effectively zero. But what if the risk had remained? What actions could be taken?

There have been several proposals for deflecting asteroids, and in this case the necessary deflection to keep us safe was deemed small.  One study found a “130 x 130 ft. patch with a lightweight reflective surface" would change the energy absorption of Apophis by 0.5% which would be enough it influence it's trajectory so it would certainly bypass Earth, IF the procedure was done by the year 2018.

Another report had more extensive suggestions. (A side note: This report also estimated the potential damage of the asteroid hitting earth at 400 billion and the cost of a deflection mission at 400 million. It suggested the course of action be taken based on financial concerns and ignored the loss of human life and suffering (ahem)).

The first two suggestions of this proposal would need to be accomplished prior to the year 2029. This is because the year 2029 is where the 0.0022% danger comes from. We knew that in this year the asteroid would come relatively close to us and if asteroid came at exactly 18,893 miles from the earth it would fly through a "gravitational keyhole" which would alter its trajectory enough to set it on a course where it would hit the planet. To miss the keyhole, the asteroid would only need to be deflected about a mile. However, if it were to pass through the keyhole, it would be to be deflected 5000 miles. The latter obviously a much harder task, and would perhaps (but probably not) be impossible.

Apophis was discovered in 2004. Image credit: UH/IA

The first proposed method was “kinetic deflection” which would consist of hitting the asteroid with a large spacecraft to knock into a slightly new trajectory. That's it. Oh, of course there are angles, masses and speeds to work out but the basic concept is pretty simple.

The second method promoted in this report for pre-2029 use is the “gravitational tractor” which is much like what it sounds. Remember, all masses in space create a gravitational pull which effects other nearby masses. Here a rocket-propelled vehicle would essentially tow the asteroid onto a safer orbit through it's gravitational pull.

If the asteroid entered the keyhole in 2029, however, and was scheduled to hit earth, neither of the above methods would be powerful enough to keep us safe. In this case a more extreme courses of action would be needed such as "buried bombs" or nuclear weapons detonated near the planet. These are the methods NASA considers most viable for moving asteroids off course. However, bombs (as well as the kinetic deflection method) would send smaller pieces of the asteroid into orbit in an uncontrolled (by us) manner, and some of these could very well end up landing on Earth and still cause substantial destruction.

Other proposals have also floated around such using a laser or giant mirror to "boil" off part of the asteroid.

Luckily, Earth seems safe for quite a while. Jupiter, on the other hand, with its massive size and gravitational pull, has taken the hit from several asteroids and comets. We can be grateful to this large planet as it is thought to be, quite literally, taking hits for us.  

Bill Nye has a nice simple video explaining these concepts if you'd like to check it out. If any of our readers have expertise in this area we'd love to hear from you!

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