Blog Archives

Cool Down With Ice Cream!

7/25/2017

There’s a heatwave hitting the midwest, and it’s important to stay cool with these high temperatures. There’s no better time to enjoy a nice, cold scoop of ice cream! You may think this chilly treat is complicated to make due to the mass marketing of hundreds of different flavors, ice cream can be simplified down to three main ingredients - cream, sugar, and ice.

History of Ice Cream

Today, ice cream can be found in almost every restaurant and corner store, and there are many, many varieties at supermarkets and even specialty shops dedicated solely to this wonderful treat! However, our ancestors weren’t so lucky; the first ice cream machine was invented in 1846.

Before that, frozen milk or cream desserts were enjoyed as far back as 54 A.D. when Emperor Nero reportedly served cream frozen in snow. Even Alexander the Great was known to enjoy snow and ice flavored with honey and nectar. During the 17th century, Marco Polo returned from the Far East with a recipe for a fruity dessert that resembled what we now call sherbet. However, this “creamed ice” was only enjoyed by the very wealthy as ice itself was difficult to obtain and to store.

Ice cream wasn’t made available to the general population until 1660! When the Europeans began moving to what was soon to be America, they brought along a recipe for this dessert. The earliest known advertisement for ice cream appeared in the New York Gazette on May 12, 1777. Later on, Manufacturing ice cream became a booming industry in America, pioneered in 1851 by a Baltimore milk dealer named Jacob Fussell.

Ice cream became an edible morale symbol during World War II. Each branch of the military tried to outdo the others in serving ice cream to its troops. In 1945, the first "floating ice cream parlor" was built for sailors in the western Pacific. When the war ended, and dairy product rationing was lifted, America celebrated its victory with ice cream. Americans consumed over 20 quarts of ice cream per person in 1946.

How It’s Made

When commercially produced, ice cream is a mixture of cream and/or milk, sugar and sometimes eggs. Most of the time, some sort of plant gum is also added as a stabilizer to improve the texture. Then the cream mixture is pasteurized - heated up for a certain amount of time time to destroy any potential harmful microorganisms. Through the process of homogenization, solid fat globules are incorporated into the liquids in milk to keep them blended.

Once the flavoring is added (vanilla extract, chocolate, or even pieces of candy), the mixture goes through a special kind of machinery to churn it, using paddles to combine air to keep the ice crystals small and freeze it at the perfect rate to create a smooth, creamy-textured ice cream.

Make Ice Cream by Hand

Ice cream is very simple to make, even if you don’t have a machine! You’ll just have to use your hands to agitate the mixture instead. Here’s what you’ll need:

One small plastic bag
One large plastic bag (have extra ready!)
1 cup of half & half
½ cup of salt
2 tablespoons of sugar
½ teaspoon of vanilla extract
Lots of ice!
Towel, optional

Step One: Combine the half and half, sugar and vanilla extract in the smaller bag. Seal it tightly, so that none of the liquid will leak out. This is your cream mixture.

Step Two: Fill the larger bag halfway with ice cubes. Sprinkle your salt over the ice cubes. You may be wondering why we put salt on the ice if we’re not eating it - and it’s for the same reason we put salt on the icy roads in the winter! Adding salt lowers the freezing point of the water, allowing the temperature of the mixture around the ice cream to get colder. Since the ice cream isn’t just water, it needs to be a little below 32°F to freeze.

Step Three: Insert the small bag filled with ingredients into the bag of ice and salt. Seal the large plastic bag. If this bag begins to leak, don't hesitate to double bag it to reduce the mess. Then, shake the bag for 5-10 minutes until the ice cream mixture begins to harden. If it’s too cold for your hands, wrap the bags in a towel and keep shaking! Feel the small bag to determine the consistency of your ice cream. Once satisfied with the consistency, remove the small bag from the bag of ice.

You can now enjoy your homemade ice cream! Scoop it up into a bowl and use your favorite toppings for a tasty treat you made yourself - or, you could eat it right out of the bag!

References:

Library of Congress - Newspaper archives

http://www.idfa.org/news-views/media-kits/ice-cream/the-history-of-ice-cream

Image Credits:

“Spumoni Ice Cream”. Released into the public domain. Uploaded on 7/18/17 from commons.wikimedia.org

Ong, Maliz. “Two Scoops of Ice Cream”. Released into the public domain. Uploaded on 7/18/17 from publicdomainpictures.net

Guevera, Cristie. “Ice Cream Case”. Released into the public domain. Uploaded on 7/18/17 from publicdomainpictures.net

Guevera, Cristie. “Bowl of Ice Cream”. Released into the public domain. Uploaded on 7/18/17 from publicdomainpictures.net

0 Comments

Midwestern and Backyard Birds

7/15/2017

0 Comments

In the Midwest of the United States of America, many people go to the lakes on summer weekends for a break from everyday life and to relax on the water. If you happen to find yourself on a lake this year, take a moment to look around and study the unique ecosystem you’ve entered. Many species of birds call the Midwest lakes their home; some of the favorites for birdwatchers include loons and bald eagles. These birds feast on the fish they catch, much like we humans do when we go fishing. Let's take a closer look at these unique birds.

Common Loons

Common Loons are famous for their eerie, beautiful calls you can often hear at night on the lake. They have four distinct calls that each have a different meaning! The tremolo is a wavering call given when a loon is alarmed, or to announce its presence at a lake. Male loons also have their own signature yodel, or territorial call. This call is typically loud and high-pitched. If a male moves to a different territory, he’ll change his yodel too! The wail is the long, haunting call that loons give back and forth to figure out each other’s location. Hoots are soft, short calls given to keep in contact with each other. Parents might hoot to a chick, or one mate might hoot to another. You can listen to samples of these calls here!

The common loon is easily identifiable with its regally patterned black and white coat of feathers in the summer. In the winter, they are plain grey with a white breast (this is also what the chicks look like until they become adults). Common loons are powerful, agile divers that catch small fish in fast underwater chases. They are less suited to land, and typically come ashore only to nest. Unlike most birds, loons have solid bones that make them less buoyant and better at diving. They can quickly blow air out of their lungs and flatten their feathers to expel air within their plumage, so they can dive quickly and swim fast underwater.

Common loons mate for life, unless one partner does not return in the spring. Male and female loons build their nests together over the course of a week in May or early June, making a mound out of dead plant materials that grow along the lake’s edge. The mother will then lay a clutch of one to two eggs and incubate them for about a month. Once the chicks have hatched, they are able to swim or ride on their mother’s back within a few hours. Most of the time, a pair of loons will reuse the same site the following year, refurbishing their old nest instead of building a new one.

Bald Eagle

In the United States of America, the bald eagle has been the national emblem since 1782. And for the native people of North America, it’s been a spiritual symbol for far longer! These large birds aren’t really bald, but their white-feathered heads gleam in contrast to their brown body and wings. You can find them soaring in solitude, chasing other birds for their food, or gathering by the hundreds in winter. Bald eagles were once endangered by hunting and pesticides, but recently have flourished under protection.

While the bald eagle is incredibly large and powerful, its calls are surprisingly weak-sounding! These are usually a series of high-pitched whistling or piping notes. Female eagles also have their own signature call - a single soft note that alerts nearby males that she is ready to mate. In one of several amazing courtship displays, a male and female fly high into the sky, lock talons, and cartwheel downward together, breaking off at the last instant to avoid crashing to the earth. Bald eagles build some of the largest of all bird nests - typically 5 to 6 feet in diameter and 2 to 4 feet tall, and ranging in shape depending on the supporting tree! These nests can take up to three months to build, and are used by the same mated pair year after year.

Fish make up the majority of the bald eagle’s diet, but they will also eat smaller birds, reptiles, amphibians, invertebrates, and small mammals including rabbits and muskrats. Even though they’re considered birds of prey, bald eagles rarely hunt for fish themselves. They will often bully osprey into giving up their food, and will push others out of the way to get to a carcass. This is why Benjamin Franklin didn’t want the bald eagle to be the nation’s mascot - he thought they were cheaters and dishonest!

You probably won’t find any loons or eagles relaxing in your backyard, but there are tons of unique birds and other wildlife that visit every so often. Try making a wildlife journal to catalogue what you see and write down how many times it’s stopped by!

Make a Bird Feeder

Common backyard birds will eat seeds on the ground or from flowers, but it’s much easier for them to eat from a bird feeder. Instead of going out and buying an expensive device, a recycled bottle will work just as well! To make your own bird feeder at home, you’ll need a plastic bottle and a couple of smaller wooden spoons.

Using a scissors or other sharp tool, poke four holes in the bottle, starting about halfway down. Each pair of holes should be right across from the other. You can then stick the handles of the wooden spoons through the plastic. Try to angle the spoon downwards so some of the bird seed spills onto it for the birds to eat. Once everything is in place, fill the bottle with your choice of bird seed and place it wherever you’d like to see some feathery friends!

References:

http://www.nationalgeographic.com/animals/birds/b/bald-eagle/

Image Credits:

PL Field. “Loon in the Water”. Released into the public domain. Uploaded on 7/7/17 from publicdomainpictures.net

Markham, Pete. “Baby Loons”. Released into the public domain. Uploaded on 7/7/17 from commons.wikimedia.org

Audubon, John James. “White-Headed Eagle”. Released into the public domain. Uploaded on 7/7/17 from commons.wikimedia.org

0 Comments

Why Do We Sweat?

7/7/2017

0 Comments

Last week, we discussed how thermal conduction heats things up. When objects get hot, there’s no real cooling system to bring their surface temperature back down, other than exposure to cooler air over time. But for animals and humans, there are a lot of steps involved. Many people view sweat as a nuisance: it can leave stains on our clothes and it often smells anything other than pleasant. However, sweating is a crucial biological function, and if we didn’t sweat, things could get very ugly very quickly. If the body didn’t have a way to cool itself off, we could constantly be suffering from heat exhaustion and even heat stroke.

How is Sweat Produced?

We have two types of sweat glands: eccrine and apocrine. The body has thousands of eccrine glands all over the place, which effectively regulate the body's temperature. As our temperature rises, the nervous system goes to work to stimulate the eccrine glands to release sweat. In a way, we are almost always sweating, even if we don’t notice it! Apocrine glands are found under the arms and groin areas. Although the body's temperature can stimulate these glands, they are also triggered by stress, anxiety, or hormonal imbalances. The apocrine glands also produce bacteria that help break down the sweat, which causes body odor. That's why we just put deodorant under the arms rather than all over the body!

Basically, the sweat gland is a long, coiled, hollow tube of cells. The coiled part in the dermis is where sweat is produced, and the long portion is a duct that connects the gland to the opening or pore on the skin’s outer surface. Nerve cells from the sympathetic nervous system connect to the sweat glands.

When a sweat gland is stimulated, the cells secrete a fluid, or primary secretion, that is similar to plasma, as it is mostly water and has high concentrations of sodium and chloride. The source of this fluid is the spaces between the cells, which get the fluid from the blood vessels in the dermis. This fluid travels from a coiled portion up through a straight duct. In apocrine glands, sweat is produced in the same way. However, the sweat from apocrine glands also contains proteins and fatty acids, which make it thicker and give it a milky or yellowish color. This is why underarm stains in clothing appear yellowish!

Why Sweating is Good For You

When sweat evaporates from the surface of your skin, it removes excess heat and cools you. This is due to a neat principle in physics, called the heat of vaporization. However, not all of the sweat evaporates, rather it runs off your skin. In addition, not all heat energy produced by the body is lost through sweat. Some is directly radiated from the skin to the air or absorbed through respiratory surfaces.

Sweating is also one of your body’s ways of getting rid of toxins. When we sweat, trace amounts of toxins are released onto the surface of your skin, instead of festering around in your body. The main toxin released in sweat is phthalates, which are found in plastics, fragrances, cosmetics, and paints. However, lots of salts and other necessary minerals are also lost in sweat. When the water in the sweat evaporates, it leaves the salts behind on your skin, which is why your skin tastes salty. The loss of excessive amounts of salt and water from your body can quickly dehydrate you, which can lead to circulatory problems, kidney failure and heat stroke. So, it is important to drink plenty of fluids when you exercise or are outside in high temperatures. Sports drinks contain some salts to replace those lost in the sweat, and sometimes are more tasty than water!

Simulation with a Paper Cup

We can simulate the rising temperature in an animal’s body with some boiling water in a paper cup. While the hot water evaporates, the cup cools down, allowing it to stay intact and not break down under the heat. Try it out at home! Here’s what you’ll need:

Several plain paper cups (without wax coating)
Several styrofoam cups
Water
Stove burner
Dry sand
Tongs to hold the cups

Step One: Turn the burner on medium heat.
Step Two: Fill a paper cup nearly to the brim with water.
Step Three: Using tongs, hold the cup of water about six inches above the heating element.

Step Four: Continue holding the cup over the heat. The paper or burn, or the water will boil.

Step Six: repeat the last three steps with some sand in a paper cup and then water in a styrofoam cup. What differences can you observe?

References:

http://health.howstuffworks.com/skin-care/information/anatomy/how-sweat-works3.htm
https://www.education.com/science-fair/article/boiling-water-paper-cup/

Image Credits:

Keil, Ernst. “The Garden Arbor”. Released into the public domain. Uploaded on 6/30/17 from commons.wikimedia.org

“Sweating at Wilson Trail Stage One”. Released into the public domain. Uploaded on 6/30/17 from commons.wikimedia.org

“Close Up of Drink”. Released into the public domain. Uploaded on 6/30/17 from pexels.com

Michuda, Dave. “Red Ceramic Mug”. Released into the public domain. Uploaded on 6/30/17 from pexels.com

0 Comments

Cool Down With Ice Cream!

Midwestern and Backyard Birds

Why Do We Sweat?

Archives

Tell us what interests you most, and we'll send you a free PDF of a lesson in that subject!

Categories