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Extreme Parachutes in West Fargo, ND!

8/19/2017

By Dr. E

Today marks the end of a hallmark week for Discovery Express. This week we embarked on the most advanced and most challenging STEM program we’ve ever had—to combine science, math, and engineering to build mid-scale parachutes, and drop them from an airplane!

Seven advanced fifth and sixth grade students from Abercrombie and West Fargo, ND participated in our Extreme Parachutes Summer Program. They were challenged to learn the science and mathematics of skydiving and parachute building. They collected strength data on a variety of fabrics available from local outlets, tested different methods of construction, and used advanced calculations to define the hemispherical shape of the parachute. They had to learn aspects of algebra, geometry, and trigonometry that they will likely not see again until at least their freshman year of high school! Following this, they had to measure, cut, and assemble their materials into a parachute durable enough to withstand a drop from an airplane at 500 feet above ground (though no students were allowed in the airplane).

To make this program happen, we collaborated with the skydivers and pilots from Skydive Fargo in West Fargo, ND. Through their expertise we were able not only to conduct realistic tests on our parachutes, but also to ensure those tests were done safely.

And I got to cross one of the items off my bucket list and do a tandem skydive myself! It’s an incredible experience—everyone should try it at least once! If you’re over the age of 18 and you live in the Fargo-Moorhead area, I definitely recommend you give Skydive Fargo a call! Visit their website here http://skydivefargo.com/.

All of our students worked hard and achieved great things during this workshop (everyone’s parachute successfully deployed, held together, and slowed down the ten pound load they were attached to). We at Discovery Express wish to extend our congratulations to each one for the great work they did. We also wish to offer special thanks to Skydive Fargo for their help and support. This workshop would not have been possible without the hard work and cooperation of everyone involved.

To read more about the Extreme Parachutes program, or to watch the news segment, visit The Forum and WDAY.

If you are interested in having the Extreme Parachutes program at your school, contact us by clicking here!
(Program only available May through September)

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How Glass is Made

8/15/2017

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Today, it would be virtually impossible to live without glass - a material that’s used in many items we use every day. From a jar of lemonade, the mirror in which we brush our teeth, windows and windshields, to computer or smartphone screens; glass is around us everywhere we go. But how did we discover and start to produce glass, and what is it made of?

What is glass?

Glass is a combination of sand and other minerals that are melted together at very high temperatures to form a material that is ideal for a wide range of uses. A form of glass occurs naturally within the mouth of a volcano when the intense heat of an eruption melts sand to form obsidian, a hard black, glassy type of stone. This was first used by humans as tips for spears. Today we have mastered the glass making process and can produce many different types of glass in an infinite number of colors formed into a wide range of products. We can even use glass in packaging and construction!

Chemically, glass is actually more like a liquid, but at room temperature it is so viscous (thick or sticky) it looks and feels like a solid. At higher temperatures glass gradually becomes softer and more like a liquid. Exposing the materials to such high temperatures allows glass to be poured, blown, pressed and moulded into a variety of shapes!

History of Glass

History of Glass

Humans have been using natural glass (obsidian) for almost as long as we’ve been alive on this planet. Archaeologists discovered evidence of the first man-made glass from 4000 B.C. That’s over six thousand years ago! However, this glass wasn’t colorless as most glass is today; the impurities in the raw minerals used to make glass made the finished product was saturated with color. We didn’t discover how to remove the impurities until the First Century A.D.In the 1670’s, George Ravenscroft learned that by adding lead to the raw materials used in the glass-making process, he could eliminate the cloudiness that prevented glass from being completely transparent.

The new glass he created was softer and easier to decorate, adding to its brilliance and beauty. It also proved invaluable to the optical industry - thanks to Ravenscroft’s invention, optical lenses (like the ones in glasses that help people see better), telescopes, and microscopes became possible.

By the late 1800’s, glass production had graduated from manual blowing to a semi-automatic process which uses automated machinery to create 200 glass bottles per hour. That’s about three times the amount that could have been produced using the old method! Today, glass making is a modern, hi-tech industry where quality, design and service levels are critical to becoming the best in the business. Modern glass plants are now capable of making millions of glass containers a day in various colors, but green and brown remain the most popular, followed by clear glass.

How is glass made?

There are three main “ingredients” needed to make glass: sand/silica, sodium carbonate, and lime/calcium oxide. The most important component of glass is the sand or silica that melts at an extremely high temperature (2000 degrees Celsius, or 3632 degrees Fahrenheit)! Sodium carbonate was originally added to the mix to lower the melting point of sand and make the process more efficient. Today, we can easily produce sodium carbonate from table salt (sodium chloride). This additive also causes the glass mixture to become soluble in water, so we have to add calcium oxide from limestone to prevent it from dissolving in water. These three ingredients are carefully weighed and mixed together to form a batch. The glass batch is then heated in a furnace to make liquid glass. Next, a machine roller flattens the glass into sheets, which are cooled (or “frozen” into a solid) first and then cut into plates.

Another process used is the floating method. Instead of rolling the glass into sheets, the liquid is floated from the furnace onto the surface of molten tin. The atmosphere is carefully controlled to allow the glass to cool before it’s cut into pieces. To make objects like vases, craftsmen blow into a glob of liquid glass with the help of a long tube.They can then blow the soft glass into shape with their hands, as seen in the image below.

Customize Your Own Glass

When perusing along the aisles of antique stores or gift shops, you may have seen some interesting designs etched into the surface of a mirror, picture frame, or glass cup. This customization is popular because it makes glass unique and personal. If you want to create your own etched glass, you don’t have to get it done professionally or deal with complicated sand blasters! With do-it-yourself kits from your neighborhood craft and hobby store, you can easily transform a piece of glass into your own work of art.

Glass-etching kits are affordable solutions for plain glassware. With the Deluxe Glass Etching Kit from Armour Products*, you can stencil a design on glass in three simple steps:

First, choose a stencil and apply it to your glass by rubbing it with the applicator stick.
Next, smooth on a thick layer of their etching cream and wait for it to do its job.
After about a minute, rinse off the cream and stencil with water to reveal your newly refurbished glass!

*Discovery Express Kids is not sponsored by, or in any way affiliated with Amour Products

Image Credits:

Barroso, Ariadne. “Glass with Water White Background”. Released into the public domain. Uploaded on 8/9/17 from publicdomainpictures.net

Cambon, Pierre. “Gladiator on a Glass Vessel”. Released into the public domain. Uploaded on 8/9/17 from commons.wikimedia.org

Storey, Cymbeline. “Examples of Ravenscroft Glass”. Released into the public domain. Uploaded on 8/9/17 from commons.wikimedia.org

Beaufort, Jean. “Stained Glass”. Released into the public domain. Uploaded on 8/9/17 from publicdomainpictures.net

Tulane Public Relations (2010). “Gene Koss demonstrates glass blowing to Homecoming crowd”. Uploaded on 8/10/17 from Wikimedia Commons and used under the terms of the Creative Commons Attribution 2.0 Generic license.

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Weeds and Why We Don't Like Them

8/8/2017

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If you have a garden, you may have noticed that along with your plants, there are some smaller plants growing where they shouldn’t! These unwanted plants are what we call weeds. According to the Merriam-Webster dictionary, a weed is defined as “any plant that is not valued where it is growing; especially one that tends to overgrow or choke out more desirable plants.” Weeds are known for growing at an exceptionally fast rate, which is why we use the phrase “growing like a weed” to describe something that had a growth spurt!

Why don’t we want weeds in our gardens?

Weeds tend to be unattractive, and they draw attention away from some of the more beautiful flowers in we desire in our gardens. This is the first explanation for why we want to pull the weeds from the ground or spray them with weed-killer. However, the most important reason to get rid of weeds is because they often use up all of the nutrients that the other plants need to survive.

A weed in a garden sometimes seems to pop up out of nowhere, but the reality is that those seeds are often already in the soil you’ve planted your garden in. If the seeds aren’t already in the soil, they’re often dropped by birds or have blown into your plants from another nearby weed. One of the most prevalent type of weed is the Canada thistle (Cirsium arvense).

Many species of finches favor the thistle seed over any other type of wild seed because it’s packed with protein and oils. Sometimes, the birds pick up too many seeds than they can carry, and the seeds that fall often end up growing into the large, spiky weed that takes over many gardens. Another easily identified weed is the dandelion (Taraxacum). These yellow wildflowers like to spread out across large expanses of grass, such as a backyard lawn. After a few days as a flower, the head of the plant closes and allows the seeds to mature. Gradually, the yellow petals are pushed out to make way for the fluffy heads of the seeds that blow away in the wind to populate another area.

Unfortunately, often weeds are much better at absorbing nutrients (such as water and fertilizer), and thus outcompeting the intended plants. If all of the nutrients in the soil are used up by the weeds, there’s not enough left to keep your plants healthy, or even alive at all. To complicate things further, these weeds will grow larger and larger until they completely overshadow your beautiful flowers or vegetables! When rays of sun can no longer reach the plant’s leaves, the poor plant can’t use the sun’s energy to make its own nutrients, causing it to wither away. Eventually, most (if not all) of your plants will die unless the troublesome weeds are taken care of.

How do we get rid of weeds?

In a perfect world, we would be able to pull weeds with little to no effort on our part. But after years and years of constantly being pulled out of the ground, many weeds have evolved to be more hardy and fit for survival.

In the picture above, you can see the roots of a Canadian thistle plant after two years of growth. It would be almost impossible to pull the entire plant out of the ground because most of the roots are intertwined. Other species of plants have adapted to being pulled straight up from the ground by evolving a corkscrew-like root. Having an uneven edge to the root makes it extremely difficult to extract the entire plant, instead of just plucking the leaves off.

It’s important to pull the whole root of the plant out because many of these weeds are creepers, which means they spread by extending their roots. Most of the time, creeping weeds also spread through seed, so it’s especially difficult to entirely get rid of them. In such a case, selective herbicides are the easiest solution, many of which target enzymes within specific plant cells. Enzyme activity in plants normally occurs in a controlled state of equilibrium, but when a herbicide targets an enzyme site it disrupts the sequence of complex chemical reactions. This disruption produces highly toxic compounds in the plant, poisoning and killing the weed.

Can you grow weeds unintentionally?

Here’s an interesting activity to try out at home, and it doesn’t require any special materials to make it work. All you’ll need is a few containers, water, and about a handful of two to four types of soil. If you have a garden, dig up a little bit of soil without getting in the way of any of your growing plants. Place this soil inside a container one might use to plant a small flower in. Repeat the process with soil from a few other locations; the side of a road and a home and garden shop are good places to start!

Once you have your containers of soil, place them in a window or similar area where they can get plenty of sun. Start watering your soil as you would if you’d planted a seed or flower in it. Within a few days or weeks, you might see a plant growing even though you never planted anything! This shows how weeds can grow without having to be planted because their seeds are often already in the soil. You can either discard your soil, or keep taking care of the plant to see what it looks like when it matures! If any of the soil types grew no plants at all, this means the soil has no weed seeds present, and would make a great choice to plant a flower or vegetable garden in the future!

References:

https://www.merriam-webster.com/dictionary/weed

Image Credits:

Schmidt, Andrew. “Weeds With Blooms”. Released into the public domain. Uploaded on 7/28/17 from publicdomainpictures.net

“European Goldfinch”. Released into the public domain. Uploaded on 7/28/17 from commons.wikimedia.org

Hume, Greg. “Dandelion Flower”. Released into the public domain. Uploaded on 7/28/17 from commons.wikimedia.org

Ross, Merrill. “Two Years Underground Growth of Canada Thistle”. Released into the public domain. Uploaded on 7/28/17 from the Department of Botany and Plant Pathology at Purdue University

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Extreme Parachutes in West Fargo, ND!

How Glass is Made

Weeds and Why We Don't Like Them

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