The Engineering Feats of Alexandre-Gustave Eiffel

 

Each month, I like to share a post celebrating the accomplishments of a scientist whose discoveries and advancements have made a significant difference in our lives. To honor the work of these amazing people, I provide a little peak into their life and share an unschool-style learning guides or unit study to guide you and your children on a path of discovery.

This month, I chose to honor the Alexandre-Gustave Eiffel who is most recognized for creating the Eiffel Tower.

Science Milestones: The Engineering Feats of Alexandre-Gustave Eiffel @EvaVarga.netAlexandre-Gustave Eiffel

When the Statue of Liberty’s initial internal designer, Eugene Viollet-le-Duc, unexpectedly passed away in 1879, the Franco American Union and Auguste Bartholdi (the French sculptor who designed Lady Liberty) hired Alexandre-Gustave Eiffel as his replacement.

While Eiffel praised and retained Viollet-le-Duc’s plans for the sculpting and connection of the copper sheets (he would use Viollet-le-Duc’s repoussé technique and armature bars), he ultimately changed the initial plans for the interior design in favor of a modern approach. The Statue’s new internal structure would not rely on weight to support the copper skin but rather a flexible, skeletal system.

Eiffel designed a tall, central pylon (92 feet, or 28 meters) to be the primary support structure of the Statue’s interior. The pylon serves as the central attachment point for a lightweight truss work of complex asymmetrical girders which forms the Statue’s body. To connect the Statue’s copper skin to the pylon, flat metal bars are bolted at one end to the pylon and to the copper skin at the other end.

While the bars hold the Statue together, they also create flexible suspension (due to their malleability), acting like springs allowing the Statue to adjust and settle into the environment. This elasticity of Eiffel’s design is important because the Statue has to withstand winds from New York Harbor, temperature changes, and various other weather conditions.

Once his plans were approved, Eiffel supervised the Statue’s internal construction until its completion in late 1883. A few years later, Eiffel began his most famous project: the Eiffel Tower, which was completed for the Universal Exposition of 1889 (Exposition Universelle de 1889) in Paris. Eiffel died on December 27, 1923 in Paris, France.

Biography

A prominent French architect and structural engineer, Alexandre-Gustave Eiffel was born on December 15, 1832 in Dijon, France. Interested in construction at an early age, he attended the École Polytechnique and later the École Centrale des Arts et Manufactures (College of Art and Manufacturing) in Paris, graduating in 1855. Setting out on his career, Eiffel specialized in metal construction, most notably bridges. He worked on several over the next fewdecades, letting mathematics find ways to build lighter, stronger structures.

Science Milestones: EiffelIn his early work designing railway bridges, Eiffel relied on sophisticated mathematical designs renowned for their lightness, grace, and strength.

Eiffel is most famous for what would become known as the Eiffel Tower, which was begun in 1887 for the 1889 Universal Exposition in Paris. The tower is composed of 12,000 different components and 2,500,000 rivets, all designed and assembled to handle wind pressure.

The structure is a marvel in material economy, which Eiffel perfected in his years of building bridges—if it were melted down, the tower’s metal would only fill up its base about two and a half inches deep.

In his final years, Eiffel turned his interest to meteorology. He continued to study the subject at length until his death on December 27, 1923.

Bring it Home

There are a variety of ways in which you can expand upon your study of Eiffel. Consider some of the following suggestions to get you started.

?Learn more about his earlier engineering projects, including the Eiffel Tower in Paris.

?Explore the science behind the Statue of Liberty, Visiting the Statue of Liberty & Chemical Reactions.

Science Milestones

Visit my Science Milestones page to learn more about scientists whose discoveries and advancements have made a significant difference in our lives or who have advanced our understanding of the world around us.

Interested in learning about others who were born in the month of January? Hop over to Birthday Lessons in December to read posts by other iHomeschool Network bloggers.

 

Meet the Women in Science with a New Card Game

As a naturalist, the history of science has always fascinated me. I recall fondly reading about the impact Linnaeus had on scientific classification in my college biology classes. I was spellbound as I discovered how Rachel Carson sparked the environmental movement with the publication of her book, The Silent Killer. Many homeschoolers are familiar with naturalist and educator, Anna Botsford Comstock, author of The Handbook of Nature Study.

women in science

I received this game in exchange for an honest review; please see my disclosure policy for details.

History of Science

For the past couple of years, I have been writing a series of Science Milestones posts to celebrate the scientists whose discoveries and advancements have made a significant difference in our lives. I have enjoyed sharing short biographies of the people who have advanced our understanding of the world around us.

In addition to the short biographical sketch, I share a list of lesson ideas and activities teachers and students can use to further explore the science these remarkable scientists have made.  I have come to realize, however, that though female scientists do exist, they have rarely received the recognition they deserve.

Women in Science card game

I recently discovered a innovative card game designed specifically for young people to learn about Women in Science. The fundamental idea of the game is to familiarize players with women who have left their mark on science. Often, these women in science did not receive the recognition they were due.

Women in Space

Photo courtesy of Luanagames.com / Francis Collie

As stated by the game creators, Anouk Charles & Benoit Fries,

It’s hardly surprising that few girls display an interest in physics or mathematics when they never hear about women who made extraordinary discoveries in these spheres.

The game is composed of 54 beautiful cards in a full color tuck-box. What I love best about these cards is the versatility. You can play the original, strategic game based on the card colors, collect the cards much like baseball or hockey cards, or play any standard card game requiring 52-cards using the logo in the top left corner of each card. Not only that, but you can also play an online version of the game.

Women in Space

Photo courtesy of Luanagames.com / Francis Collie

The original Women in Science 54-card set retails for $12 and the new Women in Space expansion set retails for $8. The cards are available in both English and French. A free printable PDF is available in Spanish. What is not to love?

Carl & Gerty Cori Change the Face of Medicine

In brilliant collaboration, Carl and Gerty Cori studied how the body metabolizes glucose and advanced the understanding of how the body produces and stores energy. Their findings were particularly useful in the development of treatments for diabetes. They were awarded the Noble Prize for their discovery of how glycogen (animal starch) – a derivative of glucose – is broken down and resynthesized in the body, for use as a store and source of energy.

cori cycleThe pair were interested in how the body utilizes energy. The couple spent more than three decades exploring how the human body metabolizes glucose. It was known in the 1920s that faulty sugar metabolism could lead to diabetes, and it was also known that insulin kept the disease in check.

The effect of insulin on blood sugar levels had been observed, but scientists did not understand the biochemical mechanism behind insulin’s effect or how carbohydrates were metabolized. In 1929, the couple described what is now known as the Cori cycle; an important part of metabolism. To put it simply, lactic acid forms when we use our muscles, which is then converted into glycogen in the liver. Glycogen, in turn, is converted into glucose, which is absorbed by muscle cells.

The Cori Cycle

cori cycleThe Cori Cycle refers to the metabolic pathway in which lactate produced by anaerobic glycolysis in the muscles moves via the blood stream to the liver where it it is converted to blood glucose and glycogen. High intensity exercise will mostly get it’s energy or ATP from the pathway of the glycolitic system.  Less intense activity will receive its energy or ATP from the aerobic pathway utilizing the Krebs cycle.

When utilizing the glycolitic system, cycle after cycle, lactate will start to build up.  Lactate from the glycolitic system will diffuse from the muscles into the bloodstream.  It will then be transported into the liver.  In the liver it is converted from lactate back to pyruvate back to glucose, which is then available to the muscles again for energy, this is called gluconeogenesis.  The whole process is called the Cori Cycle.

The more you train with high intensity exercise, the more capable the enzymes and transporters become that are needed for the Cori Cycle.  Your liver gets better at using the lactate, not more efficient (it still needs the same amount of ATP to run the Cori Cycle) but it will do the cycle faster.

Gerty Cori Biography

carl & gerty cori Gerty Radnitz was born in Prague in what was then Austria-Hungary. She received her PhD in medicine from the German University of Prague’s Medical School in 1920. It was here that she met fellow classmate, Carl Ferdinand Cori, whom she married later that same year.

The couple moved to Buffalo, New York in 1922 and began researching metabolic mechanisms. As a woman, Gerty Cori was employed on much less favorable terms than her husband and encountered other forms of gender discrimination throughout her career.

The couple moved to Washington University in St. Louis in 1931 after both were offered positions there. When the Coris were hired at Washington University, she received one-tenth Carl’s salary, even though they were equal partners in the laboratory.

Gerty and her husband continued to investigate how glycogen is broken down into glucose and in 1939 were able to both identify the enzyme that initiates the decomposition and also to use the process to create glycogen in a test tube.

She became full professor in 1947, the same year that she and Carl were awarded the Nobel Prize “for their discovery of the course of the catalytic conversion of glycogen.” She was the first American woman to win the Nobel Prize in Science.

Around this time Gerty was diagnosed with myelosclerosis, a disease of the bone marrow. She died in 1957 at the age of 61.

Bring it Home

Try this hands-on lab from Amy Brown Science to discover The Use of Glucose in Cellular Respiration

Enjoy the Carl and Gerty Cori and Carbohydrate Metabolism commemorative booklet produced by the National Historic Chemical Landmarks program of the American Chemical Society in 2004.

Read about the dip-and-read test strips developed by Helen Free and her husband, Al. Originally designed to test for glucose in urine, the test strips were such an advance that researchers have since combined 10 urine tests to check for ailments like liver failure, urinary tract infections, and others—onto one plastic stick.

Learn more about our digestive system with these hands-on enzyme labs.

Investigate What Types of Food Contain Starch and Protein?

Building Macromolecule is a paper-scissors-tape activity used to help students envision the process of synthesis, building macromolecules out of smaller subunits.

Science Milestones

Visit my Science Milestones page to learn more about scientists whose discoveries and advancements have made a significant difference in our lives or who have advanced our understanding of the world around us.

Interested in learning about others who were born in the month of August? Hop over to Birthday Lessons in August to read posts by other iHomeschool Network bloggers.

 

Rosalind Franklin: The Unsung Hero of DNA Structure

Rosalind Franklin, a scientist whose role in the discovery of DNA structure in 1953 has been forgotten by many, has a chance to be immortalized in a feature film. Throughout her career she faced sexism at nearly every turn. She also happened to be Jewish, which heightened the prejudice against her. Her name may soon be on the tips of everyone’s tongue and her role in the discovery of DNA Structure known to all. Entertainment One has acquired the script to Exposure, her life story.

In 1962 James Watson, Francis Crick, and Maurice Wilkins jointly received the Nobel Prize in physiology or medicine for their 1953 determination of the structure of deoxyribonucleic acid (DNA). Rosalind Franklin (1920–1958), a colleague of Wilkins, died of cancer at the age of 37, and was thereby not equally honored because the Nobel Prize can only be shared by three scientists. It was her work in X-ray crystallography, however, that proved critical to the correct solution to DNA structure.

Unsung Hero of DNA Structure @EvaVarga.netWhat is DNA?  

DNA is the material embedded in the cells of all living organisms that carries the genetic coding that determines how a living thing will look and function. It is found in the nucleus of each cell and is unique to every individual – whether human, mountain lion, or butterfly. Its full name is deoxyribonucleic acid, which can be complicated to say, so we usually refer to it as DNA for short.

DNA is so tiny that it can not be seen unless we use a very powerful microscope. If we could see it we would see that it looks like a twisted ladder, which scientist refer to as the double helix. Each rung or step on the DNA ladder is composed of two letters.

There are only 4 letters — A,T,G, and C — and each has a unique puzzle-like shape. This means that A and T fit together to form a rung on the ladder and G and C fit together to form another rung on the ladder.

As we read the DNA ladder, the letters combine to form 3-letter words called codons. Then, these codons combine to form sentences that we call genes. These genes are the basis for your chromosomes, which give your body a blueprint or set of instructions for life.

Every human has 23 pairs of these DNA chromosomes that determine what we look like and how to perform. We get one set of chromosomes from our mother and one set from our father. Our chromosomes determine whether our eyes will be blue or brown, what color our skin and hair will be, whether we will be a boy or girl and so much more.

The Structure of DNA @EvaVarga.net

Building a Cardboard Safari DNA Double Helix Puzzle

Discovering DNA Structure

Inspired by Linus Pauling’s success in working with molecular models, James Watson and Francis Crick rapidly put together several models of DNA and attempted to incorporate all the evidence they could gather. Franklin’s excellent X-ray photographs, to which they had gained access without her permission, were critical to the correct solution. Along with Wilkins, Franklin’s partner, the four scientists announced the structure of DNA in articles that appeared together in the same issue of Nature.

After the publication, they moved on to different projects. Franklin went to Birkbeck College, London. Before her untimely death from cancer, she made important contributions to the X-ray crystallographic analysis of the structure of the tobacco mosaic virus, a landmark in the field. By the end of her life, she had become friends with Francis Crick and his wife and had moved her laboratory to Cambridge, where she undertook work on the poliovirus.

Biography

Rosalind Franklin @EvaVarga.netRosalind Franklin was born July 25, 1920 to a Jewish family in London, England. Educated at private schools in London, she studied natural sciences at Newnham College, Cambridge, from where she graduated in 1941. She joined the University of Cambridge where she earned a research fellowship in a physical chemistry laboratory under Ronald George Wreyford Norrish. The British Coal Utilisation Research Association offered her a research position in 1942, and started her work on coals. This helped her earn a PhD in 1945.

In 1947, she went to Paris as a chercheur (post-doctoral researcher) under Jacques Mering at the Laboratoire Central des Services Chimiques de l’Etat, where she became an accomplished X-ray crystallographer. She returned to London in 1951 and became a research associate at King’s College. She was compelled to move to Birkbeck College after two years, however, owing to disagreeable clashes with her director and more so with her colleague Maurice Wilkins. At Birkbeck, J. D. Bernal, chair of the physics department, offered her a separate research team. She died on April 16, 1958 at the age of 37 of ovarian cancer.

Bring it Home

Build a model of the DNA Double Helix with the Cardboard Safari Puzzle

Create a model of DNA with colorful Wiki-Sticks

Extract DNA from Strawberries in this great lab from Marci at the Homeschool Scientist

Explore the DNA Teaching Resources from Karyn at Teach Beside Me

Challenge your students with this Transcription / Translation Lab Activity 

Download the DNA & RNA Protein Synthesis Interactive Notebook Resources from Science with Amy

Make these cool DNA Sequence Bracelets

Watch this fabulous NOVA documentary on PBS, The Secret of Photo 51

Science Milestones

You may also be interested in learning about other inventors and scientists who have made an impact in our lives.

The bloggers of the iHomeschool Network have teamed up to create fun and original unit studies on fascinating people who were born in July.

Earthworms & Tortoises: The Science Milestones of Charles Darwin

Although best known for his work on evolution, Charles Darwin was also a leading figure in establishing soil biology as a separate discipline. In 1837, Darwin presented a paper explaining how earthworms form soil. He would produce four additional papers on the same topic.The Science Milestones of Charles Darwin @EvaVarga.net

“It may be doubted whether there are any other animals which have played so important a part in the history of the world as these [earthworms] lowly organized creatures.”  ~ Charles Darwin

In his works, Darwin demonstrated the importance of earthworms in affecting the rate of weathering of mineral materials in the soil, humus formation, and differentiation of the soil profile, accomplishments that make Darwin the first author of a scientific publication on the biological functions of soil. He was the first to recognize the importance of animals in soil production.

Earthworms were not the only organism that fascinated young Darwin. He studied marine invertebrates (specifically barnacles) and avidly collected beetles as an undergraduate. Although never a model student, he was a passionate naturalist.The Science Milestones of Charles Darwin @EvaVarga.net

A lot of controversy surrounds Darwin’s work, yet he was a deist. He believed that a creator had designed the universe and set up natural laws according to which all of nature was governed. To discover the laws by which nature operated was the pursuit of a man of science.

Biography

darwinCharles Robert Darwin was born in Shrewsbury, Shropshire, on the 12th of February 12, 1809. He was the fifth of six children of wealthy and well-connected parents. The young Charles had a quietly Christian upbringing, but his family life was one of openness to new ideas.

Following in the footsteps of his father and grandfather, he entered Edinburgh University in 1825 to study medicine. However, he found the brutal techniques of surgery too stomach-churning to handle. Fortunate for Darwin, Edinburgh was one of the best places in Britain to study science. It attracted free thinkers with radical opinions that would not have been tolerated in Oxford and Cambridge.

“I saw two rare beetles and seized one in each hand; then I saw a third… I popped the one which I held in my right hand into my mouth.” ~Charles Darwin

Abandoning plans to be a doctor, at one time he considered a career and studied Divinity at Cambridge. Here, he had plenty of time to pursue his real passion, biology, and spent much of his time collecting beetles. He graduated in 1831 but before he could take a job as a cleric, his tutor recommended him as a ‘gentleman naturalist’ on a voyage around the world on HMS Beagle.

Aboard the Beagle, Darwin visited four continents over the following five years. He spent much of his time on land collecting specimens and investigating the local geology, including a five-week stop at the Galapagos Islands.

He married his cousin Emma Wedgwood in 1839. Darwin’s many books and articles forged a great reputation as a geologist, zoologist and scientific traveller. His eight years grueling work on barnacles, published 1851-4 enhanced his reputation as an authority on taxonomy as well as geology and the distribution of flora and fauna.

Charles’ contribution to the theory of evolution was specifically the natural selection bit, that organisms vary, and these variations can better suit individuals to their environment, thus boosting their chances of passing down these traits to future generations.

Alfred Russel Wallace, a friend and naturalist, had arrived at the same idea independently at around the same time. They’d even presented their preliminary findings to the Linnean Society of London, before Darwin published his On the Origin of Species.The Science Milestones of Charles Darwin @EvaVarga.net

Bring it Home

Ken Miller’s lecture, Evolution: Fossils, Genes, and Mousetraps has two segments that may help reduce some students’ anxiety when it comes to learning about evolution. In chapters 14 and 27 of the lecture, Miller explains how he reconciles his religious faith with evolution. It shows students that science and religion need not be in conflict, gives students a ‘place to stand’ if they are experiencing conflict, and it communicates respect for students’ beliefs.

Readings

Teaching about Darwin can be a controversial subject. I took great care to select books that depict Darwin’s life and describe his theory in a factual manner as opposed to books trying to persuade the reader. I believe the following books will help students understand the subject while also helping teachers avoid controversial topics.


A kid-friendly introduction to the life
and passions of Charles Darwin
by Deborah Hopkinson
2nd – 5th grades

A biography that highlights his
curiosity and determination to learn
by Alice McGinty
2nd – 5th grades

A biography in graphic novel format
by Rosalyn Schanzer
3rd – 6th grades

A biography with comical illustrations
by Kathryn Lasky
3rd – 6th grades

Features many creatures Darwin
encountered during his voyage
by Sandra Markle
2nd – 5th grades

Darwin’s personal life and its
role on his scientific discoveries
by Deborah Heiligman
8th grade & Up

A biography largely told through
intricate, packed illustrations
by Peter Sis
4th grade & Up

Part adventure story, part biography
detailing Darwin’s school years
to his time on the Beagle
by Carolyn Meyer
6th – 10th grades

His Life and Ideas with 21 Activities
by Kristan Lawson
5th – 9th grades

Science Milestones

Interested in learning more history of science? Check out my other Science Milestones posts.

To read more about those born in the month of February, visit iHomeschool Network’s February Birthdays.

Bacteria & Enzymes of Milk: The Impact of Louis Pasteur

For the past six years or so, we have purchased our dairy products direct from a local farmer.  My kids and I love the taste of raw milk and crave its distinctive flavor. We can even taste the difference between farm fresh eggs from chickens allowed to wander and graze on a variety of foods (including insects and other invertebrates) and eggs from chickens confined to a small cage their entire lives.

Bacteria & Enzymes of Milk: The Impact of Louis Pasteur @EvaVarga.netWe first tried raw milk at the home of a homeschool family in Bend, Oregon. It was deliciously creamy. We soon heard stories of friends who had experienced amazing results — ear infections, asthma, and allergies — all diminished after changing to a diet of Real And Wholesome milk. Thus began our journey towards a more wholesome diet – including raw milk.

Raw milk is milk from cows, sheep, or goats that has not been pasteurized. Pasteurization is a process that kills harmful bacteria by heating milk to a specific temperature for a set period of time. First developed by Louis Pasteur in 1864, pasteurization kills harmful organisms responsible for such diseases as listeriosis, typhoid fever, tuberculosis, diphtheria, and brucellosis.

Controversial, proponents on both sides of the pasteurization debate will cite research and anecdotal evidence to support their side. Did you know, however, that Pasteur initially developed the process for which he is most well known not for milk but for wine? As he was born in December, I thought I would share a little insight into the life and the impact of Louis Pasteur.

Science Milestones: Louis Pasteur @EvaVarga.netBiography

Born on December 27, 1822, in Dole, France, Louis Pasteur was the son of a sergeant major in the Napoleonic wars who grew up in Arbois, a small town in eastern France surrounded by farms and vineyards.

“When I approach a child, he inspires in me two sentiments; tenderness for what he is, and respect for what he may become.” ~ Louis Pasteur

An average student, Pasteur had a passion for drawing and painting. As a boy, he captured his family in a series of lifelike portraits, Pasteur: Dessins et pastels, which showed a keen eye for precision and detail. While his teachers encouraged his artistic side, his father considered painting an indulgence: what counted was solid schoolwork.

Pasteur began a career in chemistry with a post at the University of Strasbourg and quickly made a ground-breaking discovery. He showed that otherwise identical molecules could exist as mirror images (or ‘left’ and ‘right-handed’ versions). He noticed that molecules produced by living things were always left-handed. This discovery was a fundamental step forward in microbiology, underpinning modern drug development and even our understanding of DNA.

Bacteria & Enzymes of Milk: The Impact of Louis Pasteur @EvaVarga.netPasteur also disproved the age-old theory that life appeared spontaneously with a simple experiment. He showed that food decayed because of contamination by microbes in the air. He went on to argue that these could cause disease. Though his ‘germ theory’ was initially controversial (he was not a doctor, after all), it eventually led to the development of antiseptics and changed healthcare forever.

“A bottle of wine contains more philosophy than all the books in the world.” ~ Louis Pasteur

Relatedly, he discovered that microbes were responsible for souring alcohol. In a series of careful experiments, Pasteur discovered that heating wine to 55 degrees killed bacteria without ruining the taste. This process, later named pasteurization, saved the wine industry, and cemented Pasteur’s fame. Today, this process is widely used to keep food free from disease.

“Officially, I recommend the pasteurization of milk. But I still love drinking it straight from the udder.” ~ Louis Pasteur

While Louis Pasteur is most well known for developing the process of pasteurization; his work in germ theory also led him to create vaccinations for rabies, a highly contagious infection which attacks the central nervous system. It enters the body through the bite of an infected animal or through infected saliva entering an existing wound.

After experimenting with the saliva of animals suffering from the disease, Pasteur concluded that the disease rests in the central nervous system of the body. When an extract from the spinal column of an rabid dog was injected into healthy animals symptoms of rabies were produced. By studying the tissues of infected animals – rabbits, Pasteur was able to produce an attenuated form of the virus that could be used for inoculation.

Pasteur became a national hero and was honored in many ways. He died at Saint-Cloud on 28 September 1895 and was given a state funeral at the Cathedral of Notre Dame and his body placed in a permanent crypt at the Pasteur Institute.Bacteria & Enzymes of Milk: The Impact of Louis Pasteur @EvaVarga.net

Bring it Home

➤ In the lab, Milk – How Sweet Is It?, students test different samples to see which ones contain the lactase enzyme.

➤ The enzyme lactase is produced in the small intestines of infants where it breaks down the sugar lactose found in milk. Zoom in to the molecular level to see how the enzyme works in this striking animation, Lactose Digestion in Infants.

➤ Learn how a single genetic mutation that first enabled ancient Europeans to drink milk, The Milk Revolution.

➤ Check out the The Science of Milk TED-Ed lesson by Jonathan O’Sullivan

➤ After watching the short film Got Lactase?, students may explore how the enzyme lactase hydrolyzes lactose into monosaccharides, and practice graphing and analyzing data. The accompanying worksheet requires them to provide reasoning for their answers. If you have time to explore the extension portion of the activity, you can tie in anaerobic respiration and why lactase non-persistence causes pain and discomfort. (Recommend for high school level)

Science Milestones