Lab Notebooks Through History

Lab notebooks are essential, but more important than neatness is a careful documentation of observations whether the experiment works or not. Da Vinci's notebook (see yellowed page at right, his notes on mirrors) is a phenomenal work of art, as are Vesalius' notebooks (anatomical dissections below). Many famous scientists of course were extremely messy, doodled, wrote upside down, spilled things on their notebooks, etc. For those of us who are organizationally challenged, we may take heart in pioneering molecular biologist Max Delbruck's "Principle of Limited Sloppiness" that states we should be sloppy enough so that unexpected things can happen, but not so sloppy that we can't find out that it did.

One does need to start somewhere, though, so for a helpful and free online lab notebook, check out Thelabnotebook.com. A screenshot of a sample page is shown at bottom right.













Image references:
Vesalius' notebook
Isaac Newton's notebook
Leonardo Da Vinci's notebook
Curie's notebook

Classical, Modern, and Discovery-Based Science

A classical education has much to contribute to science teaching, particularly with showing students how science discoveries are made - science should not be taught as a disembodied list of facts to be memorized. Understanding science in its historical context, provides a more realistic view of how science can be fallible, how can be advanced by the efforts of individual men and women with their own personal motivations, and how different problems can be discovered and solved with the processes of close observation, testing, analysis, and communication with colleagues.

A great historical example of a classical approach to science is Faraday's Observation of a Candle series of lectures. These can be read here. This series of lectures combined so many elements of good science teaching: closer inspection of every day phenomena, a deeper exploration of facts, a thorough examination of scientific assumptions, and a testing of hypotheses. Currently there is great interest in discovery-based learning, but as it is equally important not to stamp out student-led inquiry and curiosity, it is important not to withold facts and technical information that will allow greater complexity in students' scientific thinking.

Last month, I did some science experiments at home with the kids because both were beginning to study the periodic table (pH for hydrogen). The text they were using didn't provide any historical content for why the red cabbaged could be used as an acid-base indicator, so with a little digging, we all were able to discover how the interest in acids and bases came about, how the color changes were important the textile industry, and how research into some of these color-changing substances is important for today and possibly even more for the future.

At The Origins of Acids and Alkalis, we learned that ancient Egyptians and Greeks identified different substances on the basis of taste. Vinegar was sour (acid). Alkalis came from the Arabic word al-qaliy which stood for a slippery substance left over after burning.

But the interest in acids really took off when French fabric dyers in the 16th century discovered that acids created colors that were much more vibrant (we thought of our Easter egg dyeing with vinegar).

There are many take off points for this study. Some of you may like to explore natural dyes at a site like Pioneer Thinking and Natural Dyes. We also talked about current ideas about possible health benefits of the anthocyanins and examined the structure of anthocyanins. We also tested various substances around the house, and found that most of their predictions about acids and bases were correct. But there was one exception that seemed to stump us. The kids dissolved a praline in some water, and had expected it to be a bit acidic (doesn't candy dissolve your teeth?). With a little bit of research into this unexpected result, they learned that the acid that makes dental cavities is caused by sugar because the sugar makes bacteria sticky to teeth, and it's the acid produced by the bacteria that makes holes. So what kind of science is all this? Classical-Modern-Discovery-Based Science, I think.

Yarn Picture

Our Autumn Leaf Lab

This year we seemed to have just enough good weather conditions to have beautiful fall colors for Washington state (warm days, cool but not freezing nights).

Working our way through the Periodic Table, we came to magnesium, which is to chlorophyll as iron is to hemoglobin.

These are easy experiments, and if you have autumn leaves, it's a perfect time to do them. Pluck a variety of leaves, cut or tear them into cups. Add alcohol (isopropyl, ethanol, or even alcohol-containing hand wash will do in a pinch) and mash them up with a spoon. Cover with foil and let stand for 1 hour. Then cut strips of coffee filters into the solution and watch for colors that migrate up the filters.


We generated hypotheses before starting the experiments. Hypothesis #1: In plants that drop their colored leaves, the change in color is due to a loss of pigment, rather than an increase in pigment (for instance, yellow leaves have lost their green, not gained yellow). Hypothesis #2: Plants with colored leaves that do not drop have an increase in a new pigment rather than pure loss.

I'm not completely sure you can see the results, but it was interesting. For the red and purple bushes, we could see an extra band of blue that wasn't present in the green or yellow leaves. Chlorophyll a is blue-green and chlorophyll b is yellow-green. It seemed as if the red and purple leaves had chlorophyll a.

We also made other observations as through the course of the experiment. We found the yellow leaves were the easiest to dissolve with alcohol (due to early breakdown of their cell walls?) and thought about the various designs of the leaves. The big maples seemed particularly well designed to catch sunlight (large surface area), but perhaps the addition of blue chlorophyll conferred some energy advantage on the smaller red leaved bushes? Also the bushes had more leaves and were much smaller than the big maples.

When we looked back at our hypotheses, it looked like the behavior of the green and yellow leaves supported Hypothesis #1. Although it doesn't show clearly in the picture, we extracted much more chlorophyll from the green leaves than the yellow. Hypothesis #2 was less clear because we used two red / purple-leaved bushes, one that dropped its leaves, and one that didn't. Both seemed to have both yellow-green and blue-green chlorophyll, and we couldn't determine quantity. Not surprising, more sampling would be necessary to determine something like this!

Early Science and the Study of Chlorophyll and Photosynthesis
Science of Fall Color pdf

The History of Chemistry

The earliest history of chemistry is murky because many of the activities of early chemists or alchemists was shrouded in mysticism (fire, black magic) or greed (making gold). Many of the earliest dabblers in chemistry or alchemy acted in secret or were quietly funded by wealthy individuals hoping to grow wealthier.

In the 1500's, Theophrastus Paracelsus was a colorful personality who became interested in rescuing chemistry from the alchemists who were motivated by "pagan natural philosophy", instead finding a Christian alternative use for the chemical sciences. Paracelsus was interested in how chemistry could be used to help free people from disease.

From the Catholic Encyclopedia: "He sought the cause of pathological changes, not in the cardinal humours, blood, phlegm, yellow and black gall (humoral pathology), but in the entities, which he divided into ens astrorum (cosmic influences differing with climate and country), ens veneni (toxic matter originating in the food), the cause of contagious diseases, ens naturale et spirituale (defective physical or mental constitution), and ens deale (an affliction sent by Providence)..."

Modern chemistry took another great leap when Robert Boyle decided to use his scientific expertise "to seek for God's purposes in nature. His Skeptical Chemist was an important work, moving chemistry from the world of alchemy into the realm of science. Boyle believed the orderliness of the universe reflected God's purposeful design. God established the universe according to certain natural laws, so that it worked like a mechanical clock, once the Designer had set it in motion. The scientist's duty was to discover what laws God had established. Boyle himself formulated what became known as "Boyle's Law:" the pressure of a gas is inversely proportional to the
volume it occupies."

For a pretty interactive Periodic Table clickhere.





We're working our way through the experiments in Fizz, Bubble, and Flash. It has plenty of cartoons, silly jokes and poems, and easy-to-perform home experiments.



Wikipedia: History of Chemistry
Chemistry Lab Demo Movies at Purdue (QT)
More Home Chemistry Ideas:
Popular Science
Makezine

Ancient, Modern, and Fantasy Maps: Ptolemy, GPS, and Tolkien

Lots of people love old maps. A 500 BC map, the Soleto Map was recently unearthed in southern Italy.

We have a special fondness for Ptolemy and his geography. His original maps don't exist, but he was rediscovered in the 1300's, and maps were made based on his descriptions in text. The beautiful map below is based on Ptolemy's coordinate system (before Descartes!). Ptolemy's maps would influence navigation for 1500 years, but his inaccuracies about the Earth's circumference (Eratosthenes was closer) were thought to be responsible for Columbus' underestimate of the time it would take to sail around the world.


Maps are often an essential feature of many tales of fantasy and mythology. J.R.R. Tolkien used map throughout his books to make his worlds more vivid and his son Christopher illustrated many maps like the one below.



If you have spatially-gifted kids, they may love to explore the History of Cartography, as well as the high tech combination Google Earth / NASA plus sites like Flash Earth. GPS / GIS technology has excited today's students about Modern Cartography and some may consider cartography as a career.

If you have GPS, a fun summer activity is Geocaching with the kids. Here's another site with ideas for geocaching with your family and the official Global GPS Cache Hunt Site.

References:
Mathematics and Maps pdf
Ptolemy and his Maps at Wikipedia
Ptolemy's Works at the Vatican
Tolkien and Maps Cliff Notes Lord of the Rings

Ancient Warfare: Medieval Siege Weapons

Siege weapons were an essential feature of medieval warfare. At home, catapults can be made with popsicle sticks or a plastic spoon and rubber band. Here's a page of Lego trebuchets and what looks to be a simple Lego catapult. Here's instructions for a K'nex trebuchet. Nova's medieval siege site is here.

If you have Shockwave, you can play the game Destroy the Castle, but you must adjust the stone ball weight, sling length, counterweight, distance from the castle, and wheels in order to use the trebuchet effectively.

The trebuchet must have been a scary weapon. More detail about its operation can be studied at Trebuchet Physics or History of the Trebuchet.



To see a large one in action (tossing pianos or a car), check out this trebuchet video at Youtube.com ...

At home, it might be easier to toss marshmellows or ping pong balls. You can build a paper castle or medieval town by printing up these cool templates. Print up battle-specific paper medieval knights here.

Ancient Mathematics and Science: The Circle and Navigating by the Stars

"Oak and triple bronze must have girded the breast of him
who first committed his frail bark to the angry sea."
--Horace, Odes

In this ancient Babylonian map, the world is a circle with Babylon at its center. Ancient Babylonians were the first to divide the circle into 360 degrees (how we also got our 60 min / 60 sec clocks), and they may have been among the first to use the wheel.

As it turns out circular divisions were an important tool for sea explorations, and they were essential for the growth of many ancient civilizations. Read the student links at this Navigating by the North Star lesson plan. Because of its location, the North Star is a reliable landmark that can be used for determining one's location on the earth.

The bottom figure at left shows a photograph taken with the shutter left open. The "star swirl" occurs because the other constellations rotate around the fixed position of the North Star over the course of the evening.

Read about How a Sextant Works and build one here.

Would you know how to use it to determine your latitude? If you have an accurate clock set to Greenwich Mean Time, you can also calculate your longitude.

If you have Shockwave, you can play this game Escape from Antartica and see if you can find your way home like Ernest Shackleton.

Classical Science Alive: Archimedes Vindicated!

In 212 B.C. ancient Greek and Roman historians wrote that Archimedes used a burning glass to set Roman ships aflame in the Battle of Syracuse. Over the centuries, many groups have attempted to repeat Archimedes' achievement, but failed. Many believed he couldn't have done it (one of the most recent naysayers being the TV hosts of Mythbusters), but persistent against-the-odds students and teachers at MIT finally proved Archimedes could have torched the ships.

Using this sketch model, the course instructor concluded it would be possible. 95% of the class thought it unfeasible, 5% thought, well maybe....

The rest (as they say) is history: "Open, sustaining flame occurred less than 10 minutes after the sun was in a clear patch of sky!" For more on this, including answers to ponderables such why the boats and not the sails might have been set on fire, check out these Archimedes Death Ray FAQs

References:
Archimedes Death Ray

Technorati tags: classical education, classical science, history of science, ancient Greeks, Archimedes, education, engineering

The Science of Hearing Treatments- From Ancient to Modern, to Cutting Edge

In the first century B.C., Greek physician Archigenes('Αρχιγενης) tried to cure certain hearing disorders by blasting loud noises through a tube. It was thought that fluids from the brain would build up in the ears (almost true).

The Greek physician Galen of Pargamon applied liquids that would dissolve thick fluids while administering medications that would cause patients to lose water from their bodies. Today when know that fluids can collect in the ear for many reasons, but most commonly due to infections, allergies, or impaired drainage.

Ear trumpets were first used by sailors to communicate over long distances, then in the 17th century, they became common assistive devices for the hearing impaired.

Inventor of the telephone, Alexander Graham Bell became interested in sound and sound amplification at an early age because of his speech instructor father (invented 'Visible Speech') and hearing-impaired mother (a talented painter and apparently pianist!). Alexander himself went on to become a teacher of the deaf and married a deaf woman.

He attributes his breakthrough in the design of the telephone as being due to a mistake he had made when trying to decode research article written in German - he mistakenly believed the researchers had been able to transmit vowel sounds over a wire. He would later recall : "If I had been able to read German, I might never have begun my experiments in electricity!"

Bells' tips to young would-be inventors: "Leave the beaten track occasionally and dive into the woods. Every time you do so you will be certain to find something that you have never seen before. Follow it up, explore all around it, and before you know it, you will have something worth thinking about to occupy your mind."

Do you need to review your anatomy of the middle and inner ear? If so, check out this Interactive Ear site. Ear bones are small!

Could you be a surgeon who operates on the ear? If so, take a look at this Ear Movie that shows how a tendon from a muscle behind the ear can be used to make a new tympanic membrane or "ear drum." It's a little amazing that it works as well as it does...Would you like to have been the first person who had this surgery?

Today research scientists are able to study the cellular and molecular basis of hearing. Using the scanning electron microscope, researchers can look and delicate structures that make up the hair cells (convert sound waves into electrical signals).

The ear hears when sound comes into the ear canal, vibrates the tympanic membrane, moves the three ear bones, which in turn pass the vibrating signal to the cochlea where a fluid waves activates hair cells.

Bioengineers have made cochlear implants that can allow some deaf people to hear by stimulating the auditory nerves.



Some deaf communities have asked whether cochlear implants should be given to all people, though, because of concern that this innovation could eliminate deaf culture.

Today, neuroscientists and audiologists are also using computer-based training programs to improve hearing by "training the brain" while other groups are trying silicon chips and micromachining to design more sensitive and accurate artificial ears.

References:
Ancient Greek Physician Stamp
Biography of Alexander Graham Bell
History Hearing Disorders
Ear Trumpets
Visible Speech
Alexander Graham Bell at American Memory
How the Ear Works
Alexander Graham Bell

Classics Physics Alive: New Acoustic Discoveries in Ancient Greek Theatres

In a recent article from Nature, researchers at Georgia Tech figured out the science behind the magnificent theatre of Epidaurus. For more detailed, info, click here. it turns out the answer is not from simply an optimal amplification of human frequency pitches, but also careful positioning of the stepped rows of seats to reduce low frequency background noise. Very cool

Excerpt: "They calculate that this structure is perfectly shaped to act as an acoustic filter, suppressing low-frequency sound — the major component of background noise — while passing on the high frequencies of performers' voices...In the first century BC the Roman authority on architecture, Vitruvius, implied that his predecessors knew very well how to design a theatre to emphasize the human voice. "By the rules of mathematics and the method of music," he wrote, "they sought to make the voices from the stage rise more clearly and sweetly to the spectators' ears... by the arrangement of theatres in accordance with the science of harmony, the ancients increased the power of the voice."


ARLT :: Why the Greeks could hear plays from the back row
Structure of the Greek Theatre
The Architecture of Acoustic Control (Modern)
Wired: Scientists Study Sacred Sounds / Church Acoustics

Ancient Greeks: Thales - Scientist, mathematician, philosopher, businessman

Thales of Miletus is often referred to as the father of science, the father of philosophy, and the father of geometry. He was a very clever man, and sought to understand the world through a study of its patterns, rejecting explanations from mythology.

We just discovered Julie Diggins' String, Straight-Edge, and Shadow, and here you can read its Thales Chapter. Among Thales' apparent accomplishments: predicting an eclipse in 585 B.C., successfully predicting a bountiful harvest of olives after several bad seasons (he was certain, he also cornered the market on olive presses beforehand, and made a great deal of money), measuring the height of Egyptian pyramids by "shadow reckoning", a strategy for measuring the distance of a ship at sea, five propositions (with proofs) of plane geometry, a theory of earthquakes (movement of land because it floated on water).













Of course, Thales was also wrong about many things (for instance, he thought all things were composed of water and that magnets (lodestones) had souls), but he inspired many generations of scientists, mathematicians, and philosophers to look for the patterns, rules, and relationships that existed in the natural world.

References:
Math Story / Lesson: On Thales
Wikipedia: Thales
Thales at the Internet Encyclopedia of Philosophy
The Life and Accomplishments of Thales of Miletus
Ancient Greeks

Classical Thinking in Physics and Newton's Laws of Motion

The discovery of the Newton's Laws of Motion provide many insights into how scientific discovery occurs - there are experiments and observations, consideration of unknown or untested variables in the experimental observations, theories knitted together from results and analogies in other systems, more experiments and use of different experimental paradigms, and finally discussions (and often disagreements) with others until one arrives at a consensus.

It was Aristotle who first noticed that masses of heavier weight tended to move more quickly in proportion to their size. This didn't make sense to Galileo Galilei, though, because he knew that projectiles like cannons didn't move in straight lines, but rather in straight curves. There has been a popular story (perhaps perpetuated by Galileo's biographer) that Galileo dropped two canon balls (one 10 times heavier than the other) from the Leaning Tower of Pisa to refute this law of Aristotle. There still remains some controversy over whether Galileo was actually able to show this, but he did try experiments using inclined planes (rolling balls down planes at different heights) to better control for the rates of acceleration and quantitate his results (in a vacuum or no air resistance), items of different mass should fall at the same rate. A page from one of his notebooks can be seen below.



The year Galileo died was 1642, the same year that Isaac Newton was born. Newton's great insight was to realize that a single law might be able to explain an apple falling from a tree, the curving movement of a cannon, and motions of the planets.

Putting his observations with the concept of Universal Gravitation, Newton imagined that if a cannonball were shot horizontally and fast enough from an iman imagined mountaintop, then it might actually orbit the earth. For an animation of Newton's cannon on a mountain, click here



Newton - What Really Happened with the Apple
PBS: Galileo's Experiments
The Galileo Controversy
Galileo's Notes on Motion

Movie: Like Something the Lord Made

Over the weekend, we Like Something the Lord Made, a movie about the life of Dr. Vivien Thomas, a man who overcame racism and poverty to help pioneer innovative techniques in heart surgery. It is an amazing story, one that includes a glimpse into America's segregated past, as well as the strength and resolve of Dr. Thomas and his family. The movie provides a realistic view of innovation in surgical research, as well as the personal courage and self-sacrifice such work takes on all involved.

In addition, there is a small role in the movie for Dr. Helen Taussig, a Cliffie (Hurrah! - Radcliffe, Harvard Medical School, Johns Hopkins) who had dyslexia and was also a champion tennis player, and had quite dramatic pioneering work herself in the field of pediatric cardiology. She lost her hearing by the time she had graduated from Hopkins and relied on lip reading and hearing aids, but "some of her innovations in pediatric cardiology have been attributed to her ability to distinguish the rhythms of normal and damged hearts by touch, rather than by sound."

For families: Despite the title, this is not a "Christian movie" and there is some mild profanity uttered by the chief of surgery (Blalock).

Vivien Thomas
Wikipedia: Something the Lord Made
Movie Review: Something the Lord Had Made
About Dr. Helen Taussig

Classical Science: Telling Time with the Sun

Time to run outside in the sun!

For a simple animation of how shadows vary with time and position of the sun, click here. The animation here shows you how to estimate the size of a very large object (like the Statue of Liberty or T Rex) by comparing shadows.

When Isaac Newton was a boy, he was interested in studying the patterns of how shadows moved. He eventually constructed many sundials around his house and could tell the time just by looking at the placement of shadows.

For a good background on telling the time by the sun, and a print-out template for one to make yourself, click on this NASA site. You'll have to determine your latitude before you can use the sundial accurately so that you can factor in the tilt of the earth and its curvature. There are many beautiful sundial pictures at Wikipedia.

Another device an ancient Roman could use was an horologium ex aqua, or water clock - that displayed the month and hour on a column of water. For more on how ancient Romans kept time, check here.

If you're wondering how a person in the Middle Ages might have been able to tell the time at night, they could have used a Star Clock that uses the pointers of the Big Dipper.

Technorati tags: classical education, science, astronomy, sundials

Classical Homeschooling: Backing Our Way into Physics

I want to teach my kids to be good natural scientists. Physics always seemed to be a natural science to introduce early (even toddlers negotiate their physical world), but it's easier wished than done.

I remember Richard Feynman's writing about how his father first told him about physics principles from The Pleasure of Finding Things Out, " said, 'Say Pop, I noticed something: When I pull the wagon the ball rolls to the back of the wagon, and when I'm pulling it along and I suddenly stop, the ball rolls to the front of the wagon," and I says, 'why is that?' And he said, 'That nobody knows,' he said. 'The general principle is that things that are moving try to keep on moving and things that are standing still tend to stand still unless you push on them hard.' And he says, 'This tendency is called inertia but nobody knows why it's true.'" I like that approach because it gives knowledge with an appreciation for what also is unknown. But the problem is me. I also wish I knew as much about Nature as Anna Comstock (Handbook of Nature Study, but our natural teaching moments were more likely to be planned or science-lite, relying on what knowledge I happened to have available without looking it up in a book.

Physics is a tricky subject to teach for tweens or middle school students because it doesn't have to be as complex or rigorous as high school or college prep physics, but it also deserves more than elementary school level explanations. I had started off this year with the high school Conceptual Physics book, and we even spent some time with Conceptual Physical Sciences, but although our son could read the chapters and answer the questions, it wasn't helping him look at his natural surroundings more thoughtfully or think like a scientist. And it seemed a lot like work, rather than something that was intriguing or fun.

Recently we found this delightful site that has free online Classical Physics demonstrations. It's not enough to be a stand-alone curriculum, but it terrific for bring back the fun.

Though we covered Newton's Laws of Motion, we're now revisiting what we've learned, so that understand more about the historical context that drove Newton connect ideas about the movement of the planets, with movement on earth. In order to answer his questions in a specific way, had had to develop a new branch of mathematics (calculus) to test hypotheses about what laws could predict movement.

Newton's laws would allow others to design rockets, spaceships, and rollercoasters, predict the movements of golf balls, fluids, and neutrons in a nuclear reactor. As we collect links and for study notes, we'll post them on our blog.

I'm much happier with our current track in physics because I can see our children's curiosity and excitement returning, and they're getting a better experience for what the practice of science is - observing carefully, questioning, hypothesizing, making conclusions, and then recognizing what remains unknown.

BTW, the beautiful pictures above are from that wonderful MIT physicist and teacher, Harold Edgerton, who was able to stop time and provide surprising insights into the behaviors that previously were too fast to study.

Edgerton Golf Picture
Harold Edgerton Center
Edgerton Explorit Center
High Speed Visualization Lab...Cool Pictures

Technorati tags: classical education, science, homeschooling, physics, history of science