This blog will expose readers to many facets of scientific investigation and discovery. Recent news in science will be shown and expanded on to teach far more. Biographies of scientists will give a deeper insight than what you may have read in textbooks. I hope that the posts will help improve scientific literacy, expand your interest in many fields of science, and inform you about some important scientists.
Tuesday, October 31, 2023
Pearl I. Young: Scientist, professor, journalist, technical editor
Where to start with this extraordinary woman, born in Minnesota, USA on October 12, 1895 and raised in North Dakota? Pearl Irma Young held several science-related positions in life. Her major contributions were in the NASA predecessor organization NACA (National Advisory Committee for Aeronautics), but her background encompassed several occupations and interests related to physics, aeronautical history, teaching, and writing standards for engineers. Read on for more on her story!
(Click on images to enlarge.)
To pay her way through high school, Pearl Young left home in North Dakota at 11 and worked as a "domestic", someone who helps others in housekeeping duties. She later attended Jamestown College there, and graduated with a bachelor's degree from the University of North Dakota. She graduated with with honors in 1919, with a triple major in physics, chemistry and mathematics. Additionally, she was a member of the Phi Beta Kappa Society, "America's most prestigious academic honor society". It's no wonder that the university hired her to teach physics.
Young was the first professional woman employee there and the second in all of the U.S government (the other was a physicist in the National Bureau of Standards). All other women were office workers such as mail sorters, payroll and file clerks, receptionists, secretaries, stenographers, telephone operators, and typists. The group shot below in 1930 shows only 14 women (lower right corner) among all the men.
Engineer Henry J.E. Reid was initially her co-worker (and the same age), then in 1926 he became the director of her laboratory (called "engineer in charge" at that time).
In Young's own words, "We made, designed, we repaired, calibrated -- everything about the airplane and instruments" which recorded "altitude, air speed, engine speed, and acceleration of an airplane during maneuvers". (Note: a lot of her personal history and work at NACA is included in the Caitlin Milera's PhD dissertation "Ms. Pearl Irma Young: "Raising hell" for women in STEM fields and women at NASA, 1914-1968", pages 2-5 and 108-207.)
Young, around 1929 in the Instrument Research Laboratory (Wikipedia)
She spent the summer of 1927 touring aircraft research labs in England and Germany to learn more about them.
In the late 1920s, she noticed that many NACA engineers' writing style on their technical reports was not consistent. Poor writing not only made it difficult for people to read reports but also to file them in an organized system. She pointed these problems out to Henry Reid, and is quoted as saying, "I was interested in good writing and suggested the need for a technical editor. The engineers lacked the time to make readable reports." Essentially, she went against the grain of the male engineers at NACA and their military and industry partners, who wanted reports out quickly and didn't care about quality as much.
Consequently, she was given the task of technical editing for NACA, but it wasn't until 1935 that her position officially changed from Junior Physicist government grade P-1 to Assistant Technical Editor grade CAF-7 (CAF=clerical, administrative, and fiscal), even though she was assistant to nobody. She assembled a team of eight women to edit and proofread the many NACA reports that were generated.
Covers of several types of NACA engineering reports
Young's idea was to have first drafts inspected by other engineers, and then her team took over to polish them for precision and logic. It was not always easy to convince male engineers to improve their writing, though. Besides the gender issues that she and her editorial staff faced in streamlining reports and bulletins, they were also challenged by needing to understand a variety of science and engineering topics. Fortunately, they all had degrees in some field of science. However, none of them were English majors! Young's classification changed from "assistant" to "associate" in 1941.
NACA editor assisting an engineer to write a technical report (NASA)
During the 1930s, though, she took extension classes in English and newswriting from Columbia University and the College of William and Mary. Pearl supplemented her salary by reporting and feature writing part-time for the Norfolk-Ledger Star and Norfolk-Ledger Dispatch. Her articles were about dog shows, horse shows, debuts, inaugurations, and contests, and she even had a cover story interview with Eleanor Roosevelt.
In 1943, Young transferred from the LMAL site in Hampton, Virginia to NACA's new Aircraft Engine Research Laboratory (AERL) in Cleveland, Ohio. She set up a technical editing staff there, too, and she published her most famous work, the Style Manual for Engineering Authors. It was used by many agencies for decades. Officially, this was also when her title changed to Technical Editor, a little late in the making but still well deserved.
Pearl Young (far right, seated) and her 1947 editing team (NASA Glenn Research Center History Office)
During World War II, her team's duties were vital, as LMAL's focus centered on aircraft configurations, and reports for the military had become shorter out of necessity and efficiency. Data on refinements made in aircraft were shared with the Army and Navy as quickly as possible.
Pearl left NACA altogether four years later to teach engineering physics at Pennsylvania State University for 10 years. Military veterans were returning from World War II, and she "felt there was a great need for qualified teachers in higher education". She originally wanted to teach at a military university in Japan then, but General Douglas MacArthur stymied that with his attitude that "there will be no women physics teachers in Japan as long as I'm in command". So, if was off to Pennsylvania instead.
In 1948, perhaps just to show that she was still very aware of the need for good writing skills among student and working engineers, she published a scientific paper in the American Journal of Physics, entitled The Responsibility of the Teacher of College Physics for the Student's Facility in American Prose. Her introduction (below) showed how science writers and English teachers should collaborate to produce good writing.
She loved aviation and its history. In addition to her 1927 visit to Europe, she took two trips aboard the zeppelin Hindenburg in May and June of 1936 to and from the U.S. and Germany. She said it was her "most memorable experience". During 1947, she indulged her curiosity in aeronautical history by starting a collection of biographical works on French-American aviation pioneer Octave Chanute, and later she published on it. She also catalogued information on German airship designer Ferdinand von Zeppelin, French aviation designer and engineer Alphonse de Pénaud, and the inventor of the wind tunnel, Francis Wenham.
Octave Chanute and his 1896 biplane hang glider (Wikipedia)
In 1957, she briefly returned to the NACA office (incorporated into NASA in 1958) in Cleveland. There, she had the new title of Technical Literature Analyst and wrote on subjects involving astrophysics and spectroscopic analyses of plasma. She also gave lectures at scientific conferences on pioneer aviators and technical writing.
In 1961, she retired from NASA. For two years after that, she taught physics at Fresno State University.
Pearl Young never learned to drive a car, and in her will, she left about $15,000 to the city of Hampton, VA for the construction of benches and shelters at bus stops. She traveled extensively and had a flair for photography and poetry, and people knew her for her sense of humor. She was also active in the YWCA.
On her 1927 trip to Europe, she wrote "The channel is opening her arms to us, the queer uneasiness returns, a whole continent of irregular verbs." An unsung hero in the scientific and engineering world, Pearl Young's award and recognition mostly came after she died on June 16, 1968. NASA built an auditorium named after her in 1995 and in 2014 an entire theater.
Little in life deterred her, whether as an educator, scientist, speaker, or editor. One of her diary entries says it all: "Worry is like a rocking chair; gives you something to do but gets you nowhere."
Saturday, October 28, 2023
Scientists Have Found a Way to 'Tattoo' Living Cells With Gold
Tattoos are designs imprinted on the body by injecting ink with needles just under the skin. But recently, scientists at Johns Hopkins University (Baltimore, Maryland) are working on a different sort of "tattoo". They have created technology to label a cell and not with pictures but with gold particles. They are doing this not for pretty designs, but to "monitor and control the state of individual cells and the environment surrounding those cells in real time". How is this labelling done?
How would you lay out a grid of sensors in an organized pattern on the human body? Think of placing a net on your skin, and at every place where the fibers cross, there is a sensor. Place that on the arm, back, or wherever, and the sensors can measure temperature, hormones (like insulin), blood flow, etc. Or do it with very thin circuit boards. But that's on skin. Below is a 10-year-old prototype of a skin-mounted sensor to measure body temperature, blood pressure, and electronic signals from muscles or the heart.
There are many technologies that implant such circuitry on the skin, or just under the skin like this one from Dermal Abyss that changes color when pH or glucose or albumin levels in the body change.
This type of technology has even been designed to fit deeper in the body. Here is a picture of sensor circuitry attached to a rat brain.
From the Johns Hopkins University researchers
What about going much smaller to the level of marking an individual cell? David Gracias of the Johns Hopkins University team said that if cells could be labeled with sensors, they could be used to not only monitor cells but control them in some way, maybe even control their environment, too. No further details were given.
Laying a network of electronic sensors on something as small as cells requires more precision than on or under the skin. Just how do you make them stick and not kill the cell in the process?
The technology is called nanoimprint lithography(NIL). Regular lithography is done with drawings on stone (litho-) using oil or greasy utensils, and when paper is placed on top and pressed firmly, the recording (-graphy) copy is transferred to the paper. See the short video demonstration below.
So, it's essentially one way of making a copy of a picture or text.
"Nano" refers to something very small, so nanoimprinting involves copying something at a microscopic level. Rather than jumping to imprinting circuitry first, the initial step that researchers have taken is to use metallic (gold) dots instead of sensors just to see if the overall process is feasible. Here's what they did at John Hopkins University. Gold, by the way, is often used for body sensors because it prevents signal loss or distortion when used in electronics.
1. Start with a silicone wafer. Coat that with a thin layer of a polymer called PMGI. On top of that, put a thin layer of another material called "NIL resist". Then use a silicone stamp to imprint a pattern on the NIL resist. Coat the exposed surfaces of that template with gold.
2. Using sound waves, remove the NIL resist and unnecessary bits of gold. Cover it all with another polymer called PMMA.
3. In order to lift the gold and PMMA off the silicone wafer, the PMGI is first dissolved chemically. Then, a glass cover slip is put under the PMMA/gold dot array.
4. An oxygen plasma etching process removes the PMMA to leave behind gold dots in their original imprinted pattern, now sitting on the cover slip. To lift this like lithograph paper from a stone drawing, an organic compound called cysteamine is put on the gold, so it will allow the gold to be held by a layer of gel coating.
5. In a second lithographic-like step, the gold and gel are flipped over with gel side down to expose the bare gold nanodots' surface. Gold won't stick to cells by itself, so a layer of gelatin is put on it. Then, a suspension of living cells is put on top. Cells stick to the gelatin-gold nanodots.
6. In a final lithographic-like step, all of this is flipped over again and placed in a culture dish, and the gelatin is removed chemically. Now the cells can grow in the culture dish, and the gold nanodots bonded to them can be seen on top.
If you're trying to imagine how all this works, here's a condensed diagram of the process from the point where cells are put on the gold, then flipped. The nanodots in the real photo were colored in artificially with computer imagery.
The Johns Hopkins University researchers tried the process on a non-living bead-like microparticle first. It was very close in overall size to a cell, and the nanodot pattern seemed to hold. But would this work on a not-so-smooth, not-so-round living cell? They tried it on living fibroblast cells, and as you can see from the inset picture on the right, it worked fairly well.
Microparticle with nanodots (left); fibroblast cells with nanodots (right) (From Kwok, et al., bioRxiv)
The fibroblast cells flexed and moved about gently as they grew, but the nanodots stayed attached for up to 16 hours.
All of this merely shows the feasibility of affixing metallic material in an organized array directly onto living cells. None of the nanodots performed any function, nor were they connected by wires like circuits in the picture of the rat brain. But this lays the groundwork for such a thing at the microscopic level. As Gracias said, "It's the first step toward attaching sensors and electronics on live cells." This could be used by doctors to hypothetically track the health of isolated cells, and potentially identify, diagnose, and treat diseases sooner than is done now.
Gracias and his team have also labeled fibroblasts with small sheets of gold wires. You can see two cells moving about with them in this short video (time lapse of 16 hours). They don't seem to be moving any differently than unlabeled cells.
Fibroblasts are the most common type of cell in the connective tissue of our bodies. They are not only useful in the body's structure but also for healing of wounds. They are routinely used in many types of research experiments. It's not known why the Johns Hopkins researchers chose them for their first cell experiments, but they expressed interest in labeling other types of cells for future work.
BONUS INFORMATION
Here is a 4:36 video from MIT that shows how some gold tattoos can be used decoratively or functionally (to control smartphones or computers, or to show body temperature).
Wednesday, October 25, 2023
How do you clean a space suit?
NASA is planning another crewed flight to the Moon after 51 years. Yes, it was 1972 that the last humans set foot on the lunar surface. The Artemis Program is in full swing to build an orbiting structure called Gateway as well as a surface facility called the Artemis Base Camp. A lot has changed since 1972, but an old problem that will need to be solved is still being worked on. That is how to remove moon dust from space suits.
Astronauts have a jumpsuit they wear inside the capsule, space station, or space shuttle to perform normal functions. The space suit worn outside the spacecraft faces environmental conditions significantly harsher. Suits must protect the wearer from temperature extremes, lack of air, radiation, sunlight, and injury, as well as provide the most mobility and visibility possible, ways to carry tools and operate them most efficiently. They also need to remain as white as possible to reflect sunlight and to allow others to see the astronaut, whether in space or on the Moon.
Besides the need for such suits to be durable, tough, insulating, and properly protective, astronauts who have worked on the Moon encountered a "sticky" problem that needed to be overcome. Moon dust. Collecting rock samples, walking on the lunar surface, and riding in the lunar rover all generated small particles of moon dust that were difficult to remove from the suits, electronic equipment, solar panels, and lenses. They also made tools and ladders slippery. Clogging and potentially damaging materials are obvious problems, but since the dust holds an electrical charge, some people are concerned that it may also interfere with electronics and even pose a sparking hazard.
Lunar rover kicking up moon dust on Apollo 16 (YouTube)
These particles are 50 micrometers or smaller in diameter (about 0.00078 inches), smaller than flour particles and more like ash. In comparison, the average human is 16-50 micrometers thick. Lunar material is composed of the following:
50% SiO2
15% Al2O3
10% CaO
10% MgO
5% TiO2
5-15% iron
traces of sodium, potassium, chromium, and zirconium
Moon dust from Apollo 11 (NASA)
Solar radiation bombarding the Moon's surface creates a negative electrical charge on lunar dust. That's what makes it stick to surfaces. The lack of moisture or erosion on the Moon makes it extremely powdery. Because of the fine particle size and their electrostatic charge, moon dust clings to everything. Astronauts can't help but bring it inside their spacecraft, where it floats around and clogs equipment, as well as causing radiators to overheat. It also blocks the seals on the space suits where helmets and gloves attach, and in some suit designs, where the bottom section joins with the upper torso.
Moon dust on space suit, Apollo 15 (National Air and Space Museum)
What's more, it gets into the eyes, nose, and lungs. Astronaut Harrison Schmitt experienced the first case of "lunar hay fever" aboard Apollo 17 when he inhaled the dust after removing his helmet. A flight surgeon examining suits after that flight also suffered the same congestion.
Schmitt on the moon. Note dust on legs and arms. (NASA)
In 1966, Professor Brian O'Brien from the University of Western Australia developed a moon dust detector the size of a match box for Apollo 11 (and later missions). When dust covered its solar cells, there was a decrease in voltage, and that data was beamed back to Earth every minute. To date, these are the only data we have on moon dust accumulation on the surface.
Prof. O'Brien talks about his moon dust detector (YouTube)
Moon dust may be powdery but it isn't smooth like rocks on Earth. Instead, the particles are as sharp as glass and can severely damage skin, eyes, and lungs and even cut space suits.
Washing suits in space or on the Moon does not sound feasible, but scientists at Washington State University have performed tests of spraying liquid nitrogen on dolls dressed in space clothing covered in Mt. St. Helens ash, which is similar to moon dust. They achieved 95-98% removal without damage to the suits. This process does not soak the suits. It makes use of the Leidenfrost effect, where a liquid close to a surface that is much hotter than its boiling point creates a vapor layer that prevents the liquid from boiling rapidly. It's like putting drops of water on a hot fry pan; they don't evaporate immediately. Here, the liquid nitrogen removes the dust particles by trapping them in its vapor.
Volcanic dust is light, and the suit fabric here is black.
Researchers at Hawai'i Pacific University are working on a different approach: a new type of fabric to combat this problem. Working with a $50,000 grant from NASA, they used LiqMEST (Liquid Metal Electrostatic Protective Textile). It would generate an electrical charge on this outerwear to the space suits and theoretically repel moon dust. Alloys of indium and gallium are hot items now for electronics, but using them as surface coatings is just getting off the ground. Japanese researchers have been working on this since 2011 in a slightly different way. They stitched wires into the suit's outer fabric and ran a pulsed charge through them to electrically "flick" off moon particles with 70-80% efficiency. By adding an ultrasonic transducer to the fabric, the added mechanical vibration increased removal to 90%.
Another method involves shooting a beam of electrons directly onto the suit. A joint effort between the NASA/Jet Propulsion Laboratory and Colorado University, Boulder is working on a tool called a “Moon duster” for equipment and space suits. Since moon dust is already negatively charged, adding more charge with an electron beam will make the particles repel each other. This has been shown to work on some surfaces in a vacuum on Earth with removal of 75-85% of the particles.
Removal inside the spacecraft, with liquid nitrogen or electron beam, still means the suits would have to be contained in some sort of chamber during cleaning. Otherwise, the dust that is removed would float around the spacecraft interior and defeat the whole purpose.
Here is a short video showing the results of an electron beam removing dust.
More than 1,000 species of animals use echolocation, including most bats, all toothed whales, and some small mammals. They do it in different ways, from vibrating their throats to clicking their tongues to flapping their wings to using a special organ. Some use echolocation to find prey, while others use it to avoid predators, and some even use it just for navigation. Most people realize bats create a sound from their larynx to perform these functions, but not all bats do. Some may use their wings.
Donald R. Griffin, zoologist at Harvard University, coined the word echolocation in 1944. His short (650-word) paper in the research journal Science carried the intriguing title "Echolocation by Blind Men, Bats and Radar". He briefly mentioned how bats do it in the dark with ultrasonic cries, how blind people mimic it by tapping canes, how ship captains use whistles in fog to locate cliffs or buoys, how ships use fathometers to detect the sea bottom depth or submarines, and how airplanes use radio altimeters to determine how high they are.
As for bats, genetically speaking, there are two groups: large fruit bats (which usually don't echolocate) and some echolocating insect eaters (collectively called "yin" after their taxonomic name), and the other group consisting of other small bats that use echolocation (called "yang"). About 70% of all bats use echolocation.
Bats that echolocate produce a high pitched cry from their vocal cords which then comes out of their mouth or nose. They can modulate the pitch to several wavelengths between 30,000 and 80,000 hertz. It reflects off objects, and bats can then judge the distance away, the texture, and the direction it may be moving.
A simple tutorial about bat echolocation from its voice (YouTube)
However, in 1988, Edwin Gould of the National Zoological Park, Washington, DC made a discovery about two species of Philippine dawn bats known to not create echolocation sounds. He studied 4,000-5,000 of them in caves in Kuala Lumpur, Malaysia and noticed that they have to fly in total darkness 300 meters (984 feet) to reach a thin ray of light. They make a "clapping, raindrop-like" sound that stops the moment they reach the light or when the cave itself is illuminated artificially.
Gould tested them in a dark room and got the same response to light. So, he painted the tip of one wing and noticed that it left a mark on the other wing in the dark but not the light. When he plugged their ears with cotton, he saw that they flew shorter times and with more hesitation. Navigation around objects in the dark were not found to occur any better between bats with plugged or unplugged ears. He determined that they were making the sound by hitting their wings together, but he did not know why.
Researchers at Tel Aviv University in 2014 expanded on that study with a different species of fruit bats that don't use echolocation. They found landing sites in the dark but not very accurately, and they couldn't navigate around obstacle courses, much like Gould's work. The clicking sounds from the wings were sometimes audible to humans. They, too, confirmed that wing action seemed related to the clicking sounds by using high-speed videos of the bats in flight.
Their mouths were closed when sounds were made. Sealing their mouths did not stop the clicking.
Clicking synced with wingbeat rate.
Covering wing tips with tape prevented clicking sounds.
But the researchers could not identify exactly how these bats produce the clicking.
Moreover, bat and bird wing structures are different. Coincidentally, birds called manakins are known to make loud, short "snaps" over a wide range of frequencies with their wings as they fly.
Two types of manakins (Wikipedia)
By studying high-speed videos, scientists have determined that how they make the snaps is divided into four mechanisms:
above-the-back wing-against-wing claps
wing-against-body claps
wing-into-air flicks
wing-against-tail feather interactions
Watch the short YouTube video below for 3 differences in how birds and bats fly.
Differences between bats and birds in flight
The secret to these bats’ hunting prowess is deep within their ears
The Earth's oceans contain 97% of all water, but it's unsuitable for drinking, agriculture, or most industrial uses. The remaining 3% is freshwater, but most of that (2.5%) is unavailable because it is part of glaciers or the polar ice caps, atmosphere, and soil, and may be very polluted or is too far underground to be extracted economically. That leaves 0.5% of all water on the planet as freshwater we have access to and that is usable for consumption or agriculture. Researchers have found a way that could potentially remove salt and microplastic pollution from seawater and make it usable for humans.
Why is the ocean salty? Rainwater dissolves carbon dioxide from the atmosphere to make it slightly acidic in the form of carbonic acid. This strips ions off rocks and carries them to the oceans. Also, heat from the magma that comes up from the volcanoes and seafloor vents breaks down minerals which get dissolved in the atmosphere and seawater. The two commonest elements in ocean water are sodium and chloride (which are what make up table salt).
A lot of recent news talks about the problem of microplastics in the ocean. Basically, they are pieces smaller than 5 mm (0.2 inches, about as big as a sesame seed) long that form as UV from sunlight, wave action, and washing break down bigger pieces. Some are called microbeads and are less than 1 mm in diameter; they are made specifically for scrubbing compounds and cosmetic face cleaners. Here's a short video about the topic to show two problems that microplastics create.
This article is not about cleaning up the oceans for the sake of the environment. Rather, this is to report on research done at Princeton University to develop a material to remove salt and microplastics so that the cleaned water can be used in homes and industry.
Activated carbon/charcoal is a cheap material used to remove unwanted chemicals from water. Its tiny particles are full of pores with many convoluted channels to trap organic molecules, and its own chemical nature breaks down chlorine to chloride and carbon dioxide. But because it doesn't remove all unwanted chemicals, water purification systems use it as only a first step, often followed by reverse osmosis (RO). RO systems pressurize dirty water through a membrane with pores that allow only water to pass. But it's also more expensive than activated carbon filtration.
Powdered activated carbon and diagram of one particle in action
So, what's cheaper than RO but more effective than activated carbon? Eggs.
The Princeton University researchers conceived of a material that would be porous like activated carbon. They took egg whites (albumin), which contain a lot of protein, and treated them as follows.
Egg whites are freeze-dried to remove liquid. The material forms strands of proteins bonded together.
The freeze-dried material is heated in a nitrogen atmosphere to 900 degrees C (1,650 F). This burns away everything but the carbon and changes the structure into an aerogel matrix of carbon which is very lightweight, porous, and strong.
You can see the actual changes in the diagrams and photos below from the original research paper.
Aerogels are materials made from gels and into these sorts of lattice-like networks. They can be made from various starting materials like silica or tin or carbon. The carbon ones made at Princeton University are about 4 cm (1.6 inches) long and 2 cm (0.8 inches) in diameter. When sliced in half, you can see the dense yet porous network of carbon.
Aerogel from silica (left) and from egg whites (right)
The Princeton University researchers took their aerogel from egg whites and shaped it into a 5-mm-thick (0.2 inches) filter and allowed seawater to flow through it by simple gravity (no added pressure) 50 times. They measured the purity each time.
As the seawater passes through the egg white aerogel, water travels unevenly through the carbon matrix, and ions stick to it to let only purified water come through. After 50 purification cycles, 98.2% of the ions were removed.
(h) dry aerogel, (i) water [blue] flowing through,
(l and m) saltwater ions being trapped [green = chlorine, orange = sodium, violet = magnesium,
blue = nitrogen, red = oxygen] (From the Ozden et al., 2022 report)
They then tested their egg white aerogel for its ability to remove microplastics (147 nm and 400 nm diameter) and compared it to an activated carbon filter.
In the first purification cycle, egg white aerogel removed 93.2% of the smaller plastic and 98.5% of the larger, while activated carbon removed 82% of the smaller particles.
After 15 cycles, egg white aerogel removed 99.986% of the smaller plastic and 99.995% of the larger, while activate carbon removed 98.2% (standard for other industry materials).
So, on a small scale, the egg white aerogel outperformed activated carbon. Obviously, this has to be scaled up, as the researchers noted. Before you wonder whether industry will consume a large portion of the egg supplies in the world and cause prices to rise, it is good to see what Professor Craig Arnold of the Princeton team said:
"Because other proteins also worked, the [aerogel] material can potentially be produced in large quantities relatively cheaply and without impacting the food supply."
Saturday, October 14, 2023
Hello! Alexander Graham Bell
(Click pictures to open in larger view)
Alexander Graham Bell was born in Edinburgh, Scotland, on March 3, 1847. He didn't get his middle name until he was 11, though. His grandfather was an expert on speech disorders and phonetics, and his father (all three named Alexander, by the way) was a university lecturer on philology but who focused on helping deaf people learn to speak well. His mother was almost deaf yet managed to become an accomplished pianist. So, speaking and listening were immediately part of young Alexander's life. What more led him to his scientific accomplishments, and what were they?
Alexander Melville Bell (father), Alexander Graham Bell, Alexander Bell (grandfather)
He was an average student and quit high school because he didn't like the compulsory curriculum. Aside from just 2 years of formal schooling, he was home schooled by his mother. She had instilled a strong sense of curiosity of the world in him. As a result, at age 12 he observed the slow process of husking wheat grain as he played with friends in their father's grain mill. At that father's urging to "do something useful", he then built a machine with rotating paddles and nail brushes that more easily removed the husks from the grain. His friend's father then allowed him to tinker in the machine shop on other projects.
In 1862, he spent a year with his 72-year-old grandfather, who treated him differently than his sarcastic, authoritarian father had. He gave his grandson independence, a better sense in what he wore in public, and an outlook on mankind that all deserved an education. This restored his appreciation for learning and made him think of attending university. Bell called this year a turning point in his life and that it "converted me from a boy somewhat prematurely into a man".
His father introduced him to scientist and inventor Charles Wheatstone, who was studying telegraphy and the transmission of sound. Wheatstone had improved upon a "speaking machine" originally invented in 1769 by Russian professor Christian Kratzenstein, and then in 1791 by Wolfgang von Kempelen.
Using Kempelen's book, Alexander and his older brother Melville reconstructed the device with their own improvements. Wheatstone's version could mechanically make a few simple words. Alexander and Melville did a little more, but the biggest result was both of them learning more deeply about the organs for speech.
Bored at home after that, and now being treated as a child again by his father, Alexander almost ran away to be a sailor. Instead, he found an advertisement for a "pupil-teacher" in music and elocution in a place called Weston House in Elgin, about 170 miles to the north of Edinburgh, not far to the east of Inverness on the coast. Weston House was a school for the "Board and Education of Young Gentlemen".
Alexander taught not only elocution there, but since he had taught himself how to read and play piano music as a child, he taught that to students, too. His experience with his grandfather paid off, because nobody noticed he was younger than many of his students.
His father had begun publishing in 1864 on a system of speaking called Visible Speech, which was intended to show the deaf how to better pronounce words through phonetic symbols and the positioning of mouth, lips, teeth, and tongue. So, at 17, young Alexander helped him provide public demonstrations and amazed people, especially when he could use the process to pronounce words even in other languages! He'd learned it all in just five weeks.
A sample of what "Visible Speech" looks like in writing (Omniglot)
His first experiments on vocal sounds were conducted informally in 1866 at 19 after he noticed that vowels are comprised of two pitches -- one rising, one falling. When he compared that to the sounds made by blowing across bottles with different amounts of water inside, he had a brainstorm. By putting a tuning fork in front of his mouth and voicing vowels, he determined which shape of his mouth and tongue caused the fork to resonate for a similar reason. When he learned that accomplished scientists like Hermann von Helmholtz had already learned about this, he was initially disappointed. But after he studied Helmholtz's book, he got the idea to try producing consonants as well as vowels using electrical theory. (The telegraph had already been invented in 1837 by Cooke and Wheatstone, and in the same year Samuel Morse invented the dots and dashes code for telegraphs.) Bell wanted to take the telegraph a step further into producing sounds for vocal transmission. He began investigating how to send music instead of a Morse code text over a wire.
He entered the University College London in June 1868 but stayed only two years. Both of his brothers died of tuberculosis by 1870, and since he was sick, too, his family moved to Ontario, Canada where they thought the air was better for his health. A year later, Alexander moved to Boston where he taught at several schools for the deaf.
In 1872, he opened the School of Vocal Physiology and Mechanics of Speech in Boston, where deaf people were taught to speak. Helen Keller was one of them later on in 1886! In 1873 at age 26, the budding inventor became Professor of Vocal Physiology and Elocution at the Boston University School of Oratory. His experiments were done in a rented room at his boarding house, where he had to do his research at night.
Bell's lab in 1873 at the boarding house
Others were actively working on voice transmission at the same time around the world.
Charles Grafton Page (Salem, Massachusetts) noticed the sound made when an electric circuit connected to a magnet was broken.
Joseph Henry (New Jersey) wrote about making a keyboard device with a rubber membrane using electromagnets to make words on a telegraph line.
Charles Bourseul (France) reported that flexible plates would vibrate in harmony with different air pressures and make the plates open or close an electric circuit.
Antonio Meucci (Italy) worked with early variations of the telephone in the 1850s.
Philipp Reis (Germany) invented a transmitter that sent audible sounds along a telegraph wire, and coined the term telephony in 1861.
Elisha Gray teamed up with Western Union to experiment with sending tones.
Bell tinkered with a phonautograph, initially made by Édouard-Léon Scott de Martinville and later by Thomas Edison. This copied sound waves onto smoked glass or aluminum foil. Edison's foil version could even play back the recording. Bell thought multiple metal reeds would copy the voice and replay the sound instantly at the other end by bouncing it off a diaphragm instead of having to wait to play back a recording. The problem was how to amplify the current created by the voice.
Spencer Tracy movie (1940) demonstrating Edison's phonautograph (YouTube)
But Bell needed funding because Edison and Gray were getting money from Western Bell to conduct their research. One of Bell's students, Mabel Hubbard (soon to be his wife), had a rich father, patent attorney Gardiner Hubbard, who was willing to provide capital. In 1875, his electrical parts supplier assigned Thomas Augustus Watson to assist Bell.
Thomas Watson (Wikipedia)
When Bell and Watson were adjusting reeds on their electromagnets in the lab one day, an accident caused one reed to vibrate on the transmitter, and Bell heard it coming out of the receiver. This gave him the idea that instead of a short open circuit like Morse code uses, he figured an "undulating current" (a longer connection) was what was needed to transmit sound! So, instead of using multiple reeds for each pitch, only one was needed, and he then designed his first prototype.
The "gallows" design for the transmitter of Bell's first phone (Library of Congress)
How it works is pretty simple. Using a diagram from Bell's own notebook, and some coloring added you can see the process below.
(1) Speaking into the microphone [M] sends sound waves to a paper membrane (green) that vibrates.
(2) Vibrations cause a wire [W] to generate current that goes to the receiver which also vibrates and repeats the sound.
(3) The circuit is completed because transmitter and receiver are connected through a battery to a brass rod [P], and then (4) through conductive liquid to the wire attached to the membrane.
With this concept, at age 28 he filed for a U.S. patent on February 14, 1876, and it was issued on March 7 (four days after his 29th birthday). His application for the patent was the fifth one on that day, while a competitor with a similar design, Elisha Gray, was 39th on the same day! So, Bell edged out Gray by just a few hours to get ahead of him in line. To be fair, the patent examiner noticed both applications and confronted Bell because of the similarity in design. Fortunately, Bell explained that he had filed another design patent a year earlier using mercury instead of a conductive water solution, so he had precedence over Gray.
But he had never actually made a call with the device yet.
Three days after receiving the patent, Bell conducted the first test to send a voice message with his phone. The receiver was in another room with the door closed, and when Bell spoke into the transmitter, his assistant Thomas Watson heard him say, "Watson, come here. I want to see you." and then came to Bell to announce that he had heard and understood the call!
Receiver (left) and phone transmitter (right)
June 25, 1876. At the U.S. Centennial International Exhibition, he demonstrated a working version of his telephone.
August 3, 1876. He used existing telegraph lines to speak 6 km away (from Brantford, Ontario to Mount Pleasant) as a second test of his phone.
August 4. His third demonstration was reading and singing between his home and a newly built telegraph line to the Dominion Telegraph Company office where his family listened in.
August 10, 1876 was his next test. It was made between Brantford and Paris, Ontario, 13 km away, and considered by some to be the first long-distance call.
October 9, 1876. He performed the first two-way call between Cambridge and Boston.
January 1915. Bell performed the first transcontinental telephone call, from New York City to Watson in San Francisco, 3,400 miles away.
He started the Bell Telephone Company in 1877 and a few days later married Mabel Hubbard on July 11, 1877. Two years later, he bought the rights to use Thomas Edison's carbon microphone so users wouldn't have to shout when making calls.
Bell shortly before his death in 1917 (Wikipedia)
Although he spent most of the rest of his life pursuing ways to help the deaf, he accomplished other technological feats.
He built a metal detector used in President Garfield when he was shot.
He tinkered with X-rays, discovered in 1895, and conceived of making 3D images with them, foreshadowing the CAT scan.
Soon after the Wright brothers made their historic first flight in 1903, Bell conducted many experiments on flight himself.
He published in 1917 about fossil fuel usage eventually creating a "hot-house" effect on Earth. In addition, he proposed using alcohol as an alternative fuel.
He co-invented a wireless telephone called the photophone, which used sunlight to transmit voice sounds.
He converted the Mohawk language to his father's Visible Speech and was made an honorary chief.
Bell Labs invented the bel and decibel units of measurement of sound pressure level and named the unit after him.
Bell, age 45, at the opening of the long-distance phone line between Chicago and New York (Wikipedia)
Alexander Graham Bell naturalized as an American citizen in 1882 and considered himself a native son of the United States, Canada, and the United Kingdom. He died at 75 on August 2, 1922 from complications due to diabetes. At the end of his funeral, all phones in the United States were silenced for one minute in his honor.
Here's a 10-minute video on how to make a telephone similar to Bell's.
