EKG or ECG

Electrocardiograph (1903)

Einthoven's machine provides a major boost to diagnosing heart problems.

The electrocardiograph-also known as EKG or ECG -  is an instrument designed to record minute electric currents generated within the heart, which are used to diagnose different types of heart disease. At the end of the nineteenth century, physiologists understood that beating hearts produced electrical currents, but they could only measure them by placing electrodes directly on the heart muscle.

Dutch physician and physiologist Willem Einthoven (1860-1927) adapted the string galvanometer for use in cardiology. 

String galvanometers had first been used to amplify electrical signals transmitted along with undersea cables. 

Einthoven's galvanometer, which he produced in 1903, consisted of a microscopic thread of quartz known as a "string" that was vertically suspended in a strong magnetic field. When minute currents passed through the string it deflected and obstructed a beam of light, allowing the shadow to be recorded on photographic paper.

Early prototypes were unwieldy-weighing 600 pounds (272 kg), they needed to be operated by five technicians and required patients to place both hands and feet in buckets of cold water. The instrument was, impulses as the heart contracted and relaxed. Einthoven studied both normal and abnormal electrocardiograms to give doctors reference points for interpreting the results. By the 1920s heart attacks could be diagnosed from characteristic abnormal patterns. Portable, lighter EKGs eventually came along and after world war ii the string galvanometer was superseded by direct writing equipment.

• The table-model of Einthoven's electrocardiograph was made by Cambridge Scientific Instruments in 1911.

EEG

Electroencephalograph (EEG) (1929)

Berger records the electrical activity of the human brain.

When often think of thoughts as instantaneous, but in truth, it stands to reason that they are limited by the speed of certain chemical reactions and electrical impulses in our brain. Given that the physical activities accompany thinking, it also stands to reason that if one looks hard enough, one should be able to measure the electrical activity, despite the seemingly fleeting nature of brain activity. The recording of these impulses - or electroencephalography - matured at something of a snail's pace until the work of Hans Berger (1873 - 1941).

In 1875, English physician Richard caton figured out that he could measure brain activity in animals with a galvanometer.

A Polish physician, Adolph Beck, also working with animals, advanced the topic further in the 1890s, going so far as to discover the location of some sensory impulses and noting a change in activity that took place with loud noises or bright light. The link between animal and human models was not well understood in this era, however, and it took a few more decades before anyone made this leap.

Hans Berger began experimenting with recording the electrical activity of the brain in the 1920s. Experimenting in secret, and oddly using lectures on telepathy as a cover, he refined his technique. Using his own son Klaus as a research subject, Berger recorded the first human electroencephalograph, or EEG, in 1924 and carried on his experiments for the next few years. Berger published his work in 1929 and revolutionized the world of neurology. EEG is used today to evaluate epilepsy, sleep disorders, and a host of other neurologic problems.

• An electroencephalograph is used to record the electrical activity within a volunteer's brain

Artificial Neural Network (1957)

Artificial Neural Network (1957)

Rosenblatt creates the first computer to simulate human memory.

The study of human memory was greatly changed in 1943 when Warren McCulloch and Walter Pitts wrote a paper on how neurons might work. (Neurons are the cells that makeup tissue in the part of the nervous system involved in learning and recognition.)

D.O. Hebb described the strengthening of neural connections that occurred each time they were used.

In the early days of artificial intelligence research, Frank Rosenblatt (1928-1971) - a computer scientist at the Cornell Aeronautical Laboratory in New York - was studying how the eyes of a fly work. Rosenblatt observed that when a fly perceives danger, its reaction occurs faster than the information can be processed by its brain. He then produced the perceptron, the first computer to learn new skills using a neural network mimicking human thought processes. The perceptron had a layer of interconnected input and output nodes. Each connection is "weighted" to make it more or less likely to stimulate another node. Rosenblatt's Mark 1 perceptron followed in 1960, the first machine to "learn" to recognize and identify optical patterns.

practicality grew with the advent of "backdrop" perceptrons, which include "hidden"  layers that greatly increase the complexity.

 
John Hopfield then introduced his model of neural networks, which can store memories of patterns so that when the network is presented with ven partial information, it can retrieve the full pattern - rather like humans.

Today, Neural Networks are the foundation for,

- The Optical character recognition employed in scanners.

 - Weather forecasts

 - Bomb detectors, 

 - Financial market predictions

Powered Exoskeleton

Powered Exoskeleton (1965)

General Electric creates a superstrength suit.

". . . You don't have to think about it . . . you just wear it and it takes orders directly from your muscles."

The powered exoskeleton is a good case of life imitating art. Robert A. Heinlein's 1959 novel Starship  Troopers described warriors in powered suits. The idea was used again in the Marvel Comic Iron Man, with a man inside a powerful homemade iron suit.

General Electric

Hardiman

 The idea struck a chord, and General Electric took up the task of turning it into reality. By 1965 they had produced "Hardiman," the first powered exoskeleton.

The idea behind the device was to produce a robot that reacted to the natural muscle movements of the wearer. It was designed to act like a "second skin," albeit one that weighed as much as a car. Hardiman was a 3/4 - ton monster, designed to lift 1,500 pounds (680 kg). Unfortunately, the team never managed to get Hardiman working. Any attempt to power up the full-frame caused a "violent and uncontrolled movement," and as such, the machine was never fully turned on with a person inside. One arm of the behemoth did wor, lifting 750 pounds (340 Kg) as predicted, but this was as far as the project went. The challenges in making such a monster work in a controlled way, without crushing the human inside, made it impossible to build a practical product.

• An operator demonstrates the Hardiman's arm the one part of the behemoth that worked reliably.

LSD (1938)

Lysergic Acid Diethylamide (LSD) (1938)

Hofmann discovers the world's most powerful mind-altering drug.

Lysergic acid diethylamide (LSD) is a powerful psychedelic drug. While now commonly associated with 1960s dropout youth culture, it was heralded as a wonder drug in the 1940s and 1950s and was used to treat thousands of psychiatric patients

Swiss chemist Albert Hofmann (1906-2008) first synthesized LSD in 1938, expecting it to be useful as a medicinal stimulant. In 1943 he returned to studying it and after experiencing some pleasant sensations while working with the drug he took a dose of 0.25 mg.

Hofmann bicycled home and began to experience its psychedelic effects, the world's first "trip." He reported that the morning after he felt entirely renewed and that his senses were "vibrating in a condition of highest sensitivity."

Today LSD is mainly taken as a recreational drug for its psychological effects. Common accounts are of colorful hallucinations, time distortions, loss of identity, and synesthesia. A trip can last up to around twelve hours, depending on the dose. Physical effects include hypothermia, fever, increased heart rate, perspiration, tremors, and more commonly can result in intermittent flashbacks to the trip.

Due to LSD's extraordinary impact on the psyche, it has attracted a number of high profile users, who believed that it could unlock certain aspects of experience that are otherwise hidden. Preeminent among these were countercultural psychologist Timothy Leary, who urged Americans to "turn on, tune in, and drop out," and author Aldous Huxley, who chose to be injected with LSD as he died.

On November 22, 1963, Aldous Huxley, bedridden and dying, requested on a writing tablet that his wife Laura give him a 100 microgram dose of LSD. As she went to get the drug from the medicine cabinet, Laura was perplexed to see the doctor and nurses watching TV. She gave him a second dose a few hours later, and by 5:20 p.m. he had died. Laura later learned that the TV had been showing coverage of the assassination of John F. Kennedy, who had been pronounced dead at 1:00 p.m. that day.

Blue Jeans (1873)

History of Jeans

strauss and Davis combine denim and rivets

The history of blue jeans can be traced to two men - Levi Strauss (1829 - 1902), a German who emigrated to the United States as a young boy, and the lesser-known Latvian Jacob Davis (1834 - 1908), who moved to the United States in 1854.

In 1853 Levi Stauss moved to San Franciso where he set up a company, Levi Stauss & co., selling buttons, scissors, bolts of cloth, and canvas. He also designed heavy-duty canvas work overalls for local miners. When his canvas supplies ran out, he began using heavyweight cotton twill, later known as denim.

One of Strauss's customers was a tailor, Jacob Davis, who also made work trousers. His clients were complaining that the pockets kept ripping out, so Davis devised a method of strengthening the pocket corners

and fly fastenings with metal rivets. This was an immediate success, but Davis did not have the money to obtain the patent, so he approached Strauss. An astute businessman, Stauss paid for the paperwork and the two men filed a joint patent for the new rivet-strengthened work trousers on May 20, 1873.

Davis went to work for Levi Stauss & Co., overseeing the production of the new work trousers, which were not called jeans until the 1960s. They quickly became popular and their fame as the best work trousers spread and their fame as the best work trousers spread throughout the United States. In around 1890 the patent ran out, allowing any company to manufacture riveted jeans. At the same time, Levi Stauss & Co. assigned their jeans the number 501. The term Levi's, however, was not coined by the company but by the public, and the company trademarked the name.

• Jean-wearing miners pose by a wagon in the 1890s, a portrait tailor-made for the rugged Levi's image.

Draisine (1817)

Event of Bicycle Invention

Drais invents an early form of the bicycle.

In 1815 the Tambora Volcano in Indonesia erupted, starting a chain of events that led to the invention of the bicycle. The eruption was the largest in recorded history and dumped tons of ash into Earth's atmosphere. This caused the global temperature to drop and did terrible things to crops.

Three years earlier, following some bad weather in 1812, the price of oats was climbing, and the German inventor Karl Drais (1785 - 1851) was looking for something to replace hungry horses. He designed a four-wheeled vehicle, powered by a servant sitting in the backpedaling, while the master steered from the front with a tiller. It did not catch on and Drais decided to focus instead on surveying equipment.

After the 1815 Volcanic eruption, even worse weather caused oat prices to climb higher still. The need for horseless transport was even more pressing, and so Drais tried again. He switched from four wheels to two and got rid of the pedals completely. What he invented in 1817 was called the draisine or the draisienne, depending on where you lived.

The design was simple: a light wooden frame supported the rider between the wheels, the rider used his or her feet to push, and the machine could reach speeds of 12 miles per hour (19 kph). The machine quickly became popular, despite being quite uncomfortable to ride, and was copied all over the world, but some of the cheaper imitations lacked brakes, making them particularly dangerous. After being banned from sidewalks as a hazard to pedestrians, they went out of fashion. But they led the way for the bicycles that would follow.

The History of Telescope

“With increasing distance, our knowledge fades and fades rapidly. Eventually, we reach the dim boundary—the utmost limits of our telescopes. There, we measure shadows, and we search among ghostly errors of measurement for landmarks that are scarcely more substantial. The search will continue. Not until the empirical resources are exhausted, need we pass on to the dreamy realms of speculation.”

Edwin Hubble, The Realm of the Nebulae (1936)

• The Telescope with which Galileo explored the solar system is held at the Museo Della Scienza, Florence.
• These observations - based sepia wash studies of phases of the moon were executed by Galileo in 1609

The legend goes that, playing one day in their father's spectacle shop, two Dutch children realized that if they looked through both a concave lens close to their eye and a concave lens held at arm's length, the local church tower was greatly magnified.

Their father, Hans Lippershey (circa 1570 -1619), then mounted the two lenses in a tube and tried to sell the device to the Dutch Army. Whether the credit for this invention should go tho Lippershey or to, for example, Zacharius Janssen or Jacob Metius, or even the Englishman Leonard Digge, has become a matter of considerable debate. At the very least, Lippershey is generally credited with popularizing the device and creating and disseminating designs for the first practical telescope. Soon similar instruments, known as "dutch Trunks," were appearing all over Europe.

The Italian astronomer and Physicist Galileo Galilei heard about the new device when he was in Venice in May 1609. Returning to his university in nearby Padua, he made a telescope that magnified by about one-tenth of a degree. Using this, he discovered that the sun had spots, Jupiter was accompanied by four satellites, Venus had Phases, and the moon was mountainous. These results he published in March 1610 in his work, Siderius Nuncius (The Sidereal Messenger).

Telescopic Astronomy never looked back. By 1611, the German astronomer Johannes Kepler was using a telescope consisting of two convex lenses, an instrument that gave greater Magnification but an inverted image. 

In 1668 the English genius Sir Isaac Newton invented the reflecting telescope, which uses a curved mirror rather than a large lens to collect and focus light, thus eliminating the problem of severe chromatic aberration.