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The Electronic Age

2019-06-16T03:40:00.000-07:00

We saw last time how the first generation of digital computers were built around the first generation of automatic electrical switch, the electromagnetic relay. But by the time those computers were built, another digital switch was already waiting in the wings. Whereas the relay was an electromechanical device (because it used electricity to control a mechanical switch), this new class of digital switches was electronic – founded on the new science of the electron, a science born around the turn of the twentieth century. This science concretized the carrier of electrical force as not a current, wave, or field, but as a solid particle. The device that gave birth to an electronic age, rooted in this new physics, became known (at least in the U.S.) as the vacuum tube. Conventionally, two men figure in the story of its creation: the Englishman Ambrose Fleming, and the American Lee de Forest. In fact, of course, its origins are more complex and woven from many threads, which criss-cross Europe and the Atlantic, and stretch back as far as the early Leyden jar experiments of the mid-eighteenth century. For the purposes of our story, however, it’s convenient, and illuminating (so to speak) to begin with Thomas Edison. Edison made a curious discovery in 1880s as part of his work on a new kind of electric light, a discovery that sets the stage for our story. From there, further development of the vacuum tube was spurred by the demands of two other technological systems: a new form of wireless communication, and the ever-expanding long-distance telephone networks. Prologue: Edison Edison is, in the popular imagination, the inventor of the electric light bulb. This gives him both too much credit and too little. Too much credit, again, because Edison was not the only one to devise an incandescent bulb. In additional to a variety of pre-commercial predecessors, Joseph Swan and Charles Stearn in the U.K. and fellow American William Sawyer brought lamps to market around the same time as Edison. All consisted of a sealed, glass bulb containing a resistive filament. When placed in an electrical circuit, the heat generated by its resistance caused the filament to glow. The bulb was evacuated of air to prevent the filament from burning. Electric light was already commonplace in large cities in the form of electric arc lamps, used to illuminate large public spaces. All these inventors were trying to “subdivide the light,” drawing from the flaming arc a spark small enough to enter the home and replace gas lamps with a light source that was safer, cleaner, and brighter. What Edison — or, more correctly, the industrial lab which Edison headed — did, however, was more than merely to create a light source. He – it – built an entire inter-operable electrical system for home lighting – generators, transmission wires, transformers, and so forth, of which the bulb was only the most obvious and visible component. The presence of Edison’s name in his power companies was not a mere genuflection to the great inventor, as was the case with Bell Telephone. Edison proved himself not only an inventor strictly speaking, but also an able system builder.1 To that end, his lab continued to tinker with the various components of electric lighting even after their early successes.

As part of these researches, some time in 1883, Edison (or perhaps one of his employees) decided to seal a metal plate into the incandescent lamp, along with the filament. The accounts of why he did this do not present a clear and unambiguous picture. But it was probably an attempt to alleviate the problem of lamp blackening: the tendency of the the glass interior of the bulb to accumulate a mysterious dark substance over time. Edison (if it was him) probably hoped that the blackening particles could be drawn off onto the electrified plate. To his surprise, however, he found that when the plate was wired into a circuit with the positive end of the filament, a current flowed that was directly proportional to the intensity of the filament’s glow. When it was connected to the negative end of the filament, nothing happened. Edison believed this effect, later dubbed the Edison effect, could be used to measure or even regulate the “electro-motive force,” or voltage, in an electrical power system. As was his habit, he filed a patent for this “electrical indicator,” then returned to other, more pressing matters.2

2019-05-25T21:25:00.001-07:00

A healthy diet is essential for good health and nutrition.

It protects you against many chronic noncommunicable diseases, such as heart disease, diabetes and cancer. Eating a variety of foods and consuming less salt, sugars and saturated and industrially-produced trans-fats, are essential for healthy diet.

A healthy diet comprises a combination of different foods. These include:

Staples like cereals (wheat, barley, rye, maize or rice) or starchy tubers or roots (potato, yam, taro or cassava).
Legumes (lentils and beans).
Fruit and vegetables.
Foods from animal sources (meat, fish, eggs and milk).

Here is some useful information, based on WHO recommendations, to follow a healthy diet, and the benefits of doing so.

Breastfeed babies and young children:
- A healthy diet starts early in life - breastfeeding fosters healthy growth, and may have longer-term health benefits, like reducing the risk of becoming overweight or obese and developing noncommunicable diseases later in life.
- Feeding babies exclusively with breast milk from birth to 6 months of life is important for a healthy diet. It is also important to introduce a variety of safe and nutritious complementary foods at 6 months of age, while continuing to breastfeed until your child is two years old and beyond.
Eat plenty of vegetables and fruit:
- They are important sources of vitamins, minerals, dietary fibre, plant protein and antioxidants.
- People with diets rich in vegetables and fruit have a significantly lower risk of obesity, heart disease, stroke, diabetes and certain types of cancer.
Eat less fat:
- Fats and oils and concentrated sources of energy. Eating too much, particularly the wrong kinds of fat, like saturated and industrially-produced trans-fat, can increase the risk of heart disease and stroke.
- Using unsaturated vegetable oils (olive, soy, sunflower or corn oil) rather than animal fats or oils high in saturated fats (butter, ghee, lard, coconut and palm oil) will help consume healthier fats.
- To avoid unhealthy weight gain, consumption of total fat should not exceed 30% of a person's overall energy intake.

Air Vent Cleaning Set

2019-05-23T18:13:00.000-07:00

Annoyed with all the dust and dirt in your car's air vent but can't seem to get it out? Not anymore with this Air Vent Cleaning Set! This cleaning set comes with an extremely soft brush suitable for dusting and cleaning nooks on your car dashboard such as air vents, gaps between the steering wheel, ash trays etc. There is no chance of scratching expensive rims, clear coat, chrome finish or delicate interiors as this brush is 100% Metal free!

The bristles are made at the Perfect Length to reach into motorcycle wheels, air conditioning vents, interior door panels and other tight spaces that you can't reach with normal brushes. The Air Vent Cleaning Set is also great for cleaning computers, laptop keyboards and sliding door runners.

The size of the cleaning set makes it EASY to store in the car. Its tray is good to hold all the dust and for easy disposal into the trash.

Keep your car extra clean and tidy today with this cool tool!