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The electrically literate may find this somewhat simplified article redundant; or possibly amusing. They should check out Wikipedia for any gaps in their knowledge.

But I hope this will help those for whom Wikipedia is a bit too complicated and/or detailed.

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All cartoons from The New Yorker - 1925 to 2004

 

 

Think of water in a hosepipe

 

Electricity is a means of transporting energy from a source, like the wind, to a device you use to exploit that energy, like your electric toothbrush.

The usual way of explaining electricity is to use the simile of the flow of water in a pipe (a current of water).  We are all familiar with a hose pipe.  Its pressure is analogous to the voltage; and the flow of water is analogous to the current. 

 

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The author - almost two - learning about currents and voltage

 

The work that can be done in an hour, for example if you use the jet to spin a bicycle wheel or push leaves along a path, is the pressure (like Volts) times the current (like Amps) for an hour. 

You won’t be able to squirt the water from your hose far if there is no pressure or if there is no water.  You need both.  If the pressure falls the water ceases to flow.

It’s the same with a stream (current) of electricity making its way down a conductor; for example a wire. The electrical force acting on an electrical current provides the power to do work.

Most quantities in modern physics are named after an early natural philosopher or inventor.  If we had let tradition do it, each would probably be related by some strange number, like the number of feet in a mile; or pounds in a ton.  But most new physical values use the decimal system (the rationalised MKS or SI units: meter, kilogram, second).

A Watt is a measure of Power; the instantaneous capacity to do work; named after James Watt. 

Under this system we define one Watt as equal to one Volt (electrical  force) multiplied by one Ampere (current); or Amp for short.  Read More...

Using this simple relationship you can easily calculate that 1000 Watts of power (one kilowatt) can be carried by a current of 4.17 amps at 240 volts (240 x 4.17 = 1000)

But the same power requires only 0.002 amps at 500,000 volts (0.002 x 500,000 = 1000).  So when you turn on an electric kettle or toaster it will draw around 4 amps in your home at 240V but only 0.002 amps in the very high voltage grid to bring it from the generator in the power station.

Power exerted for a period of time is called Energy.  Physicists measure energy in Joules (1 J= 1Watt acting for 1 second).  But to get to a smaller working number electricity companies like to measure energy in kilowatt hours (1 kWh =  3,600 kJ = a thousand Watts acting for the seconds in one hour) 

When your bill comes, you get charged for the Energy, the number of kWh* you used, not Power (kW).

 

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*Terminology:  1000 Wh = 1 killowatt hour (kWh); 1000 kWh=1 megawatt hour (MWh); 1000 MWh = 1 gigawat hour (GWH), 1000 GWH = 1 terawatt hour (TWh).

 


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Travel

Japan

 

 

 

 

In the second week of May 2017 our small group of habitual fellow travellers Craig and Sonia; Wendy and I; took a package introductory tour: Discover Japan 2017 visiting: Narita; Tokyo; Yokohama; Atami; Toyohashi; Kyoto; and Osaka.  

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Fiction, Recollections & News

The Greatest Aviation Mystery of All Time

 

 

The search for Malaysia Airlines Flight 370 was finally called off in the first week of June 2018.

The flight's disappearance on the morning of 8 March 2014 has been described as the greatest aviation mystery of all time, surpassing the disappearance of Amelia Earhart in 1937.  Whether or no it now holds that record, the fruitless four year search for the missing plane is certainly the most costly in aviation history and MH370 has already spawned more conspiracy theories than the assassination of JFK; the disappearance of Australian PM Harold Holt; and the death of the former Princess Diana of Wales; combined.

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Opinions and Philosophy

The Prospect of Eternal Life

 

 

 

To die, to sleep;
To sleep: perchance to dream:
ay, there's the rub;
For in that sleep of death what dreams may come
When we have shuffled off this mortal coil,
Must give us pause:
… But that the dread of something after death,
The undiscover'd country from whose bourn
No traveller returns, puzzles the will
And makes us rather bear those ills we have
Than fly to others that we know not of?
Thus conscience does make cowards of us all;

[1]

 

 

 

 

When I first began to write about this subject, the idea that Hamlet’s fear was still current in today’s day and age seemed to me as bizarre as the fear of falling off the earth if you sail too far to the west.  And yet several people have identified the prospect of an 'undiscovered country from whose realm no traveller returns' as an important consideration when contemplating death.  This is, apparently, neither the rational existential desire to avoid annihilation; nor the animal imperative to keep living under any circumstances; but a fear of what lies beyond.

 

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