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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 kilowatt hour (kWh); 1000 kWh=1 megawatt hour (MWh); 1000 MWh = 1 gigawatt hour (GWH), 1000 GWH = 1 terawatt hour (TWh).

 

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Travel

Turkey

 

 

 

 

In August 2019 we returned to Turkey, after fourteen years, for a more encompassing holiday in the part that's variously called Western Asia or the Middle East.  There were iconic tourist places we had not seen so with a combination of flights and a rental car we hopped about the map in this very large country. 

We began, as one does, in Istanbul. 

Read more: Turkey

Fiction, Recollections & News

A cockatoo named Einstein

 

 

 

A couple of days ago a story about sulphur-crested cockatoos went semi-viral, probably in an attempt to lift spirits during Sydney's new Covid-19 lock-down. It appears that some smart cocky worked out how to open wheelie-bin lids.  That's not a surprise - see below.  What is surprising is that others are copying him and the practice is spreading outwards so that it can be mapped in a growing circle of awareness. The cockies are also choosing the red (household rubbish) bins that may contain food, disregarding yellow (cans and bottles); blue (paper and cardboard) and green bins (garden clippings). Yet, now they have also been observed checking-out other potentially food containing bins.

One has even been observed re-closing the lid - presumably to prevent other birds getting to the food.

Back in the 1950's I was given a pet sulphur-crested cockatoo we named Einstein. I was in primary school and I didn't yet know who Einstein was. My father suggested the name - explaining that Einstein was 'a wise old bird'.

Read more: A cockatoo named Einstein

Opinions and Philosophy

Manufacturing in Australia

 

 

 

This article was written in August 2011 after a career of many years concerned with Business Development in New South Wales Australia. I've not replaced it because, while the detailed economic parameters have changed, the underlying economic arguments remain the same (and it was a lot of work that I don't wish to repeat) for example:  

  • between Oct 2010 and April 2013 the Australian dollar exceeded the value of the US dollar and that was seriously impacting local manufacturing, particularly exporters;
  • as a result, in November 2011, the RBA (Reserve Bank of Australia) reduced the cash rate (%) from 4.75 to 4.5 and a month later to 4.25; yet
  • the dollar stayed stubbornly high until 2015, mainly due to a favourable balance of trade in commodities and to Australia's attraction to foreign investors following the Global Financial Crisis, that Australia had largely avoided.

 

 

2011 introduction:

Manufacturing viability is back in the news.

The loss of manufacturing jobs in the steel industry has been a rallying point for unions and employers' groups. The trigger was the announcement of the closure of the No 6 blast furnace at the BlueScope plant at Port Kembla.  This furnace is well into its present campaign and would have eventually required a very costly reline to keep operating.  The company says the loss of export sales does not justify its continued operation. The  remaining No 5 blast furnace underwent a major reline in 2009.  The immediate impact of the closure will be a halving of iron production; and correspondingly of downstream steel manufacture. BlueScope will also close the aging strip-rolling facility at Western Port in Victoria, originally designed to meet the automotive demand in Victoria and South Australia.

800 jobs will go at Port Kembla, 200 at Western Port and another 400 from local contractors.  The other Australian steelmaker OneSteel has also recently announced a workforce reduction of 400 jobs.

This announcement has reignited the 20th Century free trade versus protectionist economic and political debate. Labor backbenchers and the Greens want a Parliamentary enquiry. The Prime Minister (Julia Gillard) reportedly initially agreed, then, perhaps smelling trouble, demurred. No doubt 'Sir Humphrey' lurks not far back in the shadows. 

 

 

So what has and hasn't changed (disregarding a world pandemic presently raging)?

 

Read more: Manufacturing in Australia

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