Category Archives: Science

How Electricity Works

Science

In the latest science blog for England’s North East ALBERT SIMPSON explains how electricity works.

Man’s discovery and ability to utilise the natural phenomena of electricity has perhaps changed the world like no other. From its beginnings, bringing daylight to the darkness of night, right through to its facilitation of the modern digital age, there is certainly no denying electricity’s importance.

As far as North East England is concerned few regions have played such an important part in the development of electricity as a resource to serve man and this was particularly the case in the pioneering developments of electric light during the nineteenth century.

Joseph Swan (left) Charles Algernon Parsons (right)
Joseph Swan (left) Charles Algernon Parsons (right)

The region saw the invention of the world’s first electric light bulb by Sunderland’s Joseph Swan (1828-1914), whose later Gateshead home was the first to be wired for electric light. Further north Cragside in Northumberland was the first house in the world to be lit by electricity generated from water power.

In Newcastle, Moseley Street was the first street lit by electricity and the city’s Portland Road saw engineer J.H. Holmes manufacture the first quick break electrical switch.

The Tyneside-based engineer Charles Algernon Parsons (1854-1931) can perhaps make an even greater claim, being occasionally referred to as ‘the man who invented the twentieth century’ from his development of turbines that enabled wide-scale generation of electricity. However we will leave the industrial pioneers for another day and ask a question:

What exactly is electricity?

Despite the huge role electricity plays in our lives few understand it and it is a wide ranging subject. Usually if you open any electrical text books you are quickly thrown into an array of complex laws and mathematics.

I will avoid the text book stuff and explain electricity as we most encounter it, as an energy supply channelled via wires.

My previous blog  something about nothing  explained how over ninety nine percent of each and every atom is in fact empty space and that less than one percent is mobile particle matter: namely protons, neutrons and the much tinier electrons. It also explained how interactive push and pull forces between those highly mobile atomic particles give an atom its space, volume size and shape, and how atoms are then joined to make the solids, liquids and gases of our world.

The Electricity of Wired Circuits

Electron particles do not like one another. Any electron moving the most miniscule of distance towards another electron will transfer energy in the form of a ‘push away’ to that electron and cause it to move. Any electron moving away from another electron will reduce the ‘push away’ on that electron encouraging the first electron to follow.

battery

A battery (above) produces extra electrons at its negative terminal and removes electrons from the positive terminal. Consequently, electrons in a wire attached to the negative terminal are pushed away from that terminal and electrons in the positive wire are pulled toward that terminal.

Push and pull forces between electrons act at the speed of light (300,000 metres a second) and electrons, being light in weight and not held too tightly by their parent atoms, respond quite quickly to those transmitted forces and move.

Electrons on the move transmit changed forces to other electrons so that they in turn move and cause other electrons to move and so on. That is how energy is transmitted along wires.

Some people may term the electron movements in a wire as a flow.

However electron movements along wired circuits are slower than tortoise pace. That is so because although electrons move quite quickly between atoms they spend relatively lengthy times in their atom home

I prefer the term electron drift to electron flow.

Let’s be clear, it is not electrons whizzing around circuits that put our lights on almost instantly. It is the light speed transfer of energy via electrons to the electrons in our light bulb that does that.

Amperage is just a measure of the number of electrons involved in a drift. One amp equates to 6.25 billion, billion electrons drifting across a wire cross section every single second. That is a very big number but it is only equal to the number of electrons in about one tenth of a millimetre of wire length.

That is just one half of a metre every hour. Tortoises can certainly travel much, much faster than that.

tortoise

Why we use copper in circuit wiring.

Electrons are active in the space volumes around an atom’s nucleic centre.  Scientists call such space volumes electron clouds. Each cloud can have a maximum of two electrons.

Copper atoms have 29 protons, 29 electrons and 35 neutrons. The protons have little hold on outer cloud electrons so much so that some outer cloud electrons wander from atom to atom. This electron wander phenomenon is called an electron gas. Clearly the outer electrons of copper need almost no energy to move them along a circuit from atom to atom.

Copper is a good conductor because there is little energy wasted in moving its electrons along a wire.

Air is not a good conductor. Its atoms will in normal circumstances not release electrons in battery and mains circuits, so a switch that breaks a circuit makes for an easy way of stopping electron drift in a circuit.

Tungsten was until recently much used as the element in light bulbs. Tungsten does not give up its electrons like copper does. Tungsten has higher resistance. Many copper electrons have to move and thereby push or pull to make a single tungsten electron move. When the tungsten electron moves it has much energy and when it re-engages with a new ‘atom home’ it gives up that acquired energy as radiated light and heat.

pushpull

Our UK mains supply

When a north magnet pole moves across a wire, electrons in that wire are encouraged to move in a specific direction. When a south magnet pole moves over the same wire, electrons are encouraged to move in the opposite direction.

This link between magnetism and electricity is extensively used by the rotating machines in generating stations and in wind turbines to produce our UK alternating supply or AC alternating current.

In the UK supply system, an electron push followed by an electron pull repeats itself 50 times every second.

Generated supply is three phase and at very high voltage. The high voltage is in fact a high electron push and allows the transmission of high energies at low amperages. This enables the use of light-weight overhead distribution cables. The three phases are actually three lots of similar push-pulls but they are out of sync with each other.

threephase

Our homes are generally supplied with just one of these three phases and at a transformed, lower and safer 250 volts. The electron to and fro movements in the two wire (plus earth) pin plug supply of our homes is happening as a result of energy transfers between electrons (as previously described) but now over hundreds of miles and probably via several transformers.

The live brown wire electrons are being pulled and pushed whilst the neutral blue wire electrons are being pushed and pulled.  This is happening even when our domestic switches are turned off though the electron moves in such circumstances are so small as to not register on our energy meters.

When we close a switch, in a typical home circuit, electrons move back and forth in our wiring about one thousandth of a millimetre, albeit thousands of atom distances.  This shifting of electrons back and forth in a load delivers energy to that load, say an appliance, just as it did in the direct current battery circuit.

The electrical load is the major energy consumer. It always resists electron movement but not always in the way the tungsten bulb did. For instance, the electrical machines in our homes that rotate all resist electron movement magnetically in a sort of reverse of the generating station action.

Something about nothing

AlbertScienceTyne

North East science blogger ALBERT SIMPSON examines how we make something out of nothing.

SO, you think you’re something do you? 

Well let me put you right:

You are NOTHING!

Well, 99 per cent nothing, but don’t worry, I’m just the same, in fact everyone and everything else is just the same. Let me explain. We’ll start by taking a look at the wonderful Bamburgh Castle.

Banburgh is as solid as a rock but it's 99% nothing: Photo, David Simpson
Bamburgh is as solid as a rock but it’s actually 99% nothing: Photographed by David Simpson

When we look at this imposing fortress up on the majestic coast of Northumberland it is hard to comprehend that everything we see is more than ninety-nine percent nothing. How can it be that this grand stone building and the apparently solid rock on which it stands are mostly nothing? Not to mention that they have been photographed by a person who is also more than ninety-nine percent nothing – sorry son.

You see, EVERYTHING in our world is ninety-nine percent nothing.

That’s because the tiny atoms that make up our world are all over ninety-nine percent the space of outer space. For example, one billion atoms make up the diameter of a human hair and in each atom less than one percent are matter particles.

Matter particles are protons, neutrons and the much smaller electrons. The rest of an atom is nothing but empty space. Yes, the rest is nothing but nothing.

 

pointy

 

OK, so we are nothing, but how is it we FEEL and SEE the solids, liquids and gases that SEEM to take up so much space?

Well TOUCH is only a sense of contact

It might appear to us that when we push a car or when we make love that we are making multiple contacts, but that’s not so. Atom particles don’t easily make contacts. Their speeds of motion and their interacting ‘push and pull forces’ stop them from doing so – how unromantic.

Your feeling of an object is actually the object’s particle forces and your particle forces resisting the close approach.

But atomic particle forces don’t just push; they also have a pull capability. In solids such as Bamburgh Castle, these complex push and pull particle forces combine to bind atoms strongly together.

Such binding is less strong in liquids (like Bamburgh’s neighbouring sea) allowing greater flow, and weaker still in gases including Bamburgh’s surrounding air (air is a mix of gases) where atoms and  linked atoms (called molecules) move freely.

The human body is a combination of solid, liquid and gases maintained as an entity by particle forces.  All these particles feel the gravity pull of the earth’s particle forces yet when our body particles come close to earth’s particles, the forces strongly resist contact.

When you push a car your applied forces are transmitted via the car’s particle forces to every part of the car so that the car moves as a whole. In the process not one atom particle touches another.

CarPush2

You might think that when you push on a wall no movement occurs but trillions upon trillions of atom particles make tiny adjustments throughout your body and throughout the wall and throughout the ground, that both you and the wall push upon.

Your muscles’ forces are not steady and that leads to continuous particle movements each requiring small amounts of energy that sum to much energy use.  You do not move the wall but you use a lot of energy moving particles.

Your brain ‘feels’ the push because sensors in your skin constantly respond to the local force and frequency stimuli. They send electrical signals (which are also atomic particle force related motions) to the brain along the nerve pathways that form your central nervous system.

IF IT’S ALL 99 PER CENT NOTHING HOW COME WE CAN SEE IT?

Okay so now we know – quite literally – how we all feel, so we should now be able to see things more clearly. Hang on though, how come we can SEE so much if it’s all 99% nothing?

Well, SIGHT is our brain’s interpretation of radiations

To explain how we see all this empty space we need to understand something of the sight process.

Radio and wifi waves, microwaves, heat waves, visible light, ultra violet light, x rays and gamma rays are all electro-magnetic radiations.

We experience these radiations in a number of different ways.

Our bodies feel heat radiations through skin sensors. Ultra violet and higher radiations might damage our skin while our eyes only see the radiations we call visible light . We see these as light because our eyes have evolved sensors able to monitor the small range of frequencies that make up the visible light radiations.

spectrum
The spectrum of visible light

But what are these radiations?

Well, these radiations are supposedly mass-less photon particles that travel at the speed of light through the ninety nine percent space of atoms, as well as through atom free outer space.

Photons are the conveyors of energy packets. They are the parcel couriers of the Universe. And such couriers vary considerably in energy level which is frequency related. High frequency, high energy radiations are dangerous to humans; low frequency energies are not dangerous.

When a photon encounters atomic particles there is a probability that the total photon energy will be given up. Solids absorb almost all photon energies whilst liquids, glass and the gases of our atmosphere allow various levels of photon to pass through which is why we have varying degrees of transparency.

Sight involves photon absorption by the eye’s retinas.

Every point on each eye’s retina has numerous sensors designed to respond to visible light photons. Our eye lens focuses many radiations from a single view point onto a single retina point. Like piles of interesting informative packets of energy gathered together in some grand package delivery warehouse.

The brain receives electrical signals from the retina sensors, and interprets the data as an image of colours and shapes. So our brain is the sorting office that makes sense of it all and ensures we receive the information that help us make sense of the world.

eyeeye

Hot and Cold

High levels of energy emanate as radiations from hot particle motions, like those on the sun. But radiations also occur from cold objects which radiate any surplus energy they have. Like the sun, they radiate it in all directions.

In the daytime many objects on earth are absorbing sun-radiated energy and their atomic particle motions change as a result of the absorbed energy.

Some of the absorbed energy might be retained, leading to warmth or, in life forms, cell growth might result. However most energy absorbed is surplus and almost instantly  given up as radiations in all directions.

The absorption and subsequent emission of energies by earth’s atomic particles is a never ending process. It is happening everywhere.

The shapes and colours of our world arise because the frequency-related photon packets of energy given up by earth’s objects are mostly not the same as those absorbed.

The radiation emanating from an object or life form is very much related to the object’s atomic structure. Such energies are released in all directions in a continuous process. Some energy goes back through our atmosphere and into space; much will pass to other earth objects for absorption and re-emission.

palette

What our brain sees as the colours and shapes of objects is its own interpretation of the frequency of the energies radiated from those objects.

Man takes much pleasure in extensive experimentation with varying frequencies of radiated energies in our use of paint pigments, clothing dyes, make up and multi-coloured movie screens that can deliver desired results with so much visual satisfaction.  Yet it is all so fundamentally nothing. Well, mostly.

So in summary, if you really think you’re something in this colourful, multi-sensory, hot and cold seemingly object dominated world, well you may want to think again.

Not as solid as it seems: Photo, David Simpson

Next time we will look at particle forces in motion or ‘electricity‘ as you will very probably know it.