Magnetism

Magnets in Technology

Another big subject: how magnets have infiltrated our daily lives. It’s remarkable to think how magnet based technology has shaped our lives over the last century to the point of utter dependency.

Without magnets we wouldn’t have electricity, thanks to Michael Faraday who showed that electricity, magnetism and motion are all linked.  Electric generators can be powered by wind, water, coal, oil, gas, petrol, diesel or nuclear power, without magnets they would just be producing heat.

Magnets are integral to computers, smart phones, speakers not to mention scientific instruments which help us discover more about our world such as MRI scanners or  Large Hadron Collider the largest magnetic instrument on the planet working at the quantum physics level.

Thousands of “lattice magnets” on the LHC at CERNbend and tighten the particles’ trajectory. They are responsible for keeping the beams stable, and aligned so they don’t touch the sides of the accelerator as they reach near the speed of light . 1232 main Dipole magnets are arranged along the 27 km length of the  collider each 15 metres long and weighing in at 35 tonnes (click to see the film).

At the other end of the scale magnetic nano sensors are being developed for many research applications and one area of interest which is gathering pace are those used in neuroscience.  As magnets get stronger they can also get smaller and therefore more affordable, opening up research possibilities like Magnetoencephalogram (MEG) headset technology.  I mentioned this in a previous blog which use quantum sensors (SQUIDS) to measure the weak magnetic fields produced by the brains electrical activity.

At UCL in collaboration with Nottingham University they have secured funding from the Welcome Trust to develop fully a portable headset. Professor Barnes (UCL): “Our scanner will be worn on the head like a helmet, meaning subjects can undertake tasks whilst moving freely in an open and natural environment.”

Compare this technology with Dr. Cohen’s shielded room at MIT in 1968, in which first Magnetoencephalogram was measured.

There is some overlap here with the work of Prof Joe Kirschvink, studying  Magnetoreception in Humans, more on that in the next blog post.

Without bacteria we wouldn’t have skyscrapers…

Periodic table Number :26   /    known as element  “Fe” (from latin Ferrum)

Iron is the most common element on earth by mass, it’s found in rocks and living things.  It’s in our blood which is why its red in colour due the reaction with oxygen when transferred from our lungs into the haemoglobin.  But how did it get there in the first place?  To understand this we need to take a big step back in time, 1.8 billion years ago, when atoms of iron were floating around in the oceans.  Bacteria capable of photosynthesis releasing oxygen into the sea enabled iron to be converted into hematite and magnetite minerals which sank to the sea floor.  This was fundamental to the geological process in forming iron deposits which were later covered by other minerals and compressed into rock over millions of years.

iron ore mine in Australia

Iron ore was first used in the near east and spread around the Mediterranean in all directions expanding populations as a result of more efficient tools and the ‘iron age’ began.   The end of the bronze age around 1200BC was heralded by the development of iron smelting (heating iron ore with coal) which in turn lead to the birth to the industrial revolution in Northern Europe changing societies rapidly with mass production methods.

ancient iron smelting technique in Rwanda

Skyscrapers rely on steel (99% iron 1% carbon) to give the structure enough strength to build as high as the Burj Khalifain Dubai at 828 meters, all thanks to bacteria

Today we can see chemotrophic bacteria which get their energy by oxidising molecules of iron and therefore thrive in areas rich in iron deposits so the bacterial cycle continues. .  When you see orange coloured stream beds you are seeing the specialised iron oxidising bacteria at work.

Humans need iron or we become anaemic (tired and lacking vitality) and we get this by eating food containing iron.  Humans are 10%  bacteria (by mass) and those bacteria too need iron and they have specialised ways of harvesting the iron they need from their human host. “Iron is the single most important micronutrient bacteria need to survive,” (Doyle, 2008) and without bacteria humans can’t survive.  This is one of the many symbiotic relationships animals and humans have with bacteria.

bacteria that feed on iron

References:

Doyle, 2008: Journal of Bacteriology (volume 190, issue 16) published by the American Society for Microbiology. https://www.sciencedaily.com/releases/2008/07/080731140223.htm

Iron-Oxidizing Bacteria: https://www.researchgate.net/publication/44689809_Iron-Oxidizing_Bacteria_An_Environmental_and_Genomic_Perspective

 

Magnetism as subject in Art works

Below are a few examples of magnets being used in recent years by artists.

Mickey Mouse & Goofey discovering the joys of magnetism 

An example of magnets being used in a sculpture by Caleb Charland

“suspension” by Bruce Grey

“Magnetism” By Ahmed Mater al Ziad-2012

“350 Points towards infinity” by Tatania Trouve

‘Untitled’ works by Mona Hatoum

Levitating ball by Alex Baker

Catherine Richards – ‘Cabinate of curiosity at the end of the millennium.’ 1995. this is a rudimentary Faraday Cage which sites the viewer in the box negating all magnetic fields – at least in theory.

Brainwaves are a bit like the Earths magnetic field lines

It’s amazing to me that the brain also generates magnetic fields outside of our heads.  Perhaps this is what some people call the ‘aura’ of a person but I’ll leave that for another day. Proof of these magnetic fields are evidenced in the use of very sensitive magnetic sensors which are placed on the head, usually by neuroscientists conducting experiments, which pick up electrical wave lengths via the magnetic fields they produce.  Neuroscientists can look at the graph produced by the EEG (electroencephalogram) and make diagnoses like epilepsy or sleep disorders.  Magnetoencephalogram (MEG) headset technology is able to detect magnetism deeper in the brain (without any ill effects on the subject) and can give a more detailed picture of the cognitive processes in different areas in the brain whilst performing different activities.

Magnetoencephalogram (MEG) 3D printed headset developed by Nottingham University.

Richard Brightis an artist using EEG technology in his artwork who gave a talk at London Laser Project (a Leonard initiative) based at Central Saint Martins.



check out China Blue for her EEG interactive sound sculpture

Imagining Blue

Lisa Park also uses EEG in her performance work :  http://www.thelisapark.com

 

Aurora Borealis & Cosmic Magnetism

Without the magnetic field generated by the earths liquid iron core two thousand miles beneath our feet we wouldn’t have the spectacle of the Northern Lights.

This is a phenomena whereby the magnetic field producing the North and South Poles at either end of the earth have the strongest magnetic pull.  Charged particles emitted from the sun during increased sunspot activity, also known as coronal mass ejections, create radiation also known as ‘solar wind’ which is dragged toward the North and South poles.

The magnetosphere is a magnetic shield that protects us from the majority of this solar radiation but the charged particles which do get though do so during increased activity during the suns 11 year cycle.

Here’s a video I posted on Vimeo showing the magnetic field lines of the Sun observed over a 4 year period.  The different colours correspond to the distance the field lines travel away from the surface.

The bright colours are generated when the charged electrons and protons collide with the gases in the earths atmosphere and are converted into photon energy that lucky observers can see when near the poles at night during increased sun spot activity.  Oxygen in the upper atmosphere emits green or orange-red, depending on the amount of energy absorbed.  Nitrogen emits blue or red; blue if the atom regains an electron after it has been ionized, red if returning to ground state from an excited state.

Scientists have discovered how the Earth’s magnetic field fluctuates, but also weakens and reverses dramatically every 200,000 years or more.  The next flip is overdue and scientists have observed significant weakening of the magnetic field over the last 100 years decreasing in strength about 5 percent per decade and some believe this is the beginning of a polarity reversal.  During this event the earth’s magnetic shield is reduced and the charged particles would hit the earth everywhere on the side facing the sun, creating an Aurora spectacle for everyone to see.  The downside is that there would be a corresponding increase in cancer rates as we are bombarded with harmful radiation we are currently protected from by our magnetic field.

This image shows a computer generated model of the Earth’s fluctuating magnetic field thousands of years ago based on data from lava samples which have fixed the earths magnetic field in the rock as they cooled down.

In the piecing together of the moving magnetic field over 100’s, 1000′ s and millions of years brings together unlikely disciplines analysing navigational maritime charts, ancient pottery and geo magnetic core samples.

This film  helps visualise the aurora and how the earth’s polarity is due to flip :  http://www.aurora-service.eu/aurora-school/aurora-borealis/

The Planck space observatory used by the ESA 2009 – 2013 gathered magnetic field data of our Milky Way galaxy producing this image.

GeoMagnetism

Over a series of posts I’d like to talk about lots of different aspects of this Natural force of Nature.  From Geomagnetism to the Magnetosphere and from historic Navigational compasses to Magneto-reception in animals. But first I’d like to talk about the biggest magnet on earth : Planet Earth.

The earths North and South poles exist as a result of molten iron swirling miles beneath our feet.  This liquid outer core at the centre of the earth is very active and flows in random patterns a bit like our weather.  What generates this continuous movement, is the spin of the earth in space, which is 1000 miles per hour at the equator.  Because of the spinning, a motor like effect is produced and in turn electrical currents are generated by the swirling iron.  It’s these electrical currents which are responsible for creating the magnetic fields which polarise the Earth into a giant magnet with a North and a South pole.

More interestingly the North and South poles are constantly moving and we have to make an adjustment when using a map (which has a fixed north) with a compass (which follows the moving magnetic North).  Here’s a link which explains this magnetic declination : http://www.magnetic-declination.com/what-is-magnetic-declination.php

NOAA has a very cool website about declination and this page shows where the north pole has moved over the last 400 years which was painstakingly generated from shipping logs collected from hundreds of historic journeys.  This illustration shows the movement of magnetic north over the last 100 years.  https://maps.ngdc.noaa.gov/viewers/historical_declination/

Here’s a video I posted on Vimeo showing the movement of the magnetic North Pole over the last 300 years.

As well as orienting the earth’s magnetic field lines from north to south, the magnetic field also extends out beyond the earths atmosphere creating the Magnetosphere.  Without the Magnetosphere, life on earth wouldn’t have evolved as we know it today because it shields us from the suns harmful radiation as this illustration shows.

This is also the reason we get the Northern Lights, more on this in the next post.  I’ll leave you with this rather understated quote:

“I happen to have discovered a direct relation between magnetism and light, also electricity and light, and the field it opens is so large and I think rich.”      — Michael Faraday (1899)

Magnetoreception and Migration

I’m fascinated by this subject.  For hundreds of years humans have known of animal migration, at least seasonally animals appeared and disappeared, the mechanics of which have been a mystery until recently.  Science has discovered that most animals have a sense which can detect the earths magnetic field, in short they instinctively know which way is north and south.  This is a young area of science and we are still finding out to what degree this sense plays a part in the migration patterns of animals.

The animals which have been studied and proven to have a magnetic sense are: pigeons, salmon, trout, dolphins, whales, squid, octopus, fruit flies (of course), mice (of course), moles, bats, red fox, roe deer, red deer, eels, robins, turtles, dogs, geese, in fact most migratory birds – and the list goes on.  However, it is apparently a difficult sense to study compared to the other senses which is why we don’t have a comprehensive list.  Humans on the other hand don’t seem to demonstrate a clear magnetic sense at all, although there have been studies which claim to show that we do have this magneto-receptive ability.

Here Joe Kirschvink (Human Frontier Science Program, California) wearing an EEG monitor inside a faraday cage (which neutralises the earths magnetic field and induces a new field in any direction).  Kirschvink, a respected geophysicist, suggests that human Magnetoreception is a primal sense which we may have lost but is still doing experimental work in this area with colleges in Japan.

This of raises the question as to whether Humans have lost their sense of direction both literally but also metaphorically when we consider the state of the planet in ecological terms and socio equality.  If we have lost this Magnetoreception then when in our evolutionary history did it become genetically deselected and why?  Could it have been as a result of our move from hunting & gathering to farming when we first put down roots as a species around 10,000 years ago?  Perhaps we’ll never know but for me this is a rich area of postulation that will, no doubt, migrate into my own work.

magnets, iron filings, magnetic canvas (rusted) by richard paton 2017

Early Magnetic Field Navigation

The earliest basic magnetic compass, like many of humanity’s important technological breakthroughs, owes its development to the necessities brought on by warfare. Emperor Hoang-ti (2700 B.C.) used a magical stone  hung on horse drawn wagons in pursuit of his enemies giving a tactical advantage.

Lodestone is the name given to this iron rich mineral magnetite which orientated itself along the magnetic field lines. As a consequence of its seemingly magical property became highly prized and worth its equivalent weight in silver.  The magnetic stone was either suspended by a thread or placed on a piece of floating wood (sometimes sculpted into the shape of a boat) on the surface of a bowl of water and by eliminating friction the stone naturally oriented itself along the North & South poles.

Later the Chinese found that they could magnetise an iron wire (or needle) by touching it to a lodestone. The needle would then become magnetised for a short time and could be stuck in a piece of  straw or cork to float and likewise orientate North & South. To maintain the magnetism of this early compass it was necessary to frequently slide the stone along the needle, a process known as “feeding the needle.”

Sailors in Europe became aware of this crude compass via the Arabs around 1000 A.D. and began developing it for use in Maritime exploration.

However, floating a magnetized needle on a liquid surface was not easy, especially in a rolling sea, so a pivot pin was developed onto which the magnetised needle could be mounted to rotate freely. This technological innovation was followed by the introduction of a compass “card,” which later became the “compass rose” showing North, South, East & West, and subdivided into 32 points. North was traditionally indicated on the card by a fleur-de-lis, probably because of the early use of marine compasses by the seamen from the ancient Aquitaine region of France, (according to  Norie & Wilson in 1889 ).

Over the ensuing 1000 years the compass as we know it today has changed very little but was used during that time to generate increasingly accurate maps that enabled a cumulative knowledge of the physical world.

The maps became a precious resource for explorers, merchants, politicians and their Navy’s.  Maps represented a tool for power and expansion, without the compass may not have been possible.  The compass was without doubt a key technology that shaped the world we live in today.  For hundreds of years the compass and the exploration it honed has been a fascination for many artists, perhaps because of the horizon of possibilities it represents.

For Vermeer it was something of an obsession.  Next I’ll look at  more contemporary artists who have used the compass, maps or navigation as a means to produce artwork.

Magneto Reception in Humans?

Dr. Robin Baker in the late 1970’s conducted a series of experiments based at Manchester University to find out whether or not human beings possess the physical capacity to detect the earths magnetic field.  His finding were published in the New Scientist in 1980 (article).  Unfortunately, peer reviews later discredited his findings when the repeated experiments were found to be inconclusive. 

Yet more recent scientific studies have used more controlled environments and sophisticated Electroencephalography (EEG) techniques to suggest there may be a ‘lost’ sixth sense or a ‘primal sense’ as geophysicist Joe Kirschvink presented at the Royal Institute of Navigation in London in 2016, that some people may be able to tap into better than others. 

In the same way some people have better eyesight or hearing, so it may be the same when it comes to sensing the earths magnetic field.  As in most of the animals that have been studied, from fruit flies to whales, evidence of magnetoreception has been found, it is therefore puzzling that humans appear, in an evolutionary sense, to have lost (at worst) or have an extremely weak sense (at best) of the earths magnetic field.  The reasons for this may be an evolutionary deselection of this sense in favour of the remaining 5 senses or it may be that we are surrounded by electric cables that generate magnetic fields therefore confusing our magnetic sense apparatus as it does with animals.  Yet studies continue to find out more about this ‘primal’ sense.

It’s clear from human explorations over the centuries that we need to navigate using a compass, the sun or the stars as we can’t rely on a natural sense of direction as this study by Jan Souman  showed in 2007, concluding that a “drift in the subjective straight ahead [direction] may be the result of accumulating noise in all components of the sensorimotor system”.   Here are some GPS recorded routes of participants in the experiment.  This study clearly shows how bad our magnetoreception can be and is at odds with Joe Kirschvinks claims in 2016.

Perhaps some anthropological findings can point to evidence that suggests some cultures can rely more on an ‘intuitive’ sense of direction when background noise can be eliminated.  Polynesian sailors, known as masters of navigation have been known to  travel for 1000’s of miles in the Pacific ocean without sight of land though day and night, and in thick fog without rest and sill maintain a true direction. If true this account may favour magnetoreception in their ‘sense’ hierarchy as a matter of survival in particular circumstances.  He recorded many interviews with Pacific inlanders and recounts that many of those interviewed talked of extreme situations where “they suddenly calmed down and intuitively knew the right course” [Finney, B. 1995].

However, Finney may not have been aware of the existence of Stick Charts, (rudimentary maps,)  which would have helped identify landmarks when they came into view and therefore re-setting their intuitive compass.

So it seems, in light of more recent evidence, the persuit of magnetoreception in humans may be more a romantic notion than science but I’m sure the question of whether it’s possible to tap into the earths magnetic field won’t go away until it’s proven one way or the other. 

References

“A sense of Magnetism” New Scientist, Sept 1980 (https://books.google.co.uk/books?id=FMQQnijnhsUC&pg=PA844&dq=robin+baker+new+scientist+magnetic&hl=en&ei=GU79TfWdD5Hxsgbo_q3zDQ&sa=X&oi=book_result&ct=result#v=onepage&q=robin%20baker%20new%20scientist%20magnetic&f=true).  

Finney, B. (1995). A role for magnetoreception in human navigation? Current Anthropology, 36, 500–506. (https://www.journals.uchicago.edu/doi/abs/10.1086/204386?journalCode=ca)

Jan Souman :  https://www.nationalgeographic.com/science/phenomena/2009/08/20/do-lost-people-really-go-round-in-circles/

Jan Souman :  Walking straight into circles. Curr Biol.2009 Sep 29;19(18):1538-42. doi: 10.1016/j.cub.2009.07.053. Epub 2009 Aug 20. Souman JL1, Frissen I, Sreenivasa MN, Ernst MO.

https://www.cell.com/current-biology/fulltext/S0960-9822(09)01479-1?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0960982209014791%3Fshowall%3Dtrue