Ian Russell

The Petrosains Science Discovery Centre in Kuala Lumpur asked my permission to display this quotation on one of their walls. It is also displayed in at least two science centres in the USA and once I even discovered it pinned above the staff room door in a Birmingham primary school.

Spin the domes to explore swirling patterns in coloured flow-tracing fluid. Part of a set of astronomy interactives produced for Pusat Sains Negara, the National Science Centre, Kuala Lumpur, Malaysia.

Produced for XperiLAB, Museum of Natural Sciences, Brussels, Belgium. The turbine blades can be adjusted to maximise the generator's electrical output, measured by the moving ammeter needle. 'Wind' is provided by a push-button operated fan. Various different versions are available. In this one, using sheets of special plastic, users are encouraged to design and cut out their own turbine blades that push easily onto metal spokes.

Produced for the Inspiria Science Centre, Sarpsborg, Norway, this is a highly 'exploratory' exhibit that engages people for a long time. Variously shaped lenses and mirrors can be moved around to investigate their effects on the streaks of light that shine across the table. Depending on the 'visitor-behaviour-environment', the pieces can be loose, tethered by cords or wires, or more securely attached so each can be rotated in one position.

This transparent plastic shape is mounted between polarising filters and illuminated from behind. When any of the four arms is pushed sideways rainbow-coloured stress patterns appear in the plastic, contrasting beautifully with the black background.

Produced for the University of Bath's display at the 2016 Summer Science Exhibition at the Royal Society, London. This breathtakingly beautiful exhibit enables people to experiment with dazzlingly bright, thin-film interference colours drawn up from a detergent solution. A larger, metre-high version has also been produced for Singapore Science Centre. This exhibit is remarkable durable and requires almost no maintenance.

One of the set of interactives we produced for the Wonders of Wildlife exhibition at the Museum of Natural Sciences, Brussells, Belgium. Beautifully modelled in polished stainless steel, the claw can be extended by pulling a 'muscle' opposed by a spring representing an elastic ligament. The mechanism is protected by a transparent cover.

Another, different version. (See above.)

Produced for NIHERST/NGC National Science Centre, Trinidad. Coins or balls can be rolled around it, simulating the effects of gravity on an orbiting object in space. Various different designs are possible. In this one, people simply retrieve their coins trough the large hole in the side after they have dropped onto the soft carpet inside. Some have a transparent cover, enabling shiny steel balls to be used with no possibility of them being removed by visitors. Other versions are sealed to work as profitable money-collectors.

Produced for NIHERST/NGC National Science Centre, Trinidad. Sparkling, rainbow-coloured CDs float frictionlessly on the air blowing gently through multiple tiny holes in the table surface. They collide and rebound entertainingly from each other and from the sides of the table. Children love to play with this one.

Produced for the In Motion exhibition at Edinburgh Science Festival. The forearm is raised or lowered by pulling the appropriate 'muscle'. It is protected by a transparent cover for durability.

Specially designed and produced for the new Mosasaur Gallery at the Museum of Natural Sciences, Brussells, Belgium. Mosasaurs were ancient aquatic reptiles contemporary with the dinosaurs. I was asked to think of a hands-on way to demonstrate the difference in flexibility between the thoracic (chest) and caudal (tail) regions of a mosasaur's spinal column, using fossil vertebrae for reference. I finally came up with this design, allowing people to flex the models, but limiting the the extent of movement to make damage impossible.

This is a 3D CAD rendering of my proposed design for a counterbalanced gyroscope. People can hold the red knob and spin the metal wheel with the other hand. Nothing else happens until you try to move the red knob in any direction. If you move it horizontally, you feel a strong force upwards or downwards. If you try to move the red knob upwards or downwards while the wheel is spinning, you feel a strong horizontal force.

Produced for Pusat Sains Negara, the National Science Centre, Kuala Lumpur, Malaysia. Six familiar star patterns are represented by glowing LED lights. When you press the correct name, the outline of that constellation figure also lights up.

Produced for Pusat Sains Negara, the National Science Centre, Kuala Lumpur, Malaysia. After making the tethered ball whirl around the pole, you pull the lower end of the cord, causing the ball to go around much faster as it is pulled towards the centre. This demonstrates why the anomalous observed rotation speed of galaxies has resulted in the existence of Dark Matter being suggested to account for unexpectedly strong gravitational forces. It is also great to play with...

This one was produced for the Inspiria Science Centre, Sarpsborg, Norway. (See above.)

Produced for the Oslo Science Centre, Norway. Pulling down the circular rubber diaphragm reduces air pressure inside the dome, causing the 'lungs' to inflate as air whistles in through the red orifice above. Releasing the diaphragm allows it to spring back, collapsing the 'lungs' and expelling air back out through the orifice. This exhibit has been in constant use in Oslo for many years with no maintenance issues.

A deceptively simple-looking set of gears, but the final wheel only makes one turn after the first wheel has made a million turns. To make it really interesting, the final wheel has a shelf on which a glass of clear liquid is balanced. It is amusing to watch people turning that crank handle like crazy! Larger and smaller versions of this design are available.

Produced for the Phaeno science centre, Wolfsburg, Germany. Two vehicles slide very freely along electrified metal rails. One of the vehicles has an electric fan and a sail. When the fan blows against the sail, of course the vehicle does not move. But when the vehicle is turned 90 degrees and the sail is turned 45 degrees, yes, it DOES move. This sail can be removed from the vehicle. When the fan blows towards the sail on the other vehicle, both vehicles move away from each other, in opposite directions.

I have produced various versions of this for different exhibitions. It is a 'hands-off' interactive exhibit! It is certainly interactive, because you and your friends feel compelled to walk around it, examining the invisibly supported 'moon' floating inside the black hexagonal case. Illuminated by the 'sun' at one corner of the case, it shows crescent, half-moon and full-moon phases from different viewpoints.

Beautifully made from polished, stone-like Corian and available in various colours and textures, I have supplied many of these to different places. The great advantage of my design is the total absence of focus or zoom controls. There is simply nothing that users can possibly break. The internal autofocus camera gives a sharp image of any object in the brightly lit area below it. To 'zoom', you simply raise the object closer to the camera. The image can be shown on any suitable monitor or projector. This is an extremely engaging, exploratory exhibit. 

Invented, designed and produced for Manchester Science Festival. A real pinball mechanism shoots steel, glass and plastic balls which are then deflected towards different targets depending on their mass.

Produced for the Royal Society Summer Science Exhibition 2012. There are two overlapping discs that can each be rotated by hand. On the upper disc are three different, safe, radioactive sources. The lower disc has three different 'barriers': aluminium, thin plastic and air (just a hole in the disc). A radiation detector is positioned underneath.

These infinity mirrors are two metres high. The front mirror hangs loosely and can be moved slightly while you peep through at multiple reflections seen in the second mirror. LED lighting enhances the effect. Please don't be startled when you notice me taking this photo with my iPhone!

Much larger versions of this are also available. You look through the holes to see multiple reflections between the mirrors. At the same time you can move the mirrors to see what happens.

I first produced an interactive like this back in 1987 and it has since become a popular idea. This version is more recent. I designed it with an angled mirror to reflect a lamp safely enclosed below. Both ends of many plastic light guides are arranged in two rectangular arrays. When your hand makes a shadow on one array, the shape of the shadow can also be seen at the other end.

When you put your hand into this 'black hole' a ghostly 3D image appears, floating in space IN FRONT of the unseen, black, concave reflecting surface behind it.

You get a surprise when you reach out to touch this lamp, because your hand passes right through it. It isn't there! This is related to my 'Ghostly hand' exhibit and works similarly. The real lamp is hidden below the shelf, upside down and protected by a transparent panel.

This pedestal-mounted mini-interactive is at EUREKA! The Children's Museum, Halifax. 'Wind' comes from a push-button operated fan. The turbine blades are adjustable and interchangeable. The challenge is to maximise electrical output measured by the moving needle on the meter. Most of my mini-interactives can be pedestal-mounted if required. They can quickly be dismounted at any time for use on a table top somewhere else.

One of our top favourite mini-interactives, this features a hand-cranked generator and three lamps with different power ratings. The handle turns very freely but a surprising 'drag' is felt as soon as a button is pressed, connecting a lamp. The modern, energy-efficient LED lamp causes far drag than the halogen lamp and the old-type, less efficient, incandescent lamp. 

This features a small electric motor from which the magnets have been removed. It can only be made to spin when the current is switched on and the magnet is held nearby. Reversing the magnet also reverses the direction of rotation.

Some ring magnets hover engagingly on a steel post, while others attract each other. N and S poles are indicated by red and blue colours. Another pair of magnets are pivoted so they can be turned by hand. In each case, the forces of magnetic repulsion and attraction can be experienced and investigated.

The hand-cranked electrical generator is connected to a pair of Peltier cells. These become warm or cold depending on the polarity of the applied voltage. You put your left hand on the red outline while cranking with your right hand. Your left hand feels warmer or colder depending on the direction you turn the handle.

The hand-operated pump fills the upper tank which then siphons down to the lower tank and spins the turbine wheel. A meter indicates the electrical current being generated.

You make waves by twisting the red dial backwards and forwards. The float bobs up and down, causing a red and blue magnet to move above the wire coil. A moving-needle electrical meter indicates the current generated.

Similar to my other wind turbine interactives, except that this one requires no mains electrical power connection. 'Wind' is created by cranking the handle to drive the fan. Another special feature of this design is the red horseshoe magnet that rotates above the wire coil, showing the basic principle of the generator. The circuit includes a visible diode to rectify the current.

Pressing and holding the red button causes the table to shake. Structures built with coloured wooden blocks soon collapse.

This is an authentic working model showing the principle of a real, 'hanging-gate' seismograph. A blue LED lamp leaves a glowing trail on a slowly rotating disc of 'glow-in-the-dark' plastic. The upper assembly is supported on flexible rubber mounts. This can be shaken by hand, causing zig-zags in the gradually-fading glowing trail. 

After spinning the wheel, it can be stopped by gently holding a finger against the serrated rubber rim. The energy from the rotating wheel is felt as frictional heat.

Each of the four walls is insulated differently: rock-wool, polystyrene foam, stone or no insulation. An internal lamp generates heat. The external temperature of each wall can be measured using an inexpensive infrared thermometer.

Peep through the hole to glimpse an 'infinitely' long tunnel effect that twists and bends when the mirrors are moved.

This one is an exceptionally engaging exploratory exhibit. The swinging magnet dithers chaotically above the magnets in the black disc, some of which attract it while others repel it. The black disc can be rotated to select from three different magnetic patterns.

You spin the red knob and watch the chaotic dance that follows., as are marked with different colours of fluorescent acrylic which glow brightly because of the ultraviolet LED lamps.

A red horseshoe magnet is rotated above the wire coil. When the circuit is completed with the loose wire, the moving needle in the meter indicates the current generated. Depending whether or not you choose to include the diode, the needle shows rectified direct current of waggles to-and-fro, showing alternating current.

Looking into the red eyepiece, you see a magnified reflection of your eye. Pressing and holding the red button illuminates the eye, causing the iris to contract. This mini-interactive is usually battery powered.

Twelve slightly different objects are arranged around a twelve-sided assembly of mirrors. The reflection seen in the mirrors appears to come alive when the whole thing is set spinning. I have designed several versions of this old Victorian animation novelty. This one animates a nuclear chain reaction with splitting uranium nuclei,  neutrons etc. The others showed different animals running. Any kind of 2D or 3D animation can be featured, provided that it can be shown with a cycle of twelve 'frames'.

This is more of a teaching aid than a true 'exploratory' exhibit. The molecular model shows the drug, caffeine, which you can fit snugly into the surface of an imaginary protein molecule.

You can make the heavy flywheel rotate, and keep it rotating, by sliding the red knob to-and-fro at exactly the right rate. The knob is magnetically linked to the end of the connecting-rod, so the link is broken if you fail to follow the motion of the flywheel.

The little ball leaves a turbulent trail as it rolls across the shallow tank of flow-tracing fluid. The tank is on springy mounts that allow it to be tilted in any direction, making the ball roll. It can also be spun round quickly, stirring the fluid and showing more turbulence.

Beautiful and fascinating to play with, you simply spin it at different speeds, or stop it suddenly, or reverse it, while enjoying the ever-changing, swirling patterns. 

Squeezing the bottle with your hands increases the water pressure and you clearly see the sealed plastic pipette being squashed sideways before it sinks. Challenged by the label to predict if it will sink when squeezed from the bottom, most people usually get this wrong. This exhibit is remarkably tough and maintenance-free.

The extremely thin strip of gold-leaf swings outwards whenever an electrically charged object is brought near. This might be a rubbed balloon or plastic rod. A whole series of fascinating experiments can be performed, following simple instructions in the label. Also, to dispel the misunderstanding that 'static electricity' does not 'flow', all the same experiments also work using the metal disc at the other end of the chain.

Our usual design is about 70cm tall and uses an ultrasonic transducer to create a cool water mist resembling steam. An electrical fan draws air upwards and angled inlet slots at the sides set it spinning.

Typically 50cm wide and around 1m long, these cases can be made to fit any of the mini-interactives perfectly.

This 'twisted-Savonius' interactive wind turbine is designed to spin freely in the wind and can be stopped by taking hold of the lower end of the shaft. When released, the wind makes it spin again. Or, if there is no wind, you can spin the shaft with your hands. The GRP turbine blades are safely mounted above head-height, supported by a strong, stainless steel tripod fixed to the ground.

A simple toilet-flushing mechanism is operated by pulling a rope, causing the fountain jet to squirt up almost as high as the water tank. This hands-on fountain feature is three metres high and made from stainless steel. 

This outdoor interactive exhibit demonstrates solar energy simply but effectively. In sunlight, the black surface becomes surprisingly hotter than the white surface. Durable and weatherproof, it is beautifully constructed from stainless steel and Corian.

This pedestal-mounted mini-interactive wind turbine is at EUREKA! The Children's Museum, Halifax. 'Wind' comes from a push-button operated fan. The turbine blades are adjustable and interchangeable. The challenge is to maximise electrical output measured by the moving needle on the meter. Most of my mini-interactives can be pedestal-mounted if required. They can quickly be dismounted at any time for use on a table top somewhere else.

Each of the four walls is insulated differently: rock-wool, polystyrene foam, stone or no insulation. An internal lamp generates heat. The external temperature of each wall can be measured using an inexpensive infrared thermometer.

One of our top favourite mini-interactives, this features a hand-cranked generator and three lamps with different power ratings. The handle turns very freely but a surprising 'drag' is felt as soon as a button is pressed, connecting a lamp. The modern, energy-efficient LED lamp causes far drag than the halogen lamp and the old-type, less efficient, incandescent lamp. 

The hand-cranked electrical generator is connected to a pair of Peltier cells. These become warm or cold depending on the polarity of the applied voltage. You put your left hand on the red outline while cranking with your right hand. Your left hand feels warmer or colder depending on the direction you turn the handle.

The hand-operated pump fills the upper tank which then siphons down to the lower tank and spins the turbine wheel. A meter indicates the electrical current being generated.

You make waves by twisting the red dial backwards and forwards. The float bobs up and down, causing a red and blue magnet to move above the wire coil. A moving-needle electrical meter indicates the current generated.

Similar to my other wind turbine interactives, except that this one requires no mains electrical power connection. 'Wind' is created by cranking the handle to drive the fan. Another special feature of this design is the red horseshoe magnet that rotates above the wire coil, showing the basic principle of the generator. The circuit includes a visible diode to rectify the current.

Spin the wheel, then stop it by holding a finger against its serrated rubber edge. The energy of the rotating wheel is lost as heat, which you can clearly feel.

After parking the truck, mechanically sliding out both its sides and rearranging the internal furniture, there is plenty of space for 30 visitors. 

After discussing many different ideas with the client, I designed and produced all nine of the lab-type challenges, each able to occupy a group of three children for twenty minutes.

The praxinoscope is a twelve-sided mirror that can be spun freely by hand. Around it are twelve images (or sometimes 3D models). Their reflections appear to come wonderfully alive in the spinning mirrors. I produced this version for the Museum of Natural Sciences, Brussels. I did not supply the stuffed tiger!

Beautifully made from polished, stone-like Corian and available in various colours and textures, I have supplied many of these to different places. The great advantage of my design is the total absence of focus or zoom controls. There is simply nothing that users can possibly break. The internal autofocus camera gives a sharp image of any object in the brightly lit area below it. To 'zoom', you simply raise the object closer to the camera. The image can be shown on any suitable monitor or projector. This is an extremely engaging, exploratory exhibit. 

The moving of an elbow joint by opposing muscles is demonstrated by pulling one or other of the two cords. The mechanism is protected by a transparent cover. Various other principles of body mechanics can be modelled with physical interactive exhibits.

This beautifully made, life-size, working model of a lion's claw was designed and produced for the Museum of Natural Sciences, Brussels.

Only two of the various red 'substrate molecules' fit correctly onto the active site of the blue 'enzyme' molecule. When both are in place, concealed reed-switches cause an LED to light up.

The model caffeine molecule can be fitted perfectly into just one location on the green surface of the 'target molecule'.

Turning the crank handle with the red knob causes the red plastic 'fish' to move around the tank of flow-tracing fluid. Many people are surprised to discover that moving the 'fish' pointed-end-first actually causes MORE turbulence than moving it in the other direction.

Looking into the red eyepiece, you see a magnified reflection of your eye. Pressing and holding the red button illuminates the eye, causing the iris to contract. This mini-interactive is usually battery powered.

By pressing a fingertip against a small window at the rear and also holding down the red button to illuminate it, you can see a magnified view of your fingerprint through the viewing lens. This mini-interactive is usually battery powered

Using the red knob you can pull the rubber diaphragm downwards. This reduces the pressure around the 'lungs', causing them to inflate as air flows into them from outside. Releasing the diaphragm allows it to spring back, collapsing the lungs and expelling the air. This exhibit has survived many years of heavy use in the Oslo Science Centre, Norway.

Specially designed and produced for the new Mosasaur Gallery at the Museum of Natural Sciences, Brussells, Belgium. Mosasaurs were ancient aquatic reptiles contemporary with the dinosaurs. I was asked to think of a hands-on way to demonstrate the difference in flexibility between the thoracic (chest) and caudal (tail) regions of a mosasaur's spinal column, using fossil vertebrae for reference. I finally came up with this design, allowing people to flex the models, but limiting the the extent of movement to make damage impossible.

Produced for the Inspiria Science Centre, Sarpsborg, Norway, this is a highly 'exploratory' exhibit that engages people for a long time. Variously shaped lenses and mirrors can be moved around to investigate their effects on the streaks of light that shine across the table. Depending on the 'visitor-behaviour-environment', the pieces can be loose, tethered by cords or wires, or more securely attached so each can be rotated in one position.

Produced for the University of Bath's display at the 2016 Summer Science Exhibition at the Royal Society, London. This breathtakingly beautiful exhibit enables people to experiment with dazzlingly bright, thin-film interference colours drawn up from a detergent solution. A larger, metre-high version has also been produced for Singapore Science Centre. This exhibit is remarkable durable and requires almost no maintenance.

When you put your hand into this 'black hole' a ghostly 3D image appears, floating in space IN FRONT of the unseen, black, concave reflecting surface behind it.

You get a surprise when you reach out to touch this lamp, because your hand passes right through it. It isn't there! This is related to my 'Ghostly hand' exhibit and works similarly. The real lamp is hidden below the shelf, upside down and protected by a transparent panel.

Peep through the hole to glimpse an 'infinitely' long tunnel effect that twists and bends when the mirrors are moved.

I first produced an interactive like this back in 1987 and it has since become a popular idea. This version is more recent. I designed it with an angled mirror to reflect a lamp safely enclosed below. Both ends of many plastic light guides are arranged in two rectangular arrays. When your hand makes a shadow on one array, the shape of the shadow can also be seen at the other end.

This one was produced for the National Science Centre, Kuala Lumpur.

This is a beautiful, engaging experience that can be designed in various different ways and in different sizes. Red, green and blue lamps create yellow, cyan and magenta coloured shadows. These are the 'secondary' colours and where they overlap, red green and blue shadows also appear. People are often very surprised to see the colour yellow created by the red and blue lamps.

Each box contains a different 'mystery object', with a small light source casting its shadow on a translucent screen. Each object can be rotated and examined from different angles. Designed for a display about nanotechnology research at Manchester University.

The angle between the mirrors can be changed, producing a variety of different reflection effects.

These infinity mirrors are two metres high. The front mirror hangs loosely and can be moved slightly while you peep through at multiple reflections seen in the second mirror. LED lighting enhances the effect. Please don't be startled when you notice me taking this photo with my iPhone!

A bright flash from a lamp creates frozen shadows on a screen made from glow-in-the-dark plastic. The shadows slowly fade away and the experiment can be repeated. This interactive exhibit can be made in different sizes: on a table for shadows of your hand or on a wall for shadows of your whole body.

Produced for Pusat Sains Negara, the National Science Centre, Kuala Lumpur, Malaysia. After making the tethered ball whirl around the pole, you pull the lower end of the cord, causing the ball to go around much faster as it is pulled towards the centre. This demonstrates why the anomalous observed rotation speed of galaxies has resulted in the existence of Dark Matter being suggested to account for unexpectedly strong gravitational forces. It is also great to play with...

Spin the domes to explore swirling patterns in coloured flow-tracing fluid. Part of a set of astronomy interactives produced for Pusat Sains Negara, the National Science Centre, Kuala Lumpur, Malaysia.

Produced for Pusat Sains Negara, the National Science Centre, Kuala Lumpur, Malaysia. Six familiar star patterns are represented by glowing LED lights. When you press the correct name, the outline of that constellation figure also lights up.

Rainbow coloured CD discs or other flat objects glide without friction on air blowing through many tiny holes in the surface. In space, objects continue to move until something makes them stop. This is a very popular, engaging, 'exploratory' exhibit.

The objective lens (not visible in this photo) forms an inverted image on the 'back-projection' screen. The image can be focused by sliding the lens. The unit can also be rotated horizontally to look at different places. The red eyepiece lens can be used to magnify the image. Then, the screen can be hinged down out of the way and now a perfectly clear, magnified, inverted image is seen through the eyepiece lens.

The red crank-handle must be turned a million times before the last wheel in the series turns once. To emphasise how much time this would take, people are challenged to spill the glass of clear liquid that is resting on the last wheel...!

Produced for NIHERST/NGC National Science Centre, Trinidad. Coins or balls can be rolled around it, simulating the effects of gravity on an orbiting object in space. Various different designs are possible. In this one, people simply retrieve their coins trough the large hole in the side after they have dropped onto the soft carpet inside. Some have a transparent cover, enabling shiny steel balls to be used with no possibility of them being removed by visitors. Other versions are sealed to work as profitable money-collectors.

I have produced various versions of this for different exhibitions. It is a 'hands-off' interactive exhibit! It is certainly interactive, because you and your friends feel compelled to walk around it, examining the invisibly supported 'moon' floating inside the black hexagonal case. Illuminated by the 'sun' at one corner of the case, it shows crescent, half-moon and full-moon phases from different viewpoints.

A selection of small meteorites and micrometeorites can be examined using a sliding lens. Beside this, an iron meteorite is securely fixed to the table so that it can be handled. The label will encourage people to touch it, to marvel at its immense age and to reflect on the likelihood that these objects have actually been out beyond the orbit of Mars….

When the red knob is quickly pressed downwards, with the other hand you can feel the temperature of the metal tube increase. Before a new star 'lights up', the temperature of a collapsing gas cloud rises as the pressure increases. 

A heat source warms the base of the shallow tank of flow-tracing fluid, causing numerous convection cells to become clearly visible. The flow-tracing fluid can be stirred when necessary, by rotating the tank.

The praxinoscope is a twelve-sided mirror that can be spun freely by hand to create realistic animations. Around it are twelve 3D atomic models. Their animated reflections appear in the spinning mirrors. The version in this photograph shows nuclear fission of uranium atoms, but it can also be designed to show nuclear fusion.

Each of the dials can be rotated freely and is magnetically indexed to ‘click’ into position over one of six markers in a pleasingly tactile way.

The left-hand dial is labelled:  ‘How many other habitable planets do you think there are in our galaxy?’  

The centre dial is labelled: ‘How many other planets in our galaxy do you think have some form of life?’

The right-hand dial is labelled: ‘How many other planets in our galaxy do you think have life-forms that communicate across space?’

On each dial, the pointer positions are labelled:   * Zero   * Tens   * Hundreds   * Thousands   * Millions   * Billions

People feel prompted to speculate, to discuss and to refer to the adjacent display of relevant background information about the Drake equation and its various factors. An especially engaging feature of this exhibit is the way it empowers people to ‘leave their mark’. The dial settings will display the outcome of their own thinking, to be seen, thought about, and maybe readjusted, by other visitors afterwards. 

You clearly FEEL the extra drag on the crank-handle when pressing a button to switch on a lamp. However, the high-efficiency LED lamp feels easy to light.

This is one of our most popular interactives.

The paper confetti dances up and down entertainingly when the top cover is rubbed, transferring electrical charges between top and bottom.

A rubbed plastic rod or balloon causes the delicate gold-leaf to swing outwards when brought near either of the shiny metal discs.

If you touch the disc with a finger while the charged object is near, the leaf collapses. Removing the charged object causes the leaf to swing out again. Now, if the charged object is again brought near, the leaf collapses. This elegantly demonstrates the existence of two opposite electrical charges.

Deceptively simple-looking, the three loose leads in this clearly laid-out circuit present very many experimental possibilities. The questions on the label are powerful ones. "How many ways can you find to light two lamps?" "When all lamps are lit, what do you notice about the readings on the three ammeters?" "Is it possible to light three lamps so that they all shine with the same brightness?

Two loose leads are used to find out which of the various materials allow current to pass through. Users are also prompted to search their pockets for more samples to test! The meter even registers the small current passing through the user’s skin. Current is indicated by an ammeter and a buzzer. The arrangement of the circuit and its connection to the power supply are clear and obvious. 

Holding down the red button causes a green LED to flash in the battery box. The motor's internal magnets have been removed, so it does not rotate unless the bar magnet is brought close to the coil while the current is flowing. The direction of rotation can be reversed by reversing the magnet or by moving it to the opposite side of the coil-commutator assembly. 

'Can you make an electric current by rotating the magnet near the coil? You will need to close the circuit, using the loose wire. The small, black diode near the loose wire only lets current flow in one direction. What difference does it make if you touch the wire against the screws at either end of the diode?'

If preferred, a more robust (but less tactile) version is available, with a push-button switch instead of the loose wire. 

Pressing and holding a button to switch on an electric current through the coil produces a strong magnetic field, whose pattern is shown by the compass needles.

When current is flowing a red indicator illuminates and the polished acrylic block, supporting the coil and protecting the wires, is lit up from beneath.

'Gently swing the magnetic pendulum. Watch how crazily it swings above the other magnets. Which magnets are attracting the pendulum and which magnets are pushing it away?  The north poles of the magnets are red and the south poles are blue.  You can turn the black disc to try different sets of magnets.'

This is an especially effective 'exploratory' exhibit, able to engage people's attention for a long time.

The hovering ring-magnets have red and blue coloured faces to indicate their north and south poles. Rotating one of the bar magnets by hand immediately causes the other one to flip round.

This is another popular 'exploratory' exhibit. It is strangely appealing to FEEL the forces of repulsion as well as attraction.

The compass needles are sensitive at a considerable distance from the coloured bar magnet and show the shape of the magnetic field.  

"It's in space, miss."

As well as designing this interactive display, I am also rather proud of my idea for the title. Some boys at Simon Langton Grammar School had invented a new kind of cosmic ray sensor that was launched into space aboard TechDemoSat-1 in July 2014 on a Soyuz-2 vehicle. Their project was selected for the Royal Society Summer Science Exhibition in London and I was asked to help.

This was part of my 'Where's your homework' display at the Royal Society Summer Science exhibition in June 2012. Above a nuclear radiation sensor were two independently rotatable discs. The upper disc has three different radiation sources and the lower one has three different shielding materials.

I designed this portable game for E.ON Energy, used for outreach sessions in schools, as well as various other hands-on activities to be used at the same time.

For another Royal Society Summer Science Exhibition, my client was a Cambridge University team needing my advice on how to present their medical research. In the event, we wowed visitors with these back-projected scanning electron microscope images of fruit flies that could actually be rotated and examined in real time by turning a knob in either direction.

Rather ambitious for its time, I designed and produced this exhibition featuring a multiplayer touch-screen game, for The European Commission, Directorate General XII, back in 1994.

A Mass spectrometer is a sophisticated analytical instrument that ionises chemicals, accelerates the ions electrically and separates the ions according to their mass. I was challenged to invent a hands-on mechanical model to demonstrate the principle. My solution was this rather engaging 'pinball' game that separated similar-sized steel, glass and plastic balls and shot them into different holes.

I designed this for the 2008 Royal Society Summer Science Exhibition. A research team from Cardiff University wanted a mechanical model of a blinking eye. Instead, I suggested this idea, with a looping movie of a real, blinking, human eye back-projected onto plastic dome. This gave a rather eerie 3D effect and avoided the cost and complexity of a mechanical model.

The Synchrotron Radiation Source at Daresbury Laboratory was a crucial tool in discovering the awesomely intricate functioning of the ATP synthase molecule: work which was rewarded by a shared Nobel Prize in 1997.

An interactive exhibit was required for adults instead of the usual youthful audience. Even so, it was still necessary to stop people in their tracks, then capture and hold their attention long enough to convey the necessary message.

Produced back in 1998, this was a back-lit, mechanical model using cogs and cams to demonstrate the amazing rotating mechanism now known to exist inside this molecular factory 'assembly-line' for producing ATP. But the clever bit was that this working model was actually connected to a beautiful, computer-generated 3-d image of the ATP synthase molecule projected onto a black, back-projection screen suspended between curved carbon-fibre rods. As visitors turned the mechanical model, so the projected image of the molecule rotated, convulsed, and audibly squelched on the screen, like a heap of multicoloured spaghetti.

A great centre-piece feature, this design works equally well indoors or outdoors and the dishes can be branded with a logo or any other image. An issue with most 'whisper dishes' is the need for people to stand directly in front of the dishes, obstructing the sound waves and making large dishes necessary. Another problem with conventional designs is that you have to speak with your back to each the other person, without being able to see them.

I am proud of this design, which solves both of these issues rather neatly by adding speaking tubes. My original ideas are often copied elsewhere, but please remember: you saw it here first!

My beautiful 'Twisted Savonius' vertical-axis wind turbine can be stopped from spinning and then spun again by means of a special knob below the stainless steel supporting tripod. The coloured blades are moulded in fibreglass and supported out of reach, well above head-height.

Outdoor interactives need to be especially durable and weatherproof. Solar-power interactives using involving electricity generation can be problematic outdoors. So I came up with this simple but elegant design. Facing south, the black surface becomes quite surprisingly hotter than the white surface, because of the extra solar energy it absorbs.

Energy stored in the 3m high water tank is released in the form of a fountain. A simple toilet-flushing mechanism is operated by pulling a rope, causing the water jet to squirt up almost as high as the tank. This hands-on outdoor feature is three metres high and made from stainless steel. 

This is my oldest and most popular show, ending with a fireball of burning custard powder. We find out how a British custard powder factory was destroyed by an explosion in 1981 and how to try a large number of much safer experiments at home afterwards.

Look closely at the faces (including the teacher)!

Here I connect a microscope to a video camera and projector, together with sound-effects and music. Meanwhile, as I speak, other screens show  a series of related photographs and close-up views of my hands preparing slides for examination. The live specimens include Euglena, Volvox, Spirogyra, Paramecium, Amoeba, Hydra, Daphia and living cheek cells from an audience volunteer. This picture was taken at the Royal Institution in London.

This was an audience of about 1,500 Dutch children, with delegates from the 2014 Ecsite Conference up on the balcony. On stage after the Queen of the Netherlands, I was helping to launch this international conference for science communicators. Here's a movie of the show I did: https://youtu.be/5_cd-HYL8Jg?t=1m51s

Outdoor science shows can be wonderful when the weather permits. Here, my translator was Prof. Albrecht Beutelspacher, director of the Mathematikum centre in Giessen.

This was during the 2014 Fosforo Science Festival.

It is possible to do things like this at outdoor events. Sometimes! This was one of my shows at the 2016 Einstein Island event on Lake Trasimeno, Italy.

This was another of my shows at the Einstein Island event in Italy. I do like projectiles! I was pumping air into a bottle until it shot off like a rocket. With some water in the bottle, the extra mass of this 'propellant' causes it to go very much faster and further. And young audiences always seen to like getting wet...

With my special bubble-liquid recipe, I can make bubbles that are even much bigger than this one. 

My Bubble Fest last year caused traffic jams in New Mills, Derbyshire, and attracted a huge crowd estimated at around five thousand people. 

When the wind is too strong for making giant bubbles, I can fill huge areas with swirling clouds of smaller bubbles.

For outdoor events, I like to set up tables with multi-cloured bubble-hoops and many trays of bubble liquid.

Where possible, I like to include bubbles in my educational science shows. This was an outdoor show in Italy.

Children love making their own big bubbles with several scaled-down versions of my monster-bubble setup.

My Bubble Mill invention has incredible impact on windy days. It can fill a large field with vast clouds of streaming bubbles, being chased by crowds of happy children.

As usual, I included some bubbles in my science shows at last year's Science Night Ruhr event in Gelsenkirchen, Germany.

This trebuchet throws a water-balloon up to 60 metres. Here is a delightful movie of it being operated with impressive efficiency by a team of seven-year-olds: https://youtu.be/ITxF9nvk41c

Children love playing with this at outdoor events. It always amuses me that while some choose to operate the trebuchet, many others always prefer to stand at the other side of the field, where the water-bombs are falling...

I enjoy surprising people with the formidable weight of this authentic copy of a medieval British longbow arrow, compared with the very much lighter modern target archery arrows. Very few people now have the strength and skill to shoot with a full-power ancient longbow.

This is my modern, carbon-fibre version of a weapon used to deadly effect by the Aztecs against invading Spaniards. Similar spear-throwing systems have been used since prehistoric times. With mine, I can throw a LONG distance...

Little is heard about this widely used ancient weapon. It was a predecessor of the trebuchet. Here, I am about to throw a large Jaffa orange 70 metres!

This amazingly ingenious design is many centuries old. I just had to try making a scaled-down model and it works wonderfully well. Here is the movie I made of it.
https://youtu.be/THY0kQFx0Zc