ExperimentsFaculty of Science and Engineering

Sc festScience and Engineering Festival

Dr. Musgrove’s Marquee of Marvels and Mayhem

Baking Soda Volcano

The lava is made by combining ¼ cup of vinegar, 6 drops of washing-up liquid and 2 tablespoons of sodium bicarbonate (bicarbonate of sodium).

When the baking soda mixes with the vinegar Carbon dioxide (CO2) is released which causes the foam. You can also add food colouring (red and yellow look

good) or coloured drink crystals – these make the lava nice and lumpy!!!

Using 12oz regular diet cola and 3 mintos or 12oz diet cola and 2 tablespoon salt also gives a nice effect.

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Balloon Kebab

Can you pierce an inflated balloon without it bursting? You can if you apply a bit of science!

Blow up a balloon and tie a knot in the end. Now, very carefully, take a sharp kebab stick and push it through one side of the balloon near to the knot.

Push the rest of the stick through the balloon towards the middle and then out through the top of the balloon opposite the neck.

If you do this slowly you should not hear a bang.

Why?

When you blow up a balloon the rubber stretches and the bigger the balloon the thinner its sides. A balloon is thinnest at its middle so the bigger the balloon the higher the pressure.

If you look at the balloon when it’s blown up you will see the rubber is thickest by the knot and around the top. This is where you should aim!!!

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Biometal Inchworm

1. Ensure battery is inserted properly and working!!!

2. Place rough-ish paper on table

3. Put Inchworm on paper and press switch for about 2 seconds to widen legs

4. Releasing the switch makes the legs return to normal

5. Continue pressing switch to make Inchworm “walk”

6. NB – Don’t press switch for more than 3 seconds or Inchworm will overheat!!

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Blue Redox

This reaction is a redox reaction or a reducing – oxidation reaction. Reduction is a loss of oxygen and oxidation is a gain of oxygen. An alkaline solution of glucose acts as a reducing agent (loss of oxygen) and reduces added methylene blue from a blue to a colourless (clear) form.

Shaking the solution raises the concentration of oxygen in the mixture and this oxidises (gains oxygen) the methylene blue back to its blue form.

When the dissolved oxygen has been consumed, the methylene blue is slowly reduced back to its colourless form by the remaining glucose, and the cycle can be repeated many times by further shaking.

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Cartesian Diver

You can do this experiment yourself at home – all you need is a plastic pop bottle with lid and a “diver” - a sachet of sauce (e.g. ketchup or brown sauce) is perfect.

Fill the bottle with water almost to the top. Drop in the sauce sachet and put the lid on tightly. The sachet should float just below the surface of the water until you squeeze the bottle when it will sink.

But why does it sink?

When you squeeze the bottle you are making the space inside the bottle smaller and that increases the pressure inside the bottle – the same amount of air, water and the diver are now trying to fit in a smaller space. This makes the diver sink.

By varying this pressure you can make your diver go up or down.

Can you get it to float in the middle?

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Chromatography

Is a black pen really black? Or a blue pen really blue?

When ink is made lots of different shades of colours are mixed together.

Chromatography is just a science-y way of un-mixing these mixtures!!

If you draw a dot on a piece of paper with a pen and stand the paper in some solvent (a chemical to separate the ink into all its different parts) the solvent will draw each part up the paper as the solvent rises.

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Cornflour Puddle

When cornstarch is mixed with water - about half a cup of water for every cup of cornstarch - it forms a fluid known as "oobleck". This has the consistency of pancake batter and has both solid and liquid properties. This is called a non-Newtonian fluid. Other examples of non-Newtonian fluids include quicksand, silly putty, blood and ketchup. If you squeeze or punch the oobleck, the starch particles will not move out of the way quickly, so the oobleck will feel solid.

Why do non-Newtonian fluids matter?

How these non-Newtonian fluids behave have important implications:

• If a house is built on certain types of clays and an earthquake puts stress on this material through the sudden movement, the apparently solid clay can turn into a runny liquid. • Body armour that behaves like a liquid so that you can move easily but turns into a solid on impact from stress could be useful for police or the military. • Fun! Making oobleck is a great reason to make a mess, all in the name of science!

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Disappearing Money

Are you a magician? Can you make coins disappear without spending them?

We can just by using science!!!

On a flat surface take a penny, put it under a clear drinking glass and place a saucer over the top. If you look through the side of the glass you can still see the penny.

Now, by tilting the saucer backwards, fill the glass with water and replace the saucer.

Look again – the penny has gone!!!

This is an optical illusion caused by the refraction of light.

In air, light rays travel in almost straight lines which was why you could still see the penny. But once the water was added to the glass these light rays were bent and the coin appeared to have disappeared!

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Elephant Toothpaste

This is a simple chemical reaction using yeast as a chemical catalyst. As a catalyst is something which causes a reaction without being changed itself this reaction releases lots of Oxygen-filled bubbles which mix with the washing –up liquid and food colouring to make the coloured foam. This reaction is also called exothermic because it gives off heat.

There are lots of recipes for this on the Internet!

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Energy Stick

This is a great way to see an electrical circuit at work!

Hold the stick in both your hands, one hand around each of the silver bands. Once the circuit is complete the stick will light up.

As electricity is caused by electrons flowing through a circuit when you hold the Energy Stick the electrons flow across your skin forming a circle and completing the circuit but they are so tiny you cannot see them.

How many people can you get to make a circuit?

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Experiment - Can You Stab a Potato With a Straw?

All you need is a potato and a plastic straw.

1. Holding the potato by one end (so that you don’t stab yourself in the hand!) take the plastic straw and stab the potato.

2. You may be able to break the skin of the potato a little before the straw bends in the middle.

3. Now do it again but this time place your thumb over the open end of the straw.

4. By trapping the air inside it the stabbing motion as your hand approaches the potato compresses the air and this make the straw stronger.

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Experiment - Bubble Fun

Bubbles are brilliant and a perfect way to learn about science!!

As you know, water is made up of lots of hydrogen and oxygen atoms stuck together called molecules. A glass of water contains millions and millions of water molecules. If you look at the top of this water you can see the edges curl upwards. This is called “surface tension”.

A bubble is just like this except that, without the glass, the water keeps on curling around until it forms a ball – a bubble.

To make a bubble that will float in air you need to add soap. This makes the water molecules stretch and lets you blow them up.

By experimenting you can make lots of great shapes and watch as the surface tension stretching the bubbles sometimes snaps leaving other shapes in the middle of the bigger bubbles.

Read the booklet and see lots of “experiments” you can do – especially with the cube.

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Fake Blood

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Using two chemicals you can make a fake version of blood which looks like the real thing and has the same chemical make up as haemoglobin. This is the substance that makes your blood red and carries the oxygen around your body

Falling Cards

Does a flat playing card fall quicker than a vertical card?

Hold one card flat and the other vertical. Now let them both go.

Which do you think hits the ground first? Were you right?

You should have found that the flat card stayed flat all the way down.

But what about the vertical one?

As it falls air resistance starts to build up around it and the card begins to glide and this slows the card down. If the drop is high enough the flat card will catch up to the vertical one and overtake it.

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Fire Piston

The Hyman Fire piston demonstrates the rise in temperature when a fixed mass of gas is compressed. This is how a diesel engine creates its ignition.

A portion of tinder is ignited when the contained air is compressed by a hand operated piston. You can also demonstrate the need for oxygen by attempting to re-ignite the tinder. It will only occur if fresh air is introduced to the cylinder.

By compressing the air inside the cylinder and suddenly decompressing it, you will lower the temperature and condense the water vapour inside the cylinder to form a cloud.

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Fortune Telling Fish

Can these fish really tell your fortune? Why do they move?

These Fortune Telling Fish contain the chemical Sodium Polyacrylate which is the same one used in disposable nappies!!

They move when placed on your hand because this chemical grabs on to the water molecules on your skin. As it reacts the molecules in the chemical change shape and the fishes move!!

As for telling the future – try a fortune cookie. You can eat that!!

Did you know that Sodium Polyacrylate is also used in the production of fake snow, detergents and thickening agents??

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Flying Fun Stick

Launched in the USA in 2008 and also featured at the 2008 Olympics the FunFly Stick has already won a number of awards.

The stick is a magic levitation wand that allows you to fly special tinsel ‘flyers’ – as if by magic! How does it work? Inside the wand is a tiny Van der Graaf generator, powered by 2 AA batteries. When you press the button, the motor turns and generates an electrostatic charge on the end of the wand. When the end of the wand touches one of the FunFlyers, they become charged too and become a three -dimensional object because the Funflyer is now repelling itself too.

As the charged FunFlyer is also repelled by the wand by moving the wand below it you can keep it floating in the air. The minute the FunFlyer touches another object it loses the charge and collapses. Touch it with the wand, and it will spring into life again!

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Gaussian Gun

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Very slowly roll the loose ball bearing towards the magnets. As these are very strong magnets the ball bearing and the magnets will pull themselves toward each other sharply. As a result, rather like that Newton's Cradle executive toy we used to see a few years ago, the ball bearing at the other end shoots off at a surprisingly high speed.

Gelly Worms

Using a pipette squeeze some Sodium Alginate Solution into a beaker of Calcium Chloride.

The Sodium Alginate should forms worms which can be lifted out.

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Giant Ball Bearings

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When you carefully bang two ball bearings together there is a loud 'crack'. However there is also heat generated at the point of impact. So if you crack them together with a sheet of paper in between them you discover that the heat generated actually burns a small hole in the paper! Paper burns at 451 Fahrenheit or 200°C, so this suggests that we are reaching around that temperature at the point of impact.

Giant Bubble

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Bubbles form and hold their shape due to surface tension. The easiest way to think of surface tension is to imagine that any body of water, from the sea to a raindrop, is covered by a thin elastic skin. You can see this skin most clearly in a dripping tap. Each drop hangs from the tap, held by this "skin" until it becomes too heavy and falls. (Don't take this idea too seriously though - you can't peel the "skin" off water like an orange!!)

Hand Boiler

Watch this little Boiler when you hold it in your hand and see the liquid shoot to the top.

O.K., so just how hot do you think you are?

Sorry, you’re normal. But this does demonstrate something called Charles’s Law. In this little bottle is something called Ethyl alcohol which has a very low boiling point – about the same temperature as you. When you hold the bulb in your hand the temperature inside it heats up and so does the fluid. It starts to “boil”. As the pressure inside the bottle rises it travels up the tube and tries to evaporate but, because the bottle is sealed, it has nowhere to go.

Once you put the bottle down the Ethyl alcohol will cool and the liquid will return to the bottle.

Do you think you are hotter than your friends??

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I Can Make a Rainbow!!

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You can make a rainbow too!!!

All you need is a prism (or even a glass of water) and a torch.

Visible light is made up of lots of different colours which combine together to make white light. To separate these colours just stand the prism in sunlight with a piece of paper behind it to act as a screen. Or just use a torch instead of the sun.

The prism refracts the light (makes it bend) and this breaks it up into all its individual colours.

Lenz’s Law Pipe

Why does a magnet slow down when you drop it through a copper pipe?

Because magnetic fields are the result of electric currents if you move the magnet next to a non-magnetic metal (the copper pipe) you will change its magnetic field. This field will have an opposite direction to that of your magnet.

As metals don’t like having electric and magnetic fields inside them they try to cancel them out. (This is why metals are such great conductors – electricity flows through them because the electrons are moving to cancel out the potential difference. There is a little hurricane of electrons around the magnet). This is Lenz’s Law.

When the metal attracts the magnet it creates resistance which slows the magnet down. As it slows the current decreases and this reduces the resistance. Because gravity is also affecting the magnet it speeds back up.

Finally a “happy” speed is reached

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Magnetic Patterns UsingMagnetic Fluid/FerroFluid

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This magnetic field pattern window allows magnetic fields to be seen. There are two sheets of plastic with iron filings between them floating in vegetable oil. When you move the magnets above the window you can move the iron filings to make patterns.

There are many commercial applications for these Ferro fluids - speakers and hard drives being the most common. The oily fluid prevents debris from entering hard drives when a small amount is placed between the magnets and shaft. In the case of speakers Ferro fluids remove heat from the voice coils and help dampen the cone movement.

Make Polystyrene Disappear

This is very easy with acetone, an organic solvent – you can find it in some nail-varnish removers. Polystyrene is made up of long chains of styrene molecules called polymers. Hence the name – polystyrene.

These chains are joined together until placed in the acetone where it is just like adding sugar to a hot drink. It dissolves.

This is great for recycling because the hard lump at the bottom of the acetone (styrene) can be used again to make more cups!!

The reason the styrene lump seems so much smaller than the size of the cup it started as is because the polystyrene was mostly air and it didn’t take much solvent to dissolve it.

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Memory Metal Engine

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Using a Memory Metal this Engine demonstrates heat energy being turned into mechanical energy.

Using Nitinol, a memory metal alloy consisting of approx. 50% Nickel and 50% Titanium this metal can be trained to remember a certain shape by using very high temperatures.

By placing the lower part of the Engine in boiling water the Nitinol wire tries to regain its trained shape of a straight line. This heated lower portion creates a driving force to turn the pulley and as the wire rotates the cooler upper wire is then submerged in the hot water maintaining the mechanical energy.

As long as the water remains very hot the Engine will continue to turn.

Milk Kaleidoscope

This is SO easy to do!

All you need is a saucer, some milk (the highest fat content you can find or add a little single cream), some washing-up liquid and some food colouring (3/4 different colours are better).

Pour a thin layer of milk in the saucer and drop different food colourings close together in the middle.

Add a drop of washing-up liquid ……. MAGIC!!

The washing-up liquid reacts with the surface tension and protein in the milk to allow the colouring to run through.

Check out our video on youtube: http://youtu.be/-CGWn13WRSM

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Nitinol Hot / Paperclip

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Nitinol is a metal alloy, sometimes also called 'memory metal' or more properly Shape Memory Alloy (SMA).

Shape Memory Alloys have two distinct types of crystal structure, depending on whether they are above or below the critical transformation temperature. Below this critical temperature, the alloy is flexible and can be bent easily into any shape. Once heated to the critical temperature, Nitinol shows its 'heat memory' as it transforms back into its original shape, where the atoms become locked into their previous rigid arrangement.

Plasma Ball

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At the centre of a plasma ball is a large alternating voltage of around a few kilovolts oscillating at around 30 kHz. The low density of the gas (often neon) in the globe makes discharge much more likely than in the air at atmospheric pressure. (In air a Van de Graaff generator can cause sparks at around 30,000 V/cm, whilst in the globe arcs can be created which are many centimetres long with just a few thousand volts).

These fronds of plasma make their way from the centre of the globe to the outside in a bid to reach earth. By touching the globe you create an even better path to earth which increases the strength of the discharge (spark) and is why the arcs are attracted to your hand if you touch the globe.

The alternating voltage at the centre creates electromagnetic waves with the arcs of plasma acting as antennae. This means that the extent of the electromagnetic field surrounding the ball is significantly larger than the bounds of the glass globe.

Potato Clock

Do you want to make your own clock which runs on a potato? It’s easy!!

All you need to make your potato battery are 2 potatoes (or 1 cut in half), 2 short lengths of copper wire, 2 galvanised nails, 3 alligator clips and a low-voltage LED clock – one that takes a 1-2V button battery.

Take out the battery from the clock if there is already one there. Push a nail into each potato and then a wire opposite the each nail. Using an alligator clip connect one wire to the positive terminal in the battery compartment and the other wire to the negative terminal. Finally, take the last alligator clip and clamp the two nails – one in each potato – together.

This works because there is a flow of electrons between the zinc-coating on the nails and the copper wires through the potatoes. The potatoes conduct electricity because, by keeping the zinc ions and copper ions separate the electrons in the wire are forced to move and generate an electric current.

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Reversing Goggles

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When we view the world normally, our brain reverses the images on our retina in both the up-down and right-left directions. The prisms in these goggles reverse the up-down direction only. However if you rotate them by 90 degrees, they will then reverse left-right instead. !!! Please note that if you suffer from balance problems or other medical conditions that may affect your senses please beware trying this out!!!

Roaring Balloon

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Have you ever heard a balloon roar? It’s very easy!!

Take 2 balloons. Before you blow them up place a smooth-edged coin in one (like a 1p coin) and a coin with a rough edge (like a 5p coin) in the other. Blow them up and twirl them above your head.

You should find that as you twirl the balloons the coins roll around the inside of it almost horizontally. The rougher the coin the more noise it makes and the higher the pitch. More bumps make the noise louder.

This is an example of centrifugal and centripetal forces in action – if the inside of the balloon was not there the centrifugal force would make the coin fly away but, because the balloon is round, the centripetal force pulls the coin towards the centre.

Remember Newton’s 3rd Law?

For every action there is an equal and opposite reaction.

Try it with other objects – but not sharp ones or the balloon will burst!!

Salt-Density Rainbow

Density is the measurement of how much "stuff" is packed into a specific space. That's how we get the equation for density:

Density = Mass (stuff) ÷ Volume (space).

Nearly every substance and material imaginable has a different density. This is especially the case for the solutions you make out of salt and water.

If you take lots of glasses of water, (each holding 9oz.), and add different amounts of salt to each glass you create solutions that have different densities. The more salt is mixed into a water-based solution, the higher the density of that solution. Add food colouring for a rainbow!!

FUN FACT: This dramatic salt-water density change can be experienced in real life. Although you can float in the sea, if you went to Utah's Great Salt Lake or the Dead Sea in Israel and the West Bank you would find it nearly impossible to sink.

This explains why the liquids sit on top of each other inside the straw, but how do the liquids stay in the straw?

The surface tension is strong enough to hold the solutions in the straw… as long as air pressure isn't added into the equation. That's why you need your thumb to cap the straw. This removes the air pressure from pushing down on the solutions in the straw. Remove your thumb and the added pressure forces the solutions out.

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Science Friction

Do you like skating on wooden floors but then come to a sudden stop on the carpet? Worry no more – a solution is at hand!!

The plastic surface on the underside of each skate reduces the friction which occurs when two surfaces rub against each other.

Because you are standing on the carpet the friction is greater because gravity is holding you down. If you lie on your back with your feet in the air walking is so much easier and lighter!!

But remember skating can end in a sudden bump if you’re not careful!

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NEWTON’S THREE LAWS OF MOTION:

Law 1: A body at rest tends to stay at rest. A body in motion tends to stay in motion in a straight line unless acted upon by some external force (it means pushed by something else!!)

Law 2: The force needed to accelerate an object equals the mass of the object multiplied by its acceleration, or: Force = Mass X Acceleration.

Law 3: For every action there is an equal and opposite reaction.

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Shrinking Marshmallows

Do you think your marshmallows are too big? Why not shrink them!!

All you need is an empty pop bottle, some marshmallows and a pump – the one you buy to keep your pop fizzy.

Place your marshmallows inside the bottle and screw on the pump.

Start pumping!!

After a short while you will see the marshmallows start to get smaller and smaller as the air is pumped out. This is because, as the air is removed, the pressure inside the bottle increases and the marshmallows get squashed.

But don’t worry because as soon as you let the air back in the marshmallows will jump back to their normal sizes!!

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Singing Bowl

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Rubbing the rim creates sound in the same way that running a damp finger around the edge of a wine glass makes a high-pitched note.

The motion of the finger causes vibration in the instrument, producing a sound wave. This can be heard and also seen in the water.

Smoke Vortex - Airzooka

The proper name for the air cannon device is vortex generator. The "ball" of air that shoots out of the cannon is actually a flat vortex of air, similar to rings of smoke blown by a talented cigar smoker. A vortex is generated because the air exiting the bucket at the centre of the hole is traveling faster than the air exiting around the edge of the hole. That swirling or vortex motion can be observed if a little smoke is blown into the bucket just before giving the rubber membrane a gentle push. This activity demonstrates that air occupies space... and the flying smoke rings are an added bonus.

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Sock Bubble

How to make your own

Use household materials to make a bubble rainbow! This is a safe, easy and fun project that explores how bubbles and colour work.

Bubble Rainbow Materials• a sock – preferably clean as it’s less smelly!!• liquid dishwashing soap• plastic bottle• food colouring

Make a Homemade Bubble Snake Wand

You're going to make a fat snake of bubbles. It's actually a great project even without the colouring. Here's what you do:

1. Cut the bottom off of the plastic bottle. If this is a project for kids, leave this part to an adult.2. Slip a sock over the cut end of the bottle. If you like you can hold it on with a rubber band or ponytail holder.

3. Squirt dishwashing liquid into a bowl or plate. Mix in a little water to thin it out a bit.4. Dip the sock end of the bottle into the dishwashing solution.5. Blow through the mouth of the bottle to make a bubble snake. Cool, right?6. To make a rainbow, stripe the sock with food colouring. You can make any colours you like. Rainbow colours would be red, orange, yellow, green, blue, indigo and violet. For most food colouring kits, this would be red, red + yellow, yellow, green, blue, blue + red. Apply more colouring for a more intense rain-bow or to "recharge" the sock if you need more solution.7. Rinse yourself with water when you're done. The food colouring will stain fingers, clothes, etc., so it's a messy project, best done outdoors and wearing old clothes. You can rinse your homemade bubble wand and let it air dry if you want to use again.

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Sticky Rice

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Can you pull a knife from a jar of dry rice?

Sounds easy!!

But if you push the knife through the grains, up and down, repeatedly the rice starts to settle. Refill the jar when the rice settles and do it again. Up and down. The settling rice decreases any space between the grains.

As the rice settles, the friction between the grains and the knife increases as the pressure increases. Once this friction equalises the knife will be held in place.

String Thing

The Amazing String Thing with built in UV light. Can you imagine watching an ordinary piece of string come to life – right before your eyes?The Amazing String Thing transforms an ordinary piece of string into a magical moving rainbow! Create a magical string effect nearly 3 feet high! Point it up, down, even sideways and watch as the string playfully dances in mid-air. Gently touching the string generates wave patterns and interactive shapes that seem to defy gravity.

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Torofluxus

The Torofluxus was invented in the early 1990s by a craftsman in Germany. A 28ft long ribbon of fine “flat spring steel” is woven into a torus (like a doughnut) and the ends are spot welded. It comes attached to a plastic core, and when released the spring opens up into the torus shape. If you the pass the core through your hands, the torus flows downwards gripping onto the core and shimmering like a silver bubble.

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Twirl Pipe

This is very easy to do. Just twirl it around your head!

The air molecules inside the pipe are being “fired” down it and shoot out the other end. The faster you twirl it the faster the molecules travel. This makes the sound.

The pipe needs to be corrugated as this creates tiny vortices of air each time the molecules hit a ‘bump’ and these vortices make the air fly even faster.

By twirling the pipe faster the pitch should go up and different lengths of pipe also affect the sound.

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USB Microscope

Have you ever wondered what a biscuit crumb looks like up close? And we mean really, really close. Or how about a toenail clipping? Or a flea? Or a flea eating a biscuit crumb on a toenail clipping?

If you have (then you need to try out our fascinating USB Microscope.

This smart USB-powered instrument lets you zoom in (from 20x and 200x) on any object you fancy.

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Vortex Bottle

Have you noticed that if you just turn over the bottles without spinning the water, you get a bunch of bubbles as the water dribbles from the upper bottle to the lower one?

It is important to realize that there is something in both bottles, (water in one and air in the other) which clumsily try to pass each other in the bottle necks.

Once you start the water spinning, everything changes.

According to Sir Isaac Newton's first law of motion, the water will move in a straight line unless something changes its direction. As the side of the bottle constantly changes the direction of the water the overall effect is that the water pushes itself against the wall of the bottle. Actually, the spinning air is also pushing toward the outside, but being less dense, it is shoved into the centre by the heavier water.

This is centripetal force and we see this force again and again in technology. (Washing machines throw water out of clothes during the spin cycle so less drying has to be done. Hospital labs analyse blood by centrifuging it so hard that it separates into layers (milk/cream separators also work this way). Beekeepers extract honey from the hexagonal wax cells with centrifugal spinning extractors. Fighter jet pilots wear special suits to help keep the blood in their brains from being pushed into their lower extremities during high-speed turns. Those pilots can lose consciousness when they "pull G's", so named because the force they withstand during sharp turns is measured in multiples of regular gravitational force.)

This heavy water, falling to the lower level, converts its potential energy to kinetic (moving) energy by overcoming friction and this keeps the whole thing going.

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Where Did That Yellow Come From?

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Two Clear Liquids that when mixed together form a yellow solid ????

This reaction is a precipitation reaction.

A precipitation reaction is one that results in the formation of an insoluble product. In this case a yellow solid is formed when solutions of ions are mixed. (An ion is an atom which has either a positive or negative charge)This reaction occurs when two ions combine to form an insoluble solid or precipitate.

Whirlpool in a Bottle

Can you make a whirlpool in your kitchen? YES YOU CAN!!!!

All you need is a bottle, water, a little washing-up liquid and some glitter.

Fill the bottle ¾ full of water and add a few drops of washing-up liquid. To make your tornado easier to see sprinkle in a few pinches of glitter and put the top on the bottle tightly. Turn your bottle upside down and carefully whirl it in the air. When you stop the water will keep spinning!!

Why does this happen? When you whirl the bottle you create a mini vortex that looks like a baby tornado. Because the water is spinning quickly in the centre this creates centripetal force – a force which directs the water towards the middle.

In nature you can see these vortices in tornados, hurricanes and water-spouts which form over water.

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