Introducing our Amazing Energy Machine – a Rube Goldberg machine with a difference

Introducing our Amazing Energy Machine – a Rube Goldberg machine with a difference

I hope everyone has been enjoying Science Week so far. Here in Galway we have the wonderful Science and Technology Festival that runs for two full weeks with lots of activities around the city and county. Read more

What’s in a song? The science of singing

What’s in a song? The science of singing

How is your singing voice? I’d love to tell you how good mine is but my kids would be on that like a shot; they are only too happy to tell anyone willing to listen how bad their mum is at singing. So I reserve it for the shower, solo trips in the car… or for tormenting my children. Read more

[Watch] How and why do freckles appear?

[Watch] How and why do freckles appear?

Another great question this week, this time sent in by seven year old Daniel, who lives in Singapore; Daniel would really like to be a scientist when he grows up, but I reckon he already is one as he loves asking questions and finding out lots of facts about science and nature. In fact, Daniel is a regular to this blog, he often is the first to work out the Mystery Creature of the month!

Daniel’s question is…

How and why do freckles appear?

Many of us have freckles, Daniel has them too, in fact he appears IN the video as the freckle model 🙂 If you would like to know a little more about freckles (I bet you do!) just watch this video below!

Freckles are pretty common, especially in people with fair complexions, but before we look at how and why they appear, let’s take a closer look at what they are?

What are freckles?

Freckles are small spots on the skin, they are usually tan or light brown in colour. Unlike moles or some birth marks, freckles are flat on our skin. They are completely natural and harmless.

We are used to seeing them on peoples’ faces but they can be found all over the body.

They often become more obvious or more abundant when we expose our skin to the sun and that gives us the first clue as to why they appear.

freckles

Natural Sun-screen

Freckles are the result of a natural colour (or pigment) called melanin produced by the body to protect the skin against the harmful rays of the Sun.

This process is called photoprotection and this is how it works…

When UV rays of light from the Sun hit our skin they  trigger certain cells in our body to make more melanin.

The cells that make the melanin are called melanocytes.

melanocytes and freckles

 

The melanin is sent to the outer layer of our skin where it absorbs these harmful UV rays, protecting the skin cells (and the cells’ DNA) from their damage.

Usually melanin is distributed evenly around the parts of the skin that are exposed to the sun, causing our skin to tan.

When melanin is distributed evenly we tan

Sometimes though the melanin clumps together in areas, forming little dark spots that we call freckles.

When melanin comes together in small areas of skin we get freckle spots

So basically, melanin is a little like our bodies’ natural sun screen… which kind of makes freckles like natural sun screen spots I guess.

Who gets freckles?

So do only fair skinned people get them? No, that’s not so. There are probably a lot more people with fair complexions with freckles, and freckles tend to be more noticeable on fair skinned people, but people with all types of skin tones can get them too.

Freckles can appear on all skin tones

Freckles can develop on all skin tones

Freckles tend to run in families, so if your parents have them there is a good chance you do too. The tendency to get freckles is genetics… and is connected to a gene called MC1R.

So remember, freckles are natural and harmless. They are just a sign that our body is taking care of us and keeping us safe.

A big thanks to Daniel for sending in this question; if you have a question you would like me to answer just leave it in the comments below or sent it to me by email (drhowsciencewows@gmail.com).

 

The science of elasticity, energy and rubber

The science of elasticity, energy and rubber

Energy is a great subject in science. It covers so many things and I have many other aspects that I hope to share with you soon but one thing that explains energy so well is a simple rubber band; it can demonstrate elasticity, kinetic energy and potential energy and it great to use in some really cool experiments. Here are just a few short facts on the topic.

What is Elasticity?

Elasticity is the ability of an object to return to its original size and shape after it has been stretched or squeezed.

When we pull an elastic object we are applying a force on it called a stress. If we apply too much stress to an object it will eventually reach a limit called its elastic limit.

When an object is pulled beyond its elastic limit is cannot return to its original shape.

All objects will eventually lose their elasticity due to wear and tear, friction and stress.

Potential and Kinetic Energy

Potential energy is energy stored within something. Kinetic energy is energy in motion.

If we take the example of stretching a rubber band…

When we use force to stretch an elastic object, such as an elastic band we are filling it with potential energy. When we let go of the rubber band and it springs back to its original shape, the energy released is Kinetic Energy.

Did you know… kangaroos and other animals use the combination of potential and kinetic energy to save energy while jumping and springing?

Rubber

Rubber is a material that has very good elasticity. It is a polymer, made up of a long chain of repeating molecules, that can be easily stretched and bent.

Rubber exists in both a natural and synthetic form; the natural form is latex from the sap of rubber trees.

A bit of history

The ancient Aztec and Mayan civilisations are thought to have been the first to discover and use this natural rubber. They used it to make balls for sport and rubber shoes, although the quality of this rubber was sensitive to heat and cold.

Columbus is credited with bringing rubber to Europe.

In 1839 Charles Goodyear discovered that he could stabilise rubber by mixing it with sulphur at high pressure; he called this process vulcanisation.

When Goodyear died in 1860 he was completely impoverished due to constant legal costs regarding his rubber patents.

Did you know… the largest rubber band ball ever made weighed 4,097kg and was made using 700,000 rubber bands?

 

An experiment to try

Want to try an experiment that combines rubber, elasticity and kinetic and potential energy? Why not make a catapult? Or use elasticity to launch a paper plane. You’ll find out how, and a lot more of the science behind these experiments in this post!

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A new venture

This article originally appeared in Science Spin magazine. Although the magazine is no longer in print I am delighted to be sharing some science facts and experiments in a new venture… you’ll find my new SCIENCE FOR KIDS page in each edition of Easy Parenting Magazine. I share one of our favourite experiments in the April/May edition, currently in shops. Take a look…

 

 

How to make rainbow silly putty

How to make rainbow silly putty

People are always asking me for a slime recipe that doesn’t require borax powder. This is one option, making silly putty. We love this recipe, using just cornflour and washing up liquid (or you can use liquid soap instead); just be careful that you use products that you know won’t irritate your child’s skin.

We thought we’d share this one, in honour of St. Patrick’s Day…. with all the shamrocks and the leprechauns and the rainbows 😉

You will need:

  • Cornflour
  • Liquid soap or washing up liquid
  • A bowl
  • A spoon
  • Food colouring

What to do:

Just click the arrow button on the right of the image below to find out how to make this brilliant rainbow silly putty; it is so easy and my kids loved it!


The results:

We mixed all our silly putty together for the rainbow effect but you can keep the colours separate if you prefer. This silly putty is great to play with, mold it in your hand, stretch it, fold it… it makes a great stress busting tool too! It will last for a week or more if you put it in an airtight container or plastic bag but we usually just make a new batch each time.

Let me know if you try this yourself! We have had lots of fun working on other slime recipes and will be sharing them soon so remember to check back or follow the blog to make sure you don’t miss any posts! 

The perfect pancake formula

The perfect pancake formula

We are big fans of pancakes in this house; I’m pretty casual with my batter making at this stage, I throw a few things into a bowl or blender, a bit of a mix, into the pan, quick flip and hey presto! It seems I am going about it all the wrong way. There are formulas that I should be following, such as…

  1. The batter formula

If you take your pancakes seriously, you’ll want the appearance to be just right. It’s not just luck or habit; it is all about the flour to liquid ratio, according to a group of researchers at University College London.

The thickness of the pancake determines the way the water in the pancake is released during cooking and ultimately determines the overall appearance of the finished product.

The experts devised a formula…

Mixture (ml) required per pancake : (D² x T x π) / 4

Total mixture (ml) required: (D² x T x π) / 4

… where D is the diameter of the pancake pan and T is the thickness that you want your pancakes!

And believe it or not, this pancake study has medical benefits too: the team are using what they learned to create better surgical methods for treating glaucoma, which is a build-up of pressure in the eyes caused by fluid.

pancake17

  1. The perfect batter calculator

If this all sounds a bit too complicated then don’t worry, maths students at the University of Sheffield have taken this formula and generated a calculator that does all the maths for you. All you need to do it type in how many pancakes you want, how thick you want them and how wide your pan is and voila, you get an exact recipe!

  1. The super formula

If you like your pancakes with some extra maths then don’t worry, there is a formula for you too, but hold on to your whisks, this one is pretty tricky!

100 – [10L – 7F + C(k – C) + T(m – T)]/(S – E)

Apparently, the closer you get to 100, the better the pancake.

L is the number of lumps in the batter; C is that consistency.

F stands for the flipping score, k is the ideal consistency of the batter and T is the temperature of the pan.

M is the ideal temp of pan is, S is the length of time the batter stands before cooking and E is the length of time the cooked pancake sits before eating.

Are you still with me? If not don’t worry. If everyone in your house is happy to eat your usual offerings then I’d go back to the old reliable. Me? I’m taking my inspiration from this post and I’m going to add some colour and sprinkles… without a calculator in site.

Whatever way you make your pancakes today, I hope you enjoy 🙂

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If you want to know a little more about your pancakes, from history, to ingredients, to science, check out my post over on Headstuff.org today!

Why do we lie?

Why do we lie?

I watched a great documentary on Netflix* recently all about lying… it is called Dis(honesty): the truth about lies and I would highly recommend it.


It really got me thinking about lying, why do we do it, what would happen if we don’t and is it a uniquely human activity?

First off, we all do it! If you are shaking your head in disagreement, then you’ve just lied too! Sometimes we do it for good reasons, sometimes just to save our skin, but we all lie from time to time. So why do we do it and is it a purely human activity?

WHY DO WE

We lie for a number of reasons, it may be a little white lie to make someone feel better or it might be a big lie for our own gain, or to save our skin!

Many of the lies we tell are to present a better side of ourselves; make ourselves appear a little nicer, a little smarter, or a little more popular. We don’t often even recognise these lies, we don’t realise we are doing it – we are lying to ourselves!

On a base level, we probably lie because evolution has shown us that it works to our benefit and the benefit of society. As our social connections have developed, so too have our abilities at lying. It is actually a valuable tool to have and brings with it many advantages. Lying is a sign of intelligence and is considered a complex cognitive skill.

Different types of lies and liars

There are different types of lies and different categories of liars! There are the little white lies that we all do, usually for social acceptance or compliance. There are lies of exaggeration, usually of little harm either;  and then there are the bigger lies that are often more serious and come with a lot more consequences if found out.

There are also different types of liars. We are all contributors to the pool of common-or-garden, everyday liars, but things get more serious when we look at the compulsive or pathological liar.

Compulsive liars tell lies as the norm, it is an automatic reflex and it takes a lot less effort for them than telling the truth does. Pathological liars tend to take it one step further; they lie for their own gain, with little thought to the consequences of their lies, for either themselves or others.

What happens in our brains when we lie?

Lying is a complex process; in order to do it our brains must focus on two opposing pieces of information at the same time: the truth and the lie. If we want to process or deliver a lie we need to believe that it could be true. The brain has to work much harder to lie than to tell the truth. Activity in the prefrontal cortex (at the front of the brain) has been shown to increase when a person lies. This is the part of the brain involved in decision making, cognitive planning and problem solving.

Usually when we tell a small lie, for personal gain, we feel bad. These emotions of regret and guilt are controlled by a part of the brain called the amygdala. However, the more we lie, the more we desensitize the amygdala so that it produces less of these bad feelings.

Studies on the brains of pathological liars show that they have about 25% more white matter in their prefrontal cortex, suggesting more connections between different parts of the brain. However, they also have about 14% less grey matter, the part that can help rationalise the potential consequences of each lie told.

No man has a good enough memory to be a successful liar- Abraham Lincoln

Do other animals lie?

Yes some do. One famous example that my children love to hear about is of Koko the gorilla. Koko is renowned for her sign language abilities, with an impressive vocabulary of more than 1000 words. Koko has a pet kitten that has come in handy for more than just cuddles and companionship. One day Koko tore a sink from a wall in her enclosure. When her carers returned and asked what happened, Koko signed ‘the cat did it!’

Koko The Gorilla2

When do we start lying and how often do we do it?

Some scientists believe that we begin the act of deception as young as six months old! This usually starts as fake crying, or smiling, to get attention. At that age we don’t do a very good job (although it is probably quite cute and amusing to watch) and we likely do not do it as a conscious lie.

By the age of two however, we have put in a little more practice and can deliver an outright lie with more commitment and conviction.

Adults are so good at lying that they can often lie even to themselves; on average, adults lie about 10 times a day and we can throw about three lies into a short conversation with a stranger, without even knowing we are doing it.

Are there ways to spot a lie?

Some of us are better liars than others and there is no detection system, including lie detectors, that work for all. However, many of us amateurs give away some tell-tale signs when we are lying, such as…

  • We make and keep direct eye contact (contrary to common held belief)
  • We keep our bodies very still, but we may…
  • jerk our heads a lot
  • We give more information than is necessary
  • We touch or cover our mouths with our fingers
  • We breathe at a more rapid rate
  • We cover vulnerable parts of our bodies, such as the throat, head or chest

Interestingly, we are better at lying when we lie for altruistic reasons than for our own good and these lies are more difficult to detect.

So that is the low-down on lying, and not a word of a lie 😉

Have you any facts or stories to add? I’d love to hear them, just leave them in the comments below.

*Disclosure: As a member of the Netflix Stream Team I have received a years subscription to Netflix, free of charge, and an Apple TV, for streaming purposes. As part of Netflix Stream Team I will be posting monthly updates on what we are watching and what is on offer.  All opinions expressed will be my own.

4 Valentine experiments 4 your loved ones

4 Valentine experiments 4 your loved ones

I must admit that I am not a big fan of the commercial side of Valentine’s day but I have no problem with the idea of telling someone you love just how much they mean to you. When I get to couple the sentiment with some science experimenting then my heart really does skip a beat. Check out these cool valentine science experiments that would make some pretty unique (and educational) gifts for the someone special in your life.

  1. Say it with flowers

Who doesn’t love flowers on Valentine’s Day? With a little bit of science you can add an extra twist to this staple gift. Try these CHROMATOGRAPHY flowers…

Here’s what you’ll need:

  • Some paper (we used regular white A4 paper here)
  • A selection of water soluble coloured markers
  • A pencil
  • A ruler
  • A paperclip
  • A glass or beaker
  • A jug of water
  • Some wire or pipe cleaners

Chromatography flower 1

What to do:

Fold your paper in half down the long side and then open it out again.

Using your ruler and a pencil, draw a line either side of the crease, the line should be about 2 cm from the crease on each side.

Choose the colours you would like to use and place large dots of each colour along these lines, leaving about 1 – 2 cm between each dot. Alternate the colours in whatever way you wish.

Chromatography flower 2

Once you have that done it is time to fold your paper. You need to fold along the shorter side, start at one end and fold the edge of the paper in about 2 cm. Turn over the paper and fold back another 2 cm. Turn over the paper and keep going like this until you reach the other side of the paper.

Chromatography flower 3

Keeping the paper folded, fold it in half and secure with a paperclip.

Trim the tops of the folded paper on each side. I used a serrated scissors but you could just cut into a pointy shape or round off the ends, whatever you prefer.

Pour about 1 cm of water into your glass (or beaker) and place the folded paper into the glass, as in the photo below. You want the end of the paper to sit into the water below the dots of markers, you don’t want the water level to reach the dots though.

Chromatography flower 5

Now you just need to wait a while. You should see the water creeping up the paper, spreading out the marker ink as it moves upwards. Once the water reaches the top of the paper you can remove it from the beaker and place it somewhere warm to dry.

Replace the paper clip with a strip of wire or a pipe cleaner, and twist it to close. This will be the stem of the flower.

Once dry it is time to open out the paper, into a flower shape, and see what a colourful CHROMATOGRAPHY flower you have made. You can try different types of paper, blotting paper works really well.

Chromatography flower 6

The science bit:

This experiment used a scientific technique called CHROMATOGRAPHY to separating different chemicals; in this case the chemicals are the inks in coloured markers. As the water creeps up the paper (by a process called CAPILLARY ACTION) it dissolves the different inks that make up the colour. These inks separate out as the water moves upwards and you get lovely streaks of colours through the paper.

If you prefer real flowers to artificial ones you can still use a bit of science to add some extra colour; Here are two of our favourites (click the images below to find out how to make these beautiful coloured flowers while learning all about TRANSPIRATION!).

rose

Make a multicoloured Rose (click the image to find out more).

tulips3

Or try making a rainbow bunch of flowers, click the image above to go to the blog post.

2. You make my heart spin

I’ll admit these do take an extra bit of time and effort but they are really worth it and give a nice WOW factor. Your Valentine will be amazed with a gift like this… left wondering just how you did it. This experiment requires ADULT SUPERVISION!

Here is what you’ll need:

  • Some copper wire
  • a pliers
  • a strong scissors or wire cutter
  • A battery (AA work just fine), I used a D battery here
  • A neodymium magnet (these are strong, rare earth magnets, often found in electrical appliances but can be purchased in many specialised shops)
  • Some items to decorate (optional)

Spinning heart

And this is what you do:

You can start by decorating your battery with love hearts or similar stationary if you wish.

Place the neodymium magnet on the base (minus side) of the battery, it will ‘stick’ to the metal.

Now for the tricky bit, you need to make a connection from the positive end of the battery, to the other side (the magnets in this case) to complete an electrical circuit. You can see from the photo and video below that I shaped one end of the copper wire into a heart shape with a little ‘stalk’ to sit on the top of the battery. I then wrapped the remaining wire around the battery and finally, I wrapped the end of the wire around the neodymium magnet (in this case I used two small neodymium magnets, one on top of the other). You will know if the circuit is complete as the battery and copper wire will heat slightly. However in order to get the wire to start to move you need to ensure that the wire is balanced correctly and is not wrapped too tightly around the battery or magnet. It will take a bit of patience and ‘tweaking’ to get this right, but, hopefully you will be rewarded by a lovely spinning heart 🙂

Want to know how it works?

Congratulations, you have just created a HOMOPOLAR MOTOR and, by combining an elctrical current and a magnetic field, working in specific directions, you have generated a force called LORENTZ force, that makes the copper wire move.

To put it as simply as possible, the copper wire connect to the positive and negative ends of the battery, completing a circuit and creating an electrical current that runs through the wire. The neodymium magnet generated a permanent magnetic field. In this set up the electrical current is perpendicular to the magnetic field and this generated teh Lorentz Force which acts on the copper wire, making it move!

NOTE: This experiment requires adult supervision! An electrical current can generate heat and you need to be careful that nothing gets too hot.

3. Gooey with love

Slime may not be the first thing that comes to mind when thinking of a Valentine’s day gift but this one is the prettiest slime I’ve ever made, and it has love hearts and sparkles in it, so what’s not to love. Plus… a few minutes playing with this stuff is time well spent, it is actually a great stress busting exercise, try it and see!

What you will need:

  • A bottle of clear glue
  • A jug of water
  • Bowl and something to stir with
  • A cup or small plastic cup or a second bowl
  • Borax powder
  • glitter and mini hearts (or any decoration of your choice)

Valentine's slime 1

Here is what you do:

Pour a small amount of clear glue into your bowl (we used a 10 ml at a guess). Add the little of the love hearts and glitter, just a small sprinkle of each is fine.

Give all that a good mix and then leave to the side while you make up the borax solution

In the cup (or jug) make up your borax solution; you want to dissolve 1/2 teaspoon of borax powder in a cup measure of warm water (about 240 ml); Stir until fully dissolved.

Still the glue constantly and add a very small amount of borax solution. Keep stirring all the time. As soon as the glue is no longer sticky you can pick it up in your hands and start kneading and molding it, for a few minutes.

I will admit that I had a lot of trouble coming up with a good recipe here. I am used to working with white glue (PVA) which makes great slime. The clear glue can get very rubbery slime which breaks easily. So the trick is to use small amounts and add as little borax solution as possible. Also, once the slime forms at all, take it into your hands and knead it.

You can even roll it into a ball and see how bouncy it is…


I know that borax is not easy to buy in Ireland at the moment so I will test out some alternatives and hopefully have a post next week with some borax-powder-free slime recipes!

The science bit:

Congratulation… you have just made a polymer!! In simple terms a polymer is a substance made up of lots of molecules arranged in long chains.  If you imagine that the glue is like cooked spaghetti, it slides and slips around the place quite easily.  When we add the borax to the glue it causes some of the molecules in the glue to stick together making the glue more rubbery and less liquid!  Imagine if you took those strands of spaghetti and tied them together in places, the strands would not be able to slip and slide around nearly as much! The borax and glue mixture is just like your knotted spaghetti!

4. I Lava you

This is like two science experiments in one. It is an adaptation of this Ocean in a bottle experiment.

Here is what you will need:

  • A clear bottle (plastic is safest) with lid
  • A funnel
  • A bottle of cooking oil (we used vegetable oil)
  • A jug of water
  • Red (or pink) food colouring
  • Glitter and plastic miniature hearts
  • (Antacid tablets, such as Alkaseltzer – and adult supervision!)

What you do:

First add a few drop of red food colouring to the water until you are happy with the colour.

Add about half a teaspoon of glitter and half a teaspoon of miniature hearts to the water and mix well.

Using the funnel, pour the coloured water into the bottle, filling it to about a third full.

Fill the rest of the bottle with oil (using the funnel again) and replace the lid. You will notice that the oil and water remain as two separate layers.

Hold the bottle on its side and tilt it slowly back and forwards, you will see the water moves like a coloured wave, it gives a lovely effect.

If you want to turn this into a Valentine’s lava lamp just stand the bottle back up again, open the lid and pop in half an antacid tablet (like Alkaseltzer) NOTE: these tablets are not for eating and this part must be supervised by an adult.

Pop the lid back on (don’t seal it fully though as gas will build up in the bottle) and watch your lovely lava lamp.

When it stops you can pop in another piece of Alkaseltzer and watch all over again.

The science bit:

This is a good experiment to explain density. The oil is less dense than the water so it will sit on top of the water, creating two separate layers. The layer of oil keeps the water contained within the bottom half of the water and makes the movement of the water look like waves where the two liquids meet.

When we add the Alkaseltzer tablets to the bottle we get a chemical reaction. The tablets contain an acid and a base (or alkali) in powder form. When the tablet sinks down to the water layer the tablet dissolves and the acid and base get to mix together, forming carbon dioxide gas. The gas forms bubbles, and is lighter than the water and oil so the bubbles float to the top of the bottle where they burst, leaving just a drop of water, which is more dense than the oil so it falls back down. This cycle gives a lovely lava lamp effect of bubbles and blobs rising and falling through the oil layer. We are loving this one in our house at the moment. The glitter and love hearts add a really lovely touch to the whole thing.

So there you have it… five of our favourite Valentine experiments, I’m sure you’ll agree, as well as being educational, these would make great gifts for someone you love! We hope you get as much fun out of making these as we did and remember to let us know how you get on!

HAPPY VALENTINE’S DAY!!!

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If you’d like to know a little about the Science of Love, check out this post