Whizz, Pop, Bang! Science magazine for kids

This week we had a really exciting opportunity to review a new Science Magazine for children.  It was perfect timing as Ollie is getting too old really for the magazines he's had previously (e.g. Octonauts), but the alternatives we have tried (Nat Geo Kids and Horrible Histories) weren't a good fit for him just at the moment either given his current skills, interests, and knowledge base.

Enter Whizz, Pop, Bang! Magazine.  The first things I noticed were the quality of the paper and printing (nice and sturdy for repeated enjoyment) and the lack of adverts

(the boys spend longer drooling over toy adverts than they do on the activities in other mags).  The next bonus point was for quantity of content - between the text to read, printed activities and experiments to conduct we should get at least several weeks of use out of each magazine (contrast with a maximum of a couple of hours from our usual mags).  Finally the price was a pleasant surprise.  At £34.99 for a year's subscription of 12 issues, that works out at around £2.95 an issue, (again contrasting with the mags we got previously which were between £2.99 and £3.99 when bought in store, although perhaps cheaper on subscription).  I almost forgot - there are also no cheap plastic toys and bags of sweets attached to the cover. The boys and I disagree on whether or not this is a good thing.

As with other kids magazines, the age range that the magazine suits depends on how much parental time you have to spend with your kids, with younger ones needing it to be read to them and older ones being more independent.  The age range seems wider than other mags though, which is helpful with more than one child in the household.  Little brother Toby has been getting just as much pleasure from participating in the experiments as Ollie has, and even came up with novel observations of his own that were not on the experiment plan (i.e. that the ice cube in oil didn't melt anything like as quickly as the one in water at the same temperature).  The only place where age would be an issue for us is on some of the paper based activities, but I headed that off at the pass by photocopying the activities on my printer/scanner so Ollie could do them as the instructions suggested, while Toby drew over them as he saw fit.

 We liked the mixture of practical activities to try in amongst the text.  There were even opportunities to submit results to the magazine for a chance to win prizes.  We have only had time to try out a couple of experiments so far, but the results of the shaving foam marbled planet were just beautiful, and the density experiment inspired Ollie so much that he insisted I filmed him explaining the results.  There's loads of great kitchen chemistry experiments available online, but I really liked the way this magazine not only set out how to do them clearly and simply, but also explained the science behind them in clear and simple terms too.  Very often

 science activities for kids miss out on explaining why the thing is interesting from a scientific point of view, or what the purpose is.  I also liked the way that each theme was no more than a few pages long, so the kids get a taste of lots of different topics, some briefly, others in more depth but with plenty of variety throughout.  It really supports what I'm trying to do with the boys in encouraging them to see that everything is science.  I think a printed list of experiments within the mag with ingredients and equipment needed would be useful though so I could get everything we need before I start reading - the kids were a bit frustrated we couldn't do the marble run roller coaster 'right now!' because I didn't have any pipe lagging to hand.

The science news was inspiring and relevant to the kids, and I liked the pages in each magazine which feature the life and discoveries of a different scientist each month, including female ones - a group who traditionally have been left out of the history books.  Having interviews with working scientists included in the magazines was a really good way of showing a range of different careers available and again contributed to the idea that everything is science - including making chocolate.  There's even a section on the back page to add to my store of terrible science and nature jokes.

Kids are natural scientists and engineers and often they lose this as they get older and exposed to a misconception from school that everything to be discovered has already been discovered, or that science is boring and irrelevant.  Resources such as this magazine are a vital way to address the issue and keep our science mad kids interested. It's also desperately needed as a resource at Primary School age where science is woefully under-represented in the curriculum. I think the usefulness extends to many kids in the early years of secondary school too, since when I taught 11 and 12 year olds they mostly had no science knowledge and this would be a good way to introduce it in a fun way.  As a resource for family learning, whether as part of a schooled child's leisure time or a home educated child's 'school' time it's equally valuable.  Finally, the issues contain seasonally themed information and activities, which all adds to the fun. I'm grateful to the folk behind it for putting so much hard work in producing it and getting it into print.  I will definitely be subscribing for the boys.


NB: I requested the magazine for product review for my blog because I saw an advert on Facebook and it looked like a great concept.  I'm really happy that the producers took me up on my offer and sent me all four currently in print as the magazine has far exceeded my expectations of a kids magazine.  No financial incentive involved.  Opinions and pictures are all my own.

Science and Engineering Week

This week is British Science and Engineering week (13th to 22nd March 2015) and in celebration of the fact people involved in science communication have been holding special events.  You can find out what's happening at the British Science Association microsite here.

We joined in the fun on Monday, when the Observatory Science Centre at Herstmonceux hosted a home educators discount day.  As well as old favourites, including the opportunity to test your building design against an earthquake, there were also new interactive displays, such as the medieval innovations area.

 There really is something for every age to enjoy, with the smallest babies being fascinated watching the light elements such as the plasma balls, and the toddlers loving my boys favourite - the water discovery area where they can test out different ways to raise water including an Archimedes screw and hand pump.


Each time we go the boys find something new to discover for themselves by trying out the activities while I use the interpretation boards to explain the science of what they're doing.  Being able to go in term time makes this easier as during holidays it can get very busy, making it hard for me to keep track of both boys and spend the amount of time on each activity that they would like to.  School holidays do however have the added benefit of the science shows that the centre puts on in the dome behind the main building, so we were really pleased to find out that they were running the shows this Monday too.

 After enjoying joining in the show about light, we had lunch in the very reasonably priced café.  We spent the afternoon playing with the outside elements at the centre and listening to the history of the telescopes in the domes as part of the centre tour. 

In cold weather we save the water exploration for last in case the kids do get themselves soaked, but generally they do stay dry as they build dams and direct flow to water wheels.

All in all I couldn't imagine a better way to celebrate science and engineering than by getting stuck in with hands on fun.  More fun to come before the end of the week too as we look forward to the partial eclipse on Friday (20th March 2015) at around 9.30am.  Now just need to find our stash of cardboard boxes to make pinhole cameras to safely view the eclipse ...



Notes: the site is accessible but as there are steps up from the entrance you will need to ask to go around by the disabled entrance if you have a wheelchair or can't manage your pushchair up the steps.  Inside the site is accessible with ramps where needed.  There are toilet facilities, including a disabled toilet and baby change.  There is a café serving reasonably priced food including freshly made sandwiches, soup and jacket potatoes.  Picnic benches are provided too for you to enjoy your own packet lunches.  The only safety concern to be aware of is unfenced high(ish) walkways and an unfenced pond, which used to make me very nervous when the kids were at the toddling and legging it stage.  Apparently it was not unusual for the odd astronomer to end up in the pond after finishing a shift when this site was operating purely as an observatory.

Xanthan gum slime - home made mucus from kitchen cupboard ingredients

 I discovered a new idea for making slime a couple of weeks ago.  I got a book by ethnobotanist James Wong for my birthday, and in it there was a recipe for making a hair mask using xanthan gum as a thickener.  This stuff was seriously slippery and gloopy and seeded the idea that it would make a brilliant home made ectoplasm/mucus type slime.  You may not have come across xanthan gum before unless you do a lot of wheat free baking, but it crops up in lots of foods and cosmetics as a thickener or stabiliser (E415 on food labels).  It's made by fermenting sugar such as glucose is a polysaccharide (a long chain of sugar molecules) considered safe for consumption by most sources, so is an ideal ingredient for home science - it won't matter if the kids eat a little and I found it didn't irritate our skin the way PVA and borax slime does.

Xanthan gum has a brilliant ability to increase the viscosity of liquids, with a little going a long way.  It also makes a good slime to use alongside cornflour slime to demonstrate the difference between shear thickening and shear thinning liquids.  Xanthan gum slime physically acts in the opposite way to corn starch slime, demonstrating shear thinning compared with corn starch slime's shear thickening.  In other words, stir xanthan gum slime and it gets runnier, thickening when you quit stirring it, whereas cornstarch slime is a non-Newtonian liquid, thickening as you stir it and going runny again when you stop.



We used about 2 level dessert spoons of xanthan gum (bought from the gluten free section of our local supermarket) mixed with about 400ml water, plus green food colouring and lemon essence.  I'm not completely sure about proportions because part of the fun was letting the kids add a little bit of this and a little bit of that to see what happened, but it's easy to add a little more water or powder to get the consistency you want.  We got a lumpy wallpaper paste consistency from what the boys produced (note don't ever use actual wallpaper paste for kids play as it's full of antifungal chemicals and other nasties).

 When the kids were happy with the consistency we played with it in a variety of ways, spooning it, pouring it and squishing it.  We even tested it as a glue by smearing a little on paper and sticking it to an old envelope (it works really well, pending longevity test).

 I encouraged the boys to make predictions about how viscous the slime was and whether adding more water would make it runnier or thicker and make the slime pour down a tube faster or slower.  I asked them to think about how we could experiment with the slime.

 Ollie wanted to know if the slime would sink or float, and if it would dissolve if we put it in water.

Toby was less keen on slimy hands than Ollie and was content poking it around with a spoon, while Ollie got up to his elbows in gunge.

With colds season upon us, this slime makes a good model for explaining about mucus.  Let it dry into a lump and that's a nice disgusting hard bogey, left wet sticky and slimey and it's the thick mucus from near the end of a cold or when you're a bit dehydrated, or add more water and you have a runny mucus like at the start of a cold.  You could even make a clear runny mucus and then add more gum and particles of something to represent bacteria or pollen (I used spirulina powder previously) to make a thick germy mucus.  Spirulina was also quite stinky so made a really unpleasant slime if you're really going for the gross factor.


Notes: I expected this to be a messy activity requiring a change of clothes, hence why the boys are still in their pjs at 9 in the morning - easy enough to chuck slimy things into the washing machine.  In the end though they stayed remarkable clean.

The slime is very slimy so I wouldn't do this near carpets, but from hard surfaces it washes off with soap and water with no problem.

This slime is made from food grade ingredients so it won't matter if a little is ingested, but I wouldn't recommend eating spoonfuls of the stuff either as it is an effective laxative..

Probably best to dispose of via compost heap or household waste bin, but if you do put it down the sink follow it with plenty of hot soapy water as it literally dries like glue, albeit a water soluble one.

Don't eat your slime - but do make some

 There are many things we love in this house - science, getting mucky, having fun - but 'freebie' is also firmly on that list.  This week we have been playing with a lovely freebie, a free download of the fantastic book 'Don't Eat Your Slime' by Marc Wileman.  This book is a lot of fun, and a great starting point for anyone who wants to incorporate science play into their repertoire of activities.

Each simple activity comes with easy to follow instructions and a child-friendly explanation of the some of the science principles involved.  Making slime is the first activity in the book, and as it is one we haven't done in a long time it was a good place to start.

Corn flour slime is a lovely example of a non-Newtonian fluid.  If you leave it alone it will trickle gelatinously from your fingers, but when you apply shear or tensile stresses to it (i.e. move it around) it starts to behave more like a solid than a liquid.  This has the pleasing effect that you can grab it out of a bowl, then let it ooze gently away.

There are other ways to make slime - including using PVA glue mixed with borax - but we keep coming back to the cornflour because it is non toxic, doesn't irritate the skin and won't matter if the kids eat some.  I made our slime up as shown in the book, and also added some mint essence for added sensory fun.

The book gives a basic recipe for each activity but also gives suggestions for how to play around with the materials used to make your own discoveries, for example in 'Make your own flute', after showing how to make a reed from a drinking straw and explaining the principles involved, there is an 'experiment like a real scientist' section with ideas for finding out what happens to the sound if you use shorter or longer straws, fatter or thinner ones, or even just blow harder.

Science is all about experimentation and observation, but school science lessons can be so prescriptive with regards to 'add A to B and observe C' due to time constraints that what we call experiments actually aren't - they are no more experimental than following a cake recipe.  'Experiment' can mean trying to replicate someone else's results, but in it's purest form an experiment is just trying things out - literally experimenting with things.  This book is a great way to remind ourselves that yes we can follow the instructions, but we are prompted to also experiment with each experiment.

The shortage of scientists in our country today is largely because we somehow manage to teach kids that science is hard and boring, so we need resources like this to introduce kids at an early age to what they instinctively know as tiny children - science is really fun.  So if you're looking for a way to entertain your kids, or even fancy having a go at the classic 'mints in soda' reaction yourself, click on the link here to go to the page for a free download.  If you like what you see you could even ask Marc to send one of his trained mad scientists from his company Sublime Science along to entertain the kids for you.

Science on Sea

 Last week we went to a fantastic free interactive Science Workshop for kids organised by the Hastings Pier Charity.

Hastings Pier was burned down by arsonists a few years ago and the rebuilding effort is being paid for through fundraising by this charity, but as well as working on the pier project, they are also delivering brilliant community sessions including arts and crafts and now science.

The show was run by American born, Sussex based 'science dude' Brad Gross and was the first of a series of monthly science events.

The photos I have taken don't do justice to the activities, but it was tricky getting shots without OPCs (Other People's Children) in the picture.  For better images from the event taken by the organisers follow the link from here and look at the post from the 13th December 2014.

The first part of the show was a lively interactive mixture of science concepts, mainly based around understanding our solar system and an introduction to constellations, but also with a nod to the science of the pier including weathering of the structure.  Each segment had activities for children to volunteer to take part in and lots of audience interaction.  Ollie and Toby had the chance to be planets orbiting the Sun (Ollie is Venus in the picture, Toby was Uranus).

After the first part of the show, the kids then took part in make and take away activities.  The boys had fun producing their very own star chart of the constellation of Orion with stickers and buttons and there was also a beach layering activity using breakfast cereals to try.

Brad paced the show very well for his young audience and hit that sweet spot of getting information across in a fun and memorable way to the children while at the same time making the adults laugh.  The venue was perfect too, accessible, comfortable and with panoramic views of the sea and the work in progress of the pier.

Places are limited at these free but book-ahead shows, so we'll definitely be putting our names down for future shows and hoping to get a place.  Hopefully the success of these shows will highlight the thirst for science education in the local area and we'll be seeing a lot more of these kinds of opportunities springing up in the future.

Science is fun and exciting, and the hard work of staff and volunteers preparing and delivering these kinds of events helps to spread that message to the next generation, so why not have a look to see what is already being delivered in your local area and make sure you go along to everything that you spot, because nothing says 'thank you, we want more like this' than bums on seats.

Little engineers - how to make a junk robot toy

I have written before about the shortage of STEM (Science Technology Engineering and Maths) graduates in the UK.  I think a great deal of the reason that people don't choose to study these subjects is partly because they are perceived as hard, but also there is a perception that they are boring.

This image of these subjects as hard and boring can overcome if you get to the roots of what a scientist is - an adult who never lost the curiosity in the world that a child has before they get indoctrinated to learn 'old facts' and not ask questions.  There is also the problem that most people don't know what people in these professions actually do - I'm studying Oceanography as part of my degree - currently a section on seawater, and was surprised that by funny coincidence this happens to be what Matt is studying as part of his Masters degree in Engineering.

There is an additional problem now in UK schools in that
children are underdeveloped in certain areas including those to do with
volumes, weights, measures and strengths because they increasingly have no contact with real objects in their play.  Children know how to swish a screen, but have no idea how to make a model that balances without falling over, or make estimates on whether a thing will be heavy or light, weak or strong.  According to a lady I talked to in the summer who gathers information on such things, a growing number of children are now what would have been classed as 'developmentally delayed' in the 70's because they lack such instincts.  Kids are afraid to try things out because they lack the confidence that would normally come from the repetitive play of childhood - handling objects, pouring liquids, building things.

As usual the answer isn't rocket science (pun intended), it's play with real objects.  We have a long history in the UK (and as a species) of inventing things by tinkering about with materials, and this is at the heart of helping your child to develop their creative and scientific abilities.

 The process is really simple - start with a problem that you want to overcome (plus a box full of junk such as old cereal packets, and some glue and tape).  In our case Ollie's problem was that he didn't want Daddy to go to work because he wanted him to stay home and build a tower with him.  The solution he came up with was to invent a robot that could go to work and do Daddy's job for him.  The boys worked cooperatively to put their robot together - Ollie in charge of the tape dispenser because Toby always loses the end of the tape, Toby in charge of putting tape everywhere.  They quickly found that one off-center leg caused the robot to topple over, so they had to find another box the same size to give the robot two legs.  Likewise with the arms - when they tried a big box for an arm the robot fell over, so cardboard tubes were used instead.  The last balancing lesson came with the head - sticking a box to the front unbalanced the robot, so an egg box on the top was decided on.

When happy with the shape, Ollie then pointed out that the robot needed to be metal, so I brought out the foil and the boys wrapped their robot.  Ollie wanted to know how we could be tearing metal since metal is strong, so we talked about how the strength of a material is relative to it's thickness.  He then wanted to know how it was made, so we had a quick search for a video of it being made - there's a great show 'How it's made' which has lots of episodes on YouTube - I searched 'How it's made Aluminium Foil' and quickly found a video showing how the big block of Aluminium had impurities removed, then was solidified again, the block of pure aluminium was then sent many times through heated rollers which pressed it to 5mm, before it was sent through cold rollers which pressed it to the very thin final product.

The final stage of the robot was to make it move and think, but Ollie conceded that he would have to do that bit later when he was 'a bit older and bigger'.

If you look at the actual skills involved though in this simple creative play session it's impressive what kids this age achieve.  They have worked cooperatively and with a high degree of perseverance to produce a toy that looks the way they want and can stand up without falling over - the ability to make an object balance requires an understanding of weight, shape and forces (even if they wouldn't know by these terms that this is what they know).  When something didn't work they searched for a solution both by trial and error and by using their existing knowledge from previous play.  They used their imagination to visualize what they thought a robot should look like, then tried things out until they found a configuration that both looked like their imagined robot and was structurally strong enough to play with.  They researched materials.  They even seemed to understand that this was a prototype and would require further development when they had greater knowledge and skills in the future.  This is no different to what a design engineer or a host of other STEM professionals do in their jobs.

I've chucked a lot of analytic words at describing what they were doing, not to look like I'm over analysing every element of children's play but rather to give an idea of the fact that play is science, and science is play, so lets raise kids who are confident tinkerers and understand that STEM careers are just as fun and accessible to them as any of the other fantastic professions they could aspire to.

Catch of the day - science and cooking

Apologies to my veggie followers, this is a post you may want to skip.  I am 'mainly vegetarian' - I think the term is flexitarian.  I pick the veggie option where ever possible, and mainly cook veggie myself, but I do include some ethically sourced seafood for variety and because the kids adore it.  My own reasons for being a veggie are mainly based in animal welfare concerns and an attempt to reduce our impact on the environment, but I do understand that many hard line veggies don't want to see any animal products used.  We're quite 'middle way' in most of our lifestyle choices, and this is my 'middle way' approach to dissection.

I have dissected  a few creatures at Uni, and can see that as a learning tool these dissections were useful, but I don't feel quite comfortable with using animals solely for this purpose at home.  My solution is to do edible dissection.  We go down to the fishmongers on the sea front and select a locally caught fish from our excellent local sustainable fishery - the fish is all caught using small beach landing boats.  I ask for it to be scaled since this is a bit that results in scales flying everywhere when I do it at home, but no other preparation to be done by the fishmonger. 

When we get home I let the boys have a thorough look at the fish, answering questions as they have them and asking prompting questions about form, function and lifestyle.  For example with this Grey Mullet we observed dorsal spines and discussed their purpose, investigated the mouth and discussed the lack of big sharp teeth, looked at the streamlined shape of the fish and the purpose of the gills.  We talked about the habitat of the fish and how it was caught.  The grey mullet is a bottom feeder, and once you know that the lack of large sharp teeth and the dorsal spines make sense.

After a good look at the outside, I opened the fish and we had a look at the organs.  I then showed the boys how to fillet and debone this fish and Matt pan fried the fillets, which we had with mashed potatoes and local wild samphire.  We hadn't tried mullet before and the taste was interesting, more like salmon than a white fish like cod.

This is about as ethical as I can make a dissection and if the boys want to eat meat I think it's important they know what it is and how to prepare and cook it.  As a society we have got so used to chunks of something that could be anything, wrapped in a coating and served in a bucket like pig swill, eaten without thought or respect.  I'm not advocating total global veganism, but maybe we can slow down and raise kids who know enough about their food to want to be active consumers who eat things out of choice rather than just convenience.  I also think that you can't beat hands on learning and that the combining of subjects such as science and cooking makes for a rounded experience that makes it easier for our brain to understand and retain the information that it is gathering.

Safety bit:  clean hands, work surfaces and utensils to avoid getting food poisoning.  Also, some bits are sharp, e.g. scales, spines, teeth in some species so take care.  Knives for filleting need to be really sharp, so I don't let the kids near when I'm doing this bit - they watch from a little distance.  As kids get older they could help trimming fins with scissors and eventually be taught to use a knife for filleting, but as mine are 4 and 2 this is a long way off. 

If kids are really squeamish, don't force the issue - a light tough of the fish first time is enough and then sit a little way off to watch the rest.  With repetition kids will generally lose any discomfort, but if they don't it's not a big deal - we're all made differently and maybe you have a little vegan on your hands.  I discourage mucking around with the fish - a part of what I'm trying to instil is respect for the animal.

Play dough volcano

 

Ollie was 'reading' one of his science books in the car the other day and wanted to do 'an experiment with volcanoes'.  It sounded like a great idea to me, so when we got home from swimming I decided that making a bicarbonate volcano would be a fun activity.

The first step was to make some play dough.  I like the recipe I'm giving below because it measures in cups and tablespoons rather than grams, which makes it easier for the kids to help to measure out the quantities:
2 cups plain flour
2 cups water
1 cup salt
1 tablespoon vegetable oil
1 tablespoon cream of tartar (optional but helps the play dough to keep longer without going slimey - unlikely you'll want to save the dough after this activity though so you may as well leave it out)
1-2 teaspoons colouring - we used blue because ours is a bit rubbish at being blue but makes a good rocky grey colour.

Help your kids to measure, add and stir the ingredients, then put into a saucepan and cook on a medium heat stirring constantly until the mixture thickens and looks like dough. it will obviously be hot at this point, so when we make play dough I add in another activity while we wait for it to cool.

 For our 'cooling' activity on this day Matt and Ollie made a volcano picture.  Matt drew the cone, magma chamber and vents, then Ollie coloured it.  Matt drew guide lines for Ollie's words and they worked out what to write letter by letter "What is this red stuff you've drawn inside the volcano? That's right it's magma.  What do you think the word 'magma' starts with..." with some help over shaping the letters by writing each out on a separate piece of paper (while Ollie tuts "I know how to write a 'm'!"). 

I was surprised when Ollie said that the stuff coming out of the volcano was lava and chunks of rock blown off the top - I didn't realise he had remembered that the molten rock is magma when it's inside the volcano and lava when it's outside - I've had A-level students that didn't remember the difference.





In the end they labelled the vent, cone, lava and the magma chamber, by which time Toby had made a birthday card for his friend and our play dough was cool enough for the next stage.








I save plastic pots and tubs for our experiments and activities, and today a pot which had previously contained a small fairy cake in an Asda children's lunch pack was the perfect one - small, plastic and with a push fit lid into which I could easily cut a small round hole in the centre.  I added a couple of teaspoons of red food colouring to the pot, then four teaspoons of bicarbonate of soda and put the lid on.  This formed our magma chamber and the boys modelled the volcano around it.

Next I filled a large medicine syringe with vinegar and the boys took turns squirting it into the magma chamber and laughing at the explosive results.  The first couple of goes where a bit too tame, just gently bubbling down the volcanoes sides, so Matt added some sticky tape to make the aperture in the lid of the chamber smaller.  The resulting fountains of bicarb and vinegar caused great delight.  This video isn't the biggest eruption we had, but for some reason the other footage isn't working.

So what are the science bits from this?  The bicarb and vinegar experiment is an old favourite - adding the acid vinegar to the alkaline* bicarbonate of soda causes the release of carbon dioxide bubbles.  If you add pressure by having a lid on the container with a hole in it, the results can fountain up quite impressively - for a really impressive version look online for videos of the 'mentos and cola' experiment.

What has this got to do with volcanoes?  Quite a bit surprisingly, since there are different types of volcanoes but the one that every kid draws, the cone shape, is an explosive volcano**.  Famous examples of this type include Mount St Helens and Mount Pinatubo.  These volcanoes are explosive because of the presence of gasses dissolved under pressure in hot, highly viscous (thick) magma.  When sufficient pressure builds up to blow a hole in the top (or sometimes side if the vent to the summit is plugged) of the volcano, the pressure is released and the gases suddenly come out of a dissolved state into a gaseous state which froths up the newly emerging lava to form volcanic ash, which, along with other pyroclastic material, rockets up into the atmosphere until it runs out of energy and then collapses on itself, at which point it rushes down the sides of the volcano as a pyroclastic flow, a very fast deadly wave of burning hot poisonous gases and ash.  Very few people actually die from lava flowing from a volcano - it's the pyroclastic flow which is the real danger.  The bubbles you create by adding vinegar to bicarb are about the safest way you can demonstrate how important gases are in an explosive eruption.

As always, don't be afraid to use the proper terminology if you know it when explaining and describing what's happening as kids are amazingly receptive and will surprise you with what they retain over time.  If you don't feel confident explaining what's happening, do the activity anyway and then have fun together looking up explanations in books or the internet.  Finding videos of real volcanoes is a good follow up activity, and if you have some don't forget to try floating your pumice stone foot rubber in a bowl of water - rock shouldn't float right?  Pumice is special and it's all down to those gasses that were in the magma.

Safety bit: Things to be careful of - usual care to be taken with hot stove/hot play dough while you're making the dough; during the chemistry bit be careful of getting bicarb/ vinegar in eyes - wear eye protection if you are concerned, wash eyes immediately with luke warm water if you do get any in there as both will sting.  It can be fun to see how high you can make the volcano jet out, but you don't want to be showering bystanders with the discharge so do exercise sense and start small.


*ok chemistry purists, technically it's a base because it's dry, but acid and alkali are everyday terminology.

** the other main type is an effusive volcano - one that oozes over a long period of time, such as those on Hawaii.  Once upon a time there were also vast lava flows called 'flood basalts' but we can all be glad we haven't any of these now - look up 'Deccan traps' if you want to know why.  Other less impressive but still interesting types of volcanoes are less well known, including mud volcanoes.

Milky surface tension experiment

This experiment is another kitchen cupboard favourite that we learned how to do after a lovely friend shared a video of it on my FaceBook wall.  All you need is milk, food colourings, a container and some liquid soap.

Put some full fat milk into your container, add a few drops of food colourings to make little blobs of it floating in the milk- you may want to experiment with what colouring works best as we found our blue sank and red floated.  Add a few drops of liquid soap, e.g. washing up liquid, on to the blobs of food colouring and your little ones will be amazed as straight away the colouring starts swirling out into the milk.

 The original video that was shared with me didn't have an explanation, but if your little ones are looking for an explanation this is what I think is happening: for very little ones you can tell them that the soap is helping the milk and the colours to mix together.  For older children you can talk about surface tension.  Surface tension is the ability of a liquid to resist an external force - a really good example that you can observe this effect with is to find video footage on the internet of a pond skater walking on water.  The effect is caused by the cohesive properties of molecules in the liquid - the ability of the bits to stick together.  It is responsible for lots of the properties of liquids, for example the way rain falls as drops instead of just remaining in the atmosphere as separate water molecules.

 This experiment works best with full fat milk I think because the fat molecules in the milk are evenly distributed  and when you add the food colouring to the milk the fats prevent the colouring from diffusing (mixing) quickly into the liquid as would happen if you dripped colourings into plain water.  When you add soap I think two main things happen, firstly the soap is a surfactant so it breaks up the bonds between the fat and water in the milk, plus it disrupts the surface tension of the water in the milk - it makes the sticky molecules come unstuck, both of which allows the colours to spread out.  Even more exciting, this is not now a gradual dilution that you get in plain water, the colours shoot around the dish in waves as the colours are driven by movements in the milk as the stronger surface tension areas pull away from the soapy areas where the surface tension is weaker.

After we played with the original set up a few times by replacing the ingredients with a fresh set up in a cleaned dish, we then brought in the idea of scientific method by keeping some parts of our experiment the same and just changing one part - on this day we tried using a different type of liquid soap - hand soap - to see if one soap made the colour mix in faster.  We used simple equipment to measure out our quantities to keep them standard - medicine spoons for the soap, medicine syringes for the colouring and glasses for the milk.  The boys then added the ingredients of their experiment at the same time and watched to see what happened - in our basic set up we didn't see much difference.  I thought there might be because our hand soap was a standard brand while the washing up liquid is an eco brand so I expected it to be less strong of a surfactant.  As it happened it looks like it was just as effective at breaking up the fat molecules and surface tension as the regular soap.

Plant science for junior horticulturalists

 The UK has a skills shortage in the horticultural sector, despite this area of the economy being really important both to the wealth it brings in to the country and for our self sufficiency and food security.  Botany was phased out of the schools curriculum many years ago and as the current generation of horticulturalists and plant scientists retire they are not being replaced in sufficient numbers.

I'm not suggesting we start hothousing our toddlers into a career in plant science, but by providing them with lots of varied experiences we can at least give them a flavour of the huge diversity of different things they could do in the future and perhaps nurture their preferences, fleeting and changeable as these interests will usually be in the early years.

Growing anything at all with little ones is an immensely rewarding activity that you both will enjoy, even if it's cress seeds on damp cotton wool.  The bean in a jar activity was one of the very first things I ever blogged about here and a year on this is how we have extended our early investigation.

Last year we grew our bean in a jar and did some work on recognising the parts of a plant by drawing and labelling the roots, stem and leaves.  This year we transferred our bean seedling from a jar to a transparent plastic yoghurt pot filled with soil so we could continue to watch how it grew.  The pot is on Ollie's window sill, along with our tomato seedlings, so he can keep a close eye on their progress.  When the bean plants were about a foot high I pinched out the tips to see if I could encourage them to stay small and bushy.  A week later Ollie announced with great excitement that his plants had flowers on them.

We had been reading a book from the library about a beaver growing beans on his window sill, so the boys took it as completely normal that they should grow and flower so well.

We talked about what else we would need for beans to grow and I led the conversation around to bees, which we have talked about a lot before.  Ollie suggested we put the plant outside so the bees could visit, but I offered an alternative - we could hand pollinate the flowers ourselves.  So, two days later and armed with a paintbrush, I gently teased open the flowers to reveal the anthers  (male part) complete with pollen and the stigma (female part) that we needed to transfer pollen
from a different flower on to.  We talked about how every type of plant has it's own special shape of pollen so only pollen from a bean plant can make a bean grow.  Both boys had a go at 'tickling' the pollen around the flowers, waiting patiently to take their turn at it.

 Afterwards we looked in Ollie's plant book (Inside Plants by Miles Kelly, bought from Lidls for about £2).  We looked at how the pollen gets stuck onto the stigma and then sends a tube down the style to the ovary where the male information from the pollen joins up with the female information so a new seed can start to grow.  I use the words as I've written them above as it seems to be a level that Ollie understands.  We don't want to lose their interest by droning on about things that are incomprehensible, but I think we often underestimate what children can understand if we present information simply and regularly. 

Ollie used his book to draw what was happening when we pollinated his plants.  He did it a step at a time, sometimes asking me to trace over the book with my finger to show the next bit to add.  I labelled the parts for him with Ollie helping when he knew the part and drawing on yellow arrows to the correct bits. Then he drew a bee to show how it all should have been done if we hadn't been tickling his plants with a paintbrush.  As much as possible I let Ollie lead and don't fuss if things aren't quite right - the pink petals on his flower for example are the way he has interpreted them rather than being an exact copy of the picture in the book - this is good and he gets praised for lovely pink petals, not told they look different in the book!  If you're starting to over control what your kids produce stop, sit back and just marvel at what they're actually showing you about how they interpret what they see.

Note on providing opportunities versus trying to force kids to be academic:
When we looked at the book together I asked Ollie if he'd like to make a science drawing about his experiment - if he'd said no that would have been it for the day and we would have done something else. At no point should there be any pushing of a little one who isn't interested or isn't ready.  As soon as I mentioned that you can hand pollinate flowers with a paintbrush Ollie wanted to try, and pestered for two days before we actually got time to carry it out (he wanted to do it after nursery on the two days he attends, but as he was playing box forts with Matt and Toby both nights after dinner I didn't want to interrupt that time together by reminding him about the plants and waited instead until we had a morning free).  

There's a line between providing stimulating activities to keep kids entertained, and pressurising little ones into things they're developmentally not ready for.  Ollie happens to love this stuff at 4 years old, and he did at 3 years old too, but other kids this age would be happier kicking a ball or building bricks or whatever, so the activities I do are only here online as ideas to try if they suit you and your kids. 

Every child is so different, all we have to do is try to provide them with opportunities to express that.  Toby at 2 enjoyed tickling the flowers, and then when Ollie was making his picture Toby was doing his own picture with pens and stickers in a much more patient and methodical way than Ollie did at that age, so even kids raised together will have different preferences and abilities and I don't want to add to the pressure parents have of feeling that kids 'should' be doing certain things at certain times.  Lots of kids aren't developmentally ready to hold a pen comfortably by 4, let alone write words, so there is a great deal of debate at the moment about the pressures on small children with proposed testing to be brought in for very young children to test literacy and numeracy.  The only important thing kids 'should' be doing in the early years is playing, and playing as regularly with parents and with other children as possible. 

If your kids happen to show interest in science, maths, art, history and so on then that can become part of your play.  When he does his experiments and 'writes them up' Ollie is playing at being a scientist in the same way that ten minutes later we will all be playing at building forts together and chasing away imaginary invaders.  The minute you stop playing and get out the flashcards to hothouse your little one, you are in danger of turning them off to the big fact of life that so many people are missing - playing is learning and learning should be fun so we want to keep doing it for our whole lives because it brings us joy.

Cornflour slime - one of my favourite non-Newtonian fluids

 Today I couldn't convince Toby to change out of ancient, grubby looking, hand-me-down Thomas the Tank Engine pyjama top, so it seemed like a good day for doing something really messy.

This activity is one for when you have enough time and patience to tackle a bit more of a clean up operation since, unless your small children are far better at following requests than mine, it does end up with slime covered clothes, floor and table.  Not to try to put you off, because it is brilliant fun, but I also would keep this one well away from carpets.

The basic kit is really cheap and easy to get hold of.  You will need cornflour, water and something to colour it with - food dye if you have it, but I've used turmeric or fruit tea before and they work fine.

The proportions are a cup of cornflour to half a cup of water, plus a few drops of dye.

You may need to help with stirring as the ingredients can be a bit tough to mix.  As they come together you should start to notice the shear-thickening properties of the slime - the faster you stir, the harder it is to move.  Slow right down and the slime moves much easier.

We are generally more familiar with Newtonian liquids where the viscosity of the liquid doesn't change with the pressure applied to it - you can stir that cup of tea as fast as you like, it won't get any harder to stir.  Non-Newtonian liquids act differently, in this case the liquid has 'shear-thickening' properties.  In other words, the more pressure you apply to it by stirring faster, the more viscous and difficult to stir it becomes. 

I have never met anyone who didn't embrace their inner child when faced with cornflour slime.  It defies common sense in a really appealing way that encourages play and experimentation.  In the picture of my two boys together you can see them both experimenting with pouring the liquid from a bowl or spoon to make a puddle, yet if you push the puddle with a spatula you can heap it up.

Grab a handful of the slime and so long as you keep squishing it and rolling it in your hand it stays a wobbly solid, but as soon as you stop moving it, the slime 'melts' and runs away slowly.  It also has quite a nice chalky texture, so can be a good messy-hands activity for children who can't stand dirty hands.  You can focus on talking about the way the texture changes and may wish to consider adding a scent such as a food flavouring to add to the sensory experience.  Little experimenters can find out what happens when they add more cornflour or more water to their mixture.  Making predictions is a really valuable skill for science that you can easily incorporate into this. The question 'If you add more water do you think it will make the slime runnier or thicker?' seems very basic, but small children don't have your experience and probably won't know for sure.

I'm obviously doing this activity with tiddlers, but if you have older children there's a whole world of fluid mechanics to explore with this simple mixture.  You could also try finding out about other shear-thickening liquids such as quicksand or investigate their opposite numbers - shear-thinning liquids.  There quite literally wouldn't be life as we know it without these, since blood is a shear-thinning liquid.  This is a property of ketchup which explains why if you give it a good shake you can convince it to thin enough to come out of it's bottle.  Toothpaste is another one - squeeze the tube and it becomes less viscous so it can come out, but then thick enough that it doesn't drop off your toothbrush.

If you have no idea about the science, it's still good fun and a chance to develop your child's language skills by describing new experiences.  If you do know the science, don't be afraid to use whatever level of language you know by mixing basic descriptive words with the more complex ones.  By exposure to complex language kids can surprise you with what they pick up, even if they don't know straight away what it all means you are priming them to remember the terminology in the future.  It's also fun to hear the words 'non-Newtonian liquid' from a four year old.

Should your little scientist make the leap to ask 'why does it do that?', you can nicely evade any really technical attempts at explanation with the phrase 'nobody really knows for sure, perhaps one day you will be the person to find it out'.  Ollie wants to be a crane driver and Toby just says 'choo choo', 'snake' or 'chocolate cake' to most questions, so I'm pretty sure they're not considering a future in fluid mechanics just yet.