A Simple Slice of Science – Why do we get Jetlag?

A Simple Slice of Science – Why do we get Jetlag?

For this Simple Slice of Science Dr. Simple looks at Jetlag… what is it, why we suffer from it and can it be avoided? This question originally came in from Lisa at Mama.ie when she wrote this blog post (so it only took me five months to write this response… I can’t blame jetlag for that!).

 

Why do we get Jetlag?
Why do we get Jetlag?

References:

*http://www.airspacemag.com/need-to-know/when-did-the-term-jet-lag-come-into-use-71638/?no-ist

**http://www.hhmi.org/biointeractive/mammalian-molecular-clock-model

 

Three of our favourite Science Experiments – the messy play edition

Three of our favourite Science Experiments – the messy play edition

There is a lovely linky running over on the Mama Courage blog. It invites bloggers to get over any hang ups they may have and let the kids get… well messy. Messy play is great for children as a fun, tactile, interactive activity. We are all for it in this house. I thought the linky would be a great wayto share some of our favourite messy experiments with you all.

I hope that these entice you to roll up your sleeves and get stuck in to some messy play science, just don’t look at me when it comes time to clean up!

Here are three of our favourite “messy” science experiments…

1. Making Slime

 

Of course this is top of the list… messy and slime are interchangeable really, aren’t they?

This is one of our popular slime recipes…

You will need… two bowls (or cups), borax powder (you can buy this in pharmacists throughout Ireland), water, PVA glue, some stirrers and food colouring of your choice (optional)

 

What to do…

Add one cup of water to the first bowl and mix in a teaspoon of borax powder until it is all dissolved.

Add a cup of PVA clue to the second bowl; add a cup of water and mix well.

If you would like to colour the slime add a few drops of your chosen food colouring to the glue mixture and mix thoroughly.

Add the borax solution to the glue mixture and start to stir immediately… you will notice that the glue turned to slime almost straight away.

The slime can be stored in an airtight container and will last for years once it is not allowed to dry out.

 

Time for slime
Time for slime

What is happening?…

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!

 

2. Making goo (otherwise called Ooblecks)

 

Messy but fun
Messy but fun

This stuff is very messy but oh so much fun. Not just for the kids either, once adults get their hands on this goo their is no stopping them. It makes a great stress reliever… honestly, have a go!

 

You will need… A large bowl, cornflour, water, a large spoon to mix and food colouring (optional)

 

What to do…

Mix the cornflour and water together in the bowl (approximately one cup of cornflour to two cups of water). Add a few drops of food colouring if you wish. Once it is well mixed it’s time to get stuck in. First place your hands into the goo and slowly lift them, watching how it runs through your fingers. Now try punching the surface of the ooblecks with your fist, you may be surprised with the result.

 

Here is an demo from an enthusiastic member of the Science Wows team:

 

I left him play while I was making dinner but had to take one more video to show how much fun he was having (you’ve got to watch this one)…

 

What is happening?… 

Ooblecks is what we call a Non Newtonian Fluid… meaning that it does not follow the laws of Netonian Physics.  When left to rest it looks just like a regular liquid.  However when disturbed by strong hitting, shaking or pulling it acts more like a solid.  It is a phenomenon worth studying and although still a bit of an enigma, scientists think that the material normally acts as a liquid but can produce a sudden, local reaction to rapid impact and stress, reinforcing the area and briefly solidifying the suspension.
Ooblecks takes it’s name from the green slime that fell from the skies in the Dr Seuss booh “Bartholomew and the Oobleck“.

 

3. Our version of the ‘Coke and Mentos’ experiment

 

You have probably all seen the coke and mentos experiment, maybe you have even tried it yourself. The basic idea is that you want to get as many mentos as possible into a bottle of coke as quickly as you can.

Last year I found myself minding two boys who were off “sick” from school. As the day went on it was obvious that they were getting a little less sick and a little more bored. So I decided to give them a challenge (you can read the original post here);

I gave them these …

The props
The props

… and told them to devise their own version of the coke and mentos experiment.

This is what they came up with…. (notice the poor teddies that were strapped onto the front of the skateboard!)

So what is happening?...

Firstly, this is not thought to be a chemical reaction between the coke and the mentos.  It is most likely a physical reaction known as nucleation;  The coke is full of carbon dioxide gas, to give it its fizz;  the mentos are full of tiny little craters on the surface of the sweet, the carbon dioxide gas is able to form bubbles in these “craters” producings thousands of tiny bubbles all at once; these bubbles of gas are under a lot of pressure within the bottle of coke and so come shooting out the mouth of the bottle.  If anyone knows anything about Newton and his laws they will know that every reaction has an equal and opposite reaction (Newton’s third law of motion)… so the coke comes shooting out of the bottle in one direction and the force of this propels the skate board forward in the opposite direction.  PRETTY COOL!

 These are just some of our favourite messy play experiments. Check out what others are getting up to in Mama Courage’s Messy Play Project linky.

 

 

 

A simple slice of science – Why is the sky blue?

A simple slice of science – Why is the sky blue?

This week’s question for Dr. Simple came from a source very close to home… my eight year old wants to know

“Why is the Sky blue?”

 

I told him we would put it to Dr. Simple, so here it is, in 30 seconds…

 

blueSky

 

 

If you have any other questions on this topic or another do leave a message in the comments below. There are lots of great questions coming in for Dr. Simple but he always loves getting more!

 

If you need a little convincing about all this information on light and colour you can check it out for yourself as I will be sharing some great experiments on tomorrow’s Fun Friday post!

Fun Friday – Static Electricity

Fun Friday – Static Electricity

What is Static Electricity?

Static electricity is a charge that builds up when two things are rubbed together. Matching charges of static electricity push each other away (repel) while opposite charges attract each other.

Let’s Learn More!

Everything is made up of atoms.  An atom is the smallest piece you can break an object down to while still maintaining it’s properties.

photo credit: ProLithic 3D via photopin cc

Atoms are made up of protons, neutrons and electrons.  Protons have a positive (+) charge, neutrons have no charge (neutral) and electrons have a negative () charge.

At the centre of each atom is a nucleus, this is where the protons and neutrons are found.

The electrons are found to the edge of the atom, they are constantly moving in a circular motion around the nucleus.

When two objects are rubbed together electrons pass from one to the other, making one more positively charged and the other more negatively charged.  This charge is called static electricity.

How does lightning work?

photo credit: Brujo+ via photopin cc

 

Lightning is caused by a build up of static electricity in clouds.  As the charge in the cloud grows, the base of the cloud builds up a strong negative charge.  This negative charge creates a build up of positive charge in the ground.

If the attraction between the cloud and the ground (or between two clouds) becomes strong enough, a spark of lightning will jump between the two.  This lightning is a giant spark of moving electrons travelling between the cloud and the ground.


Did you know… that the heat of a lightning bolt is hotter than the surface of the sun?

Some things give up or take on electrons more easily than others.

Objects can be ranked according to how easily they give up or take on electrons and this ranking is called the triboelectric series.  Things listed at the top of the triboelectric series give up electrons more easily than those ranked below.

Experiment to try at home

photo credit: Kevin Baird via photopin cc

1. Hair raising fun!

You will need… a balloon and a good head of hair!

What to do… blow up the balloon and tie it tight.  Rub the balloon all around your hair (this is called charging the balloon); Now move the balloon slowly away from your head and watch your hair stand on end!

So what is happening?… When the balloon is rubbed on your hair electrons are passed from your hair to the balloon.  This gives the balloon a negative charge and your hair a positive charge.  As opposites attract, your hair is attracted to the balloon and sticks to it while you pull it away.

2. Attract a can!

You will need… a balloon, a good head of hair and an empty aluminium can!

What to do… charge the balloon on your hair as before.  Lay the empty aluminium can on it’s side on a table.  Then bring the charged balloon close to the can, but do not let it touch it.  Slowly draw the balloon away from the can and watch the can follow.

So what is happening?… The aluminium can becomes attracted to the negatively charged balloon as the area around it becomes positively charged.

3. Bending water!

You will need… a balloon, a good head of hair and a running tap!

What to do… Turn on a tap to a small, steady stream of water and leave it running.  Charge the balloon on your hair as before.  Bring the charged balloon slowly towards the stream of water and you should see the stream of water slowly bend towards the balloon! (If the experiment does not work for you just reduce the flow of water).

So what is happening?… Just as with the aluminium can, the stream of water becomes attracted to the negatively charged balloon as the area around it becomes positively charged.

I hope you have some hair raising fun with these experiments :0)  If you have any questions or queries, or would like me to cover a particular subject in the Fun Friday blog, please just leave me a comment below!

I am going to take a little blogging break for a couple of weeks but will return in August for plenty more fun, facts and experiments to share.