Monthly Archives: May 2017

#TryThisTuesday: Rock Candy

This weeks Try This Tuesday takes a while, but you end up with a tasty treat!

You will need:

  • A wooden skewer or chopstick
  • Peg
  • 1 cup of water
  • 2-3 cups of sugar
  • A narrow glass or jar

pic

Clip the wooden skewer into the peg so that it hangs down inside the glass and is a couple of centimetres off the bottom.

Put the water into a pan and bring it to the boil. Pour about a quarter of a cup of the sugar into the boiling water and stir until it dissolves.

Keep adding more and more sugar, each time stirring it until it dissolves, until no more will dissolve. This might take quite a while!

When no more sugar will dissolve remove it from the heat and leave it to cool for about 20 minutes.

Pour the sugar solution into the glass or jar almost to the top. Then put your skewer back into the glass so it hangs down and doesn’t touch the sides.1st

Leave your glass in somewhere it won’t be disturbed. The sugar crystals will grow over 3-7 days. Once these have grown you can eat them!finished-product

The Science

By mixing the sugar and water together when they were really hot, you have created a super saturated solution. This means that the water contains much more sugar than in could in normal circumstances. As the water cools back down the sugar leaves the solution (mixture) and becomes sugar crystals again, forming on the skewer.

Supersaturated solutions are used in real life. In a sealed fizzy drink the drink is saturated (full) with carbon dioxide, as the carbon dioxide is put in using pressure. When you open the drink, the pressure of the carbon dioxide is decreased, which causes your drink to be supersaturated as there is much more carbon dioxide dissolved than there would be at normal pressure. The excess carbon dioxide is given off as bubbles.

#TryThisTuesday: Exploding Lunch Bag

Today we are going to make an explosive lunch!

You will need

  • One small (sandwich size) zip-lock plastic bag
  • Bicarbonate of soda
  • Warm water
  • Vinegar
  • A tissue

img_4727

Do this experiment outside, or at least in the kitchen sink. Put about a quarter of a cup of warm water in the bag with half a cup of vinegar.

Put three teaspoons of the bicarbonate of soda into the middle of the tissue and fold it up into a little parcel.

img_4779

Partially zip the bag closed but leave a little space to add the bicarbonate of soda parcel in. Put the tissue parcel in the bag and quickly zip the bag completely closed.

Put the bag on the ground and step back. The bag will start to expand and hopefully pop!

img_4782

The Science

The bicarbonate of soda and the vinegar eventually mix together, the tissue just gives you enough time to get the bag shut. A reaction takes place between the alkaline bicarbonate of soda and the acidic vinegar, this is know as an acid-base reaction. The reaction produces carbon dioxide, which begins to fill the bag. After a while the bag can no longer hold any more gas so it pops!

The reactions between acids and alkalis are used lots in real life too. Farmers can treat acidic soil with alkaline lime fertilisers to neutralise the soil and allow plants to grow. It’s also a good way to treat a wasp sting; wasp stings are alkaline so you can treat them by putting vinegar on the sting.

#TryThisTuesday: Chicken Sounds from a Cup!

This week we are going to make chicken sounds from a cup!

You will need:img_4715

  • plastic cup
  • string
  • paperclip
  • paper towel
  • scissors
  • water
  • pin

 

 

 

First put a hole in the top of your cup. We found it easiest to push a pin through and then make the hole larger with scissors.

Cut a piece of string that is about 20cm long and put it through the hole in the cup.

Tie the top end of string to the side of the paper clip.img_4716

Wet the paper towel. Hold the cup in one hand and wrap the paper towel around the string near the paper cup. Squeeze the string and pull down in sharp jerks to make the chicken noise!

The Science

Sound travels in waves, which cause particles to vibrate and causes the sound. The vibrations from the string would normally be almost silent without the cup.

When you add the cup it amplifies the sound and makes it much louder. This is because the cup is a solid object, and there are lots of closely squashed together particles in a solid object for the sound waves to hit and vibrate. The more vibrations the LOUDER the sound.

 

Interview with a Scientist: Justin, Biologist

This week we interviewed Justin, a biologist who has recently started working on a PhD looking into the microbes in woodland soils and how they relate to essential processes such as decomposition.phd

Why is your research important?

There is a lack of current understanding of woodland soils, which are really important and we rely on them a lot so we need to have a strong understanding of them to be able to care for them effectively.

What did you do before starting your PhD?

I had a year out before starting my undergraduate degree in Biology at the University of York. During this year I travelled to America and volunteered at a bat hospital. During my first degree I had a placement year working a Kew Gardens. I helped on the millennium seed bank project which aims to conserve rare seeds from plants that are at risk of extinction.

I stayed at the University of York  for my Masters Degree, but also went to Uganda in this year to study the distribution of tropical birds for my masters research. I’ve just started my first year of my PhD.

How did you decide on PhD?

I have always been interested in networks in nature, like food webs, for example. It happened that my PhD supervisor is an expert in this area so it was a great chance for me to learn more about networks.

justinWhat advice would you give to someone wanting to study at university?

Do and see as much as you can, take part in lots of different actvities and volunteer. Have a broad range of interests, not only does it look good on a CV or personal statement but it can help you discover what you want to do and it’ll help you make lots of friends once you get to uni.

What was your favourite part of university?

Meeting new people, trying new things. I tried out things like caving and scuba diving while I was at uni – things that I wouldn’t have been able to do otherwise.

Whats the best thing about being a PhD student?

Freedom learn about the things that I find interesting.

What do you plan to do in the future?

Continue to investigate how we can understand complex links between species.

Has university helped you get where you want to be?

Definitely – uni is where I want to be.

interview-justin

#TryThisTuesday: Milky Fireworks

For this week’s experiment you will need to raid your fridge and kitchen cupboards to get some milk, food colouring and washing up liquid.

Pour some milk into a dish or bowl, this works better with full fat milk (we’ll tell you why later!). Add small drops of your food colouring wherever you like in the milk.

20170509_142618

Get some washing up liquid on the end of a spoon or cotton bud and gently tap the spots of food colouring with it. 20170509_143248

The food colouring should burst out into colourful stars and wavy shapes. This happens because the washing up liquid molecules have a hydrophobic tail, these means that they don’t like water so try to get away from it by seeking fat molecules. The milk (especially if it is full fat milk) contains lots of fat molecules. So the washing up liquid moves around in the milk seeking out this fat and takes the food colouring along with it, creating these funky patterns.

This is why we use washing up liquid to clean our dishes. The hydrophobic, fat-loving parts cling to grease and fat. The head of the washing up molecules are hydrophilic, meaning they love water. The heads cling to the water and the tails cling to the grease, this pulls the grease and dirt from your plates and washes them away with the water, giving you sparkly clean dishes.

 

Happy Birthday Sir David Attenborough!

Today is Sir David Attenborough’s 91st birthday. To celebrate, we’ve written a poem looking back at his extraordinary life and hoping that someday we can follow in his footsteps.

Born in London in 1926,
He’s since won the hearts of all the Brits.
David didn’t always know all about the wild,
But his interest was sparked as a young child.
In fact, he was very much in the dark,
Until that thrilling day at Bradgate Park
When he discovered his first fossil,
Which led to a future so colossal.

In the 1950s came David’s first TV show,0e8396605fcd34cdf9f9c8d11c909679
All over the world, the team would go.
The programme was called zoo quest,
And today may have caused a protest
As it saw David catching animals for London zoo
Anteaters, chimps and rare birds too.

David soon stopped taking  these creatures
And helped conserve their wonderful features.
He showed us the magical Great Barrier Reef
And little ants that cut up and carry a leaf
To feed it to something big and fungal.
He also took us into the depths of the jungle
To see the great apes and what a thriller,
When he cuddled that huge gorilla!

David searched for a dragon on the isle of Komodo
And uncovered the secrets of the extinct dodo.
He took us to the arctic for polar bears in the snow
And in the dark showed us worms that glow.
And who can forget that time in the cave,
When a bat flew into the face or Sir Dave.

pervianfrogLook at all the species named after you,
A dragonfly, Peruvian frog and echidna too,
There’s also the goblin spider and Namibian lizard,
David Attenborough- a true ecological wizard.
Then there’s Boaty McBoat Face – what a boat,
Now named for you, lets hope it forever floats.

From showing us delightful animals on screen,
To being knighted by the Queen.
You’ve travelled the breadth of the Earth,
Now let’s celebrate the day of your birth.
So let’s have a slice of birthday battenberg,
Here’s to you Sir David Attenborough!

#TryThisTuesday: Cork Balancing

Today we’re challenging you to balance a cork on its round side, on the very end of your finger, whilst keeping your finger straight. 20161018_163129_resized

Could you manage it?

It’s quite tricky, but here’s a hint: two forks could help you out.

20161018_163159_resized

Have you figured it out yet? Remember the cork must be balanced on your finger not the forks.

The solution is to stick the forks into either side of the cork. You should then be able to easily balance it on the end of your finger.

20161018_163223_resized

There are two reasons this works. Firstly the forks add weight to the object you’re trying to balance. Because the ends of the forks hang below your finger, it lowers the centre of mass so that it sits underneath your finger, increasing the stability.

Secondly, adding the forks extends the object. By making it longer, the centre point is also stretched making it easier to locate so easier to balance the object. This is why tight-rope walkers often have long poles to help them balance.

Image result for tight rope walker