All posts by Clare

#TryThisTuesday: Easter Eggsperiments

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As Easter is coming up we’re treating you to four experiments instead of one this week! And a little video showing Ellie and Clare demonstrating each of them (or at least attempting to!)

1. Hard-boiled Egg Test

Our first eggsperiment requires a hard boiled egg so we’re going to show you how you can test if an egg is hard boiled or not.

Lay a hard-boiled and a normal egg flat on their sides and spin them. Put your finger on the eggs to stop spinning them and then let go. The one that starts spinning again is the raw egg.

This is all due to momentum. When you spin the eggs you spin their insides too. In the hard boiled egg, the insides are fixed to the shell so it behaves as you would expect. In the raw egg the insides continue to spin after you’ve stopped the shell. When you let go, the momentum of the spinning yolk carries the shell and the whole egg starts spinning again.

 

2. Egg in a Bottle

Now we know which is our hardboiled egg, we need to peel it for next experiment. This one requires a glass bottle, a match and of course, the egg.

If we place the egg on top of the bottle it doesn’t look like it’s going to fit in. But if we light the match and drop it into the bottle then after a second place the egg on top, the egg will squeeze into the bottle.

The match heats up the air in the bottle, causing it to expand slightly. The egg creates a seal so more air cannot enter. As the air cools inside the bottle it decreases the pressure and forces the egg into the bottle.

 

3. Naked Bouncy Egg

To make a naked bouncy egg you will need an egg, white vinegar and a beaker. Place your egg in the beaker and pour in enough vinegar to cover the egg. Leave you egg here overnight.

The egg shell is made mostly of calcium carbonate, this reacts with the acid in the vinegar and dissolves to leave a naked egg. It also produces carbon dioxide gas, so as your egg is soaking you may see little bubbles of CO2 forming around it.

After a day, carefully remove you egg from the vinegar and wipe away any remaining shell. You should see that it’s now quite rubbery and bouncy as well.

 

4. Bouncy Elastic Egg Drop

For this final eggsperiement you can use your bouncy naked eggs but we’re cheating a little bit and using rubber eggs. For this you will need to take two rubber eggs and join them together with a piece of elastic or a string of elastic bands.

When you hold your eggs next to one another and let go they both hit the floor at the same time as you might expect. But what do you think will happen if we just hold the top egg and let the other hang below it, which will reach the floor first when we let go?

Gravitational acceleration is the same no matter the weight or mass of an object, but when we add elastic between the eggs, this adds an extra force that speeds up the drop of the higher up egg as the elastic pulls them together.

 

#TryThisTuesday: Skipping Stones

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During our time as STEM Ambassadors, we’ve visited several beaches together. From Newcastle in Northern Ireland to Clear Water Bay in Hong Kong and even beaches closer to home in Whitley Bay and Tynemouth, we always ended up skipping rocks somewhere!

But how do we do it!? Why don’t the rocks just fall into the water?

Skipping rocks in Whitley Bay

The key is to get a nice flat rock and throw it quickly at the right angle. The large surface area allows the stone to bounce off the water’s surface.

You need to throw it fairly hard to give it enough speed to gain momentum before it hits the water. When the rock hits the surface of the water it pushes the water down whilst the water pushes the rock up. If the force pushing the stone up from the water is greater than or balances the weight of the stone then it will bounce on for another skip rather than sinking. This is why it helps to have a nice small stone.

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It is also important to get the right velocity. Velocity is the speed of something in a give direction. So we have the speed covered, now for the direction. Scientists have discovered that the optimal angle at which the stone should hit the water should be around 20 degrees. As you probably won’t be able to measure this on a causal day trip to the beach, just aim to throw the stone sideways rather than up or down.

Hopefully you’ll manage more than my measly two skips. Try beating the world record of 88 skips in a row!

Will skipping rocks in Northern Ireland
Will skipping rocks in Northern Ireland

STEM on Tour: Hong Kong!

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Recently myself and my fellow STEM Graduate Ambassadors, Ellie and Will, were lucky enough travel to Hong Kong to take part in the British Council organised Science Alive Festival at the HK Science Museum. As the festival’s theme this year was This Pale Blue Dot – we also took two Earth Science students, Hannah and Elizabeth.

Will, Elizabeth, Clare, Hannah and Ellie at the Hong Kong Science Museum

To take full advantage of this wonderful opportunity we also reached out to some schools with the help of Anthea, Newcastle’s Hong Kong Recruitment Manager. With 20 STEM workshops booked in, we took to the skies with our bags packed with as much kit as we could carry including a drill, over 20 metres of rope and a dinosaur costume.

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Hannah and Elizabeth delivering our Thinking Like a Scientist workshop

During the first three days, our time was spread amongst seven schools. We were delighted to see how bright and engaged the children were throughout our workshops, particularly in the primary schools. Each school was extremely welcoming, many of them gave us banners with their school logo on and other gifts. The Vice Principal of one school even took us to a nearby bakery after the visit to treat us to a local delicacy – a warm egg tart.

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Elizabeth science busking

The weekend snuck up on us and before we knew it we were performing our science show: The Story of Earth, at the Science Alive festival. I was setting Will on fire (don’t worry, it didn’t hurt him although I did actually singe his arm hair at one point) and Ellie was freezing flowers with liquid nitrogen. Meanwhile Hannah and Elizabeth were science busking; entertaining and educating children with science demonstrations.

The Story of Earth Show

We also ran training workshops for teachers. We taught primary school teachers how to think outside the box to raise aspirations and teach science in a more interactive and fun way. At the Hong Kong University of Science and Technology, we trained the students on good science communication practices, from science busking to written texts. We explained how they could simplify their language to make their research more accessible and easy to understand.

Ellie in her element at the beach on the HKUST campus
Ellie in her element at the beach on the HKUST campus

During our ten days in Hong Kong we had an absolute blast, educating thousands of children and adults and learning all about their culture and styles of teaching. From bursting a 3-foot confetti-filled balloon to teaching children how to make honeycomb, from visiting the highest bar in the world to seeing 10,000 Buddha statues in one room, it was an unforgettable experience.

The 10,000 Buddhas Monastery
The 10,000 Buddhas Monastery

We feel honoured to have been given the opportunity to share our activities with another part of the world and hope next year’s team will be able to have a similar adventure.

View of Hong Kong Island from the Star Ferry
View of Hong Kong Island from the Star Ferry

#TryThisTuesday: Curly Fries!

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Today we are looking at the science behind curly potato fries. First, let’s talk about how we make them.

  1. Carefully chop up a potato into straight thick chips.
  2. Boil around 250ml of water and stir salt into this water until no more salt will dissolve.
  3. Fill a bowl with tap water and place half of your chips into this bowl.
  4. When the salty water has cooled pour it into another bowl and add the rest of your chips to this.p1020750
  5. Leave both bowls of chips out overnight.
  6. The next day you should have one bowl of chips that are still hard and straight and the other bowl (with salty water in) will be full of chips that are more flexible, that you can shape into curls.

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The Science

The addition of salt to the water allows you to make curly fries due to osmosis. Osmosis is the movement of water from an area that has few molecules in the water to an area that has more molecules in it to try to even things out and create a balance.

waterin

Plants like our potato here are made up of millions of cells that have a cell membrane around its edge which allows some things in and not others. Water can easily flow through this but the salt we dissolved in it can’t. Cells are filled with lots of little molecules so water usually flows into the cells and fills them to dilute the liquid. But when we have lots of salt in the water, there are more particles in the water outside of the potato cells than inside so the water leaves the cells.

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bendyWhen cells are filled with water they are quite rigid and packed closely together making a fairly sturdy chip. When the cells are dehydrated, they are smaller leaving space between cells, allowing the chip to bend without snapping.

Osmosis is used in all plants – not just when you cut them up and put them in a bowl of water! Plants use osmosis in their roots to allow water to move from the soil into their roots.

 

#TryThisTuesday: Homemade Ice cream!

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This week we’re making ice cream but instead of using an ice cream machine, we’re going to make it using science!

You will need:

  • Two Ziploc bags – one small, one large
  • 100ml double cream
  • 50ml milk
  • 40g sugar
  • Vanilla extract
  • Ice
  • Salt

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  1. Measure out the milk, cream and sugar and place them into the smaller Ziploc bag.
  2. Add a dash of vanilla extract  then zip up the bag.
  3. Fill the larger bag 2/3 full with ice.
  4. Pour a generous amount of salt onto the ice.p1020738-3
  5. Making sure the small bag is tightly zipped up, place it inside the bigger bag with the salt and ice.
  6. Gently shake the bag for 5-10 minutes, be careful not to rip the bag!
  7. Leave the ice cream to sit inside the ice and salt bag for another 10 minutes
  8. Open up your bag and enjoy!

p1020740-2Try making different flavours of ice cream by swapping the vanilla extract for strawberry or mint extract or even cocoa powder for chocolate ice cream. You could also try adding chocolate chips.

 

 

 

 

How does this work?

Water, as I’m sure you know, freezes to make ice at 0oC. But your freezer at home is around -18oC, so how are we making the ice cold enough to freeze your creamy mixture? The secret is in the salt.

Ice is in a constant state of melting and refreezing and melting and refreezing. When we add salt, the salt particles block the path of the melted ice, stopping it from freezing back on to the rest of the ice but ice can still melt. Therefore more ice is melting that freezing.

Now you may be thinking that surely if the ice is melting that means it is getting warmer? It’s actually the opposite. For ice to melt it needs to break the bonds that are formed between the H2O molecules. This breaking requires energy which it gets in the form of heat. When a molecule melts away a bond is broken, taking heat away from the surrounding, causing the temperature to drop.

This is also the reason that salt is put on icy roads – it stops water forming ice.

#TryThisTuesday: Spinning Disk

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This Tuesday, you don’t need any equipment to try this experiment at home – you just need to stare at your screen, or more specifically the video clip below:

(don’t worry we aren’t trying to hypnotise you!)

Stare in the dot in the middle of the circle for 20 seconds, you can blink but don’t look away, keep your eyes focused there. After 20 seconds look at someone’s face, if there’s no one around you, get a face up on screen that you can quickly look at.

What did you see?

Hopefully, if it worked you should have seen the face appearing to get bigger. Obviously, it didn’t really grow before your eyes, this is simply an optical illusion playing a trick on your brain.

You see things because your eyes send messages to your brain about different types of light, shapes and movement and your brain makes up an image of the world around you. When you stare at the spinning disk for so long, your eyes continually send messages to you brain to say its spinning. Your brain gets a bit bored of hearing the same message over and over again so kind of stops listening, tunes out the messages and just assumes from now on, this is how it is – everything is spinning.

So when you look away at a face or your hands or anything really, your brain thinks it should be spinning so gets confused and spins the image in the opposite direction, making it appear to grow. After a few seconds, your brain will hopefully catch up and everything will go back to normal.

Top Revision Tips: Get some sleep!

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With exam season upon us, we thought we would help you guys out a little bit with a useful piece of procrastination – revision tips backed up with scientific research!

1. Get a good night’s sleep

We spend on average one third of our lives asleep so it must be important. There have been millions of studies looking into sleep and how it effects our minds and bodies.

Sleep is divided into five stages. The final stage is called REM (Rapid Eye Movement) sleep, named after the quick eye movements made during it. If you look at someone who is in this stage of sleep you will be able to see their eyes moving behind their eyelids (it’s not creepy if it’s for science). During this stage your brain is super active, brain scans during this phase look similar to someone who is awake but your body is paralysed. This stage is considered to be the point at which you consolidate memories into long-term memories.

Scientists in Italy looked at a range of studies focusing on the effects of sleep on the academic performance of students. The results showed students whose sleep was restricted did worse than usual in exams whereas those who were allowed extra sleep performed better. Further to this, a study by Trockel (2010) looked at lots of variables in 200 students and found those that woke up later performed worse in exams. So you might want to avoid the lie-ins during the exam period!

 

2. Don’t pull an all-nighter

Although it can be tempting to stay up all night to get some last minute revision in when you’re particularly worried about an exam, I wouldn’t recommend it. Research from Pilcher and Huffcutt (1996) looked at 19 different studies and found sleep deprivation (going a long time without sleeping) can impair your thinking and this is not going to help you in any exam.

The world record for the longest time kept awake without drugs is 11 days and 24 minutes (please don’t attempt to break this record). The record was set by Randy Gardner is 1964 and the severe lack of sleep not only effected his concentration and memory but also led to paranoia and even hallucinations. Of course this is an extreme example but studies looking at just 24 hours without sleep have found worse performance on memory tasks and slower responses after sleep deprivation. Not ideal for an exam.

3. Don’t rely on coffee

Coffee may seem harmless enough but it does contain a drug – caffeine. Although it does have its perks, as with any drug there are side effects that you won’t want around exam time. Firstly, I’ll explain the science behind what caffeine actually does once it’s inside your body. Within your body you have a molecule called adenosine which suppresses arousal and promotes sleep when it binds to its receptors. Caffeine is able to bind to adenosine receptors but does not trigger them, instead it simply sits there and blocks adenosine getting to the receptors so causes the reverse effects. This is clearly beneficial when you want to stay awake but can cause insomnia – not good as you now are well aware how important sleep is. Caffeine also stimulates the release of adrenaline – this already happens when you’re stressed so can worsen the effects and cause anxiety.

So what does the research say? Harrison and Horne (2010) conducted a study in which they deprived participants of sleep and subjected them to memory tests, some with coffee, and some without. They found those who drank coffee felt less sleepy but performed no better in their tests. Even in control conditions where participants weren’t sleep deprived, coffee made no significant improvement in their results.

If you are starting to lag with your revision and feel a little sleepy, try having a nap instead of reaching for the coffee. One study found that having a 60-90 minute nap can improve your memory recall and learning ability much better that a cup of coffee.

 

4. Manage your time well

Good time management is key to making sure you cover all the topics you need to before an exam and still leave yourself enough time for a good snooze. It can help you keep calm as well if you know you have given yourself enough time. A study of 249 students found that time management behaviours such as planning, organising, setting goals and prioritising helped reduce stress levels better than leisure activities – although leisure activities also helped reduce stress, so make time for fun when creating your revision timetable.

But it’s not enough to just make your revision timetable – you obviously have to stick to it. Another study found that self-discipline is a major predictor of academic performance.

So make a plan, stick to it and get some sleep!

Top Revision Tips: Memory Techniques

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With exam season upon us, we thought we would help you guys out a little bit with a useful piece of procrastination – revision tips backed up with scientific research!

1. Don’t keep re-reading – test yourself!

Most scientific models of how memory works agree that we have a short term and long term memory. Short term memory can hold 5-9 items whereas long term memory has a much greater capacity but not everything we see, hear or read ends up there. To help embed things in our long term memory it helps to rehearse them and practice retrieval too. This means that whilst re-reading the same notes over and over again will help rehearse them, it is also important to test yourself to see how much of it you can remember to be sure you can retrieve these memories when you need them.

2. Use Mnemonics

Mnemonics are a technique used to help remember things by association. For example you might have learnt the order of the colours of the rainbow with the phrase “Richard Of York Gave Battle In Vain” with the first letter of each letter corresponding to the first letter of the colour it represents. So it translates to red, orange, yellow, green, blue, indigo, violet. Or maybe you learnt the compass points with “Never Eat Shredded Wheat”.

If you have to remember things in a certain order for your exam, making up a mnemonic like this can be a great way to help you. Mnemonics work by creating more meaningful associations and giving you cues to help you retrieve the information from your long term memory. Researchers Shetty and Srinivasan looked into the study skills of 137 Dental students and found that the use of mnemonics were associated with higher exam scores.

Here’s a mnemonic to help you remember the geological time periods:

geology

If you use mnemonics to aid your revision, comment and let us know what they are – you might be able to help someone else out too!

3. Don’t rely on cramming

It’s a classic scene – just before you’re about to enter an exam, everyone is sat around stressing over their textbooks and flicking through sheets of scruffy notes trying to get in some very last minute revision. Is this really helpful? Studies have shown that you can generally hold, on average, 7 things in your short term memory and this fades after 30 seconds if not rehearsed and committed to long term memory. Therefore it’s unlikely you’ll remember much of what you read waiting outside the hall after you have taken your seat and read the question.

It’s much better to manage your time to allow yourself to cover everything you need properly and get it into your long term memory before the day of your exam!

4. Use Chunking

Despite the fact I have just said you can only remember around 7 things in short term memory, you can probably remember a phone number or a couple of post codes for 30 seconds right? This is because, whether you notice it or not – that information is chunked, making it much easier to remember. This is why phone numbers are usually displayed with a gap after three or four numbers and why post codes are in two parts.

Chunking, or separating your revision into relevant sections can help you digest everything and remember it more easily. If you can create links between different bits of information and put them in meaningful categories it can help you to recall the relevant information in your exams.memory

 

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#TryThisTuesday: Birthday Binary

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Here’s a little trick you can play on your friends, or someone you don’t know well enough to already know their birthday…

With the five cards below, you can “guess” anyone’s birthday. Just go through each of the cards in turn and ask them if their birthday (as in the date they were born, not the month, so if they were born on the 17th January, their number is 17) is on the card. Discount the cards their birthday is not on.

binarycards

With the remaining cards, the cards their birthday is on, add up the numbers in the top left corner and the number you get should be their birthday!

For example, my birthday is the 30th April so 30 in my number. Its on card 1,2,3,4 and not card 0 so you would add up 2+4+8+16=30.

Is it science or is it magic?

Of course it’s science! This actually works on a system called binary, which is the language computers use. Binary is written in 0s and 1s and these together look just like 101001010010010101010 to us but to a computer that might actually mean something.

In this case, when you discount a card, that becomes a 0 and the remaining cards are a 1. So going back to the example of my birthday the cards would read 11110 (reading it backwards) and in binary this means 30.

#TryThisTuesday: Book Pulling

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You’ve probably got exams coming up, maybe you’re supposed to be revising now, chances are you’re surrounded by textbooks. If so here is a quick little experiment you can try.

All you need is two large books with lots of pages, around 200 or so.

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Start by interleaving the pages one on top of the other to sandwich the books together, like so:

This doesn’t require any kind of glue or tape but the two books should now be securely stuck together. Challenge your friends to try to pull the books apart – no matter how strong they are, they won’t be able to do it!

So if there’s no glue, why is this? It’s all because of friction. Friction is a force that occurs when one object moves over another – it is the resistance that is felt. When you try to pull the books apart there is friction acting on each page opposing the movement. If you consider there are over 200 pages, this force is multiplied and so becomes super strong!

When you pull the books the pulling motion squishes the pages in the middle with a greater force, this in turn makes the force of friction greater as it acts to oppose this force. So the harder you pull, the more difficult it is to separate the books!