Monthly Archives: October 2017

#TryThisTuesday Halloween Special!

Slime Two Ways

Happy Halloween! Here’s two of our favourite ways to make spooky slime with things you’ll find lying around the house, or in your local supermarket.

Magnetic Slime

Step 1

Ask an adult to help you remove the ink tube from the highlighter using a pair of scissors and squeeze the ink into the bowl. You might want to wear some plastic gloves to avoid getting the ink all over your hands!

Step 2

Add the liquid glucose and mix (we added Halloween confetti at this point for an extra spooky edge!)

Step 3

Gradually add cornflour and mix to get a slimy consistency, then add iron filings and mix, adding more as necessary.

Step 4

Move the magnet on the outside of the cup, and watch as the slime creeps up the side!

Step 5 (optional)

If you have access to a black light, shine this at the cup to make your slime glow in the dark!

      

The science!

The cornflour and liquid glucose mix together to create a non-Newtonian fluid, a fluid that changes in viscosity (how runny it is) with a change in pressure applied to it.

When the iron filings are added and dispersed throughout the slime this makes the mixture magnetic!

The black light emits ultraviolet light which is invisible to the naked eye, but when shone on the highlighter it emits a brilliant glow!

Reversible blood slime

Step 1

Carefully cut open the lining of the nappy and shake out the crystals from inside onto a sheet of paper. You may get some cotton coming out too so just be careful to take this out before step 2!

Step 2

Put the crystals from the nappy into the bowl or container, you’ll only need about a tablespoon full, and add about 250ml water and a splash of red food colouring

Step 3

Stir the mixture and watch closely as the water is absorbed by the crystals and begins to look like a thick slime! Again, we added Halloween confetti to ours to make it even more mysterious!

Step 4

To reverse this process, and turn the slime back into water and food colouring, all you have to do is add salt and mix and watch as the process takes place.

 

The science!

The crystals that are in the lining of nappies are known as a hydrogel. The hydrogel here is a polymer (a long chain of repeated molecules) called sodium polyacrylate and is superabsorbent, meaning it expands when it comes into contact with water and can hold a huge amount of liquid!

When the salt is added, the polymer collapses due to the a change in the ionic concentration of the solution and so the water-holding ability of the hydrogel is broken.

The Science of Baking: Cake

For the next instalment in Science of Baking series, just in time for the Bake-Off
Final, Charlie Wilkinson has looked into the science of making the perfect cake.

Cake is a wonderful thing, there’s nothing quite like the first slice of homemade cake to cheer you up. We use it to celebrate birthdays for a reason! There is science in baking a cake, even if you don’t realise it.

cake

The basic ingredients for cake include the use of flour, eggs, sugar and butter. The flour and eggs are strengthening ingredients for building structure in the cake while the sugar and butter are structure weakening. A good cake feels light in texture, this lightness is due to air bubbles formed throughout the batter which creates a structure of thin layers of cake separated by those air bubbles.

Baking a cake starts with creaming your fat and sugar, this action incorporates all that air which is required to form the light texture of cake. At this point eggs are added to the mixture, beaten egg essentially protects the air bubbles in the cake from collapsing during the baking process. Flour is then gently added into the mixture, gently to protect those precious air bubbles. The addition of flour is essential for the structure of the cake, forming gluten to add structure. This is a delicate process, however – too much gluten creates a heavy consistency like bread. This is why the type of flour used is important, with cake flours with lower protein content and heavy strong bread flours with higher.

As the cake bakes air expands as water vapour and carbon dioxide is released, the egg cooks and coagulates forming a permanent risen form of the cake. Browning reactions take place on the cake surface which enhance the flavour of the cake, creating a final form of browned, risen, light, airy, delicious cake.

Black History Month: Influential Figures in STEM

October is drawing to a close, which means it’s time for our final installment of profiles for Black History Month. We take a look at astronaut and scientist, Mae Jemison, and renowned zoologist, Ernest Everett Just. We’ve barely scratched the surface of the achievements of black people in the STEM industries, but we hope we have inspired you with some amazing stories. If there’s anyone else you’d like to share with us don’t forget to comment below!

Black History Month: Influential figures in STEM

To honour Black History Month we’ve created a series of posts profiling inspiring and influential black people throughout history in the science, technology, engineering and maths industries. This week we’re looking at the achievements of pioneering botanist, George Washington Carver, and NASA’s extraordinary mathematician and physicist, Katherine Johnson. Visit the blog next week for more.

Sci-Fi vs Sci-Fact

It’s World Space Week, so naturally, we seized the opportunity to stick on our favourite sci-fi blockbusters. However, with our scientific minds always at work, we couldn’t rest easy without sharing with you those space movies that are more fiction than science…

Star Wars

Okay, so we appreciate this galactic fantasy series isn’t ever going to be exactly scientifically accurate, what with all the aliens, droids, space travel and the mystical “Force”. But those space battles that Star Wars is known for, featuring all kinds of explosions and blasts? Well, in reality, they would actually be silent. Sound waves travel via the vibration of atoms and molecules in a medium such as air. Space is a vacuum, devoid of all matter – including gases – meaning the sound vibrations wouldn’t work.

Armageddon

Even if it were feasible to land on an asteroid and drill into the centre of it (just in case you were wondering, it isn’t), the energy required to destroy this huge, Texas-sized, asteroid would amount to a LOT more than one nuclear bomb. The most powerful nuclear bomb ever detonated on earth, Big Ivan, has a total energy output of 418,000 terajoules. Leicester post-graduate students found that in order to split this asteroid in two, Bruce Willis would have had to detonate a bomb with 800 trillion terajoules of energy output.

The Martian

Ahh, a little respite from the scientific disaster that is Armageddon, The Martian is actually hailed as one of the most scientifically accurate sci-fi movies of all time. The main plot line (humans visiting Mars) looks to be scientifically feasible at some point in the future, and growing potatoes with a combination of your own excretion and Martian soil? Possible, apparently. However, whilst we’re willing to give credit where it’s due, this film is not without its inaccuracies.

The main scientific issue with this film is actually the driving force behind the whole plot – the sand storm that leaves Matt Damon’s character, Mark Watney, stranded on Mars. Whilst sand storms definitely do occur on Mars, the atmosphere is so thin compared to Earth’s that a 100mph wind on Mars would feel more like an 11mph wind does on Earth – making it unlikely to cause the destruction that sees Watney separated from his crew.

Interstellar

The astronauts in Interstellar make use of a wormhole next to Saturn, which enables them to travel from our galaxy to an entirely different galaxy in a short amount of time. According to Einstein’s theory of general relativity, wormholes are a possibility.

A wormhole is created by warping the fabric of space-time. If you think of space as a flat piece of paper, the distance is great between one end of the paper and the other. Bend the paper in half and the opposite ends of the paper are now much closer – punch a hole between the two ends of paper and you now have a tunnel which grants you instantaneous access between both ends, instead of travelling the long way from one end of the flat sheet of paper to the other.

However, astrophysicist Kip Thorne points out that in reality, there is a strong indication that wormholes through which humans could travel are forbidden by the laws of physics. Should we ever come across one, a wormhole is likely to be so unstable that the walls of it will collapse so fast that nothing is able to make it through.

Gravity

A central plot point in this film depends on Clooney’s character, Matt Kowalski, whizzing from the Hubble Space Telescope to the International Space Station using his jet pack. However, Hubble orbits at an altitude of 559 kilometres whilst the ISS sits at 423 kilometres; the distance in orbit between the two makes travelling between them completely unfeasible (especially in a jet pack).

World Animal Day

Today is World Animal Day, a day to celebrate and raise the status of animals. Humans are often thought to be the animals with the highest status and intelligence due to our effortless ability to use tools, develop language and dominate the globe. However there are millions of species that have evolved traits and talents that humans could only ever dream of. Here is our list of some of the most amazing animal adaptations.

1. Bioluminescence


Bioluminescence is the ability to emit light. Fire flies and glow worms are well known for their ability to light up but they are not alone, lots of insects and even a species of snail (Quantula striata) hold the protein Luciferin, allowing them to emit light. The protein reacts with oxygen using a specific type of enzyme – luciferase. The chemical reaction gives off the bright glowing colours.

Deep down in the ocean, there is little light from the sun so many marine animals have evolved bioluminence. Others, such as the Sea Goosberry above don’t emit their own light but can refract light to give this dazzling rainbow effect. Even if it’s not technically bioluminescent – we’re still very jealous!

2. Camouflage

In contrast to flashy bioluminescent animals that stand out, some creatures prefer to blend in…

When you think of a camouflaged animal, most people would think of the classic colour–changing chameleon but octopus and squids are the real masters of disguise. They have thousands of cells known as chromotaphores across their skin, these contain pigments and can expand and shrink to change the colour of the skin. These animals can also change the appearance of their skin’s texture and use their soft body and tentacles to morph into a different shape.

The Mimic Octopus takes this a step further and manipulates its body into the shape of other animals to fool its predators into thinking it’s a different marine species – now that would be a fun superpower to have!

3. Mimicry

All the most famous superheroes have a disguise! Like the mimic octopus, some relatively harmless animals have found a clever way to avoid predators by copying the colours, body shape and even behaviour of harmful species. This is known as Batesian Mimicry, and can be seen in animals such as the caterpillar Hemeroplanes triptolemus above, which cleverly disguises itself as a poisonous snake by blowing air into its head!

Mimicry can also happen when two harmful species that have a common predator evolve separately to have similar warning signals such as bright colours or patterns, that show the predators that they are poisonous or taste unpleasant.  This is known as Mullerian Mimicry and can often be seen in butterflies and snakes. So two entirely different (and possibly poisonous!) species of butterflies may look identical.

4. Invisibility

Glass Squid

If camoflauge doesn’t work, how about being invisible? Maybe not completely invisible, but many species have come close by evolving to become transparent. The glasswing butterfly has evolved to have transparent panes in its wings, making it more difficult for predators to spot.

The glass squid and some species of jellyfish have evolved transparent bodies making them extremely difficult for predators to spot them in the depths of the ocean.

5. Regrowing limbs

Image result for axolotl

If all these adaptations for hiding fail and you’re caught by a predator – what next? Well some species such as the Mexican salamander, the axolotl, have evolved the ability to regrow parts of the body so it’s not a big deal if something does take a bite out of them.

When an axolotl loses a limb, the cells at the cut off point lose their identity; they are no long skins cells or muscle cells and they become generic cells that are able to develop into whatever the axolotl needs them to be to regrow whatever was lost. Whilst humans have come a long way in developing amazing prosthetic and even bionic limbs, we’re unlikely to evolve the ability to completely regrow body parts anytime soon.

If you want to see some amazing axolotls yourself, take a trip to Newcastle University’s Natural History Museum, the Great North Museum: Hancock.

6. Outside Digestion

Speaking of regrowing limbs – starfish can also happily regrow spines but that’s not their only talent – they can also digest their food in a very interesting way. Instead of taking food in through the mouth, instead they take their stomach out of their body and put it on the food. Their stomach then digests the food into a mushy soup which the starfish can then draw into it’s body along with it’s stomach.

Perhaps this wouldn’t be top priority for a superpower but it is impressive! You can see the starfish in action in our aquarium at the Dove Marine Lab in Cullercoats.

7. Flight

Image result for bar tailed godwit

Moving from the seas to the skies, I’m sure many of us would love to have the ability to fly. Of course many creatures have mastered this, mainly birds and insects but some reptiles, fish and mammals, such as the flying squirrel, have evolved flaps of skin that allow them to glide through the air.

One of the most impressive flyers of the animal world is the bar-tailed godwit. This little bird weighs around 500g but is capable of flying immense distances. The longest recorded migration of this species was from Alaska to New Zealand – a distance of 11,680km! The journey took nine days and the bar-tailed godwit didn’t stop once. Very impressive considering most of us couldn’t even stay awake for nine days!

8. Echolocation

Onto another famous flyer – the bat. Flight isn’t this mammal’s only superpower as it can also navigate in the dark without sight. It does this by using echolocation. Bats send out a high frequency sound and listen for the echos coming back. By comparing the outgoing sound with the returning sound, bats tell how far away obstacles are, how big they are and even if they are moving. They are able to build up a picture of the world around them using sound, just as we are able to using sight.

This impressive power may not be so out of reach for humans. Several blind people have taught themselves how to navigate using echolocation. They produce sounds either by tapping a cane against the floor, creating clicks with their tongue or snapping their fingers and then listen for the echos, just as echolocating animals do.

9. UV Vision

Image result for uv light reindeer

Whilst some animals, like bats, have relatively poor vision, other see much more than we could imagine. The light that we can see, known as the visible spectrum, covers the wavelengths 380nm – 760nm. Ultraviolet light sits just outside this so our eyes are unable to detect it. Some animals including butterflies, some birds and even reindeer have evolved the ability to see UV.

Reindeer are thought to have evolved this ability as it helps them identify lichens for food, and urine indicating predators in the snow. To us, these would blend in but in ultraviolet light there is much more of a contrast.

10. Mind Control

Our final adaptation may perhaps be the most sought after superpower – mind control. This isn’t just the stuff of science fiction movies and comic books, some animals have actually achieved it. The green-banded broodsac is a parasitic flatworm that infects snails in order to reach birds, their ideal host species. The parasite infects the snails and causes their tentacles to bulge, making them look like a caterpillar. It influences the snail and makes them move from the shade and up to the tops of leaves and branches where they are easily visible to birds. As the tentacles now look like a delicious meal for the birds, they’re prime targets. Once eaten, the parasite is able to continue it’s life inside the bird.

Which of these animal superpowers would you like to have?

The Science of Baking: Bread

With the Great British Bake-Off gracing our TV screens once more, we’ve decided to dig a little deeper into the science behind baking. What makes bread rise? What makes cake light and fluffy? Why do we love all things sugary and baked so much? All of these questions and more will be scientifically answered in our newest series of blog posts. Neuroscience student and Social Media Intern, Charlie Wilkinson is starting us off with the science of bread…giphy-2.gifIf you’ve watched the bake off then you’ve definitely experienced the beauty of watching 12 British bakers pounding dough into the bench like it’s an olympic sport. But what’s actually going on here besides taking your BBC/Channel 4-related-aggressions out on some innocent bread.

Bread is the product of key basic ingredients including flour, yeast, water and salt. The process of making bread involves mixing these ingredients together until the flour converts into a stiff paste, this initial mixing allows for the development of gluten as the dough becomes stretchy and elastic. The type of flour again is important with breads using strong white bread flour due to the high protein content for a strong dough.

Following GBBO bread week to the next stage of rising, as the bread is covered and left to prove. This fermentation process allows gluten proteins to stick together forming networks, and the yeast cells grow. Yeast cells break down sugars using enzymes into water and carbon dioxide. The carbon dioxide gas is retained in the dough allowing for the dough to expand and double in size. Some breads require two bouts of kneading and proving to form the perfect bread.

During the actual baking process the heat of the oven penetrates the dough leading to rapid formation of air bubbles as fermentation increased. The heat increases the activity of the yeast to form more air until a point at which the heat kills the yeast cells and air formation stops. High temperatures also cause gluten strands to transform into sex-rigid strands which give bread its crumb-like structure. Sugars blend together and brown to form the colour of the bread crust during ‘browning reactions’.

So the next time you’re watching bake off with your friends and family you can delight and entertain with your extensive knowledge of breads.