The Little Scientist's Blog - Science4you

Why is yawning so contagious?

Why is yawning so contagious

It is the end of the week and we are so tired due to lack of sleep hours that we see ourselves opening again and again our mouth during our friends dinner, in the cinema or even on the sofa while watching TV, but do you know why little scientist?

There are three theories to explain why we yawn, do you want to know them? Keep reading and find them out!

A yawn...

We are always trying to control every action of the human body, but, as yawns are involuntary actions, no one will ever be able to control them. According to specialists, that is a mechanism that the body uses to import oxygen so that our brain refresh and be able to be aware preventing us from falling asleep.

Conclusion: The best way to fight against sleep is yawning!

Is yawning actually so contagious?

 We all think so, don’t you little scientist?

 There are 3 theories which are trying to explain it: Physic, Evolution and Boredom.

  • Physic: specialists had defined the yawns like a process created by our organism with the purpose of easing the gases exchange, what means getting a higher quantity of oxygen and expel the carbon dioxide in excess.
  • Evolution: regarding to the evolution theory, yawns are one of our ancestors habit since they yawned show their teeth. If it was right, yawns would be useless but we cannot keep out of them.
  • Boredom: this theory defends that yawns are associated with drowsy and boring moments, what is the most known around the World.

The mirror-neuron is a cell which is the main responsible for this mechanism, whose principal function is registering our behaviour on different situations during the day. Consequently, when we see someone yawning, the neurons register that behaviour and trigger out an auto-reflection, which is impossible to control, forcing us to repeat what we have just seen (in this case the yawn).

Do empathy and affinity matter?

Do you think that if someone that you do not know yawned, you would also yawn?

Theoretically you would, but surely you will try to do everything in your hands to avoid it because you will not want to show empathy and affinity with that person. What about people who we have affinity with? It depends, but we normally yawn without be conscious we are doing it just seconds after that person.

So, what are your conclusion little scientist? Ours is that empathy and affinity matter!


  • Yawns last around 6 seconds.
  • A yawn can increase the heart beats up to 30%.
  • Around 55% of people end up yawning after seeing someone else or even an animal doing it.
  • Olympic athletes usually yawn before any competition. 

Did you know any of these facts about yawns? Or do you know some more facts about it? Tell us what you know little scientist!


Why do mosquitoes bite us?

Why do mosquitoes bit us?

Bzzz… Bzzz… Bzzz…

Do you also think that you are the only one who is constantly attacked by mosquitoes? Well… Discover what you can do to avoid it, little scientist!

Do all mosquitoes bite?

First, you should know that not all of them bite us, only females! While males collect nectar, sap and fruit juice, females feed with our blood.

This insect has two wings and a developed horn which is able to break through human and some animal skin in order to suck blood, producing a blotched pock which itches so much that we cannot stop scratching! Moreover, they make such a disturbing noise when they fly that impede us to sleep! 

Why are we bitten?

Female mosquitoes suck blood to feed themselves, as the need it to be able to incubate their eggs. Without it, they will never hatch.

They are attracted not only by the carbon dioxide we emit, but also by our body’s heat and some chemists of our sweat like lactic acid. All of us produce those chemists that mosquitoes love so much, and even animals do it!

He has not been bitten, but I have been! Why?!

Have you ever been the only one who have been bitten and you wonder what it is the reason?

As you should know, science always has the answer, little scientist! Scientists discovered that some people are more likely to avoid mosquito’s pocks since their bodies produce some repellents or a less quantity of the chemists that attract them.

Do you remember the lactic acid? Well… Some lucky people do not produce enough quantity of it to satiate female mosquitoes!

Mosquitoes have preference for some synthetic smells too. For example, they can be attracted by some perfumes! Be careful what you use, you can increase the possibility to being bitten, little scientist.

It was also founded that people whose blood group is 0 have the double of possibilities to being attacked! Have you already checked yours, little scientist? If you have not, do it, it could give you the clues to know why the bite you!

Why does the pock get red and swelled?

When we are bitten, mosquitoes transmit us their spit, which contains a chemist that avert our blood from coagulate. Then, our organism realises and starts working immediately by activating our defences, which means that it spreads a substance called histamine. That is the reason of blush and swell!

Furthermore, if you scratch the pock, it will only go to worse, little scientist! As your body will detect that it need more histamine to combat mosquito’s spit, which will provoke even more itch!

Some advice to prevent you from being bitten:

  • Use deodorant, lotions and soaps which do not have too much smell.
  • Make use of repellents that dietiltoluamide.
  • Even it does not seem to work, wear clear clothes! Dark colours attract them since is easier to distinguish in landscapes.
  • Do not move too much… Movement reveals your position!
  • If you feel it is too hot, use a fun instead of opening the windows! A really bright breeze can become a tough obstacle for them!

You already know all advice of Science4you to avoid mosquito’s pocks, little scientist. So you now will not have to search a fly swatter every day, and the best, you will be able to play with your favourite science toys without worrying about being bitten by mosquitoes!


Why should we choose sweet potato over potato?

Why should we choose sweet potato over potato?

Since today is the Sweet Potato Day, we have “cooked” a interesting article where you could learn a little bit more about this delicious tubercle!

But first, did you know that there are two types of potatoes, little scientist? The white potato and the sweet one, one really good and another one not as good… Could you guess what each of them is? Keep reading to find it out. We are going to help you choose your next garniture!

How everything started

Potato is a tubercle which was discovered in Central and South America when Europeans arrived and saw how indigenes cultivated them, bringing them to Europe in the 16th century.

Have you noticed that potatoes can have different colours? It is produced by A vitamin, which gives potatoes a wide range of colours from white to yellow, red and even orange or pink! Do not get shocked if you see one with a different colour, little scientist!

But… what is the healthiest?

Sweet potato is, without no doubt, the best garniture for our dishes! Be careful and do not get confused by its name, little scientist, as having ‘sweet’ into its name does not means that it could not be health! In fact, the support of nutritional values (A and C vitamins, calcium, phosphor and steel) is higher comparing with white potato, so it is healthier! So, finally, we could name it The Good Potato.

Advantages and… more advantages!

Regarding to some research made by those people who are experts in this field, nutritionists, white potato and sweet potato both do have the same amount of calories, but a different types of carbon hydrates. White potatoes contain fast absorbed carbon hydrates which are quickly added to our blood, while sweet potatoes’ carbon hydrates absorption is slower, taking much more time to become fat.

Moreover, sweet potato has other benefits for your body: it fortifies your immune system, reduce your cholesterol due to its quantity if fibre and not only that, it also helps you to maintain your articulation and cartilages health as well as combat the aging! There are only advantages, little scientist!

Why do not cook a little bit and try new dishes with this new garniture, little scientist? Have a try and do not feel shy to tell how it was! We will be glad to hear and try your recipe!


Why do we get red when we are embarrassed?

Why do get red

Giving a public speech, hearing a compliment, making a mistake, falling down in front of a crowd, seeing someone we love… We all fell embarrassed in some way on these occasions, and, for sure, have ever been in one of these situations when we would like to hide as an ostrich.

Today we are going to explain you why we get so red that we seem as though we are just about to blow up on these situations, little scientist.

A blood-adrenaline mix

Getting red is an involuntary action that happens when our brain perceives something out of our comfort zone… If we start feeling embarrassed, our cardiac rhythm begins to boost and our blood vessels to widen, which produces an increase of adrenaline into our body. That changes into our body cause that the blood vessels in our face widen so much that we start getting red.

But, why does the width of our blood vessels occur? Well, the answer is that there is a release of hormones on these situations, so an improvement of the blood flow is needed in order delivers more oxygen.

Our body is the boss

As it is explained, blushing is involuntary, but do you know what is it commanded by? It is called sympathetic nervous system and is a part of our autonomic nervous system, responsible for controlling the involuntary actions of our body. That is why we hardly ever are able to avoid some of our actions as getting red. Your body is your boss, little scientist!

Curiosities about our nervous system

Now you already know why we blush, let us tell you some tips about our nervous system:

  • We can blush from few minutes to many hours! It depends on how much our body last to restore the hormonal balance.
  • Our brain is divided into two hemispheres, right and left; Our right hemisphere controls the body’s left side and the left hemisphere, the right one.
  • Every year, we lose neurons.
  • Some types of tea, caffeine and chocolate stimulate our nervous system.
  • Almost the 20% of the oxygen we breath is consumed by our brain

    By this time you might have noticed that our brain is a really complicated organ and it causes some reactions like blushing in some situations. Now you should know what is happening the next time it occurs to you, little scientist!


    Should we worry about the danger of asteroids?

    should we worry about the danger of asteroids?

    Happy Asteroids World Day!

    Today is the first ever time that Asteroid World Day is officially celebrated, so why don’t we learn about asteroids, little scientist?

    The United Nations decided to mark today as the Asteroid World Day, although it has been celebrated unofficially since 2015, to raise the people’s awareness about the danger of an asteroid impact on Earth.

    Why today?

    Today has been chosen as on this day, in 1908, there was a big impact of an 80-metres asteroid impact in the Siberian Zone of Tunguska (Russia). The asteroid did not reached the ground since it exploded in our atmosphere, though it burned up tress further than 2,000 km as well as smashed windows and pushed down people in a radio of 400km!

    Furthermore, nights become so much lighter during some days that reading a book at night without needing a bulb light was possible, could you imagine that little scientist?!

    What about asteroids nowadays?

    All of us know the theory of the extinction of dinosaurs, how it was possible? Actually, asteroids are even more powerful than we imagine. Did you know that the speed’s average of an asteroid is 90,000 km/h? So a 10-metres asteroid could have the same power as an atomic bomb!

    Nevertheless, we are protected by our atmosphere, where asteroids normally disintegrate due to the friction with the cap. In fact, shooting stars are asteroids which penetrate into the atmosphere and disintegrate, creating a fire ball rarely impact with the ground.

    Scientists are really interested in asteroids, because they usually contain a extremely rare material which is really difficult to find in Earth: iridium. It is normally used to create metal pieces of the highest quality, so if someday you find one, preserve it little scientist!


    The Asteroid Belt

    The asteroid belt is a disc of asteroids located roughly between the orbits of Jupiter and Mars, but it is not full, in fact many empty spaces between one asteroid and the next one have been discovered in the last few years.

    The top four bigger asteroids in the belt are Ceres, Vesta, Pallas and Hygiea with diameters around 500 km! But the most shocking one is Ceres, whose diameter is 950 km, bigger tan some countries such as Bahrain, Singapore and Malta!

    Here are some curiosities about the Asteroid Belt:

  •  The asteroids are mainly formed by rocks and huge pieces of ice.
  • Some of then even have satellites, as we have the Moon.
  • More than the 90% of asteroids found in Earth come from the Belt.
  • It is believed that was formed by the destruction of a planet.
  • Are you now more intrigued by astrology? Why don’t you study them by your own? Maybe you will discover a new one, little scientist!


    Do you know why the sky is blue?

    Do you know why the sky is blue?

    Do you remember being a little child travelling with your parents by car and wonder why the sky is blue? Everyone has asked it to their parents, but not all of them know the answer. We will give it to you! 

    The question about why the sky is blue has accompanied us since we were children. This doubt becomes even more interesting when we discovered that the Universe is completely dark and, during the sunset, the sky is not blue, but it is orange! Now we have two doubts, one for each colour…

    What about rainbows?

    The blue coloured sky is because of the sunlight. Why? How? Sun light goes through the atmosphere, which is full of different gases, and it results in a spread of the light that produces some colours. However little scientist, we should brush up on the two main light’s characteristics to understand how exactly it works:

  • Light goes through the waves
  • Sun light is white, but it is actually a mix of different colours (the ones which we conform the rainbow, and the ones below the infrared and over the ultraviolet strips which we can’t see).
  • Each of these colours belongs to a specific wave with a determinate long. The blue colour is the one whose wave’s length is the narrowest in the visible spectre. Could you guess what colour has the widest wave’s length? It is the red colour! I hope you have been right.


    Rayleigh’s dispersion

    What is the Rayleigh’s dispersion? Okay, let us explain it. It is a physic phenomenon that occurs every time the Sun light reaches our eyes, as it has been affected by the atmosphere’s gases. It has a weird name, but is really easy to sense though, little scientist! This phenomenon produces a spread of the light when it pierces some air particles. Then, that mix makes a light reflection which has vibration and radiation.

    Since blue has the narrowest wave’s length, the tiny air particles have enough space to join each other and they are able to absorb the light! Then, the whole space occupied by the air particles, becomes blue, so that it looks like as though the sky was blue (but it isn’t)

    What does happen in sunset?

    Don’t think that the Sun is hiding itself during the sunset! Instead, the Earth is moving away from it. Consequently, the wave’s length becomes wider so that the blue colour dissolves and we can see how the sky changes from blue to orange. Did you already know that, little scientist? Don’t forget that the red colour is the one whose waves’ length is the widest! Besides, due to the wave’s necessity of spreading and the distance between the Sun and the Earth’s atmosphere, the sky becomes orange-coloured during the sunset. 

    Now you know why the sky is coloured, you can be who explain that colourful phenomenon to your parents and friends!





    What do you know about the summer solstice?

    What do you know about the summer solstice?

    What is the summer solstice? When? And why it is celebrated in some places? We want you to know more about the upcoming event.

    Not much people know that summer solstice is celebrated as a ritual or a high important event in some countries, but it is actually. In fact, a crowd of people usually gather around Stonehenge to see the sunrise and celebrate that days begin soon to shorten again.

    What exactly is the summer solstice?

    It occurs in midsummer, when the tilt of the Earth’s axis is most aligned with the Sun. It provides much sunlight than in any other day of the year to the North Hemisphere, what means is the longest day! What from here? Days will be shortened each day until the winter solstice as our planet will be rotating away from the Sun.

    summer solstice

    It has been celebrated from thousand of year, but how did our ancestors know when it was? They imagined a sphere of stars surrounding the Earth so that when the Sun reached the most northerly point on it, it was summer solstice.

    Now you might wonder how we can know the date of it, little scientist. Actually, it is always between 20th and 22nd of June in the northern hemisphere, and this year it will take place the 21st!

    Why has the summer got to do with Stonehenge?

    Stonehenge was built between 3.000 B.C and 1.600 B.C and, in case you didn’t know, it is an astronomical monument! We don’t know what was its main purpose yet, however the primary axes of Stonehenge looks like as though it would have been aligned with specific points of the winter and summer solstice respectively.

    Stonehenge in summer solstice

    Pagans and druids used to gather in Stonehenge circle to make rituals and celebrate the summer solstice, or ‘Alban Hefin’ in Druidry (The Light of the Shore).  There were some different types of celebration, but they usually meet to have a picnic or throw a party during which someone will speak about the time of year and its significance with storytelling, music and poetry as well as all of them were well-dressed for the occasion.

    Nowadays, lot of people still meet there and repeat the celebrations of their ancestors. Moreover, is also said that if you stay inside Stonehenge on summer solstice’s day, facing the Heel Stone, you will see the rise of the Sun above it. It might be quite mystic and beautiful to see, don’t you think little scientist?

    Is it only celebrated in the United Kingdom?

    No! Of course it is also celebrated in many countries around the World! For example, in Poland is also seen as a pagan religious event and the celebration is rather similar than the British one; In Estonia, is used to mark a shift in agricultural patterns though; In Russia and Ukraine, people traditionally jump over bonfires to prove their faith and courage.

    Although it means will have less daily sunlight from summer solstice, we are really happy in Science4you as we still can enjoy another middle of the summer! However we don’t know how we are going to celebrate it yet…

    Do you know any other celebrations across the World? Or maybe you were a druid so you already know it! Anyway, let’s go out and enjoy the day!


    1 2 3 6 Next »