Sound

Sound is what we hear everyday. It is caused by vibrations. When something vibrates quickly, the sound produced would be high pitch. However, if the sound is low, that means that the vibration is less fast.

Different animals can hear sounds of different pitch. For example, bat can make very high pitch noises. This can help them move about in the darkness.

Sound is something that we cannot live without.

Spiders

Spiders are seen very often around where we live. Spiders are arachnids. They are very different from insects. They have eight legs while insects only have six. Insects have three body parts, the head, thorax and the abdomen. However, a spider has only two body parts. They are the cephalothorax and the abdomen. Spiders can live in a lot of places and are very interesting creatures.

Spiders live in almost everywhere. You will find them at the corner of you windows, railings and even under your bed. Spiders spin webs and live in them. In some cases, some spiders they live under water. They would spin a web among some underwater plant and would resurface to breathe. Then they would carry air bubbles and fill the web with air. This had to be done several times.

In other cases, spiders live in desserts. They would built a nice home under the sand and wait inside. when insects walk past the spiders home, it would step on the web at the opening of the home, that triggers the spider and it would attack its prey. This spider is known as the 'trap door spider'.

People usually have the concept that spiders are poisonous. Actually out of the 40,000 over species of spiders discovered, only 109 species are poisonous.

So do not worry and just be careful!

Colours of light

Light is very interesting. It consists of six colours in the visible light spectrum. They are red, orange yellow, green, blue and violet. Red, has the longest wavelength interval, ranging from ~700-635nm. In contrast, violet has the shortest wavelength, ranging from ~450- 400nm. As the light have different wavelengths, they refract at different angles. Thus, we can see what we cal a rainbow.

Have you ever wondered why objects are of different colours? This is because, the object absorbs all the other colours and reflect only that colour that you see. That goes to say that if an object appears to be white, that objects reflects all colours of light. However, if an object appears black, it means that the object absorbs all light.

To go further, what colour would a green apple appear to be if yellow light is shone on it. It will appear green as yellow light is the combine of red and green light.

Thank you!

Volcanoes

Volcanoes are openings in a planets surface or crust. The word 'volcano' is derived from the name 'vulcano' a vocanic island in the Aeolian island of Italy, whose name in turn originates from Vulcan, a name of a god of fire in Roman mythology. Usually, the volcanoes are found where tectonic plates are diverging or converging.

People often have the concept that volcanoes are conical mountains with lava spilling from its submit. However, this is only one of the many types on volcanoes. Other types of volcanoes include cryovolcanos (ice volcanoes), fissure vents, shield volcanoes, lava domes, cryptodomes, volcanic cones (cinder cones), stratovolcanoes (composite volcanoes), supervolcanoes, submarine volcanoes, subglacial volcanoes and mud volcanoes.

As you can see, there are many types of volcanoes however, not all of them would cause that much damage. some of them, they can cause a lot of damage and like supervolcanoes, they can cause several cooling of the Earth's temperature for many years to come. This is due to the large amount of sulfur and ash that erupted. From this, we can see that volcanoes are important in a way.

Adaptations since birth

In the wild, animals need to adapt to their environment. Some of them are given ample time to do so, while others must be born to be able to adapt to the environment immediately.

Gorillas, for example will suckle milk for three years and would be close to their parents for at least a decade. Chimpanzees are also given rather long time to learn and adapt to its environment. They learn their survival skills by observing what their parents do.

However, others are not that lucky. Dears, once they are born, they must be able to stand and quickly and even run. In the process, the mother dear would often eat up any remains on the young dear after birth, although she is a vegetarian. Dears in the wild are exposed to many predators like the bears and wolfs. Thus you will realise that when the baby dear is born, it is already very alert and would be struggling trying its best to stand.

Hippos, they prefer to give birth in the water. Reason being on shore, there is lots of danger. As the hippo is about to give birth, she would chase away all the other hippos, including the father. The hippos are considered a threat to the mother. Since the baby hippo is born in the water, it must be able to swim once it is born.

If you come to think of it, humans are not that clever!

Cells

What are cells? They are what you and I are made up of. They are the simplest form of life. The name 'cells' was first introduced by an English Scientist, Robert Hooke in 1667. He first observed the walls of the dead plant cells and thought they appeared like the cell in honeycomb. Thus the name of the simplest form of life is 'cells'.

There are different types of cells, they can be classified into two different types. They are plant and animal cells. The plant and animal cells have similarities and differences. Both of the animal and plant cells have protoplasm, a jelly-like substance which is approximately 70% of a cell. The cytoplasm is part of the protoplasm. Both of them have nucleus, mitochondrion, vesicles, cytoplasm, Golgi apparatus, vacuole, ribosome, smooth endoplasmic reticulum, cell surface membrane, rough endoplasmic reticulum and free ribosome.

However, parts like centriole are only present in animal cells and parts like cell wall, tonoplast and chloroplasts are only present in plant cells.

You may think that chloroplasts just contains chlorophyll. Actually, a chloroplast is like a bean inside filled with layers of discs containing chlorophyll. Not only so, the chloroplasts contain thylakoid, granum and stroma. The chloroplasts are parts of a plant cell which helps it make food. Thus, not all part of a plant will have chloroplasts. Only parts which appear green would have chloroplasts, the leaves. However, some plants with red leaves or other colour leaves does not mean that they do not have chloroplasts. In fact, they have hidden chloroplasts.

Cells on the whole, whether is it a plant cell or an animal cell, the cells would have similarity as they are part of the same organism.

Thank you!

Global warming

Global warming is the continues rise of the temperature of Earth's atmosphere and oceans. What causes global warming? Global warming is caused by the increasing amount of greenhouse gases trapped in the Earth's atmosphere.

The greenhouse gases are caused by human activities such as work in industries and deforestation. The greenhouse gases consists of water vapour, carbon dioxide, methane, nitrous oxide and ozone. This greenhouse gases trap heat which cannot escape from the Earth's atmosphere that easily. That is why we do not die of cold. However, due to too much human activities, too much of these greenhouse gases are being produced and trapped in the Earths' atmosphere. As a result, the Earth's temperature is rising continuously.

Many human activities have caused this to happen. Deforestation has caused many trees to be chopped down. As trees take in carbon dioxide during photosynthesis, the carbon dioxide level in the atmosphere is controlled. However, trees are being chopped down, and at the same time, carbon dioxide is constantly being produced, there is a lack of tress to absorb the carbon dioxide.

What has global warming caused? It has caused many animals to die. Some very common examples include the polar bears which lives on the North pole. In years to come, it will cause certain species of animals to face extinction.

It is important to save the Earth now or it would be too late.

Crystallization

What is crystallization? It is the process of formation of solid crystals precipitating from a solution, melt or most rarely deposited directly from a gas. The process of crystallization consists of nucleation and crystal growth.

Nucleation is the process where solute molecules dispersed in the solvent start to gather in clusters. However, for nucleation to take place, the clusters must be stable, or they would redissolve. Therefore, the solution must be saturated in order for crystallization to take place. The stable clusters constitutes to the nuclei. The nuclei would then cause more precipitation to occur. The process of nucleation is also when the atoms would move to form an atomic structure of a crystal.

Then, crystal growth is the subsequent growth of the nuclei that succeed in achieving the critical cluster size. As this is happening, nucleation continues to take place. This two processes can continue to take place in the presence of existing supersaturation. Depending on the conditions, either nucleation would predominant over growth or the other way round. This results in the different shapes and sizes of crystals.

The Maic UFO

The above video shows how a top can float in midair.

In order to achieve this, you have to fulfill several conditions. The first condition is to get the correct weight of the top. You might have to try several times. Why do you need the correct weight? the following diagram will explain it.

This is how the Magic UFO works. The magnetic repulsions force and the weight and gravity acting on the top must be equal. If the magnetic repulsion force is greater than the weight and gravity acting on the top, then the top would fly away. If it is the other way round, the top would not be able to float up.

Another important condition to fulfill would be the balance of the magnetic plate. It is somewhat the same logic as the first condition. If the plate is tilted on side of the magnetic repulsion force would not be equal and thus the top would not be able to fly properly.

I have drawn this picture and hopefully it can help you understand better. The orange part is where the magnetic repulsion force comes from. As you can see, it is in a round shape. As the force acting on the top is in a round shape, it sort of supports the top and keeps it in position- the middle. Thus if we tilt the plate, we can say that the repulsion acting on different parts of the top are different.

If you have the chance, you should try it one day. It is really fun.

Thank you for reading!