A sunset is one of the most picturesque sights on earth. The sky gets painted with the colours of red, orange and yellow as the sun goes down over the horizon. Explain why the sky takes a reddish colour at sunset.
Have you ever wondered how electricity is produced inside a nuclear reactor? The fuel used in a nuclear reactor is uranium which has an unstable nucleus. First neutrons are shot at the uranium atoms. The impact breaks apart the unstable nucleus of uranium, releasing a large amount of energy. But there is a catch. Every impact creates three more neutron particles which will break apart even more nuclei, producing an even larger amount of energy (enough to cause an explosion). To control this, neutrons are absorbed by absorbing rods which slows down and controls the reaction.Finally, the heat energy released from the above reaction is used to convert water into steam. This steam is then used to turn turbines and produce electricity.
Whenever you cut yourself and started bleeding, it usually takes only a few minutes to stop the bleeding. So how does our body make sure that we don’t lose too much blood? As soon as a blood vessel is cut open, platelets (fragments of cells found in your blood) rush into that area to close the opening. But this won’t be enough to completely stop the bleeding. So our body converts a soluble protein found in the blood into an insoluble fiber called Fibrin. These fibers cover the opening and act as a fishnet to capture more blood cells. These blood cells form a plug at the wound preventing further loss of blood. This is known as a blood clot.
Did you ever wonder how insulin, which is given to diabetic patients, is produced on a large scale to meet its ever-growing demand? This is done by using bacteria. Bacteria have many genes that are not essential for its existence. First, such a gene is located. Then it is cut out using enzymes and substituted with the gene responsible for the production of insulin in our body. Once it is introduced, the bacteria will start dividing to produce more bacteria. Since the necessary gene is present in the newly produced bacteria, they will start the process of producing human insulin. After purification we are left with insulin which is a life-saver for countless diabetic patients around the world.
The right ventricle pumps blood to the lungs while the left ventricle pumps blood throughout the body. This means that the left ventricle has to pump blood further than the right ventricle. In order to do this, the left ventricle should generate more pressure. Blood is pumped out of the heart when muscles on the walls of the ventricles contract. The thicker wall of the left ventricle which has more muscles provides the extra pressure required to pump blood to the entire body. The right ventricle does not have to pump blood to a long distance, so it has a much thinner wall.
The heart is an organ that works throughout our lives providing other organs with blood. There are two chambers in the heart called ventricles that pump blood out of the heart. The wall of the left ventricle is much larger than the wall of the right ventricle. Explain why it is so.
Have you ever wondered how the optical mouse works just by using a beam of LED light? Here’s how it works. The LED light shines onto the surface and a sensor within the mouse takes images of the surface by capturing the reflected light off the surface. Then it looks for patterns on the images. By looking at how the patterns move and change from picture to picture, the processor within the mouse is able to determine the direction and speed of movement of the mouse. Then it makes the cursor move around the screen according to the motion of the mouse. This process happens hundreds of times each second, making the cursor move very smoothly.
What will you say if you were told to describe a platypus? If you have ever seen one, at least in a picture, you would say that it is a completely harmless and innocent animal. But looks can be deceiving. The male platypus actually packs enough venom to paralyze a small animal. A small spike near its back legs releases venom that can be highly painful to humans. It is thought that the venom is used against other male platypuses during the breeding season. Isn’t this a great example where mother nature shows us that some things are not what they seem on the outside!
Saliva moistens food and helps to create a ball of food. This makes it easier to swallow food. Moistening also helps dissolve the food so that the chemicals responsible for taste can reach the tastebuds making us feel its taste. Saliva lubricates the food that we eat. This makes swallowing easier and protects the digestive tract from any damage caused by food. The enzyme amylase which is found in saliva starts the digestion of carbohydrates. The lysozyme enzyme which is also found in saliva destroys much of the bacteria found in the food, protecting us from infections and diseases.
Remember that time your mouth felt watery when you saw a delicious meal or felt the smell of it. This happens when saliva is secreted from the salivary glands. Out of the many functions of saliva list the main functions of saliva related to the food that we eat.
Can you remember how earth’s continents were pulled apart from each other? It was due to huge masses of land known as plates being carried apart by the convection currents in magma beneath the surface of Earth. Did you know that this was also the force behind the formation of mountain ranges like the Himalayas? When two plates collided it folded and crumpled earth’s surface, slowly lifting up land over a long time to form mountain ranges. You’ll be surprised to hear that this process is still going on, meaning that the Himalayas are growing in height as we speak, although at a really slow rate.
You may have seen non-woody plants wither during the dry season. Ever wondered why these small plants fall over? Unlike woody plants, these plants rely on turgid cells to stay upright and erect. Turgid cells are cells that are swollen and hard because they contain a lot of water inside them. So, the pressure inside each cell is high. This makes the plant cells stiff. This stiffness is what allows plant stems to stand up straight. When the plant doesn’t receive a sufficient amount of water, water exits the cells making them lose their stiffness which in turn causes the stems to fall over.
Ships that have hulls made of iron, come into contact with water, air and salt every time they sail. Doesn’t this combination remind you of something? Yes, iron is in contact with its worst enemies. So the threat of rusting is ever present. But how does the hull stay protected when it should rust? The answer lies with the blocks of Magnesium or Zinc that are welded onto the outside of the hull. They are more reactive than iron when they come into contact with oxygen. So when the block of metal is welded to the hull, it reacts instead of iron, sacrificing itself to protect the iron hull from rusting.
As rivers flow, minerals found in the soil and minerals released from erosion of rocks dissolve in water and reach the sea. Underwater volcanic activity and water coming up from cracks in the earth also feed the oceans with minerals. When seawater evaporates, it leaves the minerals behind. This process repeated over a long period of time increasing the ocean’s mineral content. Lakes also get fed with minerals by rivers but water in most lakes leave through outlet rivers which carries the minerals along with them. So lakes aren’t salty as oceans.
Although oceans are earth’s largest bodies of water we cannot completely utilize sea water because of its salinity and mineral content. Freshwater lakes are much smaller but contain water with less salinity and can be purified to be used as a source of freshwater. Explain how earth’s oceans became salty and why freshwater lakes are less salty compared to oceans.
Yesterday we witnessed a rare lunar event. It was a combination of a super moon, lunar eclipse and a blue moon(a second full moon in a month). A lunar eclipse occurs when the sun earth and moon are in a straight line in the above order. A super moon occurs when the moon is at the closest position to earth in its orbit making it appear larger in the sky. All these events overlapped on one day giving us a rare sight at a ‘super blue blood moon’.If you saw it count yourself lucky because the next simillar event is taking place in another 20 years!