You may have heard that exposing your skin to sunlight provides your body with an essential nutrient, Vitamin D. But did you ever wonder how it happens? The part of sunlight responsible for producing Vitamin D is a type of ultra violet radiation called UVB. As these rays penetrate the skin it converts a cholesterol found in the skin into a substance that is later converted into Vitamin D within the liver and kidneys. Isn’t it amazing how the sun, the power source of all life on earth, provides us with a source of vitamin free of charge!
Charcoal is a form of carbon. The surface of charcoal has many tiny pores which increases its surface area. When charcoal is introduced into water some contaminants in water attach to the surface of charcoal in a process called adsorption. Increased surface area of charcoal allows it to adsorb more contaminants. This purifies water to a certain degree. Nowadays, charcoal that is used for water filtration is sent through a process which increases the amount of pores increasing the surface area of charcoal allowing it to adsorb more contaminants.
Our ancestors had the habit of introducing a piece of cleaned charcoal to wells from which they got water for household activities. Explain what effect it has on water and the mechanism behind it.
A natural diamond on one’s ring might be shiny on the outside but their origin story is not that pretty. They are formed within the inner parts of earth under immense pressure and high temperature over millions of years. But do you know that scientists can also convert a piece of graphite into a diamond within a lab by mimicking the conditions that mother nature provided? This is possible because the building block of both graphite and diamonds is a carbon atom. Isn’t it amazing how changing the arrangement of atoms transforms a cheap mineral into an expensive one?
Have you noticed that some cheeses have holes when you slice them? Don’t blame mice for eating their way through the cheese. The culprit is way smaller than a mouse. They are caused by bacteria that are added in the process of making cheese. These bacteria produce carbon dioxide gas after consuming lactic acid which is found in milk. This gas creates bubbles in the cheese that look like holes when it is sliced. Apart from creating the holes the activity of these bacteria is believed to give the cheese its unique taste.
Microorganisms can be a menace as some of them are the cause for many diseases. But did you know that some vaccines that protect us from these diseases actually contain the organisms that cause them in the first place? But you don’t have to worry when the doctor injects you with them. Why? That’s because they are either killed or weakened. It’s like providing your body with weakened opponents so that it can produce the weapons required to defeat the real threat. The body will produce proteins known as antibodies that will act as weapons in destroying the disease causing organisms providing immunity from those diseases.
These glasses are partially silvered which reduces their reflecting ability. When light hits the mirror, part of the light is reflected and other part goes through without being reflected. The suspect’s room is kept brighter while the other is kept dark. Light that reflects off the glass on the brighter side masks the small amount of light coming through from the darker side. So you would only see your reflection if you were in the brighter room. On the darker room, the light coming through from the brighter side masks the small amount of light that is reflected off that side of the glass. So you would see through the glass if you were in the darker room.
You may have seen policemen question and observe suspects in a room through a glass that only lets them look at the suspect and not vice versa.(The suspect cannot see the policemen) The policeman’s side acts as transparent glass allowing the policemen to look at the suspect while the suspect’s side acts as a mirror preventing him from seeing the policemen. Explain how this glass acts like this.
While looking at a map of the world has it ever occured to you that earth’s continents are all part of one huge jigsaw puzzle? You would be correct because they were once part of a large land mass called Pangea. But what force of nature was able to pull them apart? As we all know earth’s interior has liquid magma. Land masses above the magma move around because of the convection currents that occur within the magma. This carried the continents apart and believe it or not it is currently happening right now as we speak.
Have you ever woken up in the middle of the night by the sound of someone snoring? This unpleasant sound is the result of vibrations of tissues that surround the airway to the lungs. When we sleep the muscles around the airway relax which narrows down the airway obstructing the path of air to the lungs. As the air tries to force itself down the airway the surrounding tissues vibrate producing the sound we hear as snoring.
Have you ever squinted your eyes while trying to read a small text? How does it help us see better? Squinting reduces the amount of light coming from other directions apart from the object that we want to see. This helps us to focus on the light coming from the object, giving us a clearer picture of it. Squinting also changes the shape of our eyes slightly which helps it to accurately focus the light rays onto the back of the eye. Although this is not a permanent solution for bad eyesight it can come in handy when needed.
Although the container is sealed, the fish and the air around it contains microorganisms that spoil food. They will grow on the fish and breakdown nutrients in it spoiling the fish. In a tin of salmon, the fish and the tin is sterilized under high pressure and temperature so that they are free of any microorganisms. Salt and other chemicals are added which prevents any microbial activity. The tin is sealed preventing microorganisms from entering. Since the growth and activity of microorganisms is controlled, the fish can be preserved without being spoiled.
Canned fish which are kept in sealed tins, can last for more than a year without spoiling. But if you keep normal fish in a sealed container, it wouldn’t last that long. Briefly explain why a fish kept in a sealed container spoils quickly and the principles behind preserving fish in a tin of salmon.
Testing new drugs on animal cells isn’t always accurate as testing them on human cells. But this new invention may provide the answer for it. ‘Organ in a Chip’ is a chip that has many tiny tubes lined with human cells of an organ. Everything required for the survival of cells including blood is pumped through the tubes. By introducing new drugs into the system, scientists can easily observe how different cells of an organ react to them and hope to significantly reduce the time taken for testing the drug.
All of us can recognize the world famous Statue of Liberty in the USA. But if a man who saw it being unveiled saw it now, he would be confused. It was made with sheets made of copper covering its exterior which gave it a shiny brown colour. But, as time passed the copper reacted with air and corroded, producing a compound that was green in colour. Although one would suggest to scrape off the green material and restore the statue into its old glory, it actually protects the inside layers of copper from further corrosion by preventing it from coming into contact with air.
If you want to upgrade a normal dish into something expensive and luxurious, garnishing it with gold will add that feeling of luxury and wealth. Unlike the gold found in jewellery, edible gold is pure, without any impurities and is beaten down into thin sheets before use. Gold passes safely through the digestive tract without being digested by stomach acid and enzymes thanks to its inertness. Unfortunately, gold will only be a feast for your eyes because it does not have any taste or odour.
Our skin is covered with a lot of pores/hair follicles that we cannot see with the naked eye. These cavities are connected to glands (sebaceous glands) that produce an oily substance called sebum. It moisturizes, lubricates and protects the skin and hair. When too much sebum is produced, the openings of the pores can get clogged by sebum, dead skin cells and bacteria. The bacteria trapped within the pore multiply which leads to infection, swelling and collection of pus within the pore. This forms a pimple.
Pimples are always a nuisance during your teenage years. It’ll be easier to fight pimples if we know the cause for them. Briefly explain how pimples are formed.
Feeling cold? You wouldn’t have to worry much because your body can control your temperature and restore it to normal state. But what happens when it gets even colder? Your brain tells your body to shiver. This automatic response makes the muscles of your body contract and relax rapidly. Since rapid activity of muscles requires more energy, your muscles burn more energy when shivering, producing heat that will warm you making you feel less cold on a very cold day.
If a bullet is heading your way, what would be the difference between life and death? A bulletproof vest. They made out of a light-weight material known as Kevlar. But how does this material save you from a bullet that would easily pierce your body? The answer lies within the structure of the vest. The Kevlar fibers that make the vest are so tightly arranged that a bullet trying to go past them loses most of its kinetic energy in the process of moving the fibers apart. This reduces the speed of the bullet, reducing the impact on the body.
As the clock strikes 12 midnight on New Year’s Eve, the skies light up with numerous colours from fireworks, ushering in a new year. But how does a firework produce the brilliant display of colour? It’s all thanks to the metal atoms found in the compounds included in the firework. The heat released from burning gunpowder is absorbed by these atoms and is later released as light. Since different atoms release different colours of light, we can produce fireworks that burst in different colours by changing the type of compound included in the firework.