Have you ever fallen from bed while you were asleep? Just imagine how hard it would be to avoid falling if we had to sleep in a tree. So, how do bats sleep upside down without falling down?
Wouldn’t it be thrilling if the night sky lit up with “dancing” lights? Well, people in North and South poles are the lucky ones who see such lights! These are called “aurora” or the Nothern lights .
Let’s take a closer look at what happens.As the sun is extremely hot, explosive collisions happen between its gas molecules which throw out charged particles. If the Earth gets hit by these particles(solar wind) the Earth’s magnetic field largely deflects them but, as the magnetic field is weak at the poles, particles enter the Earth’s atmosphere and collide with gas particles.These gas molecules absorb energy during the collisions and become unstable. To get stable again, the energy is released as light. This makes the aurora.
Can you name an animal who has seen a 3D movie? It’s the praying mantis!
It is believed that praying mantises have 3D vision, but it hadn’t been confirmed. So, they made a 3D movie (with bugs playing the main roles) and let the mantises watch it while wearing tiny 3D glasses (attached with beeswax). Because the mantises struck out at the bugs, this test proved that they have 3D vision. As they have simpler nervous systems, the mechanism should be far less complicated than ours. So, now the scientists are working on their ultimate goal; finding the mechanism of their 3D vision and programming a chip for robots with 3D vision using that.
Did you know that a fish has a very different view of the world? When it looks up, it sees the outside world from only one spot on the water surface above its eyes; a round “window” on the surface. What do you think the rest of the surface looks like? It is a reflection of the “underworld”(under water world). Total internal reflection of sunlight causes the surface (excluding the center part) to act as a mirror. Total internal reflection happens when light coming in certain angles(angle>critical angle)try to go from a medium with a higher refractive index to a lower one. As water’s refractive index is higher than air, certain light which comes towards surface through water gets reflected back; causing a mirror effect. Due to refraction, the fish will see the outside world only from the spot above it.
Carbonated drinks are made by forcefully dissolving CO2 gas into a beverage using high pressure. Aqueous CO2 gains energy and moves to the gaseous state when shaken.Also,CO2 from the air column on top of the beverage mix with it. When the bottle is opened, the gas try to escape because, the inside pressure is greater than the outside air pressure. Even in an unshaken carbonated drink bottle the inside pressure is high, but it doesn’t shoot out drink because the aqueous CO2 has great difficulty to escape from the drink (as gas) because of the surface tension. But when shaken, as gas bubbles are already formed inside the drink, CO2 escapes rapidly pushing the drink with it.
If you open a carbonated drink after shaking it well, it will explode and give you a shower. But if you open it without shaking, it won’t pop up. Can you explain this?
Did you know that webbed feet of birds who live near water are an adaptation to make swimming easier? Here’s the trick: as the bird pushes its foot backwards through water, the toes spread apart, causing the webs to spread out. As the webbed foot has more surface area, more water is pushed back. When the bird forces water to move backwards, water forces the bird forward as a reaction for the action(as told by Newton’s third law). These webbed feet have inspired swim fins and a new type of paddle used in water sports.
Cinnamon oil extraction is done in Sri Lanka with pride. Do you know the part chemistry plays in it? Boiling happens when a liquid’s vapor pressure just exceeds atmospheric pressure (1 atm). When a mixture of two practically immiscible liquids (water and essential oil) is heated, the liquids vaporize without disturbing each other. But, as both liquid vapors will contribute, their combined vapor pressure will exceed 1 atm at a lower temperature than if heated separately. So, both liquids will boil together at a lower temperature. As high temperature causes decomposition of organic compounds, this method (steam distillation) is used to save them from that.
Parachutes are life savers. Do you know how they work? After you jump out of an aircraft, gravity makes you accelerated towards the Earth, which makes you fall at an alarmingly high speed. When the parachute is released, the air resistance increases because the surface area which gets in contact with air increases. As the upward force is now greater, the speed decreases. Because the air resistance changes with speed, the air resistance decreases until it equals the force of gravity. As the forces are then balanced, the speed will become constant. Also it will be a safe speed.
Did you know that the location of eyes can be used to identify whether an animal is a prey or a predator? Animals with eyes on opposite sides of the head suggest that they are prey animals (cows, deer, horses). This gives vision of a larger area enabling the animal to see predators approaching from the side as well as from behind. Predators usually have eyes on the front of their heads (leopards, lions, cats). This gives them the ability to judge depth which will be useful to assume the speed of prey and hunt them.
Stains and dirt which don’t let go of clothes can be easily removed with soap water. How does this happen? There are two ways soap does this. One way is by lessening the surface tension of water (by adding soap). Then water will be able to penetrate from tiny holes in clothes with less effort. When crossing these tiny holes water will carry the dirt with it.
Dirt (non polar substances) does not mix with water (polar substance) but soap has come up with a solution. A soap molecule has a polar end and a non-polar end. The non-polar end bonds with dirt and the polar end bonds with water. In the end dirt is bonded to water indirectly. This will transfer dirt in clothes to water. So, life becomes cleaner with soap.
Did you know that the periodic table has four brand new members now? The International Union of Pure and Applied Chemistry (IUPAC), announced that the table’s seventh row was now complete. Elements 113, 115, 117 and 118 were added to the table. They will be known temporarily by their working names of ununtrium (Uut or 113), ununpentium (Uup or 115), ununseptium (Uus or 117), and ununoctium (Uuo or 118). All four are synthetic.
Did you know that some garden plants we grow have an amazing ability to absorb toxic gases? Gerbera (barberton daisy), chrysanthemum, peace lily, sansevieria and some palms are some examples of such plants. Toxic gases such as Formaldehyde, sylene, ethylbenzene and toluene are absorbed by these plants. So, in addition to the beauty, they give clean air free!
To see a full moon, the Earth should be in between the sun and the moon (the moon should be in the opposition of the sun) because, that is when the Earth will face the lit side(lit by the sun) of the moon. Normally, during full moon, the Earth, sun and moon will not be situated in a straight line. (Because the orbit of the moon around the Earth is slightly tilted relative to the orbit of the Earth around the sun.)
But when they get situated in a straight line (This happens because the moon’s orbit changes) the moon will get covered by the Earth’s shadow. Therefore a lunar eclipse will be born!
So, a lunar eclipse always happens on a full moon day.
Why do lunar eclipses always happen on full moons?
A popular method to make attractive jewellery is by gold plating.How does gold plating work? How does the jewellery magically turn gold when put into a solution connected with a battery? The process which happens is electrolysis. In this, an electric current is passed through a solution with gold ions (electrolyte) and two terminals (electrodes). One electrode is the jewellery piece and the other one is made of gold. The current splits the electrolyte and deposits gold on the piece.
We all look forward to New Year’s Eve to see fireworks light up the sky. The beauty make us feel this is heaven on earth. Do you know that fireworks make symmetrical explosions? It’s because of a basic law of physics called the conservation of momentum. The momentum of a firework must be the same before and after an explosion. So, the gun powder distribution becomes equal to both sides and gives a perfect, pretty, symmetrical display.
We always try to avoid “high pressure” in our lives. (High blood pressure, exam pressure)But, sometimes it’s really useful. Thanks to high pressure, the pressure cooker works! This is how it works. The pressure cooker is an air tight pot. When steam forms inside, the inside air pressure increases. Boiling point of a liquid increases as the surrounding air pressure increases. So, the liquid (in food) will be able reach a higher temperature quickly(because it’s boiling point gets higher). This will allow the cooking process to speed up.
A cone’s mass is concentrated towards the bottom because of the conical shape. This places the centre of mass at a relatively lower height. So, a cone tends to be in stable equilibrium. (It will not be moved against an external force such as wind and it will stay upright) So, a cone can be trusted at staying at a post on the road, as told!
Why are traffic cones shaped like cones rather than cylinders or some other shape?