There are times when you see the scientific things, but fail to understand the science behind it, or you scratch your head try to recall your science class which you have learnt in your school days.
The knowledge we garner throughout our school days sets foundations for all the other amazing things we go on to study. But science definitely doesn’t end at high school.
In no particular order, here are some mind-bending incredible facts that NLC is sharing with you.
1) Why do we see pool of water on the road and the illusion fades away as one gets closer?
Whenever you travel on road during summers, you might have observed water outspread on road, but you also know that is an illusion. So, here we tell you the science behind it. Light from the sky at a shallow angle to the road is refracted by the index gradient, making it appear as if the sky is reflected by the road’s surface. The mind interprets this as a pool of water on the road since water also reflects the sky. The illusion fades as one gets closer.
2) Why do we see the sunrise before 2 minutes of the actual sunrise and sunset after 2 minutes?
When the light rays pass through the atmosphere having layers of different densities and refractive indices, then atmospheric refraction takes place. The actual sunrise takes place when the sun is above the horizon. When the sun is just below the horizon, the light rays coming from it, on entering the Earth’s atmosphere suffer atmospheric refraction from a rarer to denser medium. so, they bend towards the normal at each refraction. Due to continuous refraction of light rays at each layer, it follows a curved path and reaches the eye of the observer.
As a result, we can see the sun 2 mins. before it rises above the horizon in the morning.
It is also due to refraction that we can still see the sun for abt 2 mins. even after the sun has set below the horizon.
3) Why is The Eiffel Tower 15 cm taller during the summer?
When a substance is heated up, its particles move more and it takes up a larger volume – this is known as thermal expansion. Conversely, a drop in temperature causes it to contract again. The mercury level inside a thermometer, for example, rises and falls as the mercury’s volume changes with the ambient temperature. This effect is most dramatic in gases but occurs in liquids and solids such as iron too. For this reason, large structures such as bridges are built with expansion joints which allow them some leeway to expand and contract without causing any damage.
4) Do you know 20% of Earth’s oxygen is produced by the Amazon rainforest?
Our atmosphere is made up of roughly 78 % nitrogen and 21% oxygen, with various other gases present in small amounts. The vast majority of living organisms on Earth need oxygen to survive, converting it into carbon dioxide as they breathe. Thankfully, plants continually replenish our planet’s oxygen levels through photosynthesis. During this process, carbon dioxide and water are converted into energy, releasing oxygen as a by-product. Covering 5.5 million square kilometres (2.1 million square miles), the Amazon rainforest cycles a significant proportion of the Earth’s oxygen, absorbing large quantities of carbon dioxide at the same time.
5) Why are some metals so reactive that they explode on contact with water?
There are certain metals – including potassium, sodium, lithium, rubidium and caesium – that are so reactive that they oxidise (or tarnish) instantly when exposed to air. They can even produce explosions when dropped in water! All elements strive to be chemically stable – in other words, to have a full outer electron shell. To achieve this, metals tend to shed electrons. The alkali metals have only one electron in their outer shell, making them ultra-keen to pass on this unwanted passenger to another element via bonding. As a result, they form compounds with other elements so readily that they don’t exist independently in nature.