14 amazing scientific knowledge not found in books

Liquids can boil and freeze at the same time, lasers trapped in water, the terrifying speed of spacecraft, turning liquid water into ice instantly. are knowledge that not everyone knows. until I was still in school.

1. If you spin the ball and drop it, it will fly

If spin the ball and then drop it down. Initially the ball still fell straight down but then. it gradually changed its trajectory into a parabolic curve and fell quite far away. The cause of this phenomenon is the Magnus effect. When the ball rotates, the movement of the air molecules on the side of the air stream in the same direction as the ball's rotation increases and on the other side the velocity of the air molecules decreases, causing the ball to fly along the path. parabolic.

In soccer, players also often apply this effect to create spinning shots.

2. The truth about sun rays

In fact, each ray of the Sun releases enormous energy, equivalent to a 100 megaton atomic bomb. The destructive power of the two atomic bombs dropped on Hiroshima and Nagasaki (Japan) was about 15 kilotons, or 0.015 megatons.

3. Prove the Pythagorean Theorem using liquid

Pythagorean Theorem: In a right triangle, the square of the hypotenuse is equal to the sum of the squares of the other two sides.

Inverse Pythagorean Theorem: If a triangle has the square of one side equal to the sum of the squares of the other two sides, then the triangle is a right triangle.

a2 + b2 = c2

The Pythagorean Theorem can be proven in an easy-to-understand way using the following fluid model.

4.  Liquids can boil and freeze at the same time

Water can exist in three forms: solid, liquid, gas. In addition, when temperature and pressure exist in a state of thermodynamic equilibrium suitable for all three phases of solid, liquid, and gas - the triple point, water can both boil and freeze. ice at the same time.

For water, the necessary conditions for it to boil and freeze at the same time are a temperature of 0.01°C and a pressure of 0.00603659 atm.

In the video, cyclohexane liquid is poured into a vessel under vacuum. Cyclohexane on the surface begins to freeze when the pressure in the tank drops and the liquid below boils, creating a continuous liquid-solid state transition.

5. Laser stuck in water stream

Thanks to the phenomenon of total reflection, light always travels in a straight line.

Scientists at the University of Utah, USA conducted an experiment to "trap" laser beams in water. They punch a small hole in the bottle's body to let the water flow out, then they shine a laser beam through the bottle at a certain angle.

At that time, the laser no longer maintains its original straight path but bends along the water flow as if trapped in it. The reason is that when the laser beam hits the water stream and is bent at a certain angle, it will refract and not continue straight. This process happens continuously so the entire light ray will be bent along the water jet.

6. What happens when you crack an egg in the ocean?

At a depth of 20m below the seabed, if you break an egg, the inside remains intact because the pressure causes the surrounding seawater to act as an eggshell.

 7. The incredible speed of the spacecraft

We all know space rockets have extremely high speeds, but it's hard to imagine how fast they are.

And the picture comparing the speed of the New Horizons spacecraft (58,000km/h) and the SR-71 Blackbird aircraft (fastest aircraft today, speed reaching 4,345 km/h) below will help you get the idea. Get a clearer view of the spacecraft's incredible speed.

8. The moment a black hole swallows a star

The cosmic black hole has extremely strong gravity, anything including light is sucked inside it. But that doesn't mean that if you get sucked in, you will sink into darkness.

When a star approaches a supermassive black hole, some of the debris will fall into the black hole. Some remaining debris will rush away at high speed, creating a halo of high-energy X-ray light hundreds of light years long.

9. Power of explosions on the Sun

On the Sun, intense radiation eruptions always occur, called solar flares. Each eruption can release a huge amount of energy, equivalent to millions of 100 megaton atomic bombs (1 megaton = 1 million tons of TNT) exploding at the same time.

In 1945, the Fat Man atomic bomb that the US dropped on Nagasaki city, Japan was only about 21 kilotons strong (equivalent to 21,000 tons of TNT).

10. How does a baby's face form in the womb?

You will be amazed when you see interesting images of the formation of a baby's face in the mother's womb. Over time, your baby's 'face' will develop from an initial ugly cavity until it has a nose, mouth and finally a complete face.

11.  Cats always land on 4 legs

No matter what position they fall in, cats always land on all four legs due to their flexible skeleton and ingenious ability to turn.

12. Can turn liquid water into ice instantly

Place the bottle of pure water in the refrigerator, keeping the temperature stable at -24 degrees Celsius for 2 hours and 45 minutes. Then, take out the water bottle and gently tap it or pour the liquid water directly onto another block of ice. Liquid water instantly turns into ice in a split second.

13. "Life-hack" helps you see when you forget your glasses

A little tip to help nearsighted people see what they need to see when they accidentally forget their glasses at home. That is looking through a small hole in the hand as shown below.

Light will focus more on the retina when we limit the viewing angle like that. That will make the image clearer.

14. The habit of cracking your knuckles does not bring any benefits

Many people worry that the habit of cracking their knuckles can cause arthritis and degeneration. However, research results on people with the habit of cracking their knuckles by doctors at Davis UC Medical Center (USA) showed no signs of cracking or arthritis. It just makes your knuckles bigger.

Marvin Fry

Update 11 April 2024