لولا الاحتكاك ما استقر شيء على شيء .. كتاب في سبيل موسوعة علمية .. الدكتور أحمد ذكي

Without friction, nothing would have stabilized.

- Were it not for friction, nothing would stabilize on anything

I write what I am writing now with a pencil and I erased a word with an eraser, with a rubber band. I threw the eraser on the desk. She was running on him and she stopped. What stopped her? It is the friction between it, which is made of rubber, and the surface of the desk, which is made of glass.

This eraser will remain in this place forever, by virtue of this friction, and unless an earthquake strikes the house and destroys it, the eraser will remain where it is and this and that chair will remain. Everything in the room will remain where it is, by virtue of friction.

I open the windows, and the wind blows softly or not softly from them, and it hardly moves anything from its place as usual, because friction keeps everything in its place.
But imagine that the friction between these things has disappeared, between them and each other, and the wind has blown, even at ease, then nothing remains in its place. Everything must move and fall. If it is fragile, it is undoubtedly broken. You will not find a book on a shelf that has lost the friction that kept it on its base on this shelf, and all the furniture becomes in constant motion, responding to the movement of every wind that blows, as no friction holds it to the ground.
Suppose that God removed the roughness of things and eliminated their friction, and you sat on a comfortable seat, then you will find yourself in the one on whom your body is preserved, or if it is wide, then in it. You slip on him, and he slides on the floor. If you try to ride on it, you will soon find yourself on the ground, and you may start running on it until a wall stops you. Rather, you cannot obtain this seat, as you cannot walk to it.
An image of the imagination, when there is no contact, a strange image.

Without friction, cars would not have brakes

Just as you must overcome friction before you can move a body on a surface, with the energy you expend in doing so. Likewise, if this body is moving, it does not stop until it opposes it, and this force is derived by the car driver. In some countries, it is called a brake, and it is called a brake or in French, a brake. The brake is nothing but a surface that the car driver presses on the running wheel (on both wheels of the car) to generate friction that absorbs the energy of movement and causes the car to stop.
The phenomenon of friction interfering in stopping movement is a common phenomenon in life, with many examples.
The cart, even if it is drawn by a horse, descends on a mountain road, and gravity increases its speed until it overtakes the horse and overtakes it, and something undesirable happens. The owner of the cart sets brakes on the wheels that operate by friction, which control the speed of the cart while it is descending, as it absorbs the energy of this descent and adjusts its speed. .

- Invention of the wheel to treat friction

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Human life is profound, rivaled only by the invention of sparklers and sails for ships, and perhaps the invention of the wheel was even more dangerous. In terms of transportation alone, the wheel enabled man to move on land and cross continents, and the sail enabled man to move in the sea and cross oceans.
The wheel did not reduce the friction that is the cause of movement, but it reduced it to the maximum degree.

- Traction friction and rolling friction

To differentiate between them, go to a car garage, or to a seller of tires with rubber tires, and choose one of them, stand it upright on a tiled floor, stand at its front and hold it at the point closest to its tire, and try to pull it along the ground.

You feel the need for a not-so-small force to move it, pulling and pulling, to overcome the friction of drag.
《Drag friction》.

Then return to the same wheel, standing it upright. From behind it, push it forward with your hand to roll it.

You feel the need for force, but it is much smaller than the force of moving it, dragging and pulling. Here you want to overcome 《rolling friction》.

This is the great victory in the invention of the wheel
And do not forget that here too, the wheel does not need friction to move. Remember that the wheels of cars on a muddy road may turn but not move forward, because the mud prevents them from contacting each other.

- How did human thought reach the wheel?

Transportation during the era of the ancients, like the Egyptians, for example, carried weights on slides, pushed them onto the ground with their weights, and facilitated their sliding on it with water they poured from under them. It seems that they transported the great, heavy stones of the pyramid from Mount Mokattam across the Nile to where the pyramid is now. These stones weighed a large number of tons.

Then it must have occurred to them to use tree trunks after making geometric cylinders from them, and place them under these flat slides, and then they would slide them onto the cylinders and they would roll.

Then came the idea of ​​two wheels attached to both ends of this cylinder, and attached to it so that they fit together. The wheel was a round piece of wood with no holes in it. Then they loosened it, and it became rays that ended in a frame on the outside of it, meeting at something like a watermelon in its middle, into which one end of an axle entered, at the other end of which we find a wheel exactly like this attached to it.
It is the wheel as we know it today.
And thus the idea was accomplished.
Then it got better over time.

Today, wheels are the mainstay of machines, which are industries. They are not for transportation and movement on the surface of the earth or anything else.

- Friction in water and air

Friction is generated from the air, and every runner feels it.
Friction occurs in the water, and every swimmer feels it.
The fish has its shapes flowing due to a wisdom, which is to reduce the friction that it finds while swimming in the water, such that it is pierced by the penetration of a sword.
And so is the bird.
They built the planes, taking their shape from the shape of a bird, to avoid air friction.

Space had no friction, which enabled the planets to rotate and for humans to exist on Earth

Yes, space has no friction.
Simple logic ruled that its absence was necessary.
Friction is an opponent. The movement and planets are intended by God to be universal and eternal. Therefore, they must be exempt from friction that continues to eat away at their circular motion until each body falls on everything that revolves around it and has a body.
So the moon would fall to the earth.
Then the Earth, Venus, Mercury, Mars, and the rest of the planets would have fallen to the sun.

An Assyrian chariot wheel with eight spokes.

A wheel with six spokes separated from the axle, connected to it with a pin, and the viewer sees it in the picture.

We see this in artificial satellites, as they revolve around the Earth under the influence of two forces: the centripetal force that repulses them from the Earth and is derived from the speed of their rotation at a known height from the Earth, and then the Earth’s gravitational force for these satellites. This force pushes the Moon to the Earth. The two forces are equal, and the artificial satellite continues to rotate in its orbit.

However, due to the proximity of the satellite orbits to the Earth, these satellites are not completely free of friction.
At those dimensions of the Earth, there are still amounts of Vase, very small, yes, and it causes very little friction, yes, but over the years its effect accumulates and reduces the speed of the satellite’s rotation. This means that it is gradually approaching the Earth.
The closer it gets, the greater the friction with the gas. and so on .
Finally, he falls to the ground.
It came down to Earth from the artificial satellites launched in the early human era in space, and after years of orbiting, it did not land.
And the natural moon, God’s moon, did not land.
This indicates the completion of the void there, or something similar. If it is not complete, then it is undoubtedly a reality, even after a million years. The law of God that occurred in creation, and is continuing.

- The universe has smoothness and roughness

To sum it up, we say:
On the ground there is a roughness in the surface of objects that causes friction, which is the most important thing.
There is softness in the earth, like the smoothness of oil and water, but it is not perfect and is rare.
Roughness, despite its hateful name, is a part of life. Without it, a person’s life in a house or a road would not be stable.
Softness, which causes the ruin of life on earth, means the life of the world outside this earth. Without it, the sun’s system would have been destroyed, the planets would have collapsed, and the earth would have caught up with the sun and been burned.