This probably refers to a commercially available plastic bags. Shopping bag is usually used to carry the  groceries from shop to car and from car to home.

Plastic bags are made of plastic, and are most commonly used as carrier bags for groceries and as garbage bags. Plastic bags have all colors and sizes, and with different prints. They are thin, light and flexible. Extensive use of plastic bags spread in the mid-1970s. In 2002, the world was prepared in various sizes and qualities of plastic bags to a total of 4-5 trillion pieces

It is a good question why plastic bags are used. Plastic bags do not decompose and burning them causes toxic fumes. Thrown to the wild and in water Plastic bags cause problems for animals. Also biodegradable plastic bags do exist, but they are not as durable.

The same plastic bag can be used several times before it ends up as garbage bag.  Others prefer to use paper or fabric bags for carrying groceries. In some places, the use of plastic bags has imposed a special tax, or they are banned altogether.

In developing countries, little boys produce empty plastic bags, for example, soccer balls themselves.

Try to keep the hand closed, and then try to pick up toys from the floor, or eat yogurt with a spoon. Fingers distinguish humans and other primates from most other animals, because they allow objects sticking. You can also try to pick up objects with toes – it is possible, but not very easy. The fingers have made it possible to use different tools.

Tools are an important stage in human development. Weapons let people to be able to hunt for food for others than himself. Some people may have to stay at home, and some have gone hunting. Later, the tools have made it possible to cut down trees, to cultivate the land, build houses, etc.

The most important finger is the thumb. The thumb moves against other fingers allowing fine mechanical thumb-index finger grip. Compared with the technological superiority of man is to relate to the brain and this grip. It is very rare in the animal kingdom: possum, koala and some primates are able to slightly similar.

You can try out the necessity of the thumb, say put, a glove in your hand so that your thumb is not in its separate compartment. Try then pick up objects in your hand.

The idea of ​​self-moving trolley is old, even though from the discovery of the idea it took few hundred years, until the German Carl Benz produced the first car with internal combustion engine. As early as the 1400s there were designs for self-propelled vehicles, including Leonardo da Vinci to consider the use of a spring force in vehicles. Later, Isaac Newton developed the idea of ​​using steam eruption to power a car.

The earliest car is said to be  Nicolas Josef Cugnot’s three-wheel steam car dating back to 1769. This car was designed for military use to haul guns and other heavy objects.

Although the car was invented as early as the turn of the century, it took more than a hundred years, until the cars started to become common everywhere. Even in grandma’s and grandpa’s youth also horse was still in use as means of transport and to haul farming equipment. Gradually, cars and tractors, however, became more common and replaced the horse-drawn carriages and gadgetry.

Originally cars were made by hand and gasoline had to ne bought from pharmacy.  One of the automotive pioneers was the American Henry Ford, who built his first automobile factory based on conveyor belts. Once automotive color range was smaller than the current one. Ford is quoted as saying that customers can choose their car in any color as long as it is black.

Today, cars are produced in factories around the world. Most of the cars are still having combustion engines consuming petrol or diesel, but, for example, ethanol and electricity -powered cars are becoming more common. Cars are responsible for pollution which is making a mess in nature, and therefore cleaner cars are being developed all the time.

The earliest reference to shoes are some kind of findings from about ten thousand years ago. People are, since time immemorial times, learned that the soles of the feet are sometimes good to be protected against the cold, sharp stones or other harmful effects. On the other hand, where circumstances permit, also being bare footed has always been in fashion.

Prior to year 1000 numbers of different types of sandals were used, among other things, the Greeks, for whom the use of the shoes had been a wealth and status symbol. Roman sandals, in turn, developed into simple boots. Celts at 1100’s used leather shoes, which were heated by the fur inside of them.

In the Middle Ages shoes could be up to half a meter long with tapered tips. In the 1500’s came into fashion unwalkable, up to half a meter high platform soles, Chopin. In 1600’s it became more common to use shoe laces to tighten the shoes. The French Sun King Louis XIV used platform shoes and made courts wild around Europe.

Previously shoes were always handmade. Shoemakers guild was appreciated and they sewed shoes together from leather pieces. Today, cobblers, mainly fix shoes and copy keys. 1700’s the shoe industry developed and mass production began. The first shoe factories were founded, and as well the first shoe store opened in Boston. When 1900s’ approached , sports shoes were invented, among other things and manufacturing of shoes became easier thanks to the invention of the sewing machine. 

Today, most shoes are manufactured in factories in large Asian countries. Shoes might be made partly by hand, but now the factory can produces thousands of pairs of shoes a day, while the shoes entirely made by hand by the shoemaker could take a week.

As stated earlier in the stars and space articles, the space according to present knowledge emerged from the Big Bang with stars and planets and everything. The sun is the closest star to us – that’s why it looks so huge. Other stars are sometimes thousands of times larger than the sun, but they are so far away that they look like small dots in the night sky.

The stars will go out, and new ones are constantly born. Because the stars are so far away, their light’s trip here takes millions of years. Thus, how we see the starry sky is really like an old photo of what the stars looked like millions or billions of years ago. It may be that some of the stars we see are actually already gone and new ones have emerged to replace them.

How, then new stars  are born? The stars are created when the cold gas clouds are condensed together under their own weight. In the end, the resulting star settles to a stable state. At this stage the star receives energy from nuclear reactions, the fusion of hydrogen. Our sun is at this stage. Our Sun is about five billion years old and it is in the middle of its life cycle.

When all of the hydrogen starts being used, moves the star to fuse helium (the same substance that is in gas balloons) and the star’s core shrinks and heats up, but the outer parts expand and cool down. Thus the star becomes a red giant. After this, the stars with the mass of our sun become planetary nebula, with a central star being a dense white dwarf. By the time the fog will disappear, and cool white dwarf remains.

Heavy stars, about 10 times the mass of our Sun, are destined into a supernova explosion, which results in a gas cloud, in addition to either a neutron star or a black hole. Supernova is a huge explosion, where the fading star burst like a bomb and throws material all around the space. A black hole is a body, which traction force is so strong, that it will suck up everything – even light. It is believed that in the middle of our Galaxy is a huge black hole, whose name is Sagittarius A.

The Moon is Earth’s only natural companion, a satellite. Moon rotates around Earth, but there are also a lot of small man-made objects, such as weather and communication satellites and old spacecraft parts – space debris. The moon has circled the earth billions of years, but not always. When people were up there in the 70s, they brought back rock samples, that have launched a theory that another planet collided with the young Earth, and the remaining pieces formed the moon. However, this theory is not the only one.

The moon reflects the sun light, and is the second brightest object in the sky after the Sun. The moon appears to be yellow, but it is actually gray and cold stone ball. Moon in the night sky has always been a fascinating destination for people. The different phases of the moon, full moon, crescent etc. depend on how the Earth’s shadow covers the moon at different times of the month. Month is the time it takes moon to circumvent the Earth.

Many other solar system planets have moons – usually more than one. Moons of other planets have different names, such as the Martian moons Phobos and Deimos. Earth’s moon, however, has no other name. Moon strongly influences life on Earth. Eg. Ocean tides are due to lunar gravity.

In the old days people imagined seeing oceans and cities on moon. It was believed that the moon is home to the moon people. Really the moon is a pretty empty place. There are only a few rocks, spacecraft parts and some equipment, like Lunar Roving Vehicles used by the astronauts. Cars could not be taken back, so they were left on the moon forever. In addition there are few American flags and golf balls that the astronauts struck while visiting .

The hedgehog is a small, spiny insect nocturnal insect-eater. The hedgehog as a species, is very old. Hedgehogs have roamed the earth almost unchanged for millions of years. Hedgehogs, may have been existing already at the time of the dinosaurs.

When grandma and grandpa went to school, old school books had a picture, which presented a hedgehog being the main enemy of the viper. The hedgehog , however, would not invade living adult snake snake. They might anyway eat the carcasses of dead snakes.

Hedgehogs natural food are beetles, Shield Bugs, millipedes, ants, earwigs and spiders. However, hedgehogs also eat caterpillars, snails, earthworms, frogs, lizards and mice. 

For your garden hedgehog you can provide, for example, boiled fish and crushed peanuts. The fish has to be cooked so that the hidden parasites die and do not spread in the body of the hedgehog. You can also provide, say, cat food, both dry and wet food, because they do not contain very large quantities of salt or strong seasonings, which can be detrimental to hedgehog. Hedgehog insectivore teeth are not suitable for milling, so hard pellets are recommended to be soaked in water before offered.

Magnetic resonance imaging is a technique that allows doctors to see inside the human being. In humans, there is no bonnet, which can be easily opened, such as in a car. It would be inconvenient if you always should do the surgery in order to get to investigate what is happening inside the human.

To view inside a person, there are number of different methods. The old method is the X-ray imaging, which enables you to easily see, for example, the skeleton. In this way, it is easy to study, say, whether the leg has a fracture. Other older methods are eg. Endoscopy, in which a small camera is inserted into the man in, for example, orally.

Magnetic resonance imaging (MRI) is one of the latest methods. A large electromagnet and a computer form a kind of camera that can take a photo of a person in slices. Magnetic picture looks a little sliced ​​potato and cone an easily see how the different layers within the human look. MRI can be used to investigate, for example, the most important part of the human body, the brain and their functions.

The house appears obvious, but all do not live in houses. Around the world, people live in a variety of ways. Recently, the paper told of a girl who lives in a train and a woman who has been living in the airport. In Thailand there are families who live in abandoned airplanes. In Mongolia it is usual to live on a thick felt-made tent, jurt. Certain tribes live in mud huts and some live permanently in a tent or caravan.

However houses have their pros and cons. Houses are easy to heat, and they provide good protection from wind, rain, wild animals and uninvited guests. On the other hand the houses are expensive and require a lot of care. Houses can not be moved. That is one reason why, for example, the circus people living in caravans.

How did you contact other people before the invention of telephone? Signal drums, smoke signals, postal wagons, couriers, telegraph? More than one persons have been considered to be the inventor of the phone. One of the best known (though perhaps not the very first) is Alexander Graham Bell. He is said to have spoken on the phone the first words: “Watson, come here, I need to talk.”

In your mother’s and father’s childhood  so-called, landline telephones were the only form of phones and mobile phones and video calls would never even been dreamed of. They could be seen only in science fiction movies. Radio phones were used by authorities and the truck drivers. In general, every home had one telephone and it was a phone in the hallway on the table. On the table, then there was a small notepad, which was used to draw doodles while the phone’s twisted cord was wrapped around your finger to pass the time during a long phone call. Normally, the phone did not show who is calling, so we always had to answer objectively with your own name or a phone number.

Today, the phone is taken for granted. People are reachable everywhere and always. The phone is a convenient way to keep in touch with relatives who live further away. Smoke signals, jungle drum and shouting would not carry very far.