# How much money is there in the world

## Dr. Wewetzer from A to Z

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The absolute zero point of the temperature is minus 273 degrees Celsius (or zero degrees Kelvin). It couldn't be colder in the universe. But how hot can it get? Physicists believe that the highest temperature is around 100 million million million million degrees Kelvin (or Celsius). That corresponds to a ten with 32 zeros. Scientists suspect that it was only reached for a tiny time shortly after the formation of space. In the center of the sun, on the other hand, it is “only” 15 million degrees.
No, that would be way too expensive. The gold medal at the Olympic Games in London this summer weighs 400 grams - if it were made of pure gold it would cost 16,000 euros! That is why it only has a thin outer shell made of six grams of gold. The inside is made of more than 92 percent silver, the rest is copper. All in all, the medal costs just under 600 euros if you only look at the material value. 1912 was the last year that the Olympic gold medal was really made of pure gold. At the time, however, it weighed only 23 grams. If it were minted today, this medal would cost just under 1000 euros.
Can cave olms breathe underwater? Grotto olms are blind, can do without food for ten years and live to be 60 years old. And they have gills like fish and lungs like land animals. The cave olms live in cave waters where they prefer to hide under stones. They rarely come to the surface. That is why they mostly breathe with their gills, the lungs are not that important. Only when a grotto olm goes ashore does it need its lungs. But that rarely happens. The cave olms can not only breathe underwater - they do it almost exclusively.
Basically it works, but it is very difficult. On the one hand, you have to hit exactly the tone that makes the glass vibrate. If you hit a glass with a spoon, you will hear this sound. On the other hand, the singer has to hold this note for a long time and sing as loudly as possible. If the singer doesn't use a trick, she's very likely still not going to break the glass. One such trick is an electric amplifier that increases the volume. The wine glass should also have fine cracks and weak points so that the vibrations of the voice make it easier to splinter.
The human brain has furrows because that's how it increases its surface area. This surface is also called the cerebral cortex. It is densely populated with billions of nerve cells, the "small gray cells". The more furrows the cerebral cortex has, the more of these nerve cells there is room on and in it. And the more our thinking skills have developed, the more the brain has folded inward. In this way, many nerve cells have found space under the rather narrow skullcap. Incidentally, the cerebral folds are not created by chance, but are largely the same in all people.
Some living beings shine by themselves. Especially in the deep sea there are many fish that generate light and thus attract prey in total darkness. Fireflies belong to the group of beetles. They light up or blink when they are flying around at night looking for a partner. The light attracts other fireflies. It is created with the help of a chemical reaction. The amazing thing is that no energy is wasted in the form of heat. So we can learn a lot from the fireflies when it comes to building economical lamps!
The Gregorian calendar is the calendar that is valid worldwide today. He was on October 15, 1582 by Pope Gregory XIII. introduced and replaced the Julian calendar, which went back to Julius Caesar. The Gregorian calendar is more accurate than its predecessor. A year there has 365.2425 days, whereas in Julian it has 365.25 days. The reason for the introduction of the new calendar was Easter, which one wanted to celebrate at the right time. That is why eleven days, which the Julian calendar had counted too little over the centuries, were suddenly added. October 4, 1582 became October 15, 1582.
We could chew and swallow grass, but our bodies cannot absorb the nutrients from the grass. Cows, on the other hand, help many trillion bacteria to break down and process the hard-to-digest grass fibers. It's a long and complicated process and it takes the cow four stomachs to do it! When we eat lettuce, we cannot absorb most of its solid constituents, fiber, either. But this fiber is still healthy. And the salad tastes better and isn't as hard and tough as grass.
The University of Leicester in England published a "World Map of Happiness" three years ago. Then the Danes are the happiest, followed by Switzerland, Austria, Iceland and the Bahamas. Germany ranks 35th (out of 178). Not bad, right? The most unhappy are the people who live in the Republic of the Congo (176), Zimbabwe (177) and Burundi (178). Important reasons for people to feel good are: good doctors, enough money and good schools.
The ancient Egyptians had more than 2000 gods. Some did the same job, for example Re and Amun were both sun gods. In addition to the main deities, there were many mini-gods in villages and in cities. Christianity knows only one God, but among Catholics there are almost 7,000 saints and beatified people who can be asked for help. The South Asian religion of Hinduism has 330,000 "supernatural beings" - that is probably the record.

Hartmut Wewetzer is a science editor. Vincent Trautmann, aged 15, helped him.
Question from: Children's editorial office
Every day around 380,000 new people are born and 155,000 die. The earth's population is growing by 225,000 people every day. That corresponds roughly to the population of a city like Magdeburg or Freiburg. And it means that 80 million more people live on the globe every year - as many people as Germany has inhabitants. Around 1900 people are born here and 2300 die every day.
Question from: Children's editorial office
This is mainly due to better nutrition. Today's food contains more vitamins, minerals and protein than it used to be. That is why we are getting much bigger on average today. Even in earlier times, it was observed how diet affected body size. In the Middle Ages, people were quite tall because they usually had good food. Later, in the 16th century, many stayed smaller than they could have been because they didn't have enough to bite and starved. In addition, people are less sick today, which is one of the reasons why the body can grow better.
Question from: Children's editorial office