Category Archives: Kurzgesagt

What is the Stock Exchange and how does it work?
The Stock Exchange is nothing more than a giant globally network tend to organize the market place where every day huge sums of money are moved back and forth.
In total over sixty trillion (60,000,000,000,000) Euros a year are traded.
More than the value of all goods and services of the entire world economy.
However it’s not apples or second hand toothbrushes that are traded on this marketplace.
But predominantly securities.
Securities are rights to assets, mostly in the form of shares.
A share stands for a share in a company.
But why are shares traded at all?
Well, first and foremost the value of a share relates to the company behind it.
If you think the value of a company in terms of a pizza.
The bigger the overal size of the pizza, the bigger every piece is.
If for example Facebook is able to greatly increase its profits with a new business model.
The size of the companies pizza will also increase, and as a result so will the value of its shares.
This is of course great for the share holders.
A share which perhaps used to be worth 38 euros could now be worth a whole 50 euros.
When it’s sold this represents a profit of twelve euro per share!
But what does Facebook gain from this?
The company can raise funds by selling the shares and invest or expand it’s buisness.
Facebook, for example, has earned sixteen billion dollars from it’s listing on the Stock Exchange.
The trading of shares though, is frequently a game of chance.
No one can say which company will perform well and which will not.
If a company has a good reputation, investors will back it.
A company with a poor reputation or poor performance will have difficulty selling its shares.
Unlike a normal market in which goods can be touched and taken home, on the Stock Exchange only virtual goods are available.
They apear in the form of share prices and tables on monitors.
Such shareprices can rise or fall within seconds.
Shareholders therefore have to act quickly in order not to miss an opportunity.
Even a simple rumor can result in the demand for a share falling fast regardless of the real value of the company.
Of course the opposite is also possible.
If a particularly large number of people buy weak shares.
Because if they see for example great potential behind an idea.
Their value will rise as a result.
In particular young companies can benefit from this.
Even though their sales might be falling, they can generate cash by placing their shares.
In the best case scenario this will result in their idea being turned into reality.
In the worst case scenario, this will result in a speculative bubble with nothing more than hot air.
And as the case with bubbles, at some point, they will burst.
The value of Germany’s biggest thirty companies is summarized in what is known as the DAX share index.
The DAX shows how well or poorly these major companies and thereby the economy as a whole are performing at the present time.
Stock Exchange is in other countries also have their own indices.
And all of these markets together create a globally networked marketplace.

The ocean conveyor belt and the Gulf Stream.
Ocean currents have a direct influence on our lives.
They determine our weather, our climate, and much more.
The ocean currents and wind systems transport heat from the equator to the poles and operate like a large engine for the global climate.
In the oceans, there are numerous currents.
The so-called ocean conveyor belt is very important for our climate.
This term describes a combination of currents that result in four of the five global oceans exchanging water with each other.
They form a worldwide circulation system.
The conveyor belt is also called the thermohaline circulation, with “thermo” referring to the temperature, and “haline” to the salt content of the water.
Both determine the density of the water.
While the masses of water may be moved in part by wind, primarily the different densities of the global oceans are responsible for their movement.
Warm water has a lower density and rises while cold water sinks.
The water’s density also increases with a higher salt content.
At the equator the heat from the sun is especially strong, resulting in a lot of evaporation and thus a rise in the water’s salt content.
That is where the Gulf Stream begins.
The Gulf Stream is very important for the European climate.
Its length of 10,000 km makes it one of the largest and fastest currents on Earth, and it’s very warm.
At roughly 2 m/s it brings up to 100,000,000 m³ of water per second towards Europe.
A constantly blowing wind, the southeast trade wind, drives warm surface water to the northwest, into the Gulf of Mexico, where it heats up to 30 °C.
The turning of the Earth and the west winds then direct the Gulf Stream towards Europe and split it up.
One part flows south, another east to the Canary Current, and a third part flows north where it releases a lot of heat into the atmosphere as the North Atlantic Current.
The water becomes colder there.
Its salt content and density rise on the account of evaporation and it drops down between Greenland, Norway, and Iceland.
There we also find the largest waterfall on Earth.
The so-called Chimneys, roughly 15-km-wide pillars with water falling up to 4,000 m.
17,000,000 m³ of water per second, or roughly 15 times more water than is carried by all the rivers in the world.
This creates a strong maelstrom, which constantly pulls in new water and is the reason that the Gulf Stream moves towards Europe.
Countless species use the Gulf Stream as a means of transport on their trips from the Caribbean to northern areas.
But it doesn’t just bring us animals; an enormous quantity of warm air also comes with it.
In order to produce the same heat that it brings to the shores of Europe, we would need 1,000,000 nuclear power plants.
That’s why we also call the Gulf Stream a heat pump.
Without it, the temperature would be significantly colder here, at least five to ten degrees.
Instead of lush fields, we would have long winters and sparse ice-covered landscapes in Europe.
In the last few years, scientists and pundits in the media have repeatedly expressed the fear that the Gulf Stream could come to a standstill due to climate change.
Because if the polar caps actually melt, the salt content in the water off Greenland would fall, as would its density.
The North Atlantic Current would no longer be heavy enough, and so it woundn’t sink as usual.
In the worst case, that would bring the Gulf Stream, our heat pump, to a stop.
Some climate experts also assume that climate change could compensate for this effect.
We know that it can be normal for the climate to change by looking at the development of the Earth over the last few million years.
There are ice ages and warm periods.
In the last ice age, a gigantic flood of melting water crippled the heat-bringing North Atlantic Current, covering the northern hemisphere in ice.
Scientists have different views on the impact that climate change will have on the global ocean conveyor belt, but one thing is clear: when the climate changes, then the complex system of ocean currents and winds, which has remained fairly stable since the last ice age, will change in ways that we don’t yet understand.

What is hydraulic fracturing – or fracking ?
Since the industrial revolution our energy consumption has risen unceasingly.
The majority of this energy consumption is supplied by fossil fuels like coal or natural gas.
Recently there has been a lot of talk about a controversial method of extracting natural gas: Hydraulic fracturing or fracking.
Put simply, fracking describes the recovery of natural gas from deep layers inside the earth.
In this method, porous rock is fractured by the use of water, sand and chemicals in order to release the enclosed natural gas.
The technique of fracking has been known since the 1940s.
Nonetheless, only in the last ten years has there been quite a “fracking boom”, especially in the USA.
This is because most conventional natural gas sources in America and on the European continent have been exhausted.
Thus prices for natural gas and other fuels are rising steadily.
Significantly more complicated and expensive methods, like fracking, have now become attractive and profitable.
In the meantime, fracking has already been used more than a million times in the USA alone.
Over 60% of all new oil and gas wells are drilled by using fracking.
Now let’s take a look at how fracking actually works.
First, a shaft is drilled several hundred meters into the earth.
From there, a horizontal hole is drilled into the gas-bearing layer of rock.
Next, the fracking fluid is pumped into the ground using high-performance pumps.
On average, the fluid consists of 8 million liters of water which amounts to about the daily consumption of 65,000 people.
Plus several thousand tons of sand and about 200,000 liters of chemicals.
The mixture penetrates into the rock layer and produces innumerable tiny cracks.
The sand prevents the cracks from closing again.
The chemicals perform various tasks among other things, they condense the water, kill off bacteria or dissolve minerals.
Next, the majority of the fracking fluid is pumped out again.
And now the natural gas can be recovered.
As soon as the gas source is exhausted, the drill hole is sealed.
As a rule, the fracking fluid is pumped back into deep underground layers and sealed in there.
However, fracking is also associated with several considerable risks.
The primary risk consists in the contamination of drinking water sources.
Fracking not only consumes large quantities of fresh water, but in addition the water is subsequently contaminated and is highly toxic.
The contamination is so severe that the water cannot even be cleaned in a treatment plant.
Even though the danger is known and theoretically could be managed, in the USA already sources have been contaminated due to negligence.
No one yet knows how the enclosed water will behave in the future, since there have not yet been any long-term studies on the subject.
The chemicals used in fracking vary from the hazardous to the extremely toxic and carcinogenic, such as benzol or formic acid.
The companies using fracking say nothing about the precise composition of the chemical mixture.
But it is known that there are about 700 different chemical agents which can be used in the process.
Another risk is the release of greenhouse gases.
The natural gas recovered by fracking consists largely of methane, a greenhouse gas which is 25 times more potent than carbon dioxide.
Natural gas is less harmful than coal when burned.
But nonetheless, the negative effects of fracking on the climate balance are overall greater.
Firstly, the fracking process requires a very large consumption of energy.
Secondly, the drill holes are quickly exhausted and it is necessary to drill fracking holes much more frequently than for classical natural gas wells.
In addition, about 3% of the recovered gas is lost in the extraction and escapes into the atmosphere.
So how is fracking and its expected benefits to be assessed when the advantages are balanced against the disadvantages?
When properly employed, this technique offers one way in the short to medium term for meeting our demand for lower-cost energy.
But the long-term consequences of fracking are unforeseeable and the risk to our drinking water thus should not be underestimated.

The Solar system. Our home in space.
We live in a peaceful part of the Milky Way.
Our home is the Solar system, a 4.5-billion-year-old formation that races around the galactic centre at 200,000 km/h and circles it once every 250 million years.
Our star, the Sun, is at the centre of the Solar system.
It’s orbited by eight planets, trillions of asteroids and comets and a few dwarf planets.
The eight planets divided into four planets like ours: Mercury, Venus, Earth and Mars, and four gas giants: Jupiter, Saturn, Uranus and Neptune.
Mercury is the smallest and lightest of all the planets.
A Mercury year is shorter than the Mercury day, which leads to enormous fluctuations in temperature.
Mercury does not have an atmosphere or a moon.
Venus is one of the brightest objects in the Solar system and by far the hottest planet, with atmospheric pressure that is 92 times higher than on Earth.
An out-of-control greenhouse effect means that Venus never cools below 437 °C.
Venus also doesn’t have a moon.
Earth is our home and the only planet with temperatures that are moderate enough to allow for a surplus of liquid water.
Furthermore, it’s so far the only place where life is known to exist.
The Earth has one moon.
Mars is the second smallest planet in the Solar system and hardly massive enough to keep a very thin atmosphere.
Its Olympus Mons is the largest mountain in the Solar system, more than three times as high as Mount Everest.
Mars has two small moons.
Jupiter is the largest and most massive planet in the Solar system.
It consists largely of hydrogen and helium and is the theatre for the largest and most powerful storms we know.
Its largest storm, the Great Red Spot, is three times as large as Earth.
Jupiter has sixty-seven moons.
Saturn is the second largest planet and possesses the smallest density of all the planets.
If you had a sufficiently large bathtub, Saturn would swim in it.
Saturn is also known for its extended, very visible ring system.
It has sixty-two moons.
Uranus is the third largest planet and one of the coldest.
Of all the gas giants, it’s also the smallest.
The special thing about Uranus is that its axis of rotation is tilted sideways in contrast to the seven other planets.
It has twenty-seven moons.
Neptune is the last planet in the Solar system and is similar to Uranus.
It’s so far removed from the Sun that a Neptune year is 164 Earth years long.
The highest wind speed ever measured was in a storm on Neptune, at just under 2,100 km/h.
Neptune has fourteen moons.
If we compare the sizes of the planets, the differences between them become even clearer.
Jupiter is the leader in terms of size and weight; small Mercury, on the other hand, is even smaller than one of Jupiter’s moons, Ganymede.
Jupiter is so massive that alone it contains roughly 70% of the mass of all the other planets and has a massive impact on its surroundings.
That’s a blessing for Earth, since Jupiter draws most of the dangerously large asteroids that could wipe out life on Earth.
But even Jupiter is a dwarf in comparison to our star, the Sun.
Calling it massive does not do justice to the Sun.
It makes up 99.86% of the mass in our Solar system.
For the most part, it consists of hydrogen and helium.
Only less than 2% is made up of heavy elements, like oxygen or iron.
At its core, the Sun fuses 620 million tons of hydrogen each second and generates enough energy to satisfy mankind’s needs for years.
But not only the eight planets orbit our Sun.
Trillions of asteroids and comets also circle it.
Most of them are concentrated into two belts: the asteroid belt between Mars and Jupiter and the Kuiper belt at the edge of the Solar system.
These belts are home to countless objects, some as large as a dust particle, others the size of dwarf planets.
The most well-known object in the asteroid belt is Ceres; the most well-known objects in the Kuiper belt are Pluto, Makemake and Haumea.
Usually we describe the asteroid belt as a dense collection of bodies that constantly collide.
But in fact, the asteroids are distributed across an area that is so indescribably large that it’s even difficult to see two asteroids at once.
Despite the billions of objects in them, the asteroid belts are fairly empty places.
And nonetheless, there are collisions over and over again.
The mass of both belts is also unimpressive: the asteroid belt has a little less than 4% of our Moon’s mass, and the Kuiper belt is only between 1/25 and 1/10 of Earth’s mass.
One day, the Solar system will cease to exist.
The Sun will die, and Mercury, Venus and maybe Earth too will be destroyed.
In 500 million years it will become hotter and hotter until at some point it will melt Earth’s crust.
Then the Sun will grow and grow and either swallow Earth or at least turn it into a sea of lava.
When it has burnt up all its fuel and lost most of its mass, it will shrink to a white dwarf and burn gently for a few billion more years before it goes out entirely.
Then, at the latest, life in the Solar system will no longer be possible.
The Milky Way will not even notice it.
A small part of it in one of its arms will become just a tiny bit darker.
And mankind will cease to exist or leave the Solar system in search of a new home.

Mechanisms of Evolution

What is evolution?
Evolution is the development of life on Earth.
This is a process that began billions of years ago and is still continuing to this day.
Evolution tells us how it was possible for the enormous diversity of life to develop.
It shows us how primitive Protozoa could become the millions of different species that we see today.
Evolution, then, is the answer to the question that we have all asked on seeing a Daschund and a Great Dane together: how is it possible for ancestors to have descendants that look so very different to them?
In answering this question, we want to focus on animals, excluding other forms of life such as fungi and plants.
The first question to ask is therefore: how can one animal develop into a whole new species of animal?
Ah, but just a quick question: what exactly is a species?
A species is a community of animals that is capable of producing offspring with one another, with those offspring also being capable of reproducing in turn.
To understand this answer better, we need to take a closer look at the following points: the uniqueness of living creatures, guaranteed through the excess production of offspring and heredity, and as a second key point, selection.
Let’s begin with uniqueness.
Every creature that exists is unique, and this is essential for evolution.
The members of a species may strongly resemble each other in appearance; however, they all have slightly different traits and characteristics.
They may be a bit bigger, fatter, stronger, or bolder than their fellow animals.
So, what is the reason for these differences?
Let’s take a closer look at a creature.
Every creature is made up of cells.
These cells have a nucleus.
The nucleus contains the chromosomes, and the chromosomes hold the DNA.
DNA consists of different genes, and it’s these genes that are life’s information carriers.
They contain instructions and orders for the cells, and determine the characteristics and traits that living creatures have, and it’s precisely this DNA that is unique to every creature.
It’s slightly different from individual to individual, which is why each has slightly different characteristics.
But how is the enormous range of DNA created?
One key factor is the excess production of offspring.
In nature, we can observe that creatures generally produce far more offspring than is necessary for the survival of their species, with many offspring dying an early death as a result.
Often there are even more offspring than the environment in which they live is able to support.
This is one factor in increasing diversity within a species.
The more offspring that are produced, the more little differences occur, and this is what nature wants: as many little differences as possible.
The second major cause of the uniqueness of individuals occurs in heredity itself.
By the way, heredity means the passing on of DNA to offspring.
Two very interesting factors come into play in this process: recombination and mutation.
Recombination is the random mixing of the DNA of two creatures.
When two creatures fall in love and mate, they recombine their genes twice.
The first time, they do this separately when they generate the gametes – that is, sperm and egg cells.
The gametes take half of the genes and shuffle them.
The second recombination occurs when a male inseminates a female.
The parents each provide 50% of their DNA, in other words, 50% of their unique traits and characteristics.
These are then recombined, or mixed, and the result is new offspring.
These offspring have a random mix of the DNA, and therefore the traits and characteristics of their parents.
This increases the diversity and differences within a species even further, but mutations are also important for evolution.
Mutations are random changes in DNA.
These can also be described as copying errors within the DNA, triggered by toxins or other chemical substances, or by radiation.
A mutation exists when part of the DNA is altered.
These changes are often negative, and may result in illnesses such as cancer.
However, they may also have neutral or positive effects, such as the blue eye colour in humans, which is one such random mutation.
In all cases, a mutation has to affect a gamete, that is a sperm or egg cell, because only the DNA in the gametes is passed on to the offspring.
This is also the reason why we protect our sexual organs during x-rays, whilst other parts of the body are not at risk.
In summary then, in the heredity process, creatures pass on their characteristics to their offspring in the form of DNA.
Recombination and mutation change the DNA so that each child looks different to its siblings, and receives a random mix of the characteristics of its parents.
There’s a key word here: random.
All of these processes are based on chance.
Random recombination and mutations result in individuals with random mixes of traits and characteristics, which in turn mix these randomly, and pass them on.
But how can so much be down to chance, when all living creatures are so perfectly adapted to their environment, for example, the stick insect, the hummingbird, and the frogfish?
The answer is provided by the second key point: selection.
Each individual is subjected to a process of natural selection.
As we have learned, each individual is somewhat different to its fellows, and there is extensive variation within a species.
Environmental influences have an effect on living creatures.
These so-called selection factors include: predators, parasites, animals of the same species, toxins, changes in habitat, or the climate.
Selection is a process that each individual is subjected to.
Every creature has a unique mix of traits and characteristics.
This mix helps them to survive in their environment, or not, as the case may be.
Anyone with an unsuitable mix will be selected from the environment.
Those with the right mix survive, and can pass on their enhanced traits and characteristics.
This is why diversity is so important.
This is why creatures make so much effort to produce offspring that are as different as possible.
They increase the likelihood that at least one of their offspring passes nature’s selection process.
They maximize their chances of survival.
A good example of this can be seen in a group of finches living on a remote island.
They are some of the most famous animals in the world of science, and are known as Darwin finches, after their discoverer, Charles Darwin, and this is the story of those finches.
A few hundred years ago, a small group of finches was blown onto the Galapagos Islands in the middle of the Pacific, probably by a big storm.
The finches found themselves in an environment that was completely new to them, a real finch paradise: an abundance of food and no predators.
They reproduced rapidly and numerously.
The islands were soon heaving with finches. This meant that food supplies became increasingly scarce.
The finch paradise was threatened with famine, and finch friends became competitors.
This is when selection intervened.
Their individuality and small differences, in this case their slightly different beaks, meant that some of the birds were able to avoid competing with their fellow finches.
The beaks of some of the finches were more suitable for digging for worms.
Other finches were able to use their beaks better for cracking seeds.
The finches consequently sort out ecological niches.
In these niches, they were safe from excessive competition.
They soon began to mate primarily with other finches that used the same niche.
Over the course of many generations, these characteristics were enhanced, enabling the finches to exploit their niches successfully.
The differences between the worm-diggers and the seed-crackers became so large that they were no longer able to mate with one another.
Different species emerged as a result.
Today, there are 14 different species of finch living on the Galapagos Islands, all of which are descended from the same group of stranded finches.
This is how new species are created by evolution: through the interaction of unique individuals, the excess production of offspring, recombination and mutation in heredity, and finally, through selection.
Why is this so important?
It tells us where the variety of life comes from, and why living creatures are so perfectly adapted to their habitats.
But it also effects us personally.
Every person is the result of 3.5 billion years of evolution, and that includes you.
Your ancestors fought and adapted in order to survive.
This survival was an extremely uncertain thing.
If we consider the fact that 99% of all the species that have ever lived are extinct, then you can consider yourself part of a success story.
The dinosaurs have disappeared, but you are alive, watching this video, because you’re incredibly special, just like all the other creatures that exist today: irreproducible and unique in the universe.