Four Fundamental Forces – Introduction

The Big Bang theory can satisfyingly explain the creation of the cosmos, but it fails to explain the interaction among various types of energy in the universe. Why did shortly after the Big Bang some elementary particles join to make protons and neutrons? And what made electrons bind to them later to create atoms? Why did these atoms then go on to build glaring stars and vibrant galaxies?

It turns out that all events in the universe can be blamed on four fundamental interactions (four fundamental forces) – gravity, electromagnetism, strong interaction and weak interaction. I am sure everybody has at least a basic overview of the first two forces, the last two, however, might be entirely foreign to some. But it is crucial to understand these interactions, since they govern the whole universe.

Take your own body as an example. First, let us dive deep into the microworld, where we can see the basic building blocks of everything. Your body is, just like everything else in the universe, made up of energy. It is of course present in many various forms, but fundamentally, it is simply energy.

The energy of the human body is concentrated mainly in the form of elementary particles – the same particles that were created just a moment after the Big Bang. These particles then form composite particles – protons and neutrons. But what keeps elementary particles together? The answer lies in the strong interaction. If we jump one level up, we can see collections of protons and neutrons – atomic nuclei. Again, we can blame the strong interaction. Going another level up, we can see electrons, devoutly whizzing around the nuclei. Here, we observe the token of another fundamental force – electromagnetism. Individual atoms then go on to form molecules – electromagnetism shows itself once again.

And finally, unless you are currently at the international space station or reading this text in a distant future on a faraway planet (most likely on Mars, as explained in one of the following chapters), it is quite likely that you are finding yourself on our tiny blue planet. And the only “force” keeping your feet on the ground instead of flying off to space is gravity – another of the four forces.

Our demonstration is over now. We have seen the essence of three of the four interactions using only the human body on Earth. If you are interested in the fourth force as well, you will have to wait a while – it manifests itself the least of the four forces. But now, let us analyse the interactions in detail, one by one. And we will start with the most sneaky and peculiar one – gravity.

https://play.google.com/store/apps/details?id=brychta.stepan.universe

Virgo Supercluster

144 MILLION LIGHT YEARS

If the observable Universe is our world, the Local Group of galaxies our neighborhood, and the Milky Way our house, the Virgo Supercluster is our city. The “city” has more than 700 galaxies in 100 Local Group “neighborhoods”, and stretches 110 million light years across. To put that in perspective, if the observable Universe is a sphere with a diameter of 1 km, large enough to contain the tallest skyscrapers, the Virgo Supercluster is a sphere 1.47 m across, about the height of a child. On that scale, the Milky Way is a tiny disk 2 mm across.

https://play.google.com/store/apps/details?id=org.kurzgesagt.app.Universe

Distance to the Great Attractor

220 MILLION LIGHT YEARS

Space looks calm, but actually our own galaxy, the Milky Way, is traveling through the cosmos at 2.2 million km an hour. This is a bit of a mystery. According to our ideas about the Big Bang, everything in the Universe should be flying apart at similar speeds. If everything is moving at similar speeds, it should look like nothing is really moving at all. When some objects seem to be moving faster than others, it’s usually because clumps of matter like galaxy clusters are exerting an additional gravitational pull. But we know of nothing close to the Milky Way that explains its drift — we just know that something must be causing it. Astronomers named the mysterious clump of matter we haven’t found yet “The Great Attractor”.

https://play.google.com/store/apps/details?id=org.kurzgesagt.app.Universe

Fracking Explained: Opportunity or Danger

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 Great Nothing

330 MILLION LIGHT YEARS

“The Great Nothing” is an enormous sphere in the Universe famous for containing a very sparse number of galaxies — space’s version of the Australian Outback.

No one knows for sure why the Great Nothing exists. The most fun (totally unfounded) hypothesis is that perhaps the void is created by an expanding Kardashev III scale civilization that has been around long enough to conquer a major region of the Universe and capture the energy of its galaxies.

https://play.google.com/store/apps/details?id=org.kurzgesagt.app.Universe