What is the size of the universe? What is it made of? How did it happen and how did it become as we know it today? Cosmology, which is the study of the origin and evolution of the universe, deals with these topics. It is currently one of the most exciting disciplines in science, spanning physics from the smallest to the largest structures we know. The new series of articles illustrates the current state of knowledge and explains why the vast majority of cosmologists seem to stick to absurd ideas such as the empty space of repulsive gravity, the emergence of the universe from nothing and the invisible matter of which 95% of the universe exists. The first three parts will be about dark matter – the invisible elephant in cosmology.
The discovery of the cosmic foam
If you look at the sky in a dark place on a clear moonless night, you will find a dull glowing band that stretches across the sky: through the constellation Sagittarius, the famous summer triangle of the eagle, the harp and the swan, Cassiopeia, the Gemini all the way to Orion , and the circle ending in the southern sky, Invisible to our latitudes all year round, across the nave and the southern cross to the bow. This is our Milky Way, our home galaxy, roughly slice-shaped with a flat outer region and a thick, balloon-shaped central region (which is a Balken Spiral Galaxy).
It measures about 185,000 light-years away, contains hundreds of billions of stars and at least many planets. Seen from above, it shows 4 outward spiral arms, which protrude evenly from the star disk due to young blue stars. Our sun lies on the inner edge of a spiral arm about halfway from the center. It spins majestically; It takes the sun 240 million years to form one orbit. Before the last voyage, the first dinosaurs were about to appear. An island in the world where the visible universe inhabits hundreds of billions. But it seems like this is just foam on much stronger ocean waves.
What is missing: In the fast-paced world of technology, there is often time to rearrange various news and backgrounds. This weekend we will take it, follow the side paths away from the creek, experiment with different perspectives and make the nuances heard.
More about the “Link is missing” section.
Our concept of the universe looked very different 100 years ago: Until the 1920s, a large proportion of astronomers assumed that the Milky Way formed the entire universe and that the numerous small, often spiral nebulae in the sky were like large nebulae. In the constellation Andromeda, they are nothing but gaseous clouds in the Milky Way – otherwise they would be millions of light-years away, which very much seemed completely absurd. Others believe that galaxies like the Milky Way were galaxies and that the universe was much larger than expected.
When larger telescopes such as the 2.5-meter Hooker telescope on Mount Wilson made it possible to dissolve the Andromeda nebula into individual stars, a controversy among cosmologists called “The Great Debate” was finally resolved in the 1920s: Edwin Hubble succeeded in it was possible to determine the distance to the nebula Andromeda for the first time is based on a specific type of variable star, whose periodic pulsation duration makes it possible to draw conclusions about its brightness. Because a certain brightness results in a clear brightness for each distance. It has reached 900,000 light-years because the ratio of the brightness of the period to stars will benefit not properly calibrated; Today we know that it is 2.5 million light-years away. But the result, in the right order of magnitude, was a gigantic leap in knowledge that degenerated the Milky Way from the degree of embodiment of the whole universe to a speck of dust in itself.