What are the theories of galaxy formation?
One says that galaxies were born when vast clouds of gas and dust collapsed under their own gravitational pull, allowing stars to form. The other, which has gained strength in recent years, says the young universe contained many small “lumps” of matter, which clumped together to form galaxies.
What is the hierarchical structure of the universe?
There are three levels of the stellar system hierarchy: 1) multiple stars and planetary systems; 2) star clusters and associations; 3) galaxies. On a larger scale, galaxies combine into 1) groups; 2) clusters; 3) superclusters; 4) hyperclusters.
Who proposed the hierarchical universe?
In Plato’s creation story, the Timaeus, we are told that the Creator fashioned a hierarchical universe, topped by the realm of fixed stars, followed in descending order by the planets, with the earth at the bottom.
What are the two models of galaxy formation?
Here we review the current status of models that employ two leading techniques to simulate the physics of galaxy formation: semianalytic models and numerical hydrodynamic simulations.
What are the two theories about galaxy?
Astronomers recognize two main galaxy types: elliptical and spiral. These differences in shape, according to one theory, are due to star formation. Stars develop inside a protogalaxy when clouds of gas mix and collide.
How are galaxy clusters formed?
Astronomers think that galaxy clusters form as clumps of dark matter and their associated galaxies are pulled together by gravity to form groups of dozens of galaxies, which in turn merge to form clusters of hundreds, even thousands of galaxies.
What has the highest rates of star formation?
Starburst galaxieshave the highest rates of star formation. 2. The largest individual galaxies in the universe are known as central dominant galaxies.
What is the importance of knowing the hierarchical of the universe?
By understanding the hierarchical structure of things, we are able to gain a clearer visualization of the roles each individual component plays and how they fit into the larger picture.
Why is the universe organized?
There are two elements to why the universe appears to be so orderly: the physical laws of that govern the universe are the same everywhere, and astronomical objects are very, very, very far from each other. Consider two objects, one much larger than the other, and both very far from anything else.
Which is biggest in the universe?
The biggest single entity that scientists have identified in the universe is a supercluster of galaxies called the Hercules-Corona Borealis Great Wall. It’s so wide that light takes about 10 billion years to move across the entire structure.
What was Einstein’s theory of the universe?
Einstein was the first to apply his ideas of space and time plasticity to the universe as a whole. In 1919, he devised a model for the entire universe: a static, spherical, perfectly symmetric cosmos, with matter homogeneously distributed everywhere, reflecting a mix of Platonic perfection and of Ockham’s Razor.
What is the correct order of the objects from smallest to largest?
From largest to smallest they are: Universe, galaxy, solar system, star, planet, moon and asteroid.