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from mrmackenzie
You might remember that we looked at some paradoxes when we studied special relativity earlier this term. Here is another situation where a paradox can arise. The German astronomer Heinrich Olbers (1758–1840) asked why the night sky was dark. At the time, astronomers believed that the Universe was both infinite and steady state (unchanging), so … Read more evidence in support of the big bang: #3 olbers’ paradox
from mrmackenzie
As we worked through the diagram explaining the stages of the Big Bang model, we looked at a section of the diagram where the Universe was hot enough for nuclear fusion. At this point, hydrogen nuclei were fusing together with other hydrogen nuclei to create helium nuclei. As the Universe expanded, it cooled and further … Read more evidence in support of the big bang: #2 nucleosynthesis
from mrmackenzie
introduction to the Big Bang from mr mackenzie on Vimeo. Georges Lemaître’s theory of an expanding Universe, which has become known as the Big Bang, was supported by Hubble’s observations. The expanding Universe idea was challenged by influential scientists who believed the Universe was both infinite (and therefore not expanding) and steady state (unchanging). Supporters … Read more evidence in support of the big bang: #1 CMBR
from mrmackenzie
In the 1920s, Edwin Hubble had access to the Hooker telescope on Mount Wilson, Los Angeles. This was the largest telescope in the world at that time. His first breakthrough was the discovery of a cepheid variable star in the Andromeda nebula. This enabled him to calculate the distance to Andromeda and he quickly realised this was … Read more the Milky Way is not alone
from mrmackenzie
The cosmic microwave background radiation (CMB) is radiation left over from the big bang. When the universe was very young, just as space became transparent to light, electromagnetic energy would have propagated through space at a much shorter wavelength. Nowadays, the temperature of space has fallen to approximately 2.7 K (that’s 2.7 K above absolute zero!) … Read more