The Big Questions: The Universe
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The Big Questions series enables renowned experts to tackle the 20 most fundamental and frequently asked questions of a major branch of science or philosophy. Each 3000-word essay simply and concisely examines a question that has eternally perplexed enquiring minds, providing answers from history's great thinkers. This ambitious project is a unique distillation of humanity's best ideas. In Big Questions: The Universe, Dr Stuart Clark tackles the 20 key questions of astronomy and cosmology: What is the universe? How big is the universe? How old is the universe? What are stars made from? How did the Universe form? Why do the planets stay in orbit? Was Einstein right? What are black holes? How did the Earth form? What were the first celestial objects? What is dark matter? What is dark energy? Are we really made from stardust? Is there life on Mars? Are there other intelligent beings? Can we travel through time and space? Can the laws of physics change? Are there alternative universes? What will be the fate of the universe? Is there cosmological evidence for God?
Similarities and differences, no one knew what gave the elements their chemical identities. That knowledge had to wait until after 1911, the year in which Ernest Rutherford and his team of physicists at Cambridge University’s Cavendish Laboratory unraveled the structure of atoms. “It is sound judgment to hope that in the not too distant future we shall be competent to understand so simple a thing as a star.” ARTHUR EDDINGTON 20TH CENTURY ASTROPHYSICIST Rutherford discovered that atoms have a.
Micrometer across and carries an electrical charge. The number of protons determines how the atom behaves chemically. In the case of hydrogen, the nucleus contains a single proton, making it the simplest kind of atomic nucleus; oxygen has eight protons; carbon has 16; and so on across the periodic table. The fact that the protons are all positively charged means they try to repel each other. To stop atoms spontaneously flying apart, nature has conspired to include other particles in the nucleus.
Sun they even named it: Vulcan. However, there is no planet Vulcan. Instead, the movement of Mercury is due to an unexpected facet of gravity that Newton’s theory does not take into account. Only when Einstein set about explaining the nature of gravity did he come across the remarkable reason for Mercury’s motion. The fabric of space Einstein’s great insight was the concept of the “space–time continuum.” This is a fabric—for want of a better word—that stretches through all space, in all.
Consequences of Georges Lemaître’s 1927 idea that the entire Universe exploded from a single compacted “atom” sometime in the remote past (see How Old is the Universe?). Gamow used this idea of a Big Bang to show that it explained the overwhelming quantity of hydrogen and helium in the Universe. He calculated that, if the Universe began with nothing but the simplest chemical element, hydrogen, then the intense heat of the Big Bang would have fused a quarter of it into helium: almost the exact.
Reactive gas, and in some circumstances it is toxic because of the aggressive way it attacks biological molecules. As oxygen accumulated in the atmosphere, it triggered a mass extinction of Earth’s early microbes, ironically destroyed by their own pollution. “If the Eiffel Tower were now representing the world’s age, the skin of paint on the pinnacle-knob at its summit would represent Man’s share of that age.” MARK TWAIN 19TH CENTURY WRITER Some ancient microbes survived by finding niches.