A Brief History of Time
In A Brief History of Time, Hawking writes about the origin and composition of the universe in easy terminology for the mass audience But don’t worry E=mc2 is the only equation that appears in the entire book.
Hawking begins with an account of the historical studies of astronomy by figures such as Aristotle and Ptolemy. The concept of a round-shaped Earth that was held by Aristotle was contrary to most others of his time. He, like Ptolemy, believed the sun and stars orbited the Earth. This hypothesis was later disproven by the work of Copernicus, Galileo, and Kepler.
By the twentieth century, Edwin Hubble discovered that galaxies are moving away from each other, meaning that at one time they were all in one place. Scientists continue to seek a theory that would encompass everything in the universe and be able to explain it all.
Space and time are examined in Chapter Two, including Albert Einstein’s theory of relativity. The big bang, which grew to be the dominant theory of the creation of the universe, becomes the basis for the third chapter and explains the building blocks of the universe. These are the smallest things from which all matter is made, and are called quarks. Nuclear forces unite the quarks into neutrons and protons and keep the neutrons and protons together in atoms.
Black holes are the central focus of the next chapter. Black holes Hawking tells us are stars that have collapsed into one very small point called a singularity and have a very strong gravitational force, thus are able to pull things, including light and stars, to their centres.
Black holes are difficult to locate because they do not let light out. They can be seen by telescopes when they suck in other stars, thus emitting x-rays. Wormholes and time travel are discussed as well. A wormhole is, in theory, a passage that could serve as a shortcut through the universe by collapsing space and time.
The Milky Way galaxy is over 13 billion years old and has some 400 billion stars and many trillions of planets and moons. The Sun System (also called the Solar or Sol System), with planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune, and Pluto are each in an orbit with its star at the centre.
Of these, the Earth formed around 4.5 billion years with its life first forming about a billion years later. Earth gave rise to a race of bipedal (hominids) life 3 million years before the current age that would in part become the ancestors of the dominant species on the planet from 70,000 BCE.
As social evolution and human civilisation grew it faced near extinction catastrophes in 22,500 BCE and 11,600 BCE. Civilisation arose again from 4500 BCE within nations what are today known as Iraq, Egypt, and Pakistan among others. The city-state and empire of Babylon/Mesopotamia between on the banks of the Tigris and the Euphrates rivers is considered today by many scientists to be the cradle of civilisation.
The Golden Age is also known as Islamic era saw advances in medicine. Breakthroughs in many scientific fields. The growing Islamic empire brought structure, urbanisation, commerce, and wealth to the population within it and that helped spur intellectual collaboration. Large cities Baghdad, Basra, Wasit, and Kufa became unified, a single spoken language was spoken and brisk trade developed. Opposed to this intellectual awakening arose a clergy who felt their power was being lost and they began opposing science, mathematics and the printing press which they claimed eroded the Islamic belief system.
As The Islamic era started coming to an end it spawned The European Era known as the Renaissance era also had many polymaths who excelled in and advanced numerous fields. On January 7th, 1610 CE, the astronomer Galileo observed the moons Io, Europa, Ganymede and Callisto in orbit around Jupiter.
The Renaissance, in turn, spawned the Modern era which today means technology, forms of government and social structures. Within this Modern era there is a wide standing belief that knowledge did not come from holy men but from human endeavour. It is this attitude that pervades modernity and everything modern.
Civilisations on Earth usually last around 300 to 400 years. The Modern civlisation will become the first Global Civilisation and is unstoppable. It started with the rise of the Internet and now has a language – English.
Civilisations rise and fall for various reasons. Technological threats like nuclear weapons, climate change, and genetically-engineered viruses may point to downfall. Human life has so greatly impacted this planet. Over 7 billion and growing are a strain on Earth’s natural resources and add to the increasing pollution of the ecosystem. The growth of technology has fundamentally altered the natural functioning of the planet.
Humans will survive but need to look out for each other more, relax and study widely if they are to move and become a multi-planetary civilisation and more 🙂
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