“The best books…are those that tell you what you know already.”
1 In the beginning there was The Big Bang.
2 Earth was one of the planets formed from the collapse of the first star, according to general cosmogonical consensus. Approximately 70.8% of its surface is covered by water.
3 We get our sunlight from the Sun, a G-type main-sequence star (G2V) at the centre of our solar system.
4 Sunlight is good for humans: it is an important source of vitamin D, and may help prevent a wide range of maladies such as psoriasis, multiple sclerosis (MS), and seasonal affective disorder (SAD).
5 Daytime occurs when a given point on Earth experiences illumination from the Sun, meaning the Sun is observable above the horizon; if this condition is not met it is considered to be nighttime. The transitionary phase from daytime to nighttime is called evening, and the transitionary phase from nighttime to daytime is called morning.
6 The theatre in which we observe the Sun, moon, and stars is called the sky; during daytime it manifests itself as blue because air scatters blue sunlight more effectively than red.
7 Ancient people believed the sky (called “firmament”) was comprised of solid materials; this cosmology has been inarguably disproven by modern science.
8 The sky above the clouds is sometimes referred to as the heavens. The first person to leave Earth completely was Yuri Gagarin, whose Vostok 1 spacecraft completed an orbit of the planet on April 12, 1961.
9 Dry land originally formed when cratons (basement and sedimentary rock from the lithosphere) amalgamated and rose to the surface of the planet.
10 The etymology of the word earth comes from the word erthe (Middle English, 1137 AD), a derivative of eorth (Old English/Anglo-Saxon, <725 AD), itself a derivative of ertho (Proto-Germanic, <500 AD); the etymology of the word sea is thought to come from the Old English word sae (sheet of water) and/or the Proto-Germanic word saiwaz.
11 The Earth naturally produces a great deal of food for humans and other animals, including grass, herbs, and fruit; many of these contain seeds, which act as the catalyst for reproduction in their species.
12 Over 80% of the 300,000+ plants on Earth are seed plants; fruits, vegetables, and grains are plants which, along with animals, constitute the vast majority of food for humans.
13 The Earth is approximately 4.54 billion years old.
14 Sol (the Sun) and/or Luna (our moon) serve many purposes, such as acting as navigation reference points, affecting seasonal change (from the tilt of Earth’s axis in tandem with revolutionary progress), creating the day-night cycle (based on rotational progress), and marking a year (one revolution around the Sun).
15 They also, obviously, are our primary sources of natural illumination, through sunlight and moonlight.
16 In addition to Sol, there are between 1 sextillion and 1 septillion stars (est.) in the universe, the closest of which (not including Sol) is Alpha Centauri, also known as Rigel Kent (4.37 light years from Sol).
17 Sunlight is comprised of roughly 50% infrared, 40% visible, and 10% ultraviolet (UV) light; moonlight is light from the Sun, stars, and Earth reflected back to our planet; it may appear to have a bluish tint when viewed with the human eye, due to the Purkinje effect.
18 The Earth’s rotation has been gradually slowing; when it was first formed, a day was only 6 hours long, and now a day is 24 hours long.
19 Earth is known as Terra in Latin.
20 It is very difficult to theorize about the first life forms on Earth, but a leading contender would be piezophiles/barophiles, which are deep sea-dwelling organisms that thrive under high pressure conditions; also of note, birds are thought to be theropod dinosaurs from the Mesozoic Era.
21 We have only discovered 2 million of the estimated 9 million species currently on Earth, the largest of which is the blue whale; 99.9% of species that have ever existed are now extinct.
22 Virtually all plants and animals reproduce through sexual reproduction.
23 The Earth is made up of 5 geologic layers: the inner core, the outer core, the mantle, the upper mantle, and the crust.
24 The genesis and subsequent major diversification of most known animal phyla occurred 542 million years ago during the Cambrian explosion.
25 Aristotle is the first known person to divide the living world between plants and animals, doing so in the 4th century BC.
26 Humans are the smartest animal on Earth, but there are many others that deserve recognition: chimpanzees, pigs, bottlenose dolphins, rhesus monkeys, parrots, elephants, rats, cats, dogs, whales, and octopi are just a few examples of highly intelligent creatures.
27 Humans are an anisogamous species, meaning we require a member of the male gender and a member of the female gender to have sexual intercourse in order to create descendants.
28 Over 100 billion human beings have ever lived.
29 Every plant species can reproduce sexually or asexually, or in many cases both; asexual methods include fragmentation, gemmae, or stolons; sexual methods include using seeds or spores.
30 Animals which eat primarily the meat of other animals are called carnivores; animals which eat primarily plants are called herbivores; animals which eat both and specialize in neither are called omnivores.
31 Humans created some amazing structures even as far back as centuries BC, summarized by the Greeks as the Seven Wonders of the Ancient World. They are, in chronological order from oldest to newest: The Great Pyramid of Giza, the Hanging Gardens of Babylon, the Temple of Artemis at Ephesus, the Statue of Zeus at Olympia, the Mausoleum at Halicarnassus, the Colossus of Rhodes, and the Lighthouse of Alexandria; of these, only the Great Pyramid of Giza remains relatively preserved.