“What if the moon didn’t exist?” - The close relation between the history of the earth and the moon, and the important role of the sea Department of Naval Architecture and Ocean Engineering Division of Global Architecture Graduate School of Engineering Osaka University Kazuhiko Hasegawa The earth emergence • The earth was born 46 billion years ago. • At that time there was no moon. The moon’s emergence • The giant planetestimal would have first appeared as a dim light in the night sky. Seeming to swell in size as it approached, the planetestimal would have filled the entire sky just before it smashed into the earth at 40,000 km/h. • Although the crash was over in ten minutes, the impact generated the explosive power of a billion, trillion tons of TNT. (Hiroshima and Nagasaki each contained the equivalent 20,000 tons of TNT) • In a matter of minutes more than 5 billion cubic miles of the earth's crust and mantle were sprayed into orbit. • Fragments of the ring around the earth created by the impact collided with one another. The moon began to assemble from the ring shards, just as the earth had formed from grains of dust ages before. The moon’s effects • The moon altered both the earth's spin and its path around the sun. • The moon affect the earth through its gravitational attraction and through the sunlight it reflects here. In turn ocean tides pull on the moon , causing it to speed up and spiral away from the earth. • The moonlight has brightened our nights and affected the evolution on of some animals. It has also served as an invaluable timekeeper that helped early humans survive the changing seasons. • The earth's slower rotation rate has been essential in shaping the life cycles of all plants and animals. Moonless earth: Solon • Different tides: – The oceans on Solon would still have tides despite the absence of the moon. driven by the gravitational pull of the sun, those tides would be one-third as high as tides on Earth today. – The range between high and low tide would remain constant throughout Solon's year. – Over the 4.5 billion years Solon would spin more and more slowly until the day become 8 hours long. The moon has lengthened the earth's day from 6 hours to 24 hours. – Today a year on Solon would have 1095 eight-hour days. The sun would be up for between three and five hours each day in the mid-latitudes, depending on the season. Moonless earth: Solon • Different winds: – Winds on Solon would be very different from those on Earth because the faster a planet rotates, the more its winds move east or west and the less they wander north or south. We can see this today on Jupiter and Saturn. – Hurricanes on Solon would be both more powerful and more frequent than those on earth, with winds regularly topping 200 miles per hour. Moonless earth: Solon • Different magnetized fields: – Magnetic fields are created whenever charged particles change speed or direction. Solon's magnetic field would be almost three times stronger than the earth's. – Solon's stronger magnetic field would present an even tougher screen around that planet than do the Van Allen belts around the earth. Solon would experience fewer auroras than does the earth. Moonless earth: Solon • Different early atmospheres: – On solon, as on Earth, hydrogen and helium would first dominate the atmosphere. These gases were part of the disk from which Solon would form. – Solon's second atmosphere would come from its interior: carbon dioxide, nitrogen, and water vapor, which were originally attached to the surfaces of rocks inside Solon. – The original outgassing of carbon dioxide from Venus gave it an atmosphere 115 times denser than earth. Venus was never struck by an atmosphere-removing, Mars-sized planetesimal. – Animas on Earth need the energy stored in oxygen to order to live; we could not function in a carbon dioxide-dominated atmosphere. Moonless earth: Solon • The final atmospheric conversion: – Solon's atmosphere would have been thicker when its oceans became saturated with the carbon dioxide. The remaining carbon dioxide must be converted into oxygen. – Extra energy is needed to combine atoms and inorganic molecules into organic molecules and life. That energy would have two sources on solon; the sun's ultraviolet radiation and the lightning. – A key to successful formation, replication, and evolution of life is the presence of large supplies of carbon. The carbon would come from the atmospheric carbon dioxide that had been dissolved in the water. Moonless earth: Solon • Spread of life: – Once formed, simple aquatic bacteria and algae would spread through the oceans. But this initial propagation of life would be much slower on Solon than on Earth. – Solon's lower tides would wash much less sand and soil into the oceans. – Solon's lower tides would produce less global ocean movement than on Earth. On Solon, perhaps a 100 times less shoreline would be uncovered by tidal water, offering far fewer surfaces on which life could reproduce. Moonless earth: Solon • The first free oxygen: – Oxygen released into the atmosphere from the oceans would remain and the conversion to a breathable oxygennitrogen atmosphere would begin. Earth reached this stage about 250 million years after it was formed. The process on Solon would take longer, perhaps as much as an extra 250 million years. Moonless earth: Solon • Lethal levels of oxygen: – Once plant life begins to flourish in Solon's oceans, the amount of oxygen sent into the air would rapidly increase. The oxygen level could be as much as 100 times higher than it is on Earth. Life can deal with only about twice as much oxygen. Moonless earth: Solon • Early plant life: – Persistent winds would inhibit leafy plant growth because wind-whipped leaves would be easily damaged or torn off. – Early plant growth on Solon would grow low to the ground to protect itself against the strong winds. – Phototropism: the sun moving three times faster. For example, cylindrical leaves that always have part of their surface facing the sun might prove a successful adaptation. Moonless earth: Solon • Effect of lower tides: – Intertidal zone is a specialized niche, occupied by life forms that can take advantage of both the water and the dry land. – Solon's lower tides would narrow the intertidal beach area, thereby making it harder for many species to maintain safe populations. Moonless earth: Solon • Effect of high winds: – Birds are lightweight, hollow-boned fliers. They fly well either with a good tail wind or in calm air, but they are handicapped by strong head winds and rough air. – Hard-shelled creatures such as tortoises and armadillos would be particularly suitable for this environment. – Ponderous creatures such as dinosaurs would probably also thrive in Solon's more windy environs, while the smaller, lighter mammals that coexisted with them on Earth would have more difficulty there. Moonless earth: Solon • Biological clock: – Many animals have clocks with 23 hours cycles, while humans have 25 hour cycles. – Biological clocks can be entrained only by external cycles that differ from their natural rates by less than 3 hours. The plants or animal lives its life based on its circadian rhythm, usually with disastrous results. Could animals do all that they need to in such short days? – The more concentrated oxygen in Solon might enable all life to do things more rapidly than on Earth. Animals could travel, hunt, eat, fight, mate, and even think faster. Life on Solon might run like a videotape on fast forward. Moonless earth: Solon • Development of the senses: – Besides the traditional five senses, at least one more passive sense began to evolve on Earth. This is the ability to detect the presence of heat or infrared radiation. Heat sensing became specialized to keep animals from burning themselves. – Visual 'speech' on Solon would be an effective alternative to oral communication. Biologically generated light that could change intensity or color would be an effective means of communication on Solon. – Nature could evolve radio communications over several hundred million years. We could consider them to be telepathic. Moonless earth: Solon • A new sense - telepathy: – Telepathy remains underdeveloped in the vast majority of people on Earth. Our brains give off weak but measurable radio waves. These signals are generated as a by-product of the brain's normal functioning. To be useful for interpersonal communication on Solon, radio brain waves would need to be more powerful and to be modulated by the equivalent of a voice box. Moonless earth: Solon • A new sense - telepathy: – Telepathy remains underdeveloped in the vast majority of people on Earth. Our brains give off weak but measurable radio waves. These signals are generated as a by-product of the brain's normal functioning. To be useful for interpersonal communication on Solon, radio brain waves would need to be more powerful and to be modulated by the equivalent of a voice box.
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