May 19, 2012

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Space Books: A Source of Knowledge and Imagination

Books on space cover a broad spectrum. There are many interesting publications that are targeted towards kids. Many of these informative books can include colorful illustrations that young children will enjoy, but the level of understanding can go up to college-level and beyond astronomy, covering anything from the observed universe to complex theories and speculative science.

We learn early on that the universe goes on forever, but scientists seem to focus on that, at 10 or 13 billion light years away from Earth, there is some kind of boundary that is the edge of the original energy from the Big Bang. The complex equations that astrophysicists have devised to explain things never seen such as black holes and wormholes are too much for the average person to comprehend.

Assuming we don’t need to know how to solve a differential equation or even algebra, it’s possible to find a book about space that is intriguing nonetheless. Books on skywatching can show the stars, constellations, and galaxies as well as comets and planets in a comical if not at least artistic fashion. With the assumption that the reader is stuck on Earth to do schoolwork or work a nine-to-five job, reading about the mysterious universe around us can at least serve as entertainment.

You can easily find something to read on the planet Earth, the solar system, and the satellites that orbit constantly. Pocket atlases are popular items as well, but the range of reading goes on until you get to authors like Carl Sagan who try to explain everything in one book. You can also read about time and the universe’s ability to make it not seem what we think from Steven Hawking.

Reading about space can also cover theories of hyperspace and travel at light speed. It can blend with science fiction, but space is so vast and unexplored that it is hard not to engage the imagination when you read about possible distant worlds, or even look up at the many stars in the sky.

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Astronomical Phenomena: Occultations – Almanacs, Books and Guides

With so many objects in space, one can move in front of the other from time to time, as seen from Earth. Eclipses have fascinated people throughout history, and folklore and religions have been influenced by them. A solar eclipse is amazing, and a lunar eclipse can spark hours of observing, but most people don’t think too much about occultations.

An occulation is very much like an eclipse, but an event is usually considered to be an eclipse when two objects similar in apparent size to one another are involved. The objects can be stars, planets, moons or any other entity, but it is the size as viewed from Earth that determines what we see. This eclipse-like event occurs when something large, like the Moon, obscures a star or other planet from view. The obscured objects have to be blocked by something that appears much larger than them.

Astronomical discoveries have been made just by observing occultations. The ring system of Uranus was discovered this way in the 1970’s. Stars that the planet passed over would dim and brighten several times before the planet moved over them. This led to speculation that there were rings, but this was confirmed when Voyager 2 passed by the planet. The space probe also found this to be the case with Neptune.

The Moon’s occultation of stars has led to discoveries such as binary stars, as one fades before the other. It sometimes passes stars right at its edge, which is a grazing occultation. When this happens, the star can actually disappear behind mountains and appear again through lunar valleys. Multiple observers who space themselves along a path have taken advantage of these events to profile the moons edge, which helps to detail the moons position, and also helped to map lunar topography before man ever went to the Moon.

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How Astronomical Calculations Were Made before the Computer Age – Almanacs, Books and Guides

With so many stars, planets, moons and other objects in space moving at different speeds, angles and distances, you would think it would take nothing less than a supercomputer to track everything. Recent discoveries show that this may not be the case, as ancient civilizations were able to track stars with relatively precise accuracy. The Egyptians built openings into structures where light from the Sun or other stars would shine in at certain times of the day or year.

Even more fascinating is the discovery made in a shipwreck near Greece, not far from the island of Crete. A device determined to be a mechanical analog computer is one of the oldest geared devices ever found. Called the Antikythera mechanism, it features different gears that were actually used before 100 BC. It has over 30 differential gears and someone could use a crank to calculate the position of the sun or Moon. The machine could also track other planets as well.

All of the gears operating together work similar to old clocks. The whole system could add or subtract angular velocities as well as compute lunar cycles by subtracting the movement of the Sun from that observed of the Moon. The structure of the device included an outer ring marked with the days of a 365-day calendar years, while an inner dial had zodiac symbols with delineations for degrees. The outer ring could also be moved to account for leap years.

The Antikythera mechanism also had components that indicated the rising and setting of specific stars and could track the positions of Venus and Mars. It was capable of even more and is an example of the things that complex mechanical systems are capable of. Even without miniaturized circuits and powerful computers, driving huge telescopes and observatories, astronomical observations could still be made thousands of years ago.

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The Tides: Surface Water Levels and the Influence of the Moon – Almanacs, Books and Guides

Like all objects in space, the Moon has gravity. Many people wonder at the fact that a distant sphere in the sky can affect things on the land they live on. It does, especially if you live near the ocean. Twice a day, the water reaches high levels and drops to minimum ones, mostly leaving people to watch and see where the water is, where it is going, and where it has been based on the texture of the sand.

The pull of the Moon’s gravity affects the oceans on a regular and predicable basis. The tides change times regularly each day as well, as they occur about 50 minutes later from one day to the next for the most part. Twice a month, when the Moon is full, and when it is dark during a New Moon, the tide is exceptionally high and lower than usual. Sometimes this exposes different parts of the sea floor and beach goers can find interesting shells and sea life that they don’t ordinarily see.

Aside from being the subject of interest from travelers and people relaxing on the beach, the tide can affect thing such as shipping, as shallower water in shipping lanes can be a hazard to large cargo ships, freighters, and tankers. In some places, boat captains must be aware of the tide schedule so they can safely time their entry and exit into harbors.

The tide can also affect fishing. The water depth can be a factor for some fish, but when the tide creates currents, the flow of the water can determine where the best places to fish are, and what kinds of fish are easier to catch.

Tidal flow can even affect how pollution moves through the water. When input into computer models, tide data can help predict how pollutants might advance and what areas they might or might not affect.

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