Exploring the Big History
By Denise Scammon
Regarding the book “Einstein’s Dreams” by Alan Lightman, some people are interested in topics of physics such as theories of time and space, but lack the scientific background to understand scholarly articles. This novel is about theories of physics, namely time and space, but written as a novel, thus making it easy to read and follow. I came away from reading this book with a better understanding of the possible theories of time and space and a reminder of the importance of critical thinking skills.
In “Maps of Time” by David Christian, religion is brought into discussions about the origin of the universe. I wonder if the translation of the Bible contains errors and that is why the Biblical account of the universe’s creation doesn’t match scientific accounts. The Bible states that God created the universe and that everything is 6,000 years old. However, (author) Christian uses scientific evidence to support the statement that the sun and planets of our solar system were created 4.56 billion years ago (p. 57). The planets’ orbits occur in the space of a flattened disk where they are held by gravity. The inner planets are smaller, rocky and dense, while the outer planets are huge, but less dense (Christian p. 59). In the early days of the universe, soft collisions formed blobs that grew into planetesimals. A scary thought: “If Jupiter had been slightly larger, then the solar system may have had two suns” and with two suns “life may never have existed as we know it today” (Christian p. 61).
In May 1998, the Hubble Space Telescope took the “first photo of a planet … three times the size of Jupiter” (Christian p. 61) which means there may be other solar systems in our Milky Way, with a central sun and planets that orbit it … and perhaps living organisms. The collisions with space matter, such as meteorites and comets, have created the Earth’s tilted rotation on its axis. The moon’s surface offers evidence of such collisions because the moon does not experience erosion.
The earth was once a blob of molten lava in which heavier metals such as iron and nickel sunk to its core, creating a magnetic field. This field is an important factor in protecting earth because it deflects “high-energy particles … and shields the chemical processes that generate life” (Christian p. 62). Lighter elements floated on the earth’s surface. As the earth cooled, steam formed in its atmosphere which condensed and fell to earth as water.
Interestingly, Christian stated “material on or in the earth has been recycled” so often and for so long that it “gives little information on the earliest stages of Earth’s formation” (p. 67). To determine the age of the universe, scientists study layers of rock and fossils. This reveals the order in which events occurred. With radiometric dating techniques, scientists can determine absolute and relative dates (Christian p. 66).
The theory of plate tectonics gave a boost to the modern creation story. While people cling to their religious belief that God created the universe 6,000 years ago, science provides evidence that it took eons for some geological formations to occur on Earth. For example, “imagining that the Alps were once undersea meant believing in a longer time period than 6,000 years” (p. 68). Volcanic activity created lava floors in the ocean that formed ridges that acted as wedges which sucked part of the ocean floor into the earth’s interior and which also pushed against the continental crust. “The Atlantic is getting three centimeters wider every year” can be better understood with Christian’s comparison “that is the same rate as our fingernails” grow (p. 70). I thought that was an unusual comparison. I didn’t know that GPS was used to measure the movement of tectonic plates. Pangaea was a supercontinent 250 million years ago, while Panthalassa was one big sea. They fragmented and now may be reconverging. Africa and India are moving north to join Eurasia (p. 73). The reason it is important to know the configurations of the early continents and seas is to learn where life forms evolved and what role the atmospheres and climates played in evolution.
Appendix 2, Chaos and order, stresses the importance of patterns. Religious beliefs are discussed, but this time the question is asked that if a God created earth, who created the God? I wonder if God = energy. The first law of thermodynamics is the law of the conservation of energy. The second law of thermodynamics states that in a closed system the amount of free energy or energy capable of doing work tends to dissipate over time (p. 507). Unusable energy = entropy.
A good summary of the early universe is that it was extremely hot and dense. As it expanded and cooled, its symmetry was broken which created differences in temperature and pressure. This allowed the electromagnetic force to become strong enough to bind electrons and protons into atoms (p. 507). Gravity gathered hydrogen and helium into clouds, which were squeezed, densified, and got hotter. Nuclear fusion reactions lit up the stars which then gave off free energy to surrounding space. “We do not know what laws are involved in creating life” (p. 511).
I like the method used to explain how Earth was born in the NOVA film “Origins: Earth is born.” The 4.5 billion year history of Earth is described as if it occurred over 24 hours, so Earth was born at midnight. Collisions of particles in space formed planets. Gravity held clumps together, and clumps grew. Scientists look for clues to the origin of Earth in the Asteroid Belt, a region of space 100+ million miles from Earth. A study was done on meteorites that fell in British Columbia near Alaska and 90+ elements were identified. Radiometric dating figured that all meteorites have the same age: 4.5-5 billion years. The film repeats a lot of what I learned from “Maps of Time.” From the film I learned that Earth’s molten core is twice the size of the Moon. The core is always spinning which creates an electric current which causes our planet to rotate and gives it north and south poles. The magnetic field fluctuates so geologists routinely search for the precise magnetic north pole to keep track of it. Today, the pole is 125 miles off the Canadian coast.
One piece of information from the film with which I was impressed is the fact that the Moon is 240,000 miles from Earth and is moving away at a rate of 1-1/2 inches every year. I can just imagine in the early days of the universe that the Earth spun around on its axis in six hours and the Moon was closer and looked incredibly huge. I love nights when the Moon is bright orange and huge. I just searched the Internet for the explanation of this phenomenon which I studied in Psychology. However, it seems the illusion is being investigated yet again. Sigh.
Sid Perkins wrote in “The Iron Record of Earth’s Oxygen” that iron can be found throughout our galaxy due to nuclear reactions which caused iron-containing stars to explode. While iron is the most abundant element in our earth, it is found mostly in Earth’s core. “Less than 6 percent of Earth’s crust is iron” (Perkins p. 24). The theme of Perkins’ essay are BIFs: banded iron formations. The source is mysterious, the large size of some bands, puzzling. I was interested enough in Lake Matano in Indonesia to Google it. I looked at pictures and diagrams of it to get a better idea of Perkins’ discussion. Basically, it’s a lake with conditions that could be very similar to the early oceans. It has microbes known as photoferrotrophs that prefer the depths that are rich in dissolved iron and phosphorous, as opposed to the photosynthetic organisms that live closer to the surface.
The Hubble Space Telescope Web site states that the telescope is 19 years old and was refurbished in May 2009. Plans are in the works to create a “census of the population of Kuiper Belt objects at the fringe of our solar system, hopefully witness the birth of planets around other stars and investigate the composition and atmospheres of other worlds.” Further away from Earth, the Hubble will take a “portrait of the universe in near-infrared light and probe the behavior of dark energy.” That sounds fascinating. Dark energy is the force that is causing the universe to expand. It is like anti-gravity.
The Paleomap Project is about plate tectonics and there are interactives and animations to illustrate the concept. Maps show ancient mountain ranges and shorelines, Earth’s climate history and future maps. The map of Earth 50 million years in the future shows a trench around North and South Americas and a ridge in the middle of the Atlantic. Then, 150 million years in the future, the ridge has moved to where the trench was around the Americas. Next, a map shows that 250 million years in the future the continents will have shifted together into what is labeled Pangaea Ultima. The Paleographic Atlas has taken over 30 years to get to this point and is still being updated.
The Web site of The Periodic Table of Videos was okay. I think I will use it as a reference source. I checked out the Hydrogen element video. Basically, a balloon is filled with hydrogen gas which is ignited with a flame which causes an explosion. The interesting tidbit of information from this video is that the explosions at Chernobyl and the space shuttle were explosions caused by the reaction of Hydrogen and Oxygen. I also looked at the Fe, or Iron, video. The speakers in the video pronounced aluminum like ah-loo-min-yum with the accent on the min syllable rather than the loo syllable. That was quite funny.
John Bullitt’s “Hearing Earth: Rumblings of a Complex Planet” on NPR’s site was very cool. The sounds of Earth recorded simultaneously all over the world with seismographs. Since the sounds are too low for us to hear, Bullitt speeded up the recordings. Each second of the condensed recording equals four minutes of real time. I liked the whoosh noise which Bullitt says is the natural background noise of Earth, made up of the sound of waves and swells crashing on the Earth’s crust.
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