12 October 2019

My Geographic Identity

Even a predominantly geographic personal identification is not a singular thing. It has many levels of resolution. And, this list does not even consider that people have associations with places that they work, places where they work out, places that they used to live, and places that they feel connected to because they have family and friends there.

* My side of the bed (perhaps sixteen square feet).

* My room in my house (a couple hundred square feet or so). Some art in my room (my photographs):

* My home (about 1/15th of an acre a.k.a. 2,887 square feet), also my subdivision lots.

* The area where my "immediate neighbors" live (about 5 acres), also my subdivision shown below via the City and County of Denver.

* My neighborhood (about 2000 acres a.k.a. about a one mile radius from my home a.k.a. about 3 square miles) defined as the area within easy walking distance of my home. Also overlapping areas from smaller to larger in area including my precinct, my census tract, the officially defined West Washington Park neighborhood (further divided into Byers and West Washington Park proper), the greater combined Washington Park and West Washington Park neighborhood, my zip code (3.5 square miles), my "home school attendance zones" within the school district for elementary school, middle school and high school respectively, my state house district, and my city council district.

A church in my neighborhood (my photo):

A bar near my neighborhood (my photo):

* My larger region within or near the city that I live in (about 30-50 square miles), either central Denver or Southeast Denver depending upon how you divide up the city, also my recycling pickup zone, my Denver School Board district, my state senate district, my RTD i.e. regional transportation district director district, the portion of the city that was formerly the city of South Denver, the portion of the city that was formerly in Arapahoe County, and the survey Township and Range in which I live (about 36 square miles).

* The City and County proper of Denver where I live (155 square miles), which is contiguous with the school district and state judicial district in which I live. Also, my Congressional District which is almost, but not perfectly contiguous with the City and County of Denver, which is also a district for the election of state school board and CU Regent candidates (189.62 square miles).

* The Denver metropolitan area where I live, i.e. Denver, Adams, Arapahoe, Broomfield, Jefferson, Boulder and Douglas counties (4,482 square miles). Also regional governmental areas (DRCOG i.e. the Denver regional council of governments, RTD i.e. the Regional Transportation District (2,342 square miles), SCFD i.e. the Scientific and Cultural Facilities District, and the Mile High stadium district), my allegiances to various professional sports franchises that represent the Denver area, such as the Broncos, Avalanche, Nuggets, Rockies, Rapids and Outlaws, and the telephone area codes associated with my metropolitan area (303) and (720).

The larger regions of the state where I live (perhaps 18,000-45,000 square miles), i.e. the Front Range and the I-25 corridor. Also, the South Platte River basin (24,300 square miles which is located in parts of three States: Colorado (79 percent of the basin), Nebraska (15 percent of the basin), and Wyoming (6 percent of the basin)). The South Platte River basin is shown below via the U.S. Geological Survey:

* The State of Colorado where I live (104,185 square miles).

The Mountain West states consisting of eight states (855,767 square miles). Also, the Mountain Time Zone.

* The Western United States (1,751,206 square miles).

* The United States of America (3.797 million square miles).

* North America  (9.54 million square miles).

* The Americas (16.43 million square miles).

* The Earth (196.9 million square miles of surface area). Photo taken by Apollo 17:

* The Solar System (roughly a 175 billion mile diameter disk a.k.a. about 11 light hours, with about 600-800 million square miles of solid surface area). The solar system, as far out as Neptune, to scale:

The surface area map below is from xkcd via a Creative Commons license.

Fun facts: Former planet Pluto has a similar amount of surface area to the continent of Australia. Africa has a similar amount of land area to the Moon. The surface of Venus bears the closest resemblance to Christian descriptions of hell.

* The Local Interstellar Cloud, a.k.a. Local Fluff, is the interstellar cloud roughly 30 light-years across through which the Solar System is moving (image below via Wikipedia).

* The Local Bubble (a.k.a. Local Cavity), which is a relative cavity in the interstellar medium of the Orion Arm in the Milky Way galaxy. It contains the Local Interstellar Cloud, which contains the Solar System. It is at least 300 light years across (shown below via Wikipedia, the dot in the middle with text attached to it is our sun).

* The Orion Arm (a.k.a. the Orion-Cygnus Arm) of the galaxy where the solar system is located, about half-way between the center of the Milky Way galaxy and the furtherest extent of this arm within it. It is about 3,500 light years wide and about 10,000 light years long.

* The Milky Way galaxy (roughly a 105,700 light years in diameter disk with about 100 billion stars and a supermassive black hole at the center) (an edge on view of the Milky Way from Earth and Earth orbit compiled from multiple images via Wikipedia is below).

* Our "local group" of galaxies (roughly 10 million light years in diameter including about 30-50 galaxies) (via Wikipedia with the Milky Way depicted as the center):

* The Universe (roughly a 28 billion light years in diameter sphere at the moment). The image below is approximately linear in years (except for the first few moments which are smaller than they appear) and has roughly logarithmic dimensions in two dimensional diameter representing the three dimensions of space which are roughly symmetric. The scientific consensus regarding this image starts to break down in the area all of the way at the beginning labeled "inflation" (which cosmologists who support some version of the inflation hypothesis say lasted for less than a second), but everything beyond the first hour or so after the Big Bang (depicted as a flash of light) does have solid, consensus support except that there is some dispute regarding the true exact cause of what is labeled as "dark energy accelerated expansion."

N.B. We have no real idea "where" within the universe we are located spatially relative to any helpful big picture landmarks. The observable universe is basically homogeneous subject to a very, very subtle large scale cellular filamentary structure that extends as far as we can see in distance which is also back in time, in every direction. 

It doesn't even really make sense to talk about a "center" of the universe because observable space itself has expanded from a space definitely smaller than the solar system and quite plausibly smaller than a basketball at the beginning of the Big Bang to what exists today. All space in existence today maps back in time to this tiny immediate Big Bang vicinity area that set the initial conditions for everything. Thus, not only has the stardust that makes up our planet moved around within space; the space itself within which that movement took place has been massively stretched out.

Space-time itself is also bent by gravity. Topologically, at the largest observable scale space-time in the present day is almost, but not quite perfectly, topologically flat. It has an overall slight curvature in four dimensions that is analogous to the curvature of the surface of a three dimensional sphere that is called de Sitter space. This is unfortunate, because we have all sorts of wonderful mathematics to describe anti-de Sitter space which is analogous to the curvature of a hyperbolic plane in three dimensions, but the math needed to describe a universe like our own is much harder than less beautiful. 

Truly topologically flat space-time that observes special relativity (i.e. with no bending of space-time caused by gravity) is called Minkowski space. It turns out that the large scale curvature of the Universe is so slight, and the curvature induced by the gravity of large objects is also modest away from black holes, neutron stars and other very massive and very dense objects (i.e. away from strong gravitational fields), that the far more mathematically easy to deal with Minkowski space is used as a working approximation of the topology of space-time for even extremely high precision physics applications at short distance scales like quantum physics, and for the estimating for practical purposes effects of gravity at the fringes of galaxies, galactic clusters, or small systems of nearby galaxies, which in general relativity is only slightly different from Newtonian gravity (except that gravity bends light as well as influencing the trajectories of matter in space).

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