THE ASTRONOMY OF GRAND CENTRAL TERMINAL ------------------------------------- John Pazmino NYSkies Astronomy Inc email@example.com www.nyskies.org 2013 August 1 initial 2017 September 23 current Introduction ---------- In July 2013 American Museum of Natural history hosted a week-long astrocultural conference, Inspiration by Astronomical Phenomena, or INSAP. INSAP circulates around the world, meeting every three or so years to showcase art, song & dance, structures, civic activity inspired thru astronomy. It convenes at or near a notable astronomy place of interest, this time at the Museum and adjacent Hayden Planetarium. One major item in the INSAP program was a tour of Grand Central Terminal to inspect its many astronomy points of interest. This tour was handled by NYSkies Astronomy Inc, one of the cosponsors of the INSAP conference. Grand Central Terminal -------------------- I pass over the incredible history of this building and railworks and describe the present facility. The Terminal, abbreved 'GCT' occasionally here, is one of new York City's two great rail stations. The other is Pennsylvania Station. While that rail facility was completely rebuilt in the 1960s, partly to accommodate a relocated Madison Square Garden arena on top if it, GCT is almost entirely preserved or restored in its original aspect. New sections were added in sensitive harmony with the old structure. It is 'Grand Central Terminal', not '... Station'. The tracks end here at bumpers or blocks. Penn Station's track pass thru the depot, allowing trains to enter and leave thru either end. At GCT trains enter and leave only at one, the north, end of the depot. There are '... Station' places nearby, such as the three subway stations that work the Terminal and the US Postal Service post Office branch. The Terminal is the newest in a series of railroad depots on its site, 42nd Street at Park Avenue on Manhattan. It opened in February 1913 as the headquarters and main depot of the new York Central Railroad. Today Grand Central Terminal is owned and operated by Metro North Railroad, a New York State agency providing rail service to the northern sectors of the New York City region. In the 1990s Metro North began an all-points rebuild of the Terminal. Besides repairing and replacing facilities, it sensitively preserved historicly significant features. The building was previously enrolled in the City's landmark preservation program, requiring review and approval of substantial alterations to the public areas of the depot. Metro North not only restored some astronomy items, such as the iconic Sky Ceiling, but added all-new ones. These include the Chinese starmap and cosmograms in a newly built section of the Terminal. The tour ------ On one afternoon of the conference the INSAP delegates divided into two groups, there being about 60 who opted for the walk. The Museum carried the groups to GCT by hired bus. Because delegates came from all oeer the world, for most this was their first visit to Grand Central Terminal. Some were puzzled why a train station was so important an item of INSAP. The groups took turns, with one doing the tour while the other sightseed in Midtown. After about two hours the groups swopped places. Both groups assembled again at GCT after the second walk for the bus back back to the Museum for evening events and viewing Manhattanhenge. Each walk stayed entirely within the public areas of the Terminal with no attempt to enter restricted zones. Photography was allowed every where on the walk. Delegates were asked to make sure that camera flash was shut off. Camera flash could be mistaken for gunfire, a plausible incident in today's high alert period. Along the walk NYSkies elaborated on the astronomy features with show-&-tell pictures and running dialog. Many delegates were scholars and historians, who added comments for some of the items they inspected along the walk. In the sections below I describe the astronomy of Grand Central Terminal in the sequence visited by the INSAP tour. 42nd Street face -------------- In 42nd St and adjacent streets are lamp poles, specially crafted for New York City. They started replacing the old cobraheads in the mid 1990s to reduce the waste of light spilled into the sky and improve the street aesthetics. These lamps cover several districts around Grand Central Terminal. These lamps, and those in other districts of the City, are part of the ongoing conversion of urban life into one of planet-friendly sustainable culture. On top of GCT is the Met Life skyscraper, once the largest office building in the world. It was built as the PanAm building for the airline in the 1960s. Psychological it exhibited the replacement of old-fashion trains with modern airplanes. The airline went bust and the building was sold to the Met Life insurance company. East of GCT is the Chrysler tower, for a couple weeks the world's tallest building, surpassing the Eiffel Tower. It was the headquarters of the Chrysler automobile company, who decorated the building with gargoyles made from car parts! The idea ws to show how modern cars replace old-fashion trains. Both Pan m and Chrysler are gone from their former homes, but the trains still run thru GCT, more now than ever before. PanAm, no longer in the airline business eventually became a small, and thriving, railroad in New England! Clock and statues --------------- Over the main entrance on Park Av is a clock and classical statues. They represent two constellations, a planet, and an asteroid. The figure of Hercules is one constellation. Mercury is the planet. Minerva is asteroid #93. The other constellation is Aquila, the eagle under the figures. This clock and statue is the largest piece ever built bu Tiffany, who has other -- smaller -- pieces thruout GCT. There is an other Aquila over the entrance at Vanderbilt Av and 42nd St. It, with others perched around the depot, were saved from the prior railroad station on this site. Main Concourse ------------ The central hall of GCT is the Main Concourse. The floor here is one level below the street. From now on the entire INSAP tour was below street level. This space is not the largest interior room in the world, as some descriptions claim. It is ample, about 40 by 80 meters in plan and about 40 meters to the crown of the vault ceiling. It is the mixing bowl for people entering it from all four sides to distribute them to trains, office towers, shops, street, subways. The sides are commonly named for the adjacent facilities: Vanderbilt Av, Met-Life, Lexington Av, 42nd St. The Met-Life building is reached from the Concourse by a bay of escalators. Under the Met-Life tower are the blocks and platforms. They connect to the COncourse thru the gates on both sides of these escalators. The Vanderbilt and Lexington ends of the Main Concourse have stairs, and the 42nd St side has ramps to the street and ticket windows. Mind the passing trains! ---------------------- During the tour INSAP faced a peculiar daner, being driked by passing trains! Trains in GCT aten't constrained to the tracks. The depot uses small electric tractors to get from place to place. They often haul wagons of supplies and tools, forming little trains scooting around the depot. To shift between the upper and lower levels, the trains zip along the ramps connecting the two decks. They always have the right- of-way over foot traffic. When a train approaches, sometimes blowing its horn, visitors must step aside and let it pass. INDSP delegates were amused by these little trains! Ticket windows ------------ Each ticket taken here removes a ride by car, abating air pollution, luminous graffiti, degradation of lifestyle. It suppresses demand for more highways, parking fields, billboards, and other car- culture fixtures. The City region is all the more accommodating to personal endeavors, such as the astronomy profession. To promote and support travel by transit the federal government set offers TransitChek. Riders enroll thru their employer or proper accounts for self-employment. They then receive a cash reward each month for riding transit in place of driving a car. About 1-1/2 million riders in and around the City benefit from TransitChek. From the reduction of luminous graffiti by enrolling in TransitChek, the program among astronomers is often known as the 'light pollution reward' program. The displaced cost of carfare stays in the rider's pocket to carry on life. Information booth --------------- In the center of the Main Concourse is the information booth, topped by a massive four-face clock. There is no glass cover or shield because reflections off of it would hinder reading the clock. The illuminated field behind the hands is made of opal! Railroads in the 19th century demanded accurate timekeeping to operate effectively and safely. At first each railroad maintained time according to the longitude of a home point such as the main depot or head offices. They had staff astronomers or surveyors to monitor the Sun and regulate their clocks. Each railroad had its own mean solar time, differing from other railroads by their longitudes. The confusion, with loss of business, life, property from mistakes in matching times across railroads became intolerable. In the 1880s the Canadian and American railroads instituted timezones. Ideally these are 15-degrees zones. Within a timezone all clocks are set to the same time, that of the zone's central meridian. The timezone system was inaugurated by ceremonies at the previous Grand Central Terminal. The Main Concourse clock, and all timekeeping in Metro North Railroad, is governed by international atomic time and synchronized every second. Lexington stairs -------------- The Main Concourse was designed to have two grand stairs, at both the Vamderbilt and Lexinmgtpm sides. Only the Vanderbilt stair was built. The well for the Lexington stair was occupied by assorted concessions, such as the Kodak service center with its world's largest color diapositive photograph. The Lexington stair was installed in the 1990s renovation. It resembles the Vanderbilt stair but has enough differences for future historians to tell their distinct vintage. The two stairs and the information booth stand in the line of 43rd St. From the top of Lexington stair the sightline aims thru windows above Vanderbilt stair and into 43rd St. On the Manhattanhenge days the Sun sets directly over the Vanderbilt stair. The windows are usually soiled, diffusing the Sun into a soft glowball. This is not strictly a true sighting of Manhattanhenge, which requires the flanking towers along a street to frame the setting Sun. Never the less the scene is wonderful and the real Manhattanhenge is to hand right outside along 42nd St. With a bit of skipping, both views can be captured on the same day. Sun splashes ---------- The windows around the Main Concourse have borders of an acorn-*- oak-leaf design. This relates to the theme of the original New York Central Railroad as once a small acorn that over the years grew into an oak tree. On days when the Sun shines thru these windows, the border makes pinhole solar images on the floor of the Main Concourse. The round shape of the splashes is the real shape of the Sun, not of the holes in the border. They appear elliptical from the slanted incidence of the sunbeams. The windows on the 42nd St side throw their splashes on every sunny day of the year, centered on 1:30 PM EST or 2:30 PM EDST. That's when the Sun shines in the line of Manhattan's north-south avenues. The Lexington windows create the splashes in certain morning hours after the Sun climbs above the United Nations at 43rd St and 1st Av. The Vanderbilt windows can not produce splashes on the floor because the Sun shines thru them for only a brief time at sunset near the summer solstice. The splashes fall on the walls behind the Lexington stair but are obscured by texture and signs. The Met-Life windows do not get direct sunlight. Light coming thru them is reflection from the tower's facade and the splashes are distorted. To verify that direct sunlight is making the splash, block the sunbeam. From which window does it come? The image is amazingly good. Large sunspots, when present, and limb darkening are discernible. A smooth white card held at right angle to the Sun's rays yields a clean clear image. When picking a splash to examine, go for a dimmer one. It is made from a smaller hole in the window border and the image is sharper. Sky Ceiling --------- This is the signature fixture of Grand Central Terminal. It is part of just about all discussions of the depot. It is a magnificent artwork inspired by astronomical phaenomena, the zodiac from Aquarius thru Cancer. It is famous, or notorious, for being mirror-reversed relative to the sky. This placement came from the model used by the railroad, a 18th -century style of starmap, which in that era was normally plotted in reverse. The artist for the ceiling simply didn't know that. Besides the reversed aspect, there are artistic liberties here and there, which a good sky watcher will catch. For example, the Pleiades in Taurus are missed out and Orion is flipped right way round and shoved off of the celestial equator. In spite of these touch-ups, this ceiling holds the largest map of the sky in human history, about 40 by 80 meters. About 60 stars were lighted by bulb-&-wire when the depot opened. By the 1960s the wiring was so deteriorated that most of these stars were dark. Metro North fixed the lights with fiber optics in the late 1990s, then replaced that with LEDs in the 2-thous. The map also was filthy with a coat of dark scum. Metro North at first assumed it was condensed fumes from locomotives. Metro North cleaned the ceiling from an arched crawler stage that spanned the Concourse from 42nd St to Met-Life sides. This method avoided building a forest of scaffold on the floor up to the ceiling, which would have impeded traffic across the floor. In the cleaning process the dirt was found to be condensed nicotine from the millions of cigarettes and cigars people consumed under the ceiling. As a reminder of the ceiling's condition before the restoration, a rectangular parch of the ceiling was left as is in Cancer, where the Met-Life and Vanderbilt sides of the Main Concourse join. Redstone hole ----------- In the late 1950s the Space Race broke out between US and USSR, Russia already fielded orbiting satellites while the US had several failed launches.To reduce fear and panic among Americans the US Army arranged an exhibit of an American rocket in GCT. The Army's Redstone Arsenal mounted a Jupiter rocket, the same model that launched Explorer-1, America's first successful satellite. It stood at the bottom of where the Lexington stair is now. Back then there was an empty well. To prevent topplling, a cable was attached from the nose cone to structural beams above the Sky Ceiling. A hole was cut in the starmap for this cable. After the exhibit he hole was not fully sealed closed. It is a dark spot between star Hamal and the Northern Fish of Pisces, in the zenith when viewed from the foot of the Lexington stairs. It is today used for taking stunt and publicity pictures of the Main Concourse. Apple store --------- The Apple computer company just opened a major sales outlet on the balcony above the Main Concourse. It is reached by the Lexington stair. In keeping with the current concern against offending nature, the store is sensitively illuminated. The lighting is so shielded, that unless the store was known, it is all but invisible from the Concourse floor. The artificial sky on the ceiling suffers no luminous graffiti from this Apple store, making it a model for other stores, exposed to the open air, to likewise be more considerate of the real night sky. Arrival Hall ---------- The Arrival Hall is an alcove where in former decades important incoming trains discharged their riders. Visitors welcomed and greeted the riders in this room, next to the high-40s tracks.. Until a about 2012 a mock-up of the train announcer was displayed in this room, with a mannequin, desk, chalk-board, telephone, office props. Today the display is removed, leaving only the chalk-board with its hand-written train arrivals. This relic impresses the crucial need for accurate and consistent time in railroad operations. Railroads often employed astronomers to monitor and regulate their clocks. In the earlier years of railroads each company used its own base longitude for local mean solar time. The pandemic confusions among times of different railroads leaded to the creation of timezones in the 1880s. This room in a few years will be replaced by an access into the the new third and fourth decks of GCT. These are building right now about meters under the street for eight additional tracks. The removed diorama parts are in storage for possible future placement else where in the Terminal. Grand Central North ----------------- In the 1990s an all-new section, Grand Central North, was added to GCT. This is a hall perpendicular to and nestled between the two decks of platforms. It is under about 45th, away from the Main Concourse, to add access to GCT at its north flank. Grand Central North has stairs to streets in the mid 40s and to lobbies of nearby office towers. Riders can get to and from their trains without always having to walk on-street to the Main Concourse. Stairs and escalators join the hall up and down to the platforms of both levels. The hall connects to the Main Concourse by two 'spines' made from platforms on the upper deck. They are walled off from trains as long corridors. The spines are of plain decor with a few conveniences along it. Riders may walk between Grand Central North and the Main Concourse, like in inclement weather, by the spines. Chinese starmap ------------- Of the two spines, the one next to the Lexington stairs was visited by INSAP. The other, near the Vanderbilt stairs, was skipped. Near the north end of this spine, just where stairs join it to the Grand Central North hall, is a genuine Chinese starmap on the wall. It's made of glazed tile, apparently enlarged from a small original picture and shows severe aliasing. The central part, from the north celestial pole to the tropic of Cancer is filled by a mosaic of men inspecting a small celestial globe. The rest of the map is detailed with Chinese constellations and labels. Many asterisms are identifiable, even tho they are depicted in stylized form. The ecliptic and equator are plotted as well as an outline of the Milky Way. The chart is right way round like that of a modern planisphere and extends to the southern horizon limit of a mid north latitude, like that of Beijing. Cosmograms -------- Stairs near the Chinese map reach the transverse hall of Grand Central North. Its walls are filled with mosaics of cosmograms! They depict both the heliocentric and geocentric models of the cosmos. Labels, in Latin, are clearly legible for the classical planets, Moon, and outer shell of stars. The two schemes side by side help understand the concepts of each. The outer rim of the cosmograms is the sphere of the stars, the confining shell of all existence. When the Sky Ceiling was under restoration, Metro North posted signs explaining the work. It noted that the Sly Ceiling was mirrored because it showed the universe from OUTSIDE the solar system. Many astronomers ridiculed the railroad for such a silly explanation as 'bad astronomy'. A transparent viewgraph with 'NYSkies' printed on it demonstrates that the explanation isn't so silly at all. An INSAP delegate picked a cosmogram, helio or geo, and stood inside of it. The viewgraph was placed on the starry border of the cosmos. for this exercise. From within the solar system the word 'NYSkies' is frontward. The delegate moved over to outside of the cosmogram. From the other side of the viewgraph, outside the solar system, the word is mirror-reversed. Perfectly good astronomy. Reversed Moon ----------- On an other wall in the Grand Central North hall is a tiled photograph of the full Moon! Only the limb is depicted. The whole center is filled with blank tile. The visible parts are detailed enough to identify craters and maria, specially on the north limb. The whole thing is, uh, mirror-reversed! Perhaps the artist got a full Moon picture produced by a telescope that, by its optics, yielded a mirrored image. Some telescopes do produce mirrored images, causing no end of frustration to newcomer astronomers. Or perhaps the reversal is deliberate, to carry the mirrored scene of the Sky Ceiling. Lower deck -------- Grand Central Terminal is the world's only double-deck railroad terminal. The upper level has about 40 tracks; the lower, about 25. The upper level connects directly to the Main Concourse, with its tracks seen thru gates on the Met-Life side. The lower level is a dining hall with serving counters around the walls and free-range seating on the floor. Passage between the two levels is by stairs or ramps. The ramps converge on the lower level in front of the Oyster Bar restaurant and the whispering Gallery. . Trains berth at tracks reached by gates along the north side of this hall. A small information booth sits in the middle of the floor, connected to the one in the Main Concourse by in internal spiral stair. Whispering Gallery ------------- -- The forebay of the Oyster Bar has a tiled arched ceiling, the Whispering Gallery. The contour is two intersecting ellipses with paired foci in opposite corners of the hall. A voice uttered ny a delegate from one focus, against the corner pillar, is clearly and easily heard by an other delegate at the opposite corner. Two pairs of delegates can speak together with no interference between them. The trick works because the distance from one focus, to any point on the ellipse, to the other focus is the same for all points. Sound sent out from one focus, toward any point on the ellipse, arrives at the other focus in the same time and in phase. The sound is both amplified and free from echo. Sound reaching the other focus from any other place in the Whispering Gallery is weak and echoed. Ellipses are the curves followed in orbital motion. The Sun is at one focus. The other is empty. By maths on the back of an envelope it can be seen that a steady angular rotation about the empty focus produces a variable angular speed about the Sun. For ellipses of small excentricity this variable rotation is very nearly that given by Kepler's Law of Areas. The maths uses the focus-point-focus geometry. Global warming ------------ Next to the Whispering Gallery,are a couple ventilation grills, examples of the hundreds thruout the Terminal. In past years they were only for heating by steam furnaces. There was no air-condition in GCT before the Metro North renovations. Air-condition was not a standard feature when the Terminal was built and none was later installed by the New York Central Railroad. . Metro North learned that the ordinary AC system, with compressors and heat exchangers, would not work properly in the Terminal. It turned to a method common in New York but rare else where in the US. It;s chilled air made from high temperature steam. Tanks of lithium bromide and water are charged with the hot moist air from the Terminal's spaces. Steam heats this mix to trigger a chemical reaction that sucks heat and moisture out of the air. The cool dry air is circulated back to the spaces. This system is common in New York because the City enjoys a strong steam service. Steam is piped to customers as a utility like electric and gas. Other towns, even large ones, lack such steam service. To run a steam AC a separate steam boiler must be provided. Under one scenario of global warming, a time comes when the hot Earth triggers the halides of the ocean to suck heat and moisture from the atmosphere. The cooling is possibly so severe that the planet falls into a deep freeze. The inconvenient truth is that what seems like a newly worked out mechanism for the planet was already in routine use in New York for almost a century. This feature concluded the INSAP tour of astronomy items in Grand Central Terminal. The tour group was taken back to 42nd Street to meet up with the other group and continue with other activities of the day. Several delegates mentioned that they will look for Manhattanhenge, part of INSAP's program for sunset. Conclusion -------- Grand Central Terminal, altho never intended as a seat for astronomy erudition, houses a rich collection of items inspired by astronomical phenomena, They range from the signature Sky Ceiling to more subtile stairs and ticket counters. They are both part of the original construction in the early 20th century and all-new additions. With the ongoing renovations, on a given day certain astronomy fixtures may be closed off by barriers or, like in the Arrival Hall, dissembled. There are still enough on view to occupy a studied visit. NYSkies was proud and thrilled to show INSAP the astronomy of what at first looked like just a large train station. The delegates in the tour expressed amazement that new York can possess such a public facility with major features inspired by astronomical phaenomena. For the astronomy-minded visitor to New York, please let NYSkies show you Grand Central Terminal, the station at the center of the universe.