John Pazmino
 NYSkies Astronomy Inc 
 2013 August 1 initial 
 2017 September 23 current 

    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 
    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 
    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 
    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 
    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 
    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 

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 
    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. 

    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 
    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 

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. 

    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