THE ASTRONOMY OF GRAND CENTRAL TERMINAL
-------------------------------------
John Pazmino
NYSkies Astronomy Inc
nyskies@nyskies.org
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.