Munich Trip Report

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Accomplished

Problems caused me to terminate the trip at this point. I did not visit Paderborn nor Berlin.

Transportation - SFO to Munich on Lufthansa, seat companion was a German working for Bayer who had just been to drug conference in San Jose, CA - Great fun - He gave me the word that in Munich, beer is "liquid bread" ;-)) I hardly got a chance to listen to my German language training CDs.

You don't want to know about the trip back - Stay out of Paris airports during their ever present labor "work actions". And I was in the Charles de Gaulle Airport Terminal "E" two days before its roof collapsed, killing some tourists.

Housing (hotel) in Munich - I stayed 6 days in the Germania, a block from the main train&subway station. Certainly not fancy, no spas, pools, ... but clean and well run. Paid the Internet special of 50 Euros/night (regular rate is 65 Euros or $75 currently) which included a nice breakfast buffet.

Deutsches Museum Handout gives general facts and map of the facility. Also in .pdf format from the museum web site. Being a science/technology museum freak, I was in heaven.

This museum seems the best!

This Presentation: I could not cover the whole museum in 4 days, but 4 days is about the limit of my attention span and feet. (I have been known to request and use a wheel chair to save the knees and feet, but the Deutsches Museum is definitely not wheel chair friendly and I didn't see any wheel chairs offered.)

So you will get a small sample of what I saw that interested me most. In approximate chronological order:

  1. An astronomical instrument for measuring the elevations of stars. (1764, maybe similar to such made and used by Tycko Brahe?)
  2. A Junkers JU-52 trimotor aircraft 1931
  3. The Zuse III computer reproduction (original in use 1942)
  4. The Zuse IV computer (delivered to ETH Zurich in 1950)
  5. Messerschmitt Me 262 A-1a world's first production jet aircraft (1944)
  6. UNIVAC first mass-produced computer (1951)
  7. IBM 650 early business computer (announced 1953)
  8. Device to convert from astronomical coordinates to alti-azmuth coordinates of usual large radio telescope
  9. Picture of 15 meter sub-millimeter radio telescope. (1986)
    Background for the sector (next below)
  10. A sector of a 15 meter millimeter radio telescope.


Wall Quadrant

An astronomical instrument for measuring the elevations of stars.

This was called a "wall quadrant" with a radius of about 2.15 meters (7 feet).

Overview of the Wall Quadrant

detail of the scale

I added the comments
Placard
Southern wall quadrant
Johann Georg Nestfell (1694-1762), Wurzburg, 1762

In the 17th and 18th centuries, wall quadrants were frequently used instruments to measure and determine the elevations of stars culminating and transiting the meridian. Quadrants were permanently attached to wall in an exact north-south direction.
A quadrant facing south covered elevations between 0-90o (southern wall quadrant). For larger angles (between zenith and celestial north pole) a second intruments facing north (northern wall quadrant) was installed.
In the cross hair eyepiece of the rotatable telescope, a star was observed on its meridian transit and the elevation was read off the large quarter scale (radius 2.15 m) with an accuracy of a few arc seconds.


A Junkers JU-52 trimotor aircraft

1931

I found this exhibit interesting because

  • some of the "skin" of the aircraft had been removed to show internal construction
  • the water pipe type valves in the cockpit (not seen in current cockpits!!)

    Note skin removed for viewing internal construction

    Note side wheel for trim tabs?

    Note water pipe type valves

    The Zuse III computer reproduction

    Placard
    Z3: the First Functional Program-Controlled Automatic Calculating Machine

    Zuse's "conditional combinatory logic" and "abstract switching techniques" enabled him to make a direct reconstruction of the Z1 as a relay calculator. In this, he took the advice of his friend Schreyer. Starting in 1938, Zuse built an arithmetic unit, later called the Z2, using relays. This experimental device provided him with valuable experience.

    In mid-1940, Zuse began building the Z3. It was operational in May 1941. The arithmetic unit was electromechanical, constructed of 600 relays; the store used 1400 relays.

    The Z3 cost about 25,000 reichsmarks. It was damaged in a air raid in 1943, and destroyed in 1944.

    The 1941 Z3 was the first fully functional, freely programmable binary automatic computer. The program sequence consisted of just one loop.

    The Z3 was about as fast and capable as Harvard ( & IBM) Mark 1 Automatic Sequence-Controlled Calculator by Howard Aitken completed 2 years later. The Z3 featured floating point for engineering calculations.

    Overview

    Left bay is memory
    Right bay is arithmetic and control

    Attractive console

    I bet Konrad Zuse and
    Seymour Cray would have
    gotten along well. ;-))

    Docent demoing

    He let me enter two three
    digit numbers and multiply them.

    Back of control bay

    Note the telephone stepping relays,
    The bottom thing is a commutator
    to help break circuits adding to relay life

    film-reader-punch

    This used 35 mm movie film, available,
    instead of paper tape, fragile, hard to splice, and not available

    relays

    Just regular telephone relays.
    Unfortunately, the Z3 needs maintenance. Starting about two years ago, it now makes mistakes.

    There is a reproduction of Konrad Zuse's earlier Z-1 in Deutsche Technik Museum in Berlin.

    For reference: In the 1939 time frame, John Atanasoff was making the first electronic computer at Iowa State College (now University), but it was limited to solving large (30 variable) simultaneous equations. In a word, it was much faster but not general purpose. See "The First Electronic Computer, The Atanasoff Story" and ABC study and simulation.


    The Zuse IV computer


    Early Z-4
    Z-4 delivered to ETH in Switzerland

    Left half

    including memory in flat horizontal box

    Z-4 Mechanical memory

    access time, about 1/3 second
    cheap and reasonably reliable (for its day)
    The position of a wall in front of the Z-4 makes photography difficult with out a wide angle lens.

    This was the first computer delivered to an educational institution, or anywhere, in Europe. It was retired in about 1956.

    While working on the Z-4, Konrad Zuse created Plankak?l, the world's first computer language. For a discussion, see http://www.epemag.com/zuse/part5.htm

    Don Knuth's book "Selected Papers on Computer Languages" (2003) Amazon, is a must for people interested in the early development of computer languages.

    In Chapter 1, "The Early Development of Computer Languages", Knuth gives a 7 page discussion of Plankak?l and an interesting example.


    Messerschmitt Me 262 A-1a


    world's first production jet aircraft (1944)

    Placard
    . Messerschmitt Me 262 A-1a
    . Messerschmitt AG, Augsburg, 1944
    . Fighter aircraft with jet propulsion.
    First jet plane to be built in seried and used in action.
    Wing span 12.56 meter [41 feet]
    Weight 6100 kg [13,420 pounds]
    Speed 870 km/h at 6000 meters
    [522 mph at 19,700 feet]
    Max Altitude 12000 meter
    Range 1000 km [600 miles]
    Engine Junkers Jumo 004B
    Schub: je 8.8 kN (900 kP) [thrust 2000 pounds]
    Weapon 30 mm machine gun
    [ Wikipedia says "Guns: 4 ? 30 mm MK 108 cannons (A-2a: two cannons)" ]

    Side view

    Top view

    Engine


    UNIVAC


    first mass-produced computer (1951)

    Overview

    Component door

    Component detail

    Inside wiring

    Memory

    Memory installed
    I didn't see a placard, so offer this
    BRL Report


    IBM 650

    early business computer
    (announced 1953)

    Front

    Modules

    Module detail
    I didn't see a placard, so offer this BRL Report

    There appears to be a drum (or two?) below the front panel. IBMers say that the drum *really* spun - some say 12,000 RPM (200 times a second), others say 22,000 RPM (366 times a second). In any case, a lot faster than most.


    Picture of 15 meter sub-millimeter radio telescope.

    Placard
    Submillimeter telescope

    Stars are formed in galaxies like the Milky Way in the cold dark clouds of dust. To better understand how stars are formed, the composition of the clouds must be analyzed. This is done by investigating many of the molecules which radiate at characteristic wavelengths. These emissions are detectable in the milimeter range and lower.

    From 1986 to 1989, four identical telescopes were commissioned to pursue these investigations. The telescope pictured here in Chile and three in the South of France, interconnected to form an interferometer.

    Total weight of one telescope

  • 135 tons (metric) Number of panels
  • 176 Mirror diameter
  • 15 meters Wavelength range
  • 0.7 - 4 mm Pointing accuracy on the sky
  • 2 - 3 seconds of arc Resolution on the sky an 1 mm wavelength
  • 17 seconds of arc

  • A sector of a 15 meter millimeter radio telescope


    Sector

    7.5 meters high

    Support

    to help get 0.05 mm accuracy

    Motors

    to help keep 0.05 mm accuracy

    Edge Detail
    Placard
    ReflectorSegment from a submillimeter telescope

    Development and production MAN Technologie AG, Munich, 1986

    Radio waves can be diverted by metal surfaces and focused in a focal point. The smaller the wavelength to be reflected, the more exact the surface of the mirror has to be. With a wavelength of 0.8 mm, the mirror may not vary be more than 0.05 mm from the ideal forn - the paraboloid.

    Panels made of light-weight, extremely dimensionally stable plastic and strengthened with carbon fibers (CFK) are used for the reflector surface. The panels are coated with aluminized fiol. A framework of struts supports the reflector. the individual panels are adjusted by motors.


    Coordinate transformer to convert from astronomical coordinates to alti-azmuth coordinates of usual large radio telescope

    Optical telescopes, even up to the 200" (16.6 foot, 5 meter) Mt. Polomar telescope, are with some difficulty mounted on a pivot to rotate parallel the earth's axis. This makes driving them in synchronization with the earth rotation to track celestial bodies relatively simple.

    Radio telescopes of sufficient precision (1/8 wavelength) can be made much larger, (say 25 to 100 meters in diameter,). This is so large that mounting them and driving them identical to many optical telescopes is prohibitively expensive. They are almost universally rotated about a vertical axis. With this alti-azmuth system, tracking celestial bodies as the earth rotates is much more complicated, involving rotation about the vertical axis, change in elevation (and rotation of the feed horn to maintain proper polarity). Van Snyder points out that "JPL's Deep Space Network has several 37 meter Ha-Dec-mounted antennae. Our 70 meter antennae are Az-El mounted. When built they used a mechanical frammistat to convert Ha-Dec pointing to Az-El pointing. I suspect there's a PC, or maybe an FPGA, that does it now."

    In the 1950s and 1960s, when many large radio telescopes were made, the computers to perform the trig continually to solve the guidance problem were large, expensive, and required frequent maintenance.

    The following device was used at the Stockert/Eifel radio observatory and is special purpose approach to solving this guidance problem.

    (This was used before digital computers became cheap and handy)
    Inputs to the device were:
    a) vertical axis into the center unit - polar axis, angle
    b) horizontal axis into yoke - declanation angle
    Outputs were angles of
    a) azimuth of radio telescope - angle of square box
    b) elevation of radio telescope - angle of inner yoke


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    Originated May 22, 2004
    Updated May 2012