Saturday, January 29, 2011

City night sounds

Machines are awake and aware - while the humans are sleeping. This sounds like science fiction but it is easy to realize. Just switch on a sound recorder in your hotel room and open the window. The recorded sounds are mundane and predictable: car traffic - airplane traffic - birds - hotel guests walking - you snoring - people talking on the sidewalk - streetcars - ambulances. But the overall statistics give a unique profile of each place.
1rotterdam night sounds

The first time I did this in Rotterdam - in a quiet suburb. The Rotterdam sound map says the level is less than 50dB at night. The steady hum of the highway can be heard all the time. No individual sounds are visible in the graph, everything is smoothed by distance from the sound source.
2london night sounds

The second time was in London – in a quiet corner of the city. My room was on the ground floor and anyone could have walked in from Regent's Park while I slept. I could not open the windows. But you can see the cars driving by in the recording.
3berlin night sounds
The third time was in Berlin, next to a very busy street, the Prenzlauer Alee. Maybe 65dB. The sound level is changing periodically. Traffic lights form clusters of cars that stay close together. This causes high peaks in the sound level.
Could we resolve one of these peaks into the different cars that cause the peak? I didn't succeed. Even spectrum analysis is unable to separate the cars. Their sound looks too much like white noise.

Some things are constant in every location:
  • Cars dominate the urban soundscape. Interesting sound drowns in boring noise.
  • Night is much quieter than day.
  • The quietest part of the night is around 3:00 AM. The best time for sound recordings.
Marcel Minnaert has not written a specific chapter about night sounds. But he mentions them often while writing about other phenomena:
  • At night sounds can travel much further because of temperature inversion in the lower atmosphere. This is an omnidirectional effect. Sounds can also travel much further downwind, but this is a unidirectional effect. So it is not only the greater silence at night that makes some sounds more audible. 
  • In nights with copious dew (= inversion) one can hear the sea-waves at distances of 13 km inland.
  • Measuring the speed of sound using a thunderstorm works better at night, because the lightning is more visible and the silence makes observation of the thunder easier. In a silent place outside the city lightning and the corresponding thunder can be studied up to distances of 100 km (30-40 km is easy to do).
  • Echoes are observed best at night. In a silent night the echo produced by a row of beech trees could be heard up to a distance of 500 meters. A special kind of "whistling" echo is produced by corrugated iron walls or roofs. This is also best observed at night.
  • At night one can hear the difference in the sound of one's footsteps while walking along walls or bushes. And one can hear the rustling sound produced by the blood flow in one's own ears.
And ... Marcel Minnaert did not find car sounds boring. He wrote a whole chapter about listening to machines and analysing which "part" of the sound is produced by which "part" of the machine. More about that in a future blog entry.

Rotterdam sound maps
De natuurkunde van 't vrije veld. Deel II, Geluid, warmte, elektriciteit (Part 2: Sound, temperature, electricity), Marcel Minnaert

Wednesday, January 26, 2011

Guilty places

A guilty place is a concept of the Durch artist Armando. Woods and trees are especially suspect:

The edge of a wood, for example. The trees in front must have witnessed some things. The trees behind them, you can hardly blame them, they could never see anything. But the edge of the wood, the forest border, it has seen things happen. There are many forest edges, here and there, about which I know a few things. I visit them occasionally. I have been taught that I should not blame them for anything.

Tomas Ross (crime author) and Iona Hogendoorn (photographer) have written a book about Guilty places in the Netherlands. They present 41 places where something violent and dramatic has happened in both ancient and recent Dutch history.

On the left Strand Nulde where the body parts of a 4-year old girl were found in august 2001. The girl was systematically mistreated by her stepfather with fatal results. Then her mother and the stepfather disposed of the body by dumping it at a deserted beach near the highway.
On the right the Hoekpolderviaduct in Rijswijk where four teenagers threw a sidewalk tile through the windscreen of a car on the highway below. The 30-year old woman driver later died in hospital.

It is always good to remember victims and to protect their names from oblivion. And to remember how unnecessary their deaths were. Recently I discovered another Dutch guilty place that would have deserved a place in this book. So I must write about it, so it is not forgotten.

On Monday, 7 October 1946 a plane crashed into the gym at the christian high school at the Jachtlaan in Apeldoorn. The building collapsed, leaving 22 boys dead. Five pupils and their teacher survived the disaster.

The crash was caused by the 23-year-old sergeant-pilot Max Christern who had permission to make a half-hour solo flight near the Valkenburg airbase, to get acquianted with the Firefly airplane. But against all rules, he flew directly to Apeldoorn to greet his mother. He performed a few stunts above the market square and did some low flying stunts near the Jachtlaan. In one maneuver he lost control. The right wing hit the school and the Firefly crashed on the roof of the gym, where 27 boys of class 2C were training. The fuel tank ripped open and flaming fuel flowed through the broken roof. Burning students jumped into the school pond. Twenty-two fourteen-year old boys died. The pilot Max Christern died instantly. His mother died of a heart attack when she heard the tragic news.

This was not the only time that pilots from the Valkenburg airbase ignored the regulations:
  • In 1946 another Firefly made and emergency landing in Calais when the crew was supposed to make a reconnaisance flight above The Netherlands only.
  • In 1965 two drunk aircraft repairmen took off in a Neptune airplane and crashed in the North sea.
Even today there a rumors of dangerous stunts by military pilots like flying under transmission lines, bridges and flying so low that the propellers leave two furrows in the reedland. This is not commonly known.

Tomas Ross & Iona Hogendoorn, Schuldige plaatsen in Nederland, 2007, Thomas Rap, Amsterdam
Marc van Alphen, Willem Geneste en Prudent Staal, 'Terg mij niet' De geschiedenis van marinevliegkamp Valkenburg, Van Wijnen, Franeker, 2007

Friday, January 21, 2011

Tiny catastrophes

little catastrophes

Dew condenses on a curved glass surface.
Some time later a random drop becomes too heavy and slides down the curved surface.
As it descends it absorbs other dewdrops and grows heavier.
Once a dewdrop starts falling it's downfall is irreversible.
How much of our lives is governed by processes that behave in the same manner?
In a chain reaction, positive feedback leads to a self-amplifying chain of events.
Cascading failure is ... when one of the elements fails (completely or partially) and shifts its load to nearby elements in the system. Those nearby elements are then pushed beyond their capacity so they become overloaded and shift their load onto other elements.
A catastrophic failure is a sudden and total failure of some system from which recovery is impossible. Catastrophic failures often lead to cascading systems failure.
Bifurcation theory studies and classifies phenomena characterized by sudden shifts in behavior arising from small changes in circumstances. This may lead to sudden and dramatic changes, for example the unpredictable timing and magnitude of a landslide.
Marcel Minnaert does not mention cascading processes in his observation guidebooks. But as an astrophysicist he should have known about positive feedback and singularities. I will have to check if "black holes" were known in his time.

Saturday, January 15, 2011

Alternative reality model

It is many years ago that I discovered the “orb” and the “rod” phenomena on the Internet. The New-Age-type community that has since formed around the “orb” phenomenon is very interesting. On the other hand the “rod” phenomenon has faded into obscurity.

It is easy to make fun of the orb “believers”. Many studies have demonstrated that orbs are natural optical phenomena. But it is more fruitful to see them as original researchers:
  • They observe the world with curiosity - which is always good to do.
  • They gather big sets of observational data - using the scientific method.
  • They analyse the data and reach original and creative conclusions.
 Scientists and sceptics will disagree with their conclusions. But their originality and creativity are undeniable. I have read the two books that are available in the Rotterdam library and give the most interesting conclusions below.

From the book Orbs and other light phenomena by Ed Vos:

At first I tried to find a rational explanation for the light spheres on the photographs. Being a professional photographer with an education in the exact sciences it has always been a challenge for me to analyse unexpected occurrences in photographs. But slowly I had to admit that this was a special phenomenon.

The book contains detailed analyses of orb pictures and their brightness, texture, colour and shape. Some of the conclusions are:
  • Orbs are a multi-dimensional (energy) phenomenon.
  • Orbs have consciousness and we can communicate with them, both vocally and telepathically.
  • Some people photograph more orbs than others because their frequencies resonate more with the orb frequencies.
  • Sometimes orbs manifest themselves in both the visual and audible frequencies.

And the book Enlightenment Through Orbs by Diana Cooper and Kathy Croswell adds the following conclusions:
  • Orbs are manifestations of angels and spiritual masters. They want to stimulate our curiosity so that we research the phenomenon.
  • The orb-shape has been chosen because the circle symbolizes wholeness and completeness.
  • Some orbs are manifestations of the archangels. Specifically: Michael, Gabriel, Uriel, Chamuel, Metatron, Sandalphon, Purlimiek, Gersisa and Butyalil.
  • Other orbs are manifestations of spirits, elementals and unicorns (ascended seven-dimensional white horses belonging to the angelic sphere).
The combination of modern technology, medieval and renaissance esotericism, semi-modern physics and New Age is very interesting. The study of orbs reminds me of the esoteric communication experiments of John Dee and Edward Kelley. It is a modern method of scrying and angelic communication. An alternative reality model - a creative postmodern re-mix of ideas.

Designing such a model is quite difficult. As a thought experiment I tried to imagine more explanations for the orb phenomenon. My limited imagination gave only these few:
  • Orbs are common manifestations of the microscopic black-holes as postulated by Stephen Hawking. They evaporate very quickly and give off energy in many frequency ranges.
  • Orbs are cosmic rays striking the sensor of the camera and creating a cascade effect, thus blurring the impact point to a textured circle.
  • Orbs are energy and/or information consuming life forms. Notice their similarity with some lichens. Starting from a point sized infection they spread through the emulsion or pixel matrix with the speed of light.
And another explanation is given by SCP-020 The unseen mold:
  • SCP-020 is a fast-spreading fungal organism that is capable of affecting the senses and behavior of living creatures, including humans. Samples of SCP-020 exhibit an unknown effect that renders them effectively invisible to direct observation, even when under a microscope. SCP-020 is only visible to humans when viewed through photographic or video surveillance.
And a final one is from the Fortean Times forum:
  • They are extremely round ghosts.
I hope to write more about alternative reality models - especially those that include observation and analysis like this You-tube video: The skies, sun and moon are different.

Sunday, January 9, 2011

"Brennschluss" constellations

In his story "The man of the crowd" Edgar Allan Poe refers to a certain German book that: “does not permit itself to be read” (Es lässt sich nicht lesen). I have come across several of these books and have recently "finished" a most (in-) famous one: Gravity's rainbow, by Thomas Pynchon.

The first third of the book was mind bending, complex but full of great ideas. A fantastic invocation of the chaos that Europe must have been in the closing days of the second world war. But the next two thirds were too hard for me to read, so I just scanned through the rest of the book.

But two quotes from the book make the exercise worth while. This is the first one:

That would be fuel cutoff, end of burning, what’s their word . . . Brennschluss. We don’t have one. Or else it’s classified.
A switch closed, fuel cut off, burning ended. The Rocket was on its own.
There’s a Brennschluss point for every firing site. They still hang up there, all of them, a constellation waiting to have a 13th sign of the Zodiac named for it. . . but they lie so close to Earth that from many places they can’t be seen at all, and from different places inside the zone where they can be seen, they fall into completely different patterns. . . .

This idea of invisible constellations - that are still present - is so powerful that I have looked at the sky and tried to determine if I could see them from Rotterdam.

But first some facts about the A-4 rocket:
  • Brennschluss took place after 65 seconds. Then the rocket was 24 km distant from the firing site and 22 km high. It's speed was 1600 m per second.
  • The maximum height reachable was 80-90 km if fired normally. If fired vertically the maximum height cold be 240 km.
  • Maximum range was 320 km and the impact speed was 900 - 1100 m per second.
  • More than 1100 rockets were fired from The Hague and they caused 2700 casualties in England.
In a rough sketch it looks approximately like this:

Which means that the "constellation" is visible from approximately this area of Europe - a radius of 530 km centered on the coast of The Netherlands (for convenience I ignore the other firing sites):

And this is how I imagine such a constellation would look like. Notice the tiny white dot in the sky (better at bigger picture size). This afternoon I made a picture of the sky to illustrate this blogpost and just at that moment a tiny airplane flew over and reflected the sunlight. It was a magic moment. I didn't realize then that I had caught it on camera.

The picture illustrates the "constellation" feeling well. But the dot is not exactly in the right place. I calculated that it should be roughly at azimuth 285 - altitude 26 degrees. So it should be behind the trees or even further to the right, and should be three times as high in the sky. The calculation is quite tricky and I could have it wrong.
- - -
The second great quote is:

Proverbs for Paranoids
Nr. 3: If they can get you asking the wrong questions, they don’t have to worry about answers.

I'm looking for plausible examples of this in real life, in my newspaper archive. I have the feeling that "they" - whoever you think "they" are - must find this  a very useful method to keep "us" in the dark. It would be fun to confirm this paranoid fantasy.

Thomas Pynchon, Gravity's Rainbow, Paperback edition, 912 pages, Vintage, 2000, ISBN 978-0099533214
V2 (raket)
Die A-4 (V2) Rakete
Distance to the Horizon

Saturday, January 1, 2011

Bird feeding graph

First try - room for improvement

I'm always surprised how fast the birds come when I feed them. The first seagull arrives in a few seconds. They always float in the sky like biological satellites. Then – by some silent bird telegraph – the whole flock of seagulls is attracted.

Sometimes the ducks see the bread first. They live just around the corner. They make a lot of noise and attract all the other ducks to the food. The jackdaws and crows arrive last. They are shy and don't dare to come near while I'm watching. They always try to take away a piece of bread, to some safer place.

I'm trying to solve the puzzle of the bird telegraph. My first attempt was to set up a webcam and to study how the birds arrive and leave.
Preliminary results:
  • The arrival of the birds is lighting fast. They notice that I will be feeding them even before I throw the first piece of bread.
  • In 2 minutes the flock has reached it's maximum, stable size.
  • After 2 minutes the birds start leaving. I assume that they have taken big chunks of bread with them.
  • In 7 minutes all the food – a big bag full of bread and nuts – is gone.
Further research:
  • Where do the birds come from? From what place? From what distance?
  • Does the size of the food determine how long the birds stay?
  • How big is the area in which the birds search for food?
Research method improvements:
  • I need a webcam with a much bigger resolution. It's almost impossible to see the birds. Counting the birds is difficult and error prone.
  • Using a program like CrowdCompiler to map the flight and walk paths of the birds is impossible in such a bad resolution. See these CrowdCompiler results:
  • 15 seconds between pictures is too slow. Things happen much faster than that.
  • I should park the car next to the feeding place and put the camera much nearer to the birds.
Second try - total failure

Today - January 1st - I tried a better setup, 1.2 kg of old bread, put close to my car, webcam all installed and tested. But no birds came. I only saw a few pigeons and jackdaws flying fast and high overhead. Then a flock of 25 seagulls came near but they didn't dare to land and feed. I think they're still in shock from the fireworks of last night.

Decoding the "hochsitz"

I have never looked from the train windows so attentively as during the trip home from Berlin. In the white abstract landscape I had spotted the classic German "HOCHSITZ" - a wooden perch built for hunting.

At that moment I started hunting myself. I was hooked - I wanted to collect and analyze these improvised architectures and decode their placement. As a city person I know little about hunting - but I'm not opposed to it. Man has always fished and hunted, and hunters (and gatherers) have intensive and intimate relationships with nature.

It was hard to spot and photograph the perches from the high speed train. Other travellers must have wondered about my obsessive behaviour. But I wanted to collect as many samples a possible. This is the rest of the collection:

My first guess at the placement rules for these perches was:

  • In a rural area, not too near a village but also not too far.
  • Camouflaged by trees or bushes.
  • Clear lines of sight covering a large area.
  • Covered in the back (many were next to the railway and thus impossible to photograph).
But checking a few German hunting websites shows that I have less than half the story right:

  • Location is all important: seeing, hearing, lines of fire, directions from where the game is expected to come, direction of sunrise, sunset and moon.
  • Often at the boundary between forest and farmland.
  • You must be able to walk to, and enter the perch without disturbing the game so the prevalent wind direction must not be towards the game. There must be enough cover to reach the perch.
  • Building a perch disturbs the game and it will take some time before they get used to it. You should first build a light temporary structure and try it out one year long.
A fascinating domain with classic rules - the same traditions you read in cultural anthropology books.

Financial crisis fallout

I have laid hands on a big stack of "old" quality newspapers from October to December 2010. Most of these are Financial Times. I'm slowly digging through this stack of several kilograms and performing an experiment. The experimental questions are:
  1. How much can I - as a total amateur - understand of the financial system? Can I spot invisible domains in the system?
  2. How big is the difference between foresight and hindsight? Can I predict trouble spots in the system? Can I predict problems for 2011?
So I'm looking at the financial system from the hacker's perspective. In the meantime I find a lot of interesting and curious details in these newspapers. For example:

One of the effects of an economic downturn is that fraudsters cannot keep up their Potemkin facade anymore. In the Internet bubble we had Enron and Parmalat. In the housing bubble we got Madoff. There is an enormous amount of fraud, failure, human misery and suffering condensed in this tiny (7*7cm) advertisement.

Saturday, November 13th, 10 A.M.
New York Sheraton Hotel & Towers, Metropolitan Ballroom
811 7th Ave. @ 53rd St., NY, NY 
Jewelry * Watches * Antiques * Art * Furniture 
All belonging to Bernard & Ruth Madoff 
Preview: Brooklyn Navy Yard, Sands Street Entrance, 
Bldg #25 on Friday, November 12th, 1·7 P.M. 
Gaston & Sheehan Auctioneers, Inc. NYC 1332970 
(512) 251-2780 or (512) 990-2838 

Financial Times, 2010

Invisible telecom frontier

While walking through the beautiful erosional countryside around Maastricht I passed this invisible boundary. In the same place and time our three mobile phones switched from the Dutch to the Belgian network. It was really spectacular. This is the spot on the "Silexweg", in the woods near the soccer field:

And this is the map - also showing the nearest mobile network transmitters:

As you can see in the Google Map we had just crossed the Dutch - Belgian border.  The landscape is dotted with beautiful cast-iron Belgian border markers (from the 1850's) that have been lovingly and meticulously documented.

And the antennas of the Dutch mobile network have been mapped just as meticulously, though probably less lovingly. A similar mapping has been done for the Belgian mobile network. It is interesting to note how the electromagnetic and geographic borders do *not* overlap.

There is a name for this phenomenon and it has been researched in depth by the Dutch telecommunication authorities. It is called "unwanted roaming". The conclusions from this research are:

Unwanted roaming occurs when you physically move a mobile phone to a location on Dutch soil where the Dutch network is absent and / or where the signal level of the Dutch network falls below a minimum usable value. This will make the unit look for a different network than its default network. When a usable signal is present from a foreign network, the device will connect to this network.

At all measurement locations signals from mobile telephone networks from Germany and Belgium are present. But at all locations further than 15 km from the frontier, the Dutch providers have more than sufficient field strength, so the risk of roaming is virtually nil.

The results of measurements and statistical research have shown that in the worst case - on the frontier - only limited unwanted roaming occurs. The biggest risk of roaming occurs for UMTS networks.

The measurements do not suggest that operators in Belgium or Germany have tuned their network to forcibly roam Dutch users to these foreign networks.

Onderzoek ongewenste roaming in de grensstreken, Provincie Limburg, Agentschap Telecom, 16 februari 2009