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Stu Savory's Blog
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Thursday, May 31, 2007
Number 42 : The world's worst cocktail :-( S erved to me - a poor unsuspecting tourist - as the 'special drink of the house' in a bar in Chania on Crete. It tasted like a mixture of the essence of drain-cleaner and nasal-passage-residues both stirred into a sickly sugary slop. Uuuurrrgh! Gimme a St. Patrick's day goat-piss-shandy any day; it HAS to be better ! The Drinks Menu read Pan-Galactic Gargle-Blaster. No wonder they are forbidden here!
Wednesday, May 30, 2007
The Minoan palace at KnossosUpon going into retirement I made a list of things I want to do before finally shuffling off this mortal coil. Then I struck off the ones we cannot afford and sorted the rest by some sort of priority, bearing eventually decreasing physical capabilities in mind. One of those things was to experience early cultures and in particular to see for myself the Minoan culture on Crete (ca. 2900-1100 BC). The Minoans were a peaceful ancient civilization in Crete in the Aegean Sea (Mediterranean). They were one of the civilizations that flourished in and around the Med during the Bronze Age of Greece. Based on depictions in Minoan art, Minoan culture is often characterized as a matrilineal society centered on goddess worship. Back in 1900 Sir Arthur Evans excavated the Minoan Palace at Knossos discovering many archeological treasures. So it was off to Crete to get some first-hand viewing. Minoan Palaces, such as the one at Knossos, were technologically advanced: expanded drainage systems, aqueducts, and deep wells that provided fresh water to the inhabitants. The palaces were multi-storied and contained exterior and interior staircases, light wells, massive columns, huge storage jars, and fresco murals. Some of the murals have been particularly well restored (remember they are well over 3000 years old). Here are my photos of some of them :-
All of the smaller stuff has been removed for display at the archeological museum in Heraklion, which unfortunately is closed for restoration until july. Bummer :-(
Thursday, May 24, 2007
Criticism from Crete ;-)
KPHTH We oldies recently spent a week in Crete (the block letters show the Greek spelling) because I wanted to see for myself the remains of the Minoan culture first hand, do some deep canyon hiking, explore the mountain 'roads' and perhaps even do a spot of sunbathing :) We also enjoyed some great Cretan food - often advertised in English with some hilarious spelling mistakes (more on this later) - and even found a place where a waiter was loudly proclaiming his food and/or this blog as 'Crappy savory waffles' ;-) And he was right ! One of the hilarious notices was for a 'parking lot' obviously reserved for customers and ladies-of-ill-repute ! Talking of stuffing, one thing to be avoided is Cretan goat sausage, freshly slaughtered in the gutter! I gave up after two of them, so fatty :-( Another place was offering Wishky (sic!), Ness Cafe (which probably
tasted Gotta run now, but I'll be showing you photos of the Minoan palace at Knossos in a later blogpost and some canyon-hiking scenery. Some 'mountain roads' scenery too. Of interest to cryptographers is the Disc of Phaestos there; more on that later too.
Wednesday, May 23, 2007
A Six-Pack @ Breakfast ;-)
Puppies really do put on weight at an amazing rate! Seven weeks ago these six weighed about 300 grams each at birth. During the first week alone, just on their mother's milk, the six totalled a weight increase of 3½ kilos. So their poor mom - who had produced at least this much milk in a week - looked as thin as a skeleton with an udder :-( But as you see, they're weaned now; which is just as well, since they each weigh about 5 Kg now, totalling more than their mother weighs. Their mom is gradually losing her udder now and is putting some weight back on herself, and now has time to enjoy playing with her six lively pups ( and disciplining them) ;-)
Monday, May 21, 2007
A Layman's look at Lie group E8Once upon a time I was attending a reception for new staff at a university. The chancellor was moaning about the difficulty of assigning resources fairly. This had been triggered by the fiscal demands of the various faculties, in particular the experimental physicists. He was asked which faculty he would then prefer? He preferred the Philosophers, "They only need pencil, paper and a wastepaperbasket!" . I quipped "I would prefer Theoretical Physicists, they don't even need the basket ;-)" This joke is dedicated to the folks over at Cosmic variance, sundry Theoretical Physicists, Cosmologists, String Theoreticians and academic bloggers supreme ;-) Whatever! I want to tell you a little about Lie group E8 today, so just string along... Sophus Lie (pronounced 'Lee'), 1842-1899, was a norwegian mathematician who was the first to investigate the symmetry properties of 3-D objects. Later, his concepts were extended to higher dimensions and other Lie Groups were found, including the Group of interest today, E8. All together now : "Old MacLie, he had a Group, E8,E8, oh!" Some of you may be asking "What's a Group?" Remember back in november I told you how to multiply complex numbers (2-D)? Well, when rotations (twirls) can be added and subtracted they form the elements of a Group (I'm using the word group in its mathematical sense, as you may have guessed). Now if the rotations are continuous and differentiable - as is the case for rotation of a cone, cylinder, or sphere, we call it a Lie Group of the simple type. As usual the rotations are represented by square matrices. Not the 3*3 matrices of 9 elements we use for 3-D objects though. Lie Group E8 represents the symmetry of a 57-dimensional object (maybe a Heinz sauce bottle ?) which has 248 manifoldly(sic!) different ways of rotating. So each of these matrices is 248*248, giving us over 2*1011 components. The picture below is a 2-dimensional graphical representation of the 57-dimensional Lie Group E8.  Why am I telling you this NOW? Well, Jeffrey Adams and other mathematicians at the University of Maryland have recently succeeded in describing the elements of E8 in their entirety. Each is a constant or a polynomial of degree less than 32. Details are reported in "Science", Vol.315, page 1647ff, should you want to read the details ;-) Why is this interesting AT ALL? Because theoretical physicists who are interested in a unified and symmetric description of the 4 forces of nature (electro-magnetism, weak nuclear, strong nuclear and gravity = EWSG) can now use these results in their String Theory investigations. String Theory says that elementary particles can be described by minute strings vibrating in at least 10 dimensions. These are called N-branes depending on their dimension N. So a 1-brane is like a line, a 2-brane is what you usually think of as a membrane and a point (called George? ;-) is a no-braner ;-) Unfortunately, String Theory has produced nothing which could be used to make an experimental prediction which could actually be tested - remember the non-existent waste-paper basket I joked about wryly at the start of today's blog? But now the work of Adams et al thoroughly exploring Lie Group E8 may lead to some experi-mental tests. Until then, string theory may just be like the Emperor's clothes ??? Enough philosophising, where's MY waste-paper basket? 
Sunday, May 13, 2007
Bulldog Puppy6 : Happiness is here again :-)
'Tis Mothers' day here in olde Germany. What better day to introduce you Frieda's pups. I've linked some more photos here :-
 Oh, BTW, they're English Bulldogs of course, if you didn't recognise that already :-)
Thursday, May 10, 2007
The eyes of the be(er-)holders
W hatever happened to all the women in the intersection set? Barbarella the bachelors' dream and others of her ilk? Sigh! Thus was the tenor of the conversation amongst the lads in the pub last night, weeping into their beers. Sitting in the pub you note, not out on the chase, surveying the modelling catwalks, nor stalking college halls for good-looking female students. Just supping. Sitting there, apathetic, dumb and boring middle-aged men. Balding, fat paunches flopping out of their wide and grubby beer-stained shirts; sitting so that the mirror behind the bar could ask no question of their blurred argument. Carpe Diem, lads . . . And since we are on the subject of Carpe Diem in the Most Girls part of the set . . . Meanwhile we read that Paris Hilton is to be sent to jail. Like her brain, she will have to get used to having just one cell. Could we bribe the gaoler to 'lose' the key? Please? She too comes under the rule of law. Why not? She's come under everything else ;-)
Tuesday, May 8, 2007
Cry 'God for Harry, England and St.George!'Harry goes to Irak? Or not? The MoD is all in a dither :-(B rit readers who have a problem with satire should skip the rest of this post; yes, that means you Colonel Blimp ;-) "Cry 'God for Harry, England and St.George!' " - Henry V's famous rallying cry -
comes to mind as the MoD dither about sending Harry Wales [son to Di(e)]
in Irak, where he would become a prime target for the occupation-resistance fighters.
The latter have said they would cut off his ears and send him home to granny. Of course,
if they applied the knife about 666 (sic!) millimeters lower, they could kill
two birds (for want of another word) with one snip, thus putting at ease those
conspiracy theorists who don't want a possible riding instructor's son anywhere
in the line of We are told by the MoD that Harry had to make his will before departing to Irak. His Mum (Di) left him £20 Mio, some of which he spent on clothing. So Jews throughout the world now have to worry about who will inherit Harry's SS uniform ;-) On a more serious note, my sympathies go to the 11 poor sods under his command, in his tank or whatever. Their own personal risk is increased manyfold, just because Harry wants to play at sodjers :-( If the occupation-resistance fighters / terrorists capture Harry and just chop off his ears (an operation Charles might have found useful at his age), they are likely to be less generous with the other eleven, poor sods. On these humanitarian grounds alone, I think little Harry should be man enough to stand down, stay at home, and have fun e.g. putting a chelsea bun in the oven ;-) It's a strange world where both Al Quaida and Miss Davy are both hopefully humming the Snow White theme song "Some day my prince will come" ;-) P.S. Why hasn't Dubya set a precedent, drafted his daughters and sent 'em to Iraq?
Friday, May 4, 2007
Flying Blind : Instrument flight explained
There
have been several mails asking me to blog more about flying.
Elsie (Rhode Island, USA) wrote "I've always want to learn to fly. When I was
younger, I had the opportunity to purchase a small prop (Piper Navajo) with a group
of friends. I had to decline as I was spending too much time travelling and would
never have been able to log enough hours to get my license. So I saw no point.
I've been thinking about it again a lot lately...". Writing from the UK,
Brain (sic! I assume that's a typo and your real name is Brian)
asked "What exactly is Blind Flying? When we say politicians are flying blind, we
usually mean they've got their eyes shut and are pressing on regardless. But pilots on the
other hand seem to know what they are doing...". Whereas Madeleine (France) asked
"What are all those instruments for in an aeroplane?" And young Hamish (Scotland)
asked impishly "Do airliners need maps? If they're in the clouds they can't see the ground anyway!"
Now let me walk you through these eight basic instruments, left to right, top to bottom, even though this is
NOT the sequence in which I look at them!
Starting with the four in the top row.
This is the Airspeed Indicator. It shows you your speed relative to the air mass
you are flying through, which is what keeps you aloft. Your speed over ground may/will
usually be different, depending on the winds you encounter, be they head-winds, tail-winds,
or cross-winds. Actually this is not quite true, there are calibration errors due to the
angle of attack of the wings, and air density errors depending on the air
temperature and your altitude etc. but lets keep it simple : it is showing you the
indicated airspeed (IAS). In this example the IAS is 100 knots. For anachronistic reasons
knots, feet, gallons etc are the system of units used by the airlines.
Russia, gliders etc use the metric system(!).
This is the Artificial Horizon. The scale around the outside shows us
the angle of bank,
10°, 20°, 30°, 60°, even 90°. At 60° of bank you would experience
two Gees of acceleration, that is to say you would weigh twice as much as you normally
do. To avoid this passenger discomfort airliners restrict themselves to at most
25° of bank. In the centre is a fixed horizontal bar with a dot in the centre; this represents the plane and its wings.
Behind that is a moving plate, top half blue to represent the sky and lower half
brown to represent the earth. (I'm ignoring Russian instruments which are different).
The plate turns as the plane banks and sinks as the plane climbs or rises as the plane
sinks, just as you would see the natural horizon do, if you could see it out
of the window. There is a knob below it (see photo near the top) to let you set the horizon when the plane
is standing level on the ground. I'll ignore caging the gyros for aerobatics :-)
This is the Altimeter. It is a barometric instrument. It shows you the altitude
in feet above the isobar (air pressure level) shown in the little cutout window at
the 3-o'clock position. In this case the reference isobar is set to 997
hectopascal (about 997 mm of mercury on a barometer). For anachronistic reasons
american altimeters are set in inches of mercury.
The little knob at the 7 o'clock position turns to let you set the reference level
in the little window.
There are 3 standard settings :
1013 hectopascal = 29.92 inches is the level set when flying at high altitudes,
the same for everybody, ensuring no collisions due to instrument altitude conflicts.
QNH (Normalised Height) is the setting for lower level cross country flights. The nearest control tower can tell you this on the radio, it is
the air pressure at a fictional sea level at the location of that tower,
so it changes as you fly around. QNH is the setting for terrain avoidance, you can read the height of terrain and obstacles from your maps.
QFE (Field Elevation) is the air pressure at the airfield you are approaching to land.
Thus when you land there your altimeter will read zero feet.
Thus dialling the QFE into the altimeter gives you your height above the runway you are approaching :-)
The tower will tell you the current QFE over the radio too. Mountain airfields use the QNH tho'.
This is the Automatic Direction Finder(ADF) for Non-directional beacons(NDB).
There are different kinds of approach aids, airports will have an ILS (Instrument Landing System) about which I will write more below.
The NDB is an older aid, it broadcasts a MW signal in all directions. If there is no ILS,
there is one NDB on the approach path aligned with the runway you are approaching.
It will often be about 4 miles out, co-located with the outer marker (explained below).
In this picture you have passed the NDB, it is now behind you
(at 190° from your heading) and 10° off to your left. There are no knobs to adjust
on this simple version of the instrument. There is often a red flag which pops up to warn
you if the (dialable) receiver is getting no signal. You need to dial in the frequency of each NDB you want to use, they are different.
The frequencies are given on you instrument-map (Hamish, I'll be telling you about those later, OK?)
And in the bottom row, left to right, we have :-
This is the Turn and Slip Indicator, otherwise known as the poor
man's artificial horizon, an instrument which it pre-dated and for which it
serves as a safety backup. It is two indications in one instrument. At the bottom is the
Ball which works just like a builder's spirit level, showing you if the
airplane is slipping. Rule-of-Thumb (feet, actually) tread on the ball
(the rudder pedal on the side where the ball is) to cancel the slip and
keep the ball in the centre. The oblong needle moves to the left or right to show
you the rate of turn of the aircraft. Unfortunately, turn and slip are not independant,
making it harder to fly needle-and-ball than to use the artificial horizon (AH).
However you need to keep proficient with it, lest the articial horizon fail.
Gliders may have no AH, just this :-(
This is the Gyro-Compass. Aircraft have a magnetic compass, which follows
Magnetic North (not usually the same as True North, especially at high latitudes).
Magnetic compasses swing off course when the plane is banking, accelerating or slowing
and swing wildly in turbulence. On average they point north, but are an unstable
instrument. For this reason planes also have a gyro compass, which do not have the
problems listed here and are much more stable. Unfortunately, they don't know where
North is! So there is a little knob (at the 7 o'clock position) to let you set
the gyro-north the same as the magnetic north whenever the magnetic compass is stable.
You need to reset it every ¼ hour or so as the world turns under you :-)
The airplane symbol is fixed and the disc with the compass rose turns behind it,
showing your heading
at the aircraft's nose (here it is 80° ). East(E) is 90°, S is 180° and W is 270°.
N is both 360° & 0°. Heading is not the same as track, unless no crosswind!
This is the Variometer. It shows you the rate of sink/climb. The large numbers
are the calibrations, in this (light) aircraft it goes from +4000 ft/minute to -4000 fpm.
The small number 5 indicates 500 fpm, a normal ascent/descent rate for a light aircraft.
In this picture we are descending at 450 fpm. Rates beyond about 2000 fpm will cause some
passengers to get ear-aches due to the rapid changes in air pressure. If this happens
to you, hold your nose and blow to equalise the pressure on each side
of your ear-drums :-) Airliners, which descend much faster, have a pressurised cabin.
The pilots can adjust the 'descent-rate' of the cabin air pressure independently
of the true descent rate. But sometimes they are painfully optimistic, especially
if you have a cold. Even worse for babies and pets, since they don't know to hold their noses and blow :-(
This is the most complicated instrument shown here. It is the VOR/GS indicator. VOR (VHF Omnidirectional Range) / Glide Slope.
On the receiver you dial in the frequency of the VOR or GS you want to use. You get those
frequencies from the instrument map (patience, Hamish, I'm getting to your answer,
bear with me). Then - using the knob at the 7 o'clock position - you set the direction
(to/from) the ground based VOR transmitter which you are receiving.
Here the direction 030° has been set at the top. The number 210° at the bottom
is the reverse direction, so you don't need to calculate it when in a hurry :-)
If you are not on the radial you chose (030° here) then the vertical needle will be deflected to the left or right.
Each dot of deviation on the central horizontal scale is a difference of 2° for a VOR.
On a Glide Slope the precision is much better. The horizontal needle shows you whether
you are
on, above, or below the Glide Slope (usually set to a 3° slope).
The barber-pole stripes inside at the
4 o'clock position are warning us here that the instrument is inactive, no
signal being received on the frequency chosen. Below the dial are three coloured lamps,
these light up when you pass the fan markers on the glide slope. The Outer Marker (OM) is 4 miles out, the Middle Marker(MM) is ½ , so they are telling you how far you have to go to the threshold of the runway on approach.
So, folks, given all this background information, and if I tell you that
this instrument panel (repeated below) is shown on an NDB approach to runway 08, you
now have 3 seconds to scan these instruments and tell me if you are going to make the
runway, or if not, what you need to do to ensure a safe landing? ;-)
Pilots should answer the question please, before proceeding to my explanation
under the picture below.
Look at the articial horizon. We're level, sinking with our nose below the horizon. That's OK.
Look at the compass. Our heading is 080°, the expected runway heading.
Altitude 1000 feet, sinkrate 450 fpm, so 2 ¼ minutes to ground.
Speed 100 knots, so 3.75 NM to ground. If that's right, then we must have passed the OM (and the
co-located NDB) which were 4 NM out. Check the ADF, yes, the NDB is behind us.
Hold on, the NDB track is 10° off to our left. So we need to correct 20°
to our left to heading 060° to get on track 080° to the runway; we deduce we have a crosswind from the left.
Unless our company or the approach plate deems otherwise, our regular IFR licence puts
our minima at 200 feet altitude and ½ mile visibility. So if we can't see the
runway environment (lights etc) from ½ a mile away at 200 feet altitude
we need to follow the missed approach procedure. Busting minima can kill you!
Now let's look at some IFR (instrument) maps which Hamish asked about.
There are basically two kinds, sharing a common set of symbols : the en-route airway maps and the approach plates.
As Hamish suggests the en-route maps do not show terrain, but show location,
frequency, morse recognition codes of the VORs and NDBs.
The straight lines joining them are the airways. An en-route map looks like this :-
The compass-rose circles about the size if a one Euro coin represent the VORs.
The one at the 9 o'clock position in this map is labelled as the Moulins VOR.
It transmits on 113.1 Mhz using the callsign MOU in morse (given as -- --- ..-).
We count 10 airways crossing there. The black triangle in the centre of the rose
tells us that this is a compulsory reporting point. To whom do we report passing overhead MOU? We call
Paris Control on 129.15 Mhz (see radio info block at the three o'clock position).
The NDB symbols are dotted annular rings and look like this
The other kind of instrument map is an approach plate. It looks like this :-
This is a DME (Distance Measuring Equipment) arc approach to runway 02 in Bowling
Green (Kentucky, USA). Dial the VOR/DME receiver to 117.9 MHz and identify (BWG).
Head for the IAF = initial approach fix (at the 5 o'clock position on this approach plate).
Follow an arc of 10 NM radius from BWG at 2500 feet until intercepting the radial 204°.
Track 024° inbound. The runway is 2.0 NM beyond the VOR.
Field elevation is 613 feet AMSL. If you miss the approach climb straight
ahead before turning back to the VOR within a 3 mile radius. Caution : there is an
obstuction reaching to 766 feet AMSL on the extended centreline.
The highest obstruction within the 10 mile radius is 1053 feet AMSL
at the 11 o'clock position. Everything you need to know to make a safe approach
all on one map :-)
If this all sounds easy peasy, let me assure you it is not! After all, if
the weather were great, good visibility, high cloud base, you would be
making a visual approach "Field in sight" from the 10 miles out or more :-)
So why are you on an instrument approach?
Often, real instrument approaches are made flying through turbulent crud
to minima as mentioned above. Gusting cross-winds add to the 'pleasure'.
Remember I said 200 feet minima? Bowling Green has a 153 foot obstruction on the extended centreline, so don't bust minima!, 'cos that obstruction is only 47 feet below
your minimum altitude! How accurate is your altimeter?
Certified to 3 hP (= +/- 24 ft). 23ft clear?
Well, I hope this short outline has answered everybody's questions in a manner
understandable to most/all of you. For more info here is some further reading:-
Meanwhile, on the iPod, I am listening to Mike Oldfield's song about making
instrument approaches in an old Beech 18 in really stormy weather. It is called
Five Miles Out
and is a great number. Here are
the lyrics.
Don't play it to your passengers though ;-)
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 Comments Policy Gallery (12 photos) Impressum Maths trivia Recent readership Search & Sitemap Skyline Meme Links  RSS Feed Dr. Stuart Savory, who is an overeducated, grumpy multilingual ex-pat Scot, blatently opinionated, old (1944-vintage), amateur cryptologist, computer consultant, flying instructor, bulldog-lover, Beetle-driver, textbook-writer, long-distance biker, blogger and webmaster living in the foothills south of the northern German plains. Not too shy to reveal his true name or even whereabouts, he blogs his opinions, and humour and rants irregularly. Stubbornly he clings to his beliefs, e.g. that he's not really evil, or even anti-american, in spite of Dubya's efforts to convince him that he should be. Oh, and he really has fun with his English Bulldog bitch.
Link Disclaimer ENGLISH : I am not responsible for the contents or form of any external page to which this website links. I specifically do not adopt their content, nor do I make it mine. DEUTSCH : Für alle Seiten, die auf diese Website verlinkt sind, möchte ich betonen, daß ich keinerlei Einfluß auf deren Gestaltung und Inhalte habe. Deshalb distanziere ich mich ausdrücklich von allen Inhalten aller gelinkten Seiten und mache mich ihre Inhalt nicht zu eigen.
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. The NDB in the centre of the map is
labelled Montceau les Mines, it broadcasts on 317.5 KHz
sending MM in morse for identification. There are lots of other
details which I'll ignore here.
This blog is not (even politically) correct. It consists of 72% satire & sarcasm,
31% scientific reporting, and at least 4% arithmetical errors ;-) Thus everything blogged
here should be taken with a pinch or 3 of NaCl.
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