For Berrimilla's first circumnavigation, the International Space Station
and the North West Passage, go to

Saturday, November 21, 2009

Freaks of the airwaves

Just possible there may be another Macca gig sometime after 0700 Sydney time Nov 22, 2000 UTC Nov 21. ABC Radio Australia, program Australia All Over.

SJ - instructions not followed! So much for reinforcement - and the HF died again just as I'd downloaded the 3 liner with the half page of unnecessary crud attached. Grateful if you could advise no more emails possible unless relayed through you but phone ok. Iridium too precious for extraneous garbage. Murphyalatermate.

Quickie to catch the propagation window

0630/21st position 2700 01132 trip 110 (all over the place...) and 1596 to CT

SJ - thanks mate and assumed as much - but never any harm in a bit of reinforcement!
Izz 'n'G Kool and gluey doods - thanks too.

Another trawl through the wheelie bin.

In a Eureka! moment, while engaging the neuronic trio in an explanation of the difference between magnetic and true courses I discovered (stumbled across) the origin of phosphorescence. Nothing to do with dinoflagellates, just the detritus of sloppy navigators. Everyone knows that Einstein hated the idea of entanglement in which one of a pair of particles can be shown to be 'known' to the other no matter how far across spacetime they may be separated. He called it spooky and kept trying to find an explanation because it appears to defy his general theory of relativity. Navigators have known about it since Prince Henry set up shop at Sagres - if you draw a line on a chart, all those entangled particles on the chart have their spin established by your pencil and all their partners out here on the ocean fire up and make a glowing line on the water that corresponds to the line on the chart. Then you come out in your ship and sail along it and before you can say dinoflagellisticexpiallidocious you have got to where you were going! Good, conscientious navigators always switch off the excited particles on the ocean as they pass so as not to confuse us lot who follow but we're not all so punctilious and phosphorescence is the result - terazillions of those excitedly spinning particles left behind by sloppy navigators higgledy-piggledy all over the ocean.

The difference between magnatic and true will have to wait - not half such fun.

One for the mythbusters if they haven't done it already, or any competent mathematician who can find the numbers. I have heard it said that there is a significant chance that in any day you breathe air that has been circulated so comprehensively by the world's meteorological systems to the extent that any breath might contain a molecule from Nelson's dying breath, or one of Henry VIII's belches (or worse) or Nefertiti's sneeze or a dinosaur's bellow. Presumably, the further back in time the more likely. So what are the chances that a molecule in the air I'm breathing now was once breathed by a slave building the Sphinx?

Or in similar mode, the human body is mostly water, which is circulated in the same way - what chance any part of me was once in the bilge of Leif Ericsson's Viking ship on the Greenland coast? Or of the puddle that Raleigh spread his cloak over for Elizabeth 1? Or even part of Raleigh before she had him shortened by a head for being presumptuous?

Enough already!

On ignoring the oblate shape of our spheroid

The GPS has two sets of numbers upon which we gaze with hopeful yearning - our latitude and longitude co-ordinates. Each reads degrees and decimal minutes & right now our latitude is 26.07.897 S read as twenty six degrees seven point eight nine seven minutes south. For the navigationally challenged, one minute of latitude is equal to one nautical mile so we are roughly 7.9 miles south of 26 degrees. The last digit (the 7 of .897) is one thousandth of a nautical mile or about 2 metres so as we sail along, the numbers increase or decrease depending on our direction. We are heading south west, so the latitude numbers (degrees and minutes south) are increasing by roughly 0.005 for every boat length we sail. The longitude numbers (now 012.38.023 W) are decreasing by roughly the same amount. Only roughly because a degree of longitude at 26 south is less that a nautical mile. Purists, please ignore the problems raised by diagonals and oblate spheroids for this little exposition. For the first time for what seems days, both sets of numbers are counting in their respectively correct directions. South is increasing and west is decreasing. YAY!

Another concept is Velocity Made Good or VMG. This is a calculated number based on our course and speed over the ground relative to where we are going. It is almost always different from our speed through the water and our speed over the ground but it is the best indicator of how efficiently we are sailing the boat and choosing our courses. On the last tack, our VMG for Cape Town was about 1 knot - then came the wind change we have been crossing all the appendages for and we tacked and now VMG for CT is 4.2 knots - much better but still not good enough to get us there by Dec 5th. We need a constant VMG of about 4.8 for that. Our speed through the water is about 6.2 knots and speed over the ground is 5.4 knots so we are in an adverse current of about 0.8 knots. Our required course over the ground for CT is 130M and we are actually making 167M which explains some of the discrepancies. Perhaps another burst on the difference between Magnetic course (M) and True course (T) and variation in another post.

Deborah, thanks for ISS and Atlantis info. As you can imagine, a big news hole out here - can't even get the Beeb world service without major hassle. I'm about to try using the mast as an antenna. Big Hi to Andrew - the Needles in 90+ knots I can only imagine.

Another word of explanation: Our ISS viewing times are roughly the 20 minute periods before sunrise and after sunset - while the ISS can see the sun and reflect its light towards us if they are anywhere near us bur as the sun is below our horizon the sky is dark enough for us to see the reflection quite easily.

Norm - thanks - jeers and ribald laughter from the crowd is what gets one foot out in front of the other again and again in those last 6km.