Monday, December 8, 2014

Forceful companion eating

Science writer Brian Clegg details some large scale effects of gravity on bianary star systems:

"When binary stars are relatively close together,  the tidal forces each star can produce are considerable. Unlike planets, stars aren't solid, so often this results in plumes of stellar material being ripped from one star by the tidal forces and collected by the other as it forcefully eats its companion."

from Gravity, 2012


Macfarlane on Border Crossings

In Robert Macfarlane's recent book The Old Ways, he accounts for walks on paths as old human movement itself.  One such path he writes about is the Broomway, a notorious tidal path off the Essex coast of England:

We lack - we need - a term for those places where one experiences a 'transition' from a known landscape onto  . . . somewhere we feel and think significantly differently.  I have for sometime been imagining them as 'border crossings'.  These borders do not correspond to national boundaries, and papers and documents are unrequired at them.  Their traverse is generally unbiddable, and no reliable maps exists of their routes and outlines.  They exist even in familiar landscapes, there when you cross a certain watershed, treeline or snowline, or when you enter rain, storm or mist, or pass from boulder clay into sand, or chalk into greenstone.  Such movements are rites of passage that reconfigure local geographies leaving known places outlandish or quickened, revealing continents within countries . . . .
That hour, walking out - back - into Doggerland, was an hour I will never forget.  We did not know where the sand would slacken to mud, and yet somehow it never felt dangerous or rash.  The tide would hold it out and we had two hours in which to discover this vast revealed world: no more than two hours, for sure, but surely no less.  The serenity of the space through which we moved calmed me to the point of invulnerability, and thus we walked on.  A mile out, the white mist still hovered, and in the haze I started to perceive impossible forms and shapes: a fleet of Viking longboats with high lug rigged square sails; a squadron of fulucca, dhows and sgoths; cityscapes (the skyline of Istanbul, the profile of Houses of Parliament).  When I looked back, the coast line was all but imperceptible and it was apparent that our footprints had been erased behind us, and so we splashed timelessly on out into the tidal mist.  It felt at that moment unarguable that a horizon line might exert as potent a pull on the mind as a mountains summit.

here, ink and silverleaf on paper, book page from collaborative project with artist Teresa Getty

The Doggerland to which MacFarlane refers was an area of land that connected Great Britain to mainland Europe during and after the last Ice Age. It was then gradually flooded by rising sea levels around 6,500 or 6,200 BC. and now lies under the southern North Sea.  So, the moon's gravitational pull not only allows pedestrian travel on otherwise unwalkable paths to islands off the coast of Essex, it allows for time travel as well.