🚀 go-pugleaf

Dette m� da v�re nogle radioamat�r eksperimenter v�rdigt:

Ved hj�lp af f.eks. 1000 fasede radioantenner kan du lave afb�jende 
radiokegler, der kan g� bagom forhindringer - og sikkert ogs� modtage 
bagom forhindringer - f.eks. m�nen eller et h�jt bjerg. Ydermere spredes 
radiokeglen ikke. Kan nogen forklare ud af artiklen hvorfor?

Ved modtagelse burde de muligg�r at radioteleskoper kan n� endnu l�ngere 
ud - f.eks. bagom M�lkevejens centrum?

LoS (Line-of-Sight) krav for optimal radioforbindelse er ikke n�dvendig 
for f.eks. mikrob�lger - og muligvis kan langt mindre sendeeffekt benyttes:

Nov 30, 2012, Light bends itself round corners:
http://physicsworld.com/cws/article/news/2012/nov/30/light-bends-itself-round-corners
Citat: "...
Five years ago physicists showed that certain kinds of laser beam can 
follow curved trajectories in free space.
...
The concept of self-bending light was inspired by quantum mechanics and 
the realization in 1979 by Michael Berry and Nandor Balazs that the 
Schr�dinger equation could support "Airy" wavepackets of particles, 
which accelerate without an external force.
...
To do this they passed a centimetre-wide ordinary laser beam through a 
device known as a spatial light modulator that adjusted the phase of the 
beam at thousands of points across its width.
...
their interference produced a region of maximum intensity that curved 
sideways in the shape of a gentle parabola across the beam as it 
propagated forward, along with a number of fainter regions on one side.
...
other intriguing characteristics. One is that it is non-diffracting
...
The other unusual property is that of self-healing. This means that if 
part of the beam is blocked by opaque objects, then any disruptions to 
the beam's intensity pattern could gradually recover as the beam travels 
forward.

A limitation of the Florida work, however, is that Airy beams can only 
be bent through relatively small angles up to about 15 degrees.
...
A month later, two teams produced such beams in the lab � each bending 
light a 60-degree arc.
..."

Glenn/OZ1HFT