New Foundation License, Amateur Regulatory Changes Introduced in Australia
Australia has introduced an entry-level Foundation Amateur Radio license and established a new overall
licensing and certification structure. The Australian Communications and Media Authority (ACMA) put the
new regulations into effect October 19. Other rule changes combined Novice and Novice Limited licensees
into a new Standard license class, and all Limited, Intermediate and Unrestricted licensees are now
Advanced licensees with full amateur privileges. Wireless Institute of Australia (WIA) President Michael
Owen, VK3KI, welcomed the "long-awaited" changes--in particular the new Foundation license--and
expressed the hope that they would encourage newcomers.
Brigades On The Air
Worksop Amateur Radio Society is planning a new ‘On The Air' initiative. Following on from Museums
On The Air, Islands On The Air and Jamboree On The Air, the club wants to launch Brigades On The
Air under which radio amateurs would set up special event stations at local fire stations. The idea was
first put forward by ex-fireman Ken and has gained the support of the Worksop club. The
Nottinghamshire Fire Brigade has also agreed in principle to have an annual event staged at its
headquarters. Ken said: "We have checked to make sure that our radio equipment does not cause any
interference to their equipment." The club is planning special Brigades On The Air QSL cards and also
a certificate for those who contact the most number of stations. All profits from the initiative will go to
the Fire Service Brigade Benevolent Society. The Worksop Amateur Radio Society is keen to hear
from any other clubs interested in participating in the Brigades On The Air initiative.
Contact Clive, M0HHF, at email address: clivem0hhf@aol.com (GB2RS)
Science snapshot: London's bridge is swinging 'round
Over hill and over dale, soldiers march everywhere. Except bridges. There, synchronized steps might set a
bridge to swinging up and down and then apart, so instead soldiers break step. The flip side of this
phenomena seems to have afflicted London's Millennium Bridge, which tourists' steps somehow set to
swinging sideways in wild fashion, only a few days into its 2000 opening. The force of feet on a bridge isn't
the worry, rather it is their rhythm, says Cornell University's Steve Strogatz. If the frequency of the marchers
matches the bridge's own structural frequency, this "resonance" may begin to shake the whole works up and
down. This seems to have happened to cavalry troops who famously collapsed a bridge near Manchester
England in 1831. But on the Millennium Bridge, the situation was a little trickier, Strogatz writes in the current
Nature. For one thing, the bridge started oscillating wildly sideways instead of up-and-down. The engineering
firm that designed the bridge determined that it took about 160 walkers to set the structure swaying, and that
its sideways resonance frequency, unfortunately, seemed to match two footsteps a second -- a natural stride.
But all those tourists were walking across randomly, so how did they fall into rhythm and set the bridge to
swaying? "That's what makes it interesting," says Strogatz, an expert in natural synchronization, an area of
study that encompasses the coordinated flashes of fireflies and fatal heartbeats. His analysis shows that the
bridge, "does not move until the walkers cross a certain threshold and then it really takes off." What happens
at that threshold -- about 160 walkers -- is that just by chance enough will randomly step down simultaneously
to give a very small sideways motion to the bridge, via resonance. That tiny initial sway sets more people to
alter their step to match it, says Strogatz. The neat part is they do this unconsciously, he adds, with the
resultantly larger swing setting the bridge to swaying even more, making more people join, until, "people are
actually changing their stance, looking like novice ice skaters," he says. The bridge designers damped down
the swing by bulwarking the bridge. While some blamed its novel suspension design for the sway, its sideways resonance swing could have happened to any relatively loose bridge if enough people walked over it, Strogatz
says. "Anywhere you have crowds, you can have some interesting things happen."
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