HAMNET Report 23rd October 2022

Michael ZS1MJT, our Western Cape HAMNET Regional Director, sent me a report about the Stellenbosch airshow held last Saturday. He says:

“On Saturday 15 October the Civil Aviation Authority held an international disaster reduction awareness campaign and HAMNET was asked to set up a display as part of the Aeronautical Rescue Coordination Centre (ARCC) section. The idea was to create awareness of all the different organizations involved when incidents happen. Other units there were SAPS diving unit, K9, SARZA, EMS, Stellenbosch Fire and Rescue, Accident and Incident Investigations Division, Air Traffic and Navigation Services.

“HAMNET WC set up a field station, banners and our gazebo. The idea was to try to make contact with some of the YOTA and CQ Hou Koers participants, activating on the same day, and, in this way, also educating visitors to the show as to how and where we can communicate. We also had SARTrack and APRS running on a laptop so we could explain how it works and everything we can do when we are called upon.

“The HAMNET stand was set up by 08h00 and we awaited the start of the show. Weather was a bit on the overcast side and later in the day, it rained. Fortunately, we had put up our gazebo, so we remained dry.

“HAMNET members that joined were:  ZS1SJ, ZS1MJT, ZS1ZV, ZS1BR, ZS1WW, ZS1ISS and ZS1RBT. We were also joined by a visitor to our region, Gert ZS2GS.

“During the course of the day, interesting talks were presented and there were some ‘flight’ challenges posed for the participating light aircraft pilots, testing their navigation and landing skills.

“This was a great opportunity to network with like-minded people, and mingle with the public. The show ended at around 17h00.”

Michael thanked all who participated. And thank you, Michael, for the report.

Grant ZS6GS, our HAMNET National Director has reported that Greg G0DUB has announced that the next QO-100 geostationary satellite comms exercise in IARU Region 1will take place on 29th October – that is, this coming Saturday. Details are at https://www.iaru-r1.org/about-us/committees-and-working-groups/emcomm/exercises-tests-and-meetings/qo-100-emergency-comms-exercise-oct-2022/
Greg has asked operators to feed station call signs through to him before the event as he is generating messages for each station. Thanks, Grant.

James, ZS1RBT, an active HAMNET member in the Western Cape has created his own QO-100 station, and has offered to set up his gear in a place convenient to our local members for Saturday’s exercise if there is enough interest.

The idea would be that HAMNET members here participate in the upcoming QO-100 exercise on 29 October, with the aid of ZS1RBT, and at the same time get an understanding of how the system operates for when we do get our own one up and running.

This is an excellent idea, and thank you to James for offering. All Western Cape operators interested in seeing how it all works are asked to make contact with Michael ZS1MJT so he can gauge whether the idea has merit.

Now here’s some advice for those of you planning on a Summit On The Air adventure or other type of DXpedition. Don’t do it alone! Go in a group. And here is why.

James Riordin, writing in Sciencenews.org says that even sperm cells gotta stick together! He says that bull sperm swim more effectively when in clusters, a new study shows, potentially offering insight into fertility in humans. In simulated reproductive tracts of animals like cattle and humans, the behaviour increases the chances that groups of cooperative bovine sperm will outpace meandering loners as they race to fertilize a female egg cell, physicist Chih-kuan Tung and colleagues reported on  September 22nd  in Frontiers in Cell and Developmental Biology.

The benefits of clustering don’t come down to flat-out speed. “They are not faster,” says Tung, of North Carolina Agricultural and Technical State University in Greensboro. “In terms of speed, they are comparable or slower” than sperm traveling alone. Like the sperm equivalent of herds of tortoises racing individual hares, the winners are not necessarily the swiftest but rather the ones that can stay on target.

On their own, sperm tend to follow a curved path, which is a problem, because the shortest distance between two points is a straight line. But when sperm gather in groups of two or more, they swim along straighter routes.

Whether alone, or in groups, sperm naturally tend to swim upstream. However, clusters of sperm in the experiment did a better job heading upstream into the mucus flow, while individual sperm were more likely to head off in other directions.

So combined singlemindedness of purpose will get you to your high site activation sooner than if you’re wandering around on your own. Biology doesn’t behave inefficiently!

And you heard it here on the HAMNET Report, first!

On 9th October, a beam of light more energetic than astronomers had ever seen, zipped past our planet, temporarily blinding detectors on several NASA satellites. The beam came from a Gamma-Ray Burst (GRB), the most energetic type of explosion known to occur in the universe (apart from the Big Bang), and which is believed to accompany the birth of some black holes.

Within hours, dozens of telescopes all over the world were pointing in the direction of the burst’s source, confirming that this, indeed, was one for the books. The event, officially named GRB221009A, has since earned the nickname BOAT (“brightest of all time”), and astronomers hope it will help shed light on the mind-boggling physics behind these cataclysmic phenomena.

“It’s a once in a century event, maybe once in 1,000 years,” Brendan O’Connor, an astronomer at the University of Maryland and George Washington University, told Space.com. “We’re just really in awe of this event and feeling very lucky to be able to study it.”

The gamma-ray burst of October 9 stood out even among the long-firing gamma-ray bursts previously observed, its photons bombarding satellite detectors for about 10 minutes. The energy those photons packed was higher than any that had been measured before. At 18 tera-electronvolts, some of the GRB221009A photons outperformed by at least a factor of two the most energetic particles produced by Earth’s most powerful particle generator, the Large Hadron Collider.

The burst’s afterglow, caused by the interaction of gamma-rays with cosmic dust, was out of the ordinary as well, outshining any other seen before despite the fact that GRB221009A emanated from a part of the sky obstructed by the thick band of the Milky Way galaxy. The burst was so powerful that it ionized Earth’s atmosphere and disrupted long wave radio communications.

Definitely a “Wow” signal for the astronomers!

This is Dave Reece ZS1DFR reporting for HAMNET in South Africa.