HAMNET Report 2 June 2019

NewsHub reports that Elon Musk has enraged astronomers around the world, who are warning his SpaceX company is putting the future of astronomy at risk. Musk plans to encircle the world with 12,000 Starlink communications satellites, and launched the first 60 into orbit a few days ago.

The satellites are high-reflective, and they’re currently lighting up the night sky with a spectacular ‘train’ of lights. But scientists fear his plan for space domination could have dramatic adverse effects on their research.

A number of senior figures say the satellites will cause a massive spike in light pollution in the sky, affecting the use of large, sensitive ground-based telescopes. “The potential tragedy of a mega-constellation like Starlink is that for the rest of humanity it changes how the night sky looks,” Ronald Drimmel, from the Turin Astrophysical Observatory in Italy, told Forbes. “Starlink, and other mega constellations, would ruin the sky for everyone on the planet.”

Mark McCaughrean, the senior advisor for science and exploration at the European Space Agency, warns a drastic increase in visible satellites is a “chilling thought”. “The more I think about this, the more of a disaster it seems and not just for astronomers,” he tweeted.

“Just trying desperately to scramble for any possible way this can go well,” agreed science writer Mika McKinnon.

US astronomy student Victoria Girgis took a photo of what they look like passing in front of her telescope with a 25-second exposure. The result was a night sky smeared with satellites.

And Royal Institution of Australia lead scientist Alan Duffy, an astronomer at Swinburne University, warned the completion of the Starlink network will only make things worse. “A full constellation of Starlink satellites will likely mean the end of Earth-based microwave-radio telescopes able to scan the heavens for faint radio objects,” Duffy told ScienceAlert. “The enormous benefits of global internet coverage will outweigh the cost to astronomers, but the loss of the radio sky is a cost to humanity as we lose our collective birthright to see the afterglow of the Big Bang or the glow of forming stars from Earth”, he said.

Musk has defended his actions, variously arguing that the International Space Station also has lights, that his satellites won’t have any impact, SpaceX is working to mitigate any impacts, that even if they did have an impact it was for the “greater good”, and scientists need to upgrade their equipment anyway.

I, in turn, wonder what the effect on the Square Kilometre Array will be in Southern Africa. I am amazed that the concept of 12000 satellites, causing light and electronic pollution everywhere around the globe, got as far as the launch of 60 of them!

Writing for Phys.org, Mike Williams of Rice University says that wearable devices that harvest energy from movement are not a new idea, but a material created at Rice University may make them more practical.

The Rice lab of chemist James Tour has adapted laser-induced graphene (LIG) into small, metal-free devices that generate electricity. Like rubbing a balloon on hair, putting LIG composites in contact with other surfaces produces static electricity that can be used to power devices.

For that, thank the triboelectric effect, by which materials gather a charge through contact. When they are put together and then pulled apart, surface charges build up that can be channelled toward power generation.

In experiments, the researchers connected a folded strip of LIG to a string of light-emitting diodes and found that tapping the strip produced enough energy to make them flash. A larger piece of LIG embedded within a flip-flop let a wearer generate energy with every step, as the graphene composite’s repeated contact with skin produced a current to charge a small capacitor.

“This could be a way to recharge small devices just by using the excess energy of heel strikes during walking, or swinging arm movements against the torso,” Tour said.

“The nanogenerator embedded within a flip-flop was able to store 0.22 millijoules of electrical energy on a capacitor after a 1-kilometer walk,” said Rice postdoctoral researcher Michael Stanford, lead author of the paper. “This rate of energy storage is enough to power wearable sensors and electronics with human movement.”

The weekend of the 23rd to 26th of May was a busy time for the Peninsula Wilderness Search and Rescue (WSAR) teams. Four difficult rescues took place, two of them ending badly.

On the 23rd, a team responded to assist a climber injured after some rocks had fallen on him at Llandudno Corner. A helicopter lowered rescuers to the site, where two victims were found. A climber with a minor ankle injury was hoisted out and delivered to the landing zone, while a second more seriously injured patient was immobilised and packaged for safe hoisting and delivery to the landing zone.

On the 24th, a man was discovered just off a path in Newlands Forest to be deceased, and was carried off the scene down to a Metro Rescue Vehicle before being handed over to Forensic Pathology Services.

On the 25th, a climber became stuck on a ledge after sustaining an ankle injury above Woodstock Cave on Devil’s Peak. Again, a helicopter evacuation was needed, and two rescuers were lowered to the ledge. The hiker was secured in a special “nappy harness”, hoisted to the helicopter, and delivered to the awaiting ground crew at the landing zone.

And, on the 26th, a report was received of a cardio-pulmonary resuscitation being attempted on a person who had collapsed in Tokai Forest. Rescuers were able to drive along the forest jeep tracks to reach the area known as “level four”, near where a middle-aged man was found to have suffered a cardiac arrest while mountain biking with friends. Members of that group had immediately begun CPR while summoning help. After more than an hour, attempts to revive him were abandoned by the Metro Medical Rescue Technicians, and he was declared dead on the scene. Police Services attended to the removal of his body.

WSAR conveys its sincerest condolences to the families and friends of these two men.

HAMNET in turn salutes the work of the groups of volunteers comprising WSAR who took part in rescuing or retrieving the various parties.

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