AZ Central: Grand Canyon tourists exposed for years to radiation in museum building, safety manager says.
“For nearly two decades at the Grand Canyon, tourists, employees, and children on tours passed by three paint buckets stored in the National Park’s museum collection building, unaware that they were being exposed to radiation.
Although federal officials learned last year that the 5-gallon containers were brimming with uranium ore, then removed the radioactive specimens, the park’s safety director alleges nothing was done to warn park workers or the public that they might have been exposed to unsafe levels of radiation.
In a rogue email sent to all Park Service employees on Feb. 4, Elston “Swede” Stephenson — the safety, health and wellness manager — described the alleged cover-up as “a top management failure” and warned of possible health consequences.
In his letter to colleagues, Stephenson apologized for the untimely notice. He stressed that exposure may not be severe depending on how close individuals got to the source, how long they were exposed, what they were wearing, and other factors. He also emphasized that employees will not necessarily suffer health consequences, but should consider receiving a medical screening.
“Of particular concern are 1000s of children attending ‘shows’ in very close proximity to the uranium,” he wrote. Those presentations lasted a half hour or more, he said, yet radiation dosages could have exceeded federal safety standards within seconds.
Link via MetaFilter.
The Washington Post: Opportunity, NASA’s record-setting Mars rover, is declared dead after 15 years. “A eulogy for the spacecraft that transformed our understanding of the Red Planet.” By Sarah Kaplan.
“Opportunity’s historic mission, which uncovered signs of Mars’s watery past and transformed our understanding of the Red Planet, has finally come to an end after 15 years, NASA declared Wednesday.
The cause was system failure precipitated by power loss during a catastrophic, planetwide dust storm that engulfed the Mars rover last summer.
“It’s going to be very sad to say goodbye,” said John Callas, the mission’s project manager. “But at the same time, we’ve got to remember this has been 15 years of incredible adventure.”
Opportunity’s mission was planned to last just 90 days, but it worked for 5,000 Martian “sols” (which are about 39 minutes longer than an Earth day) and traversed more than 28 treacherous miles — two records for NASA.”
Link via MetaFilter.
NPR Science: As Magnetic North Pole Zooms Toward Siberia, Scientists Update World Magnetic Model.
“North is on the move, and that’s a problem for your smartphone’s maps.
Earth’s geographic north pole is fixed. But the planet’s magnetic north pole — the north that your compass points toward — wanders in the direction of Siberia at a rate of more than 34 miles per year.
That movement may seem slow, but it has forced scientists to update their model of Earth’s magnetic field a year earlier than expected so that navigational services, including map-based phone apps, continue to work accurately.”
NPR: The North Magnetic Pole Is Shifting East, Fast. “NPR’s Ari Shapiro speaks with Nature reporter Alex Witze about a rapid shift in the Earth’s magnetic poles.”
3Blue1Brown: The most unexpected answer to a counting puzzle and So why do colliding blocks compute pi? and How colliding blocks act like a beam of light…to compute pi. (YouTube, 5:12min and 15:15min and 14:40min)
The connection between the initial experiment and the calculation of π is surprising, and finding two different solutions in physics is even more astounding. The videos are extremely well done, and the presentation helps a lot with understanding the mathematical manipulations.
Link via Futility Closet.
BBC News: Parents’ vaccine side effects fear ‘fuelled by social media’.
“Fear of a vaccine’s side effects is the top reason for people refusing them, a report from the Royal Society for Public Health (RSPH) suggests.
Among parents, this was fuelled by social media, with up to half exposed to negative messages about vaccines.
The Society’s report called for social media platforms and the press to do more to combat “fake news”.
Millions of lives have been saved through vaccination, and side effects are rare, it said.
“The spread of misinformation – if it impacts uptake of vaccines – could severely damage the public’s health,” said Shirley Cramer, chief executive of the RSPH.
England’s chief medical officer Prof Dame Sally Davies recently said parents should ignore myths spread by anti-vaccine campaigners and get their children vaccinated.”
Sehe gerade, dass der Kinderdok mir zustimmt: Impfgegner sind eine Bedrohung für die Globale Gesundheit.