We need to celebrate the successes on the infectious diseases front and there has been a huge one that has been overshadowed by the focus on covid-19.There are many diseases that are water borne and create immense suffering to people who do not have access to clean water. One of those diseases is caused by the guinea worm. The good news is that tremendous strides have been made in combating it.

While the COVID-19 pandemic continues to rage around the world, another disease could be on its way out. Only 14 cases of infection with Guinea worm – a parasite that causes painful skin lesions – were reported in humans in 2021.

This is the lowest tally ever for an infection that, as recently as the 1980s, was found in more than 20 countries and infected 3.5 million people a year (see ‘On the way out’) – however, a remaining reservoir for the parasite in animals means eradication could be a while off, if indeed it is possible, say some scientists.

“It’s pretty amazing,” says Adam Weiss, director of the Guinea Worm Eradication Program of the Carter Center, which is headquartered in Atlanta, Georgia. The centre announced the numbers in late January. “Fourteen people on a planet of almost eight billion. It’s mind-bending to think about.”

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There has emerged a rough rule of thumb for face masks that says that when it comes to reducing the chances of transmission of the covid-19 virus, N95 masks are the best, with paper surgical masks next, and cloth masks the least effective, compared to wearing no mask at all Now the CDC has come out with a study that provides a more quantitative comparison.

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There is a very strong desire among some segments of the population to make contact with dead people. This desire has been exploited by charlatans, people who claim that (for a fee, of course) they can channel your loved ones. The methods used have varied over time. In the US, the rise in interest in communicating with the dead coincided with the Civil War that saw massive numbers of dead people that left their families devastated and seeking some form of comfort.

In the mid-19th century, in the early days of photography, the husband and wife team of William and Hannah Mumler created a sensation by taking photographs of people that showed the ghosts of their dead loved ones hovering around them, such as this one of the ghost of Abraham Lincoln standing behind his wife Mary Todd Lincoln.
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The pandemic with its virus mutations has rekindled my interest in the mathematics of evolution. Way back in 2007, I wrote a 20-part series of blog posts on evolution. This was way ‘out of my lane’, as the kids say these days, since I am a physicist and have zero formal training in biology, having taken my one and only course in that subject when I was in eighth grade. But I did this for the same reason I write about a lot of things, in order to force myself to learn about a topic that interests me and to sort out my ideas.

One of the things that had intrigued me is how a mutation that occurs in just one organism could become not just dominant in the population but end up being the only one. In some posts in the series, I discussed the mathematics of how this happens, which I have edited and reproduce here.
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When it comes to wearing masks during the pandemic, not all masks are equal in the protection they provide. From what I have read, cloth masks seem to provide the least protection, though they allow the wearer colorful options and the ability to make some kind of statement, though why some people feel the need to make statements through their attire is something that I find puzzling. The blue surgical masks appear to be better than cloth and the N95 masks are the best. But while the surgical masks are relatively cheap, the N95 masks are pricey (ranging from $1 to $3 each) and that raises the question of how long one can use them and whether they can be reused.

The good news is that the answer is yes, based on the fact that the coronavirus has a survival time of about 72 hours when outside a host.
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The space telescope has reached its destination of the second Lagrange point.

The mirrors on the space observatory must still be meticulously aligned and the infrared detectors sufficiently chilled before science observations can begin in June. But flight controllers in Baltimore were euphoric after chalking up another success.

“We’re one step closer to uncovering the mysteries of the universe. And I can’t wait to see Webb’s first new views of the universe this summer!” the Nasa administrator, Bill Nelson, said in a statement.

“Wow, what a ride this last month it’s been,” said Amber Straughn, a deputy project scientist for Nasa.

The telescope has been described as a “time machine” by scientists and will enable astronomers to peer back further in time than ever before, all the way back to when the first stars and galaxies were forming 13.7bn years ago. That’s a mere 100m years from the Big Bang, when the universe was created.

The Webb will also hunt for signs of extraterrestrial life.

Considered the successor to the Hubble, which orbits 330 miles (530km) up, the Webb is too far away for emergency repairs. That makes the milestones over the past month – and the ones ahead – all the more critical.
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Whether chasing optical and ultraviolet light like the Hubble or infrared light like the Webb, telescopes can see farther and more clearly when operating above Earth’s distorting atmosphere. That’s why Nasa teamed up with the European and Canadian space agencies to get Webb and its massive mirror – the largest ever launched – out into the cosmos.

So far, things have gone really smoothly for this highly complicated mission but there are still challenges ahead. One can only hope that now that the major hurdles have been overcome, especially the whole business of unfolding of a tennis court size structure from the small confines of a rocket nose cone, that some small glitch does not ruin things.

The whole operation reflects great credit on all the engineers and scientists who were involved in designing, building, and launching it.

(Previous posts in this series: Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10, Part 11, Part 12, Part 13, Part 14)

This series started by asking a simple question, whether a charged particle and a neutral particle would fall at the same rate when dropped from the same height and reach the ground at the same time. You would think that it would have a simple answer. But no. After a fairly long journey, we arrived at the conclusion that they would. But in the process, the series had to address a whole host of related issues along the way. While many of those were seemingly resolved, there are some fundamental questions that remain murky.

We saw in part #13 that the mass of a point charge like an electron is not a simple thing, because an electric charge has an associated electric field that itself has energy and thus should be thought of as contributing to the mass, except that the field energy density goes to infinity at zero distances, which is of course awkward for point-like charges. By looking at the radiation reaction force created by an accelerating charge, we learned about something called the acceleration energy Q that increases with the speed of a charge, and the energy radiated by a linearly accelerating charge comes from this source.
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