A delivery, a butterfly and the light in bubbles

Welcome to Positive Times, October seventeenth, twenty twenty-six. From the Italian mountains to projects in Bangladesh, we'll follow four stories, then explore the colours of soap bubbles.

UNICEF delivers medicines for leishmaniasis in Pakistan

On October sixteenth, UNICEF reported delivering seventy-five thousand vials of medicine to Pakistan's authorities to support treatment during a leishmaniasis outbreak in Khyber Pakhtunkhwa. According to the agency, over ten thousand five hundred cases have been reported in the province since the start of the year, including more than four thousand four hundred children under sixteen. The disease spreads through infected sand fly bites and can cause skin sores. The vials reached Peshawar and are due to reach selected facilities. Vials delivered do not equal patients already treated. The delivery is an important first step; distribution still needs to be followed closely over time.

• UNICEF Pakistan · UNICEF provides 75,000 vials of medicine to treat children affected by leishmaniasis in Khyber Pakhtunkhwa

Val Sesia surveys add detail about invertebrate life

On October fifteenth the Val Sesia protected areas reported that twenty twenty-six surveys recorded a male large blue butterfly in Val Vogna. This is the first record for the Natura two thousand site surveyed, not a species new to science: one sighting cannot count the whole local population. In Monte Fenera park, another survey counted sixty-five butterflies of a different species along a route. That number concerns the butterflies observed there, not every butterfly in the park. These observations help people follow habitats without turning every sighting into a general conclusion.

• Aree protette della Valsesia · Tre specie di invertebrati, nuove scoperte nelle Aree protette della Valsesia

UNDP signs twelve agreements for community projects in Bangladesh

On October fifteenth in Dhaka, the United Nations Development Programme signed agreements with twelve organisations in Bangladesh. The twelve projects concern biodiversity, ecosystem restoration and sustainable livelihoods. Areas include the Sundarbans, the Cox's Bazar and Teknaf coast, and the Hakaluki and Tanguar wetlands. Their goals include restoring mangroves and wetlands and protecting habitats. The signatures are a fact; environmental and social results still need to be checked.

• UNDP Bangladesh · UNDP Partners with 12 Organizations to Protect Biodiversity and Build Climate Resilience

SatSeaBio tests a way to observe marine life while sending less data

An October sixteenth update from the European Space Agency describes SatSeaBio, a project combining underwater cameras, an autonomous platform and communications to shore, including by satellite. The project aims to study marine life near offshore infrastructure. In two tests, the agency says, sending selected short clips instead of the corresponding full videos reduced the data volume needing transmission by more than ninety-nine point eight per cent. A candidate platform has already powered a camera at sea. Integrating and validating the whole system in a longer deployment remains to be done: two tests do not guarantee the same reduction everywhere.

• ESA Space Solutions · SatSeaBio

Why does a soap bubble change colour?

For our discovery: why does a soap bubble show colours without being painted? Light travels through a thin film of soapy solution. Some is reflected from the outer surface, and some from the inner surface. The waves overlap and can reinforce or weaken each other: this is interference. Different components of light respond differently, so the light reaching our eyes can appear coloured. In the experiment cited, a film held on a support helps show the principle; it does not describe every bubble in a room. In the experiments gravity pulls the liquid downward, changing the film thickness and observed bands. The viewing position matters too. Watch one near a window and move slightly: a single shade does not measure thickness.

• University of Iowa · Department of Physics and Astronomy · Thin Film Interference — Soap Films
• University of California, Santa Barbara · Physics Lecture Demonstrations · Soap film interference
• University of Colorado Boulder · Physics Undergraduate Labs · Interference in a Soap Film
• University of Toronto · Nigel Morris · Capturing the Reflectance Model of Soap Bubbles
• Purdue University · Department of Physics and Astronomy · Color in Thin Films

Find the full readings and sources in today's edition of Positive Times. Thank you and goodbye.