12 October 2026 (Mon)

The back of the eye is lined with cells that take in light. Retinitis pigmentosa is an inherited disease in which those cells slowly die. More than a hundred genes can cause it, so making a medicine for each gene was a long road.

Instead of repairing the dead cells, the researchers gave the job to other cells. When the light-catching cells are gone, the cells that used to carry their signals to the brain are still there. Into those cells they injected the gene for a protein that opens when amber light falls on it. Then came goggles with a camera, turning the scene in front of the person into flickers of amber light shone into the eye. Seven of the ten became more sensitive to light, and of the eight who finished the behaviour tests, four improved at spotting objects or pointing to where they were. Finding a doorway and following a line on the floor worked too. Reading or recognising a face, however, is beyond it.

When a star runs out of fuel it sheds its outer layers and leaves the hot core behind. That core is a white dwarf. If heavy elements show up in such a star's atmosphere, something nearby is falling into it.

Researchers at the University of Warwick went back to Hubble data gathered twenty-five years ago. In one white dwarf's atmosphere they found zinc, copper, aluminium, silicon and titanium — and niobium, more than a thousand times as abundant as in the Sun. Heavy elements like that are not made by burning in a star's core; they build up as a dying star slowly gathers neutrons. So the team reads it this way: material thrown off as the star died gathered again into a planet, and pieces of that planet are now raining onto the star. The data also hold the trace of a planet going round every 4.4 days.

Hydrogen is a fuel that leaves only water behind when burnt. Today, though, most of it is taken from natural gas, and carbon dioxide comes out in the process. Splitting water instead is clean, but it needs electricity and expensive metal catalysts.

What the team built is a crystal in which metal ions are linked by organic molecules, leaving tiny pores throughout. The organic part contains sulphur. Under light the bond between two sulphur atoms briefly breaks, leaving a state that reacts readily, and that energy moves electrons so that hydrogen comes off. What marks this crystal out is that the organic part, not the metal, does the job of catching the light. It also forms by itself in water at room temperature.

In summer, patches of snow along the Antarctic coast turn green or red. It is the tiny algae living in the snow multiplying. Researchers at the University of Colorado Boulder collected snow algae across five degrees of latitude along the Antarctic Peninsula, choosing places with penguin colonies and places without.

Counting the cells and measuring what was in them, they found much more phosphate in the deeply green snow. Penguins eat at sea and leave their droppings on land, and those droppings are rich in phosphate. Given plenty of nutrients the algae stay green as they grow; when conditions are poor they make a red pigment that shades them. The trouble is the light. Red snow takes in about 20 per cent more sunlight than clean snow, and green snow about 40 per cent more — and melts that much faster.