PhotoTat is a tattoo ink under study composed of photochromic molecules. Almost invisible, it colors in seconds with UV light and erases with intense white light. The new technology could be used for medical tattoos visible only in clinics, but it has only been tested on one person and safety …
The prime numbers form the Ulam Spiral: the diagonal alignment and the link with quadratic formulas
In the Spiral of Ulam the prime numbers are not arranged randomly, but occupy diagonal lines that have to do with relatively simple formulas. In 1963, to pass the time during a boring conference, the Polish-American mathematician Stan Ulam began writing down the natural numbers in the shape of a …
Collision between two helicopters in Nepal on Everest, one dead and 3 injured: why landing at 4,200m is difficult
Collision between two AS350 helicopters on Everest, Nepal. At around 4,200 metres, with thin air and without a control tower, the landing leaves very little margin for error for the pilots. The causes have not yet been clarified by the authorities. Today, November 3 2026, two helicopters AS350 yes they …
