Global temperature changes

Sciences et technologies — Thu, 03 Sep 2026 16:39:43 GMT

This animation shows the temperature from 1880-1884 to 2013-2017, as compared to a baseline average from 1951 to 1980. Blue colors were cooler and red warmer.

Source : https://commons.wikimedia.org/wiki/File:Global_temperature_changes.webm — NASA's Scientific Visualization Studio: Kel Elkins (USRA), Lori Perkins (NASA/GSFC) — licence domaine public.

YBCO video

Sciences et technologies — Thu, 03 Sep 2026 15:17:10 GMT

A superconductor or a high-temperature superconducting ceramics is an alloy of oxides of yttrium, barium and copper in proportions (which you see on the screen) YBa2Cu3O7-x and abbreviated as YBCO. In order to demonstrate the properties of this object let’s conduct an experiment. First, let’s take a small piece of ceramic and then put a piece of styrofoam and a powerful neodymium magnet on top of it. Next, the superconductor is cooled with liquid nitrogen down to -196 degrees Celsius. After the ceramic is cooled, take a piece of styrofoam out from underneath of the magnet. The effect of levitation is caused by the ceramics cooling down to the critical temperature, it then becomes a superconductor, as well as a perfect diamagnetic. This means that it can repel any magnetic field, as well as create its own when being near a strong magnetic field. The phenomenon is called the Meissner effect. If the magnet is lifted the conductor next to it begins to lift with it as well. The magnet and the superconductor are almost like "frozen" together in space.

Source : https://commons.wikimedia.org/wiki/File:YBCO_video.webm — Maxim Bilovitskiy — licence CC BY-SA.