91热爆

There has been scepticism over North Korea鈥檚 claims of an H-bomb test due to the lower than expected magnitude of the tremor. Hugh Chalmers from VERTIC explains how traces of radioactivity in the air could confirm whether or not it was a hydrogen bomb.

Event Horizon Photo
Scientists are preparing ground based telescopes around the world to take a picture of the event horizon at the black hole at the centre of the Milky Way. 91热爆 science reporter Jonathan Webb reports on this and the latest space stories from the American Astronomical Society in Florida.

Pink Pigeons
Despite populations of the pink pigeon in Mauritius reaching roughly 400, the species is still threatened by extinction because of a lack of genetic diversity. Scientists are using genomics to select breeding partners in order to safeguard their diversity.

Metallic Hydrogen
Scientists think they have come close to creating a metallic state of hydrogen more than 80 years after it was first predicted. Dr Ross Howie from the HPSTAR institute in Shanghai explains how he and his colleagues from Edinburgh University exerted the equivalent pressure at the centre of the Earth on a tiny amount of hydrogen to create a mixed-state form of hydrogen.

New Solar Cells
A new type of solar cell has been developed by researchers at Oxford University鈥檚 physics department that could make current solar cells up to 30% efficient. The team made perovskite solar film and layered over the more common silicon cells which allows the cells to absorb a much wider range of light.

(Photo caption: Kuo Kai-wen, director of Taiwan's Seismology Center, points at the locations from a monitor showing North Korea's first hydrogen bomb test site 漏 SAM YEH/AFP/Getty Images)

Presenter: Jack Stewart
Producer: Ania Lichtarowicz