Physics and Astronomy

Black holes really are holes – objects without a surface – say Drs Christine Done and Marek Gierlinski in a paper accepted for publication in the Monthly Notices of the Royal Astronomical Society. Having an “event horizon” rather than a surface is the property that makes something a black hole but, by definition, it’s impossible ever to see one directly. However, these new results give direct evidence of the existence of such holes in spacetime.

Drs Done and Gierlinski set out to track

Though Einstein put his foot down and demanded that nothing can move faster than light, a new device developed at the University of Rochester may let you outpace a beam by putting your foot down on the gas pedal. At 127 miles per hour, the light in the new device travels more than 5 million times slower than normal as it passes through a ruby just a few centimeters long.

Instead of the complex, room-filling mechanisms previously used to slow light, the new apparatus is small and, in the wor

Most people are familiar with the fact that sensitive instruments known as seismographs can detect earthquakes taking place many hundreds or thousands of miles away. By studying the waves from these tremors, scientists can find out about the conditions deep inside our rocky planet.

In the same way, astronomers are now able to measure millions of sound waves that propagate throughout the Sun, causing it to vibrate or ring like a bell. This technique, known as helioseismology, is the solar eq

In January 2002, a moderately dim star in the constellation Monoceros, the Unicorn, suddenly became 600 000 times more luminous than our Sun. This made it temporarily the brightest star in our Milky Way. The light from this eruption created a unique phenomenon known as a ’light echo’ when it reflected off dust shells around the star.

The brightness of V838 Monocerotis, as astronomers call the star, has long since returned to normal levels. Observations by the NASA/ESA Hubble Space

Early on the morning of 30 June 1908, the vast forest of western Siberia was illuminated by a strange apparition: an alien object streaking across the cloudless sky. White hot from its headlong plunge into the Earth’s atmosphere, the intruder exploded about 8 km above the ground, flattening trees over an area of 2000 square kilometres.

Despite the huge detonation, equivalent to a 10 megaton nuclear warhead (about 500 times the energy of the Hiroshima atomic bomb), there were few if any casu

Dramatic images reveal unique star explosion

In the early months of 2002, astronomers scanning the sky saw something highly unusual – and they still don’t know exactly what it is. A star suddenly flashed to 600,000 times its previous brightness. For a brief time, it was the brightest star in the galaxy.

As the light from the outburst spread into space, it reflected from surrounding rings of dust to reveal a spectacular, multicolored bull’s eye that is now 3 light