A teacher says, “Okay, class. Today we’re going to be talking about the tenses. If I say ‘I’m beautiful,’ which tense is it?”
Little Johnny raises his hand and says, “Obviously past tense, Miss.”
Pulsar discoveryIn 1967, the first pulsating radio source (pulsar) was detected by an alert graduate student, Jocelyn Bell, then working under the direction of Prof. Anthony Hewish at the Mullard Radio Astronomy Observatory, Cambridge, England. A special radio telescope was used, with 2,048 antennae arrayed across 4.4 acres. By 13 Nov 1998, one thousand had been found. The pulsing of the radiation has clock-like precision , up to 1,000 times per second. A pulsar is believed to be a neutron star with exceedingly rapid spin. Rotational periods range from 1.57 milliseconds to 5.1 sec. Pulsars prompted studies of quantum-degenerate fluids, relativistic gravity and interstellar magnetic fields. Similar behaviour of a star flashing in the optical spectrum was detected on 18 Jan 1968.Optical pulsars remain very rare.« |
