Gravitational waves are ripples in spacetime which are created whenever objects with mass move. They were predicted by Albert Einstein in 1916 on the basis of his theory of general relativity. They were first directly detected on 14 September 2015.
To make gravity waves strong enough to be detected, something very massive must accelerate very fast. Sources of detectable gravitational waves include binary star systems composed of white dwarfs, neutron stars, or black holes.
In physics, gravitational waves are ripples in the curvature of spacetime that travel outward from the source. Albert Einstein predicted them in 1916 on the basis of his theory of general relativity. In theory, gravitational waves transport energy as gravitational radiation.
In general relativity, gravitational waves cannot travel faster than the speed of light. They do not exist in the Newtonian theory of gravitation, in which physical interactions propagate at infinite speed. However, the detection of gravitational waves proves the last prediction of Einstein’s general theory of relativity.
In 1993, the Nobel Prize in Physics was awarded for measurements of the Hulse-Taylor binary star system that suggests gravitational waves are more than mathematical anomalies.
Gravitational waves have been detected from the collision and merging of two neutron stars. The first detection was on 17 August 2017 by a team in Pasadena, California.
The project is run by the LIGO Laboratory at Caltech. The detector is in the huge Livingston woodland in Louisiana. The detector is two two and a half mile (~4 km) long completely straight pipelines at right angles. Inside each pipe is a laser which measures any change in length. Once the gravity wave event was detected, telescopes searched for visual images of the cause. The VISTA telescope in Chile got the image.
The merging happened in a galaxy called NGC 4993. This is about 40 mega parsecs or 130 mega light years away in the direction of the Constellation Hydra. By comparison, the nearby Andromeda Galaxy is only 2.5 million light years from Earth.
Such events, as well as supernovas, are the sources of heavier elements such as gold and platinum.
Silver Street railway station
Silver Street is a railway station in Sterling Way, Edmonton in North London, close to Fore Street.
The next station away from London is Edmonton Green and the next towards London is White Hart Lane. Trains terminate at Liverpool Street station in the City of London.
Rock pigeon
The rock pigeon (otherwise known as a rock dove or common pigeon) ("Columba livia") is a member of the bird family Columbidae, commonly referred to as simply pigeons. They can be seen scrounging around dumpsters, picking up French fries dropped near the door to a fast food restaurant, and begging from picnickers in the park. They have long necks.
Twelfth Night
Twelfth Night, Or What You Will is a play written by William Shakespeare. It is a comedy.
Orsino, the Duke of lllyria, is in love with the Countess Olivia. She is not dating men for seven years because of the death of her brother, so she turns him down. Meanwhile, Viola was shipwrecked in Illyria but she has been rescued by a captain. She has lost her twin brother, Sebastian. She dresses herself as a boy and uses the name Cesario, so she can get work as a page for Orsino. As Orsino's page, Viola is sent to Olivia with love letters. Viola finds out, to her dismay, that Olivia has fallen for her (as a boy) rather than Duke Orsino. Also, Viola has already fallen in love with the Duke.
Sebastian (Viola's twin, thought to be dead) comes ashore in Illyria. He thinks Viola has drowned in the shipwreck. A man named Antonio has rescued him from the surf; at some risk to himself, because Antonio fought against the Duke at one time. Meanwhile, in Olivia's house, Sir Toby Belch (her cousin) has tricked Sir Andrew Aguecheek into supporting him, by convincing him that he could be a suitor for Olivia. So with the help of Maria, Olivia's maid, and Feste, a clown, Belch plots to make a fool of the steward. Maria writes a love letter to Malvolio that will make him think Olivia has fallen for him. Malvolio falls for the joke and dresses crazily as the letter says to. Not knowing it is a joke, the Countess is horrified and has Malvolio locked away as a madman.
Belch tries to get Sir Andrew to fight a duel with Viola's "Cesario" character as she leaves but Olivia has a crush on Cesario. Viola and Sir Andrew prepare for a duel that neither one wants. Antonio intervenes to defend Cesario, because he thinks he is his friend Sebastian, and is arrested for piracy against Orsino. Olivia has become engaged to Sebastian. Viola still does not recognize Antonio. Later, Belch and Sir Andrew talk to Sebastian, who does not back down from Aguecheek when challenged and beats him in the duel. Meanwhile, Olivia has met and become engaged to Sebastian.
Antonio is brought before the Duke for questioning, and Viola tells all about the duel. Antonio tells everyone how he dragged "this man" from the surf, saving his life. Then Olivia comes in, searching for her new husband, which she thinks is Viola. Adding to this confusion, Belch and Aguecheek enter claiming that Viola/Cesario has violently assaulted them. In the midst of Viola's denials, Sebastian shows up. The brother and sister recognize one another and are reunited. Sebastian helps to explain the confusion over who fought and married who.
In the end, Orsino and Viola are in love. Olivia and Sebastian are happily wed, and Olivia fusses at Belch and Maria for their abuse of Malvolio, who vows to get even. Belch agrees to wed Maria to make up for getting her in trouble. Everyone, except unhappy Malvolio, lives happily ever after. Orsino welcomes Olivia and Sebastian and he now realises he is attracted to Cesario. He promises to marry her as soon as she is dressed as a woman again.
Hinckley
Hinckley is a town in the Leicestershire.
Quokka
The quokka ("Setonix brachyurus") is a small marsupial about the size of a large cat. Like other animals in the macropod family, such as kangaroos and wallabies, the quokka eats grass and small plants, and is mainly nocturnal. It lives on some small islands off the coast of Western Australia, mainly on Rottnest Island near Perth, and Bald Island near Albany. A small number live on the main land in the protected area of Two Peoples Bay, which they share with Gilbert's Potoroo. The quokka is the only member of the genus "Setonix".
The quokka weighs between and . It is around long with a tail. This is short for a macropod. It has a solid build, rounded ears, and a short, broad head. It looks like a very small, fat kangaroo, but it can climb small trees and shrubs. It has rough fur which is a brown colour, fading to pale brown underneath. The quokka eats a small amount of its waste products.
It is about the size of a domestic cat.
The quokka is a social animal and lives in large groups. They eat grass, sedges, succulents and leaves. They can become very sick if fed with things like bread, given to them by visitors to Rottnest Island. Visitors are now told not to feed them. Quokkas breed at any time on the mainland, but in late summer on Rottnest. The female quokka has two babies (called "joeys") in a year.
The quokka moves in the same way as a kangaroo, using both small and large hops.
Quokkas are not scared of people, so you are able to get quite close to them, particularly on Rottnest Island. It is against the law on Rottnest Island to handle or touch the animals in any way. A A$100 fine can be given by the Rottnest Island Authority for picking up a quokka. People can even be taken to court and get a fine of up to $1000. These fines have been used in some unusual cases where quokka have been hurt or killed by visitors to Rottnest.