Dark matter: The world’s brightest physicists know it’s there, but can’t say for sure what it is.It is invisible, mysterious, and to most people — irrelevant to everyday life. But what if it could reach out and touch us? What if it already has, and so deeply that it just might be responsible for putting us here?One Harvard physicist is exploring that idea, and pondering the possibility that dark matter may have triggered the most famous cosmic collision ever — the one that did in the dinosaurs and opened the way for mammals to take their place.Theoretical physicist Lisa Randall, the Frank B. Baird Jr. Professor of Science, sees intriguing lines of evidence that tie dark matter to comets in the solar system’s distant Oort cloud, and from there to the 66-million-year-old impact crater on Mexico’s Yucatán coast.Randall first explored the idea last year in an article, co-authored with Assistant Professor of Physics Matthew Reece, in the journal Physical Review Letters. Inspired by the intricate chain linking dark matter, Earth, dinosaurs, and modern life, Randall decided to take a deep dive into the subject for her new book, “Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe.”“I was just fascinated by this story,” Randall said. “It was really nice for me to be able to communicate about dark matter through its potential connections to what we see today.”The book, to be published Oct. 27, takes the reader on a tour of the universe, from the Big Bang to today, from the story of life to mass extinctions, from the distant galactic disk to Earth’s K-T boundary layer — a thin, globe-spanning blanket of dust that scientists believe is evidence of the cataclysmic impact that ended the dinosaurs’ reign.The book suggests that a thin disk of dark matter could have influenced weakly bound comets in the outer regions of the solar system as it revolved around the center of the Milky Way, and may have been the ultimate cause of the impact. Randall admits that the disk hasn’t been found, but said that current data allows for it, and that instruments that might detect it aren’t far off.Randall makes liberal use of anecdotes and analogies to explain complex scientific ideas. We learn something about Randall, too: She skis, has a robot that vacuums her floors, and was once taken not for a cosmologist — one who studies the universe’s broad structure — but a cosmetologist.The dinosaurs’ demise is a dramatic example of connectedness. Scientists are reasonably sure the killer made an enormous impact, though there’s some question whether it was from a rocky asteroid that would have originated within the solar system or a comet originating at its far fringe, in a vast assemblage of icy bodies called the Oort cloud, far beyond the orbit of Pluto.If the dinosaur killer was a comet, the next question is, what gave it the initial push toward Earth? Scientists confronting that question have an additional clue: The impact that caused the dinosaurs’ extinction wasn’t the only one in the planet’s history. There have been several, in fact, and there’s some evidence that they occur at regular — at least on a galactic scale — intervals of between 30 million and 35 million years.The Oort cloud is so far away and the time scales involved so vast that investigators have sought answers outside the solar system, which circles the galactic center every 240 million years or so, moving up and down through the flattened plane of the galaxy as it does. Some researchers have explored whether that passage could possibly bump a comet onto a collision course with Earth, but the band of visible matter in the galactic disk is diffuse enough that the collisions it would trigger don’t match the timing of those on Earth.This is where dark matter comes in.While dark matter is invisible, it isn’t completely undetectable. All matter exerts a gravitational pull, and it is through dark matter’s gravitational effects on visible objects in the universe that scientists know it’s there.Unlike visible matter, however, dark matter isn’t concentrated in the galactic disk. It is thought to be spread in a sphere around the galactic center that extends well above and below the concentration of stars and other ordinary matter.But what if, Randall asked, there were more than one kind of dark matter? After all, there are many kinds of visible matter, and there’s a lot more dark matter than visible matter. Scientists estimate that 85 percent of all matter in the universe is dark, so why should it all be one kind?If there is a dark particle that is able to emit energy, as ordinary matter does, it would cool and condense, naturally forming a rotating disk around the galactic center. The hypothesized size of dark-matter particles — about 100 times larger than a proton — would create a disk up to 100 times thinner and 20 times denser than one created by visible matter, thin enough that the collision timing would match.“Suppose dark matter had its own photon,” Randall said. “It could radiate and form a disk and the consequences could be very interesting.”Randall, whose past work has dealt with concepts such as supersymmetry and extra dimensions, said that apart from research, educating the public about science is a high priority. Her three previous books were aimed at a general audience, and she’s worked in music, as well, writing the text for an opera based on her study of extra dimensions.To Randall, the story of the dinosaur impact — one of five known mass extinctions — resonates today in disturbing ways.“It’s so important to understand history,” Randall said. “There’s a sixth extinction going on. We’re losing so many species on this planet.”This sixth extinction is a product of human activity. If readers of “Dark Matter and the Dinosaurs” take away nothing else, Randall said, she hopes they gain an understanding of just how interconnected elements of the universe can be, and how strongly humans are linked to non-human life on the planet.
Share NewsSports Results of the 2011 LIME DABA Premier Division Playoffs by: – September 1, 2011 Share 19 Views no discussions Tweet Sharing is caring! Share The Premier Division playoffs action continued on Wednesday , August 31st played at the Lindo Park hard court with two exciting game 2 encounters.In the first game of the evening, the former National Champions, Gatorade Blazers came up against the 2011 Ball-a-rama Champs Dragon Stout Pros with a 1 – 0 lead in the best of 3 series, looking to close things out and punch their ticket to the finals. The Blazers started the game in spectacular fashion, jumping out to an early 27 – 17 lead at the end of the 1st Quarter.From that point on, the Pros always seemed to be on their heels trying to playing catch up and although they were able to make a good run in the third quarter, they clearly ran out of gas in the 4th Quarter. At the end of the game the final score read 77 – 67 in favour of the former Champs, Gatorade Blazers. Top scorers for Blazers were Thomas Felix with a game high 22 points, Javeed Joseph with 18 points, Ricky Toussaint with 14 points and Jeff Jeremie supporting with 10 points while Ramal Carbon and Hakeem Dangleben each had 17 points, and Shaka Dangleben had 15 points in a losing effort for the Pros.The Blazers have now earned their place in the finals where they will be looking to regain their Championship glory.In game 2, the undefeated National Champs, Sign Men X-Men were also looking to close out their series against No-Look and revive their rivalry in the finals against the Blazers. No-Look, however were not prepared to rollover and play dead. With both teams missing their big men in Garth Joseph for No-Look and Peter Ricketts for X-Men, the game was a lot more up tempo and frenetic than their normal style of play, which resulted in a lot of turnovers and fast breaks for both teams.The No-Look team got out to a great start with veterans Bernard Mills and Fletcher LeBlanc doing most of the damage in the 1st quarter, combining for 13 points, which was more points scored by the whole X-Men team in the quarter, 11. No-Look held a 21 – 11 lead at the end of the 1st Quarter. X-Men outscored No-Look 13 – 10 in a low scoring 2nd Quarter and the score at halftime was 31 – 24 for No-Look. No-Look stepped up their defense in the 3rd quarter and took a commanding 47 – 35 lead heading in the 4th Quarter.It was a different story in the final quarter as X-Men stormed back into the game and were able to cut the lead to 3 points with just over 1 minute left as No-Look seemed to panic and make poor decisions on offense. No-Look, however would not be denied as their star player Bernard Mills took charge of the game, scoring all of his teams points in the final quarter, which included making his free throws down the stretch to seal the victory for his team.At the end of the night, it was No-look handing X-Men their first loss of the 2011 season with a narrow 57 – 54 win. Top scorers for No-Look were Bernard Mills with a game high 28 points, Ken Leslie with 12 points, and Fletcher LeBlanc chipping in with 10 points, while Davidson Toulon had 18 points, Simon Joseph had 12 points and Ivan Jno Baptiste had 10 points in a losing effort for the X-Men.No-Look’s win ties the best of 3 series at 1 – 1, with game 3 guaranteed to be a thrilling encounter as it’s a do or die game for both teams, with the winner heading to the finals to challenge the Gatorade Blazers.By: Damien SorhaindoDominica Amateur Basketball Association
LocalNews High Court judge denies bail application for Kessler Alcendor by: – January 24, 2012 Share Share 65 Views 2 comments Share Tweet Sharing is caring! Kessler Alcendor of GoodwillHigh Court Judge Brian Cottle has denied bail to a male adult of Goodwill despite articulate and persuasive representation by his attorney Bernard Wilshire.Alcendor and Joseph Alexander jointly appeared before Magistrate Candia Carette-George on January 6th, 2012 in relation to five firearm related charges and were both denied bail based on the Police Prosecution’s objection who argued that they needed additional time to carry out their investigations.On Tuesday before the opening proceedings of the January 2012 Criminal Assizes officially began, Justice Cottle announced that the Court would hear an urgent bail application regarding Alcendor.Wilshire told the Court that the matter of liberty of any human being is a matter of urgency considering that his client has been imprisoned for a month and that the others who were jointly charged with him have been granted bail. He added that of significance was the fact that one of magistrate’s concerns in not granting bail was that Alcendor committed this alleged offenses while on bail for previous offenses. Wilshire stated further that the trial is scheduled to commence in April of 2012 while his client’s girlfriend is pregnant and having complications in his absence and needs his support during this trying time. According to Wilshire the principle in law that a person is innocent until proven guilty should also be looked considering that his client has pleaded not guilty to all of the charges. Justice Cottle told Wilshire that is concerned that his client armed himself with a shot gun without a valid license and use it to seek out people who were adverse to him in public knowing that he was already on bail for other offenses.Wilshire explained that the circumstances under which these offenses occurred were significant as his client only attempted to assist his friend who was robbed of his gold chain. He noted that the incident was not pre-meditated but merely a reaction to a perceived threat. An action Wilshire admitted was “undesirable” but understandable. According to Wilshire his client is in a stable relationship and comes from a close family who unfortunately lives in a “rough part of town” where there is a growing culture for persons to take matters into their own hands. He says there is frequent complaint from the public that police officers do not respond when they are called for assistance.Justice Cottle said in response to Wilshire’s argument that his client should be granted bail considering that the others with whom he was jointly charged had been granted bail, that he could only adjudicate on matters before him.Justice Cottle told Wilshire unfortunately he did not serve the Director of Public Prosecutions and so they could not respond and although he had been extremely articulate and persuasive he could not identify the error which the magistrate therefore the Court will not grant bail at this time.He also told Wilshire that it is within his discretion to make fresh application when and as he sees fit.Dominica Vibes News