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Tweaking the universe

first_imgScientists with the European Space Agency’s Planck satellite program released findings last week that refined our understanding of the universe, showing it to be a little older, containing a bit more mysterious dark matter, and expanding a tad slower than previously thought. The satellite, launched in 2009, provided the most precise map so far of what scientists call the “cosmic microwave background,” the faintest echoes of the universe 370,000 years after the Big Bang, the originating cosmic explosion. That later time represents a key moment in the universe’s history, when the hot gas from the Big Bang finally cooled enough to become transparent, allowing radiation to escape for the first time. In a question-and-answer session, Gazette Staff Writer Alvin Powell talked with Harvard Astronomy Department Chair Avi Loeb, the Frank B. Baird Jr. Professor of Science and a theoretical astrophysicist studying the early universe, about the findings.GAZETTE: What can you tell us about the Planck satellite and the data that was released last week?LOEB: This experiment is the most precise map that we have ever had of the temperature fluctuation of the cosmic microwave background. The bottom line is not really revolutionary or paradigm-changing, however. Basically, it’s a confirmation of the standard model of cosmology, but with much better data than we had.GAZETTE: What is the cosmic microwave background?LOEB: The cosmic microwave background is the radiation left over from the universe’s early hot, dense phase.The universe became transparent to this radiation about 370,000 years after the Big Bang. Prior to that, the gas was much too hot to make atoms. Free electrons in the gas were able to scatter the radiation very effectively. As soon as the universe cooled below a few thousand degrees, electrons and protons combined to make hydrogen atoms. Once electrons were trapped in atoms, radiation was able to stream freely.What we see from the cosmic microwave background is that there were small differences in the temperature or the brightness of the radiation from one region to another, and that’s what we’re trying to map.GAZETTE: Why does the temperature of the early universe matter, and how is that related to the universe today?LOEB: Variations in temperature in the microwave background represent variations in the density of matter in different regions. That’s how objects were made. The Milky Way galaxy, for example, was made from a region that had higher-than-average density that ended up collapsing on itself.So when we look back in time at the microwave background, what we’re looking at is the initial conditions that led to the formation of structure we see today in the universe.That’s why it’s so important, because it teaches about the early conditions in the universe that led to the formation of structure and complexity in the form of galaxies and groups of galaxies today.It is sort of like a Rosetta stone. By reading it off, by reading those maps and statistically measuring the level of variation, we can actually decipher what the initial conditions in the universe were.It’s also important for fundamental physics, because the nature of dark matter and dark energy, as well as the question of what produced these variations in the density of matter from one place to another, remain a puzzle.GAZETTE: What revisions did the new measurements make in our understanding of the universe?LOEB: It made the universe a little bit older than we thought, 13.82 billion years old instead of 13.75 billion years. It’s not a major revision.If you look at the cosmic pie in terms of the budget of matter in the universe today, the amount of dark energy went down. It was previously 72 percent and is now 68 percent. Ordinary matter stayed at 4.5 percent, and dark matter is now 27.5 percent. These are very small changes. Overall, the picture remained the same.The other thing that changed is the Hubble constant, the rate of expansion of the universe. The best value for it now is 68; previously it was close to 70 kilometers per second per megaparsec.The other thing was that in recent years there were suggestions for revisions to the standard model of cosmology. Some people suggested there was a fourth generation of neutrinos (low-mass subatomic particles). We know of three neutrino species in particle physics, but there may be evidence in some data sets for a fourth neutrino. The need for a fourth neutrino was removed with the Planck data.Planck also addressed questions about whether the geometry of the university is flat or curved. According to Einstein’s theory of gravity, space-time can be curved. Planck found that the universe is flat.Early on, the universe inflated from very small to a huge scale. That inflation served as a cosmic iron. It basically flattened any ripples that were imprinted on space because it took a small region and stretched it, just like when you take a balloon and blow it up. When a balloon grows very big, the radius is so huge that when you’re sampling a small portion, it appears very flat.That’s what inflation did; it inflated the universe to have a very flat geometry. We know that to the precision of a tenth of a percent now.So basically what Planck is doing is tightening the error budget that we have on all the cosmological parameters, but it doesn’t change the standard cosmological model.GAZETTE: There was some mention in reports of the data showing the universe being lumpier than initially thought. What about such anomalies?LOEB: The microwave background is lopsided slightly … the statistics of the variations of the temperature in one hemisphere is different from the opposite hemisphere. I would say the evidence is sort of marginal. It doesn’t make the entire community say, “Oh, something is fundamentally wrong with the standard model.”On the other hand, it’s on the borderline of being peculiar, and so some people are thinking about it. Maybe it does give us a hint of something beyond the standard model of cosmology.Then there’s a cold spot in one region of the sky, which was also known before, though Planck showed us the crispest image we have. If you ask yourself, “What’s the chance of seeing a cold spot of this size,” it’s not negligible; it’s quite possible that this is just random.There is another anomaly. On large scales, the microwave background sky appears to be smoother than we expect. On small scales, it seems to be perfectly matched to the standard cosmological model. But on very large scales, it seems to be smoother than expected. Again, it makes some people uneasy, but it’s still marginal.A reasonable cosmologist would sleep well and say it’s just a fluctuation and random deviation, but there are some who are thinking about it. It may be possible that it tells us something about physics beyond the standard model.GAZETTE: So what are the overall lessons from the Planck data?LOEB: The big picture is that it confirms what we thought about the standard model of cosmology.The truth, though, is that we still don’t understand what the dark matter is, and we don’t know what dark energy is. So even though we can pat ourselves on the back that we know the composition of the universe to a very high precision, and we sort of understand how to describe statistically the initial conditions of the universe on the microwave background sky, we still have gaping holes in our understanding of the substance of these components, and that remains unanswered by the Planck data.To answer those questions, we need more data in cosmology, or maybe laboratory experiments that will reveal the identity of the dark matter and, possibly at some point in the future, what dark energy is made of.It sharpens our ignorance about the nature of the dark matter and dark energy. It makes it even more exciting to figure out what they are.last_img read more

Kenny Leon Discusses Directing Hairspray Live! in the Wake of the Election

first_img Tony-winning director Kenny Leon will give audiences an opportunity not to escape our political climate, but to process it through art and storytelling when Hairspray Live! airs on NBC on December 7. The 1960s-set musical centers on a fight for representation and social justice—a fight that persists in 2016.When asked at a press conference on November 16 why now is the time to present Hairspray, Leon responded, “Where were you last week? It’s actually a blessing to be in the throngs of this after [the presidential election]; it emphasized the role of artists in our world. It gave me an opportunity to talk to the company about the importance of what we do.”While Leon describes the show as a “feel-good musical about inclusion,” its call for justice is no less resonant. Motormouth Maybelle’s marching cry “I Know Where I’ve Been,” to be performed in the telecast by Jennifer Hudson, asserts, “There’s a dream in the future; there’s a struggle that we have yet to win” and “To sit still would be a sin.” The final anthem “You Can’t Stop the Beat” is a reminder that progress is both constant and vital.“We are aware of the Black Lives Matter protests. In subtle ways, you layer that in,” Leon explained in a press call in October. “Hairspray is still relevant because there are still places where people are not looked at equally. These historic stories give us an opportunity to say something about now.”As Leon explores ways to indicate a contemporary relevance in his presentation, the text speaks for itself in many cases. The director’s outlook mirrors the sentiment expressed in cautiously hopeful songs like “I Know Where I’ve Been.” “We haven’t dealt with our original sin of slavery,” says Leon. “Once we have dealt with that and our history adequately, we can look at our future in beautiful ways.” Kenny Leon on the set of ‘Hairspray Live!'(Photo: Alexander Goyco) View Commentslast_img read more

Most hedge fund index returns explained by alternative beta – Towers Watson

first_imgJames Price, investment consultant at Towers Watson, said: “There might be some alpha in an individual strategy. However, when you start to collate the hedge funds together, the overall returns take on the properties of the opportunity set they are using.”Price said the exposures to alternative betas did vary, but that approximately 60-70% of the returns could be explained by combining alternative betas.“As an asset owner, you could access those alternative betas through other means,” he said.“We tried to think very carefully about how we use this, and make sure what comes through is logistically consistent, and replicate what could have been.”The research showed that, from 1999 to 2013, a minimum of 70% of HFRI composite returns could be explained by a combination of betas.However, the paper also highlighted additional diversification benefits provided by the use of alternative beta.The use of hedge funds in pension fund portfolios has commonly been for diversification benefits.However, with hedge funds using equity, value and macro strategies, the diversification away from traditional portfolios could be overstated.The correlation between alternative beta strategies, while providing additional and cheaper returns, could also add diversification benefits, Towers Watson said.Its analysis showed the average correlation coefficient between equities and credit to be around 0.59, with 1 meaning the two assets are perfectly correlated in returns and losses.However, the use of a foreign exchange carry strategy, another alternative beta category, and momentum equities only yielded a 0.03 coefficient.Equities and volatility premium strategies have a correlation of 0.22, and equities versus a value strategy was negatively correlated at -0.22.“They have very good diversification properties,” Price said, “especially compared with equities and bonds, which investors already own in their portfolios.“It’s a way of injecting additional diversification into a portfolio. It is important to think about these risks. There is many different ways to look at the portfolio, and alternative betas is a valuable additional tool.”Towers Watson said genuine alpha was a source of uncorrelated returns and worth its weight in gold.However, pension funds should consider the fees being paid for alpha, which can be achieved through beta strategies, it said.The paper added: “Over-diversified hedge fund strategies risk moving to industry-average returns and therefore closer to the returns that can be captured with beta. This is exacerbated when funds of hedge funds are used.” More than half of returns experienced by hedge funds could be explained by factors termed as ‘alternative beta’, rather than true alpha, research shows.Analysis from Towers Watson showed that, after studying an equity long/short strategy between 1996 and 2013, 84% of the returns, on an aggregate basis, derived from beta strategies.Within a equity long/short strategy, what the firm referred to as alternative beta was defined as the premium received for the volatility of equities, the momentum of stocks and the size of the equity investment.Looking at the HFRI Composite Index, the representative index for hedge funds, 84% of the returns could be explained by a combination of bulk and alternative beta strategies, the consultancy said.last_img read more

Van Gaal favourite to replace Moyes

first_imgLouis van Gaal has emerged as the front runner to replace David Moyes after he was axed by Manchester United just 10 months into his six-year contract. Press Association Holland head coach Van Gaal has emerged as the favourite to replace Moyes with senior figures at United holding the 62-year-old, who is out of contract after the World Cup, in high regard. Sources close to the club have made it clear the fact that Van Gaal will be in Brazil with Holland this summer would not be an obstacle to the Dutchman taking over. Talks could take place over the coming days as United want to install Moyes’ successor quickly. It is easy to see why United are interested in Van Gaal. The Dutchman lifted the Champions League with Ajax and he also won titles in Germany and Spain. The former Barcelona and Bayern Munich coach is also used to working with big-name players and attracting big signings – neither of which were part of Moyes’ track record. Van Gaal has made it clear he wants to move to the Barclays Premier League when his contract expires and is the bookmakers’ overwhelming favourite. Van Gaal was linked with the Tottenham job, but United’s illustrious history, and a £150million transfer kitty, make the vacancy at Old Trafford far more attractive. Borussia Dortmund coach Jurgen Klopp ruled himself out of the running, telling the Guardian: “Man United is a great club and I feel very familiar with their wonderful fans. But my commitment to Borussia Dortmund and the people is not breakable.” Moyes paid the price for a dreadful campaign when he was dismissed following a meeting with United vice-chairman Ed Woodward at the club’s training ground on Tuesday. United’s most-decorated player Ryan Giggs, a player/coach under Moyes, will take charge “until a permanent appointment can be made”, the club said. Pep Guardiola was considered when Sir Alex Ferguson retired last summer, but the Spaniard went to Bayern Munich, where he intends to remain. “I want to stay at Bayern for two more years,” Guardiola told a press conference. “Bayern are my team, I’m comfortable here.” Other potential candidates include Paris Saint-Germain manager Lauren Blanc, who played for United for two years, Ferguson’s former assistant Carlos Queiroz, whose contract as Iran coach expires in the summer, and highly-rated Atletico Madrid manager Diego Simeone. For now, Giggs is the man charged with restoring some pride to United following what has been a truly awful campaign. What Giggs lacks in experience, he makes up for with passion and a will to win. The 13 Premier League winner’s medals he owns prove that. Giggs is expected to be assisted by Nicky Butt, who is currently in charge of the under-19s and also coaches the reserves. Phil Neville and Chris Woods remain in their posts as first-team coaches, but Steve Round and Jimmy Lumsden – both brought in by Moyes last summer – have been fired. A throng of camera crews and photographers turned up at the AON Training Complex, but they had missed Moyes, who slipped in during the early hours of Tuesday morning. Moyes was sacked shortly after 8am, but the 50-year-old remained at the training ground for a few hours so he could thank and say goodbye to his players. He then left via the back exit away from the cameras. Moyes knew he was on his way out when reports emerged on Monday claiming he had lost the faith of United’s owners, the Glazer family. The fact that the news was leaked almost 24 hours before Moyes’ dismissal angered some, including Gary Neville. “I don’t like it, it’s not the way in which the club should portray itself,” the former United defender told Sky Sports News. “It could have been dealt with a lot better. “The idea of giving people three and four and six-year contracts and then getting rid of them after 10 months is foreign to me. “However, there’s no disguising that the football this season has been poor, the results have been poor, as a fan I’ve not enjoyed watching it – I’m sure David Moyes himself hasn’t enjoyed watching it.” Moyes may have been at the helm for less than a year, but he can have few arguments about his dismissal. Exactly one year ago United won a record 20th title with four games to spare. Now they are in seventh, 23 points behind leaders Liverpool. The list of unwanted records broken by Moyes is as embarrassing as it is long. United are guaranteed to end the season with their worst points total in Premier League history, they have failed to qualify for the Champions League for the first time in almost two decades while Moyes’ home record is the worst of any United boss since 1978 when Dave Sexton was in charge. That is why Moyes will go down in history as the third shortest serving United boss behind Walter Crickmer and Lal Hilditch. Moyes never looked capable of dealing with the pressure of being United boss, he struggled in the transfer market, and his reign was dogged by rumours – denied by the Scot – that he did not get on with a number of his players. Perhaps it was telling that not one United player tweeted about Moyes’ dismissal following the announcement. Former United striker Michael Owen did take to the social media platform and he summed up the situation perfectly. “Huge news at Old Trafford but with the summer looming and a huge transfer kitty available, United had to be 100% Moyes was the right man,” the former United striker said. “Evidently they didn’t have the confidence in him in which case makes the timing absolutely right. Now the big question is who’s next?” Van Gaal looks likely to be that man. United want to make the appointment quickly so the new boss can succeed in the transfer market, unlike Moyes. last_img read more