Friday, September 13, 2013

A study in Nature Communications last month reported the University of St Andrews near Edinburgh, Scotland was briefly home to the world’s fastest spinning manmade object. Physicists accelerated a microscopic sphere of atoms to 600 million revolutions per minute; it then, according to press coverage, disintegrated. Wikinews contacted the team to learn more.

The experiment was designed to explore the boundary between conventional physics, which applies to larger objects, and quantum physics, which applies only to extremely small objects. Subatomic particles obey a very different set of rules than the items we see every day, but the behaviour of particles at just above quantum levels remains enigmatic.

The team wanted to expand upon research using single atoms or molecules, instead constructing a four-micrometre thick sphere of calcium carbonate, in a crystaline form called vaterite, in a bid to examine systems containing over a million atoms. The ball was so small it could be manipulated using lasers; light beams exert a force called radiation pressure.

With the ball held within a vacuum by a laser trap, the scientists were able to apply a twisting force through the light’s polarisation (orientation) as it passed through the ball. The vacuum eliminated air resistance so that scientists could look for evidence of quantum friction, a proposed force that slows spinning particles without external assistance.

The spinning sphere turned into a miniature gyroscope, stabilising itself. The ball cooled as it span to ?233°C (?387°F, 40 Kelvin).

The research was carried out by Dr. Yoshihiki Arita, Dr. Michael Mazilu, and Professor Kishan Dholakia. Wikinews was able to ask Mazilu some questions about his research.

((Wikinews)) What first got you interested in researching quantum friction?

Michael Mazilu: The fundamental aspect that raised our interest is the mechanism that stops an object [rotating] infinitely fast in absence of friction. Quantum friction is one possible but debatable mechanism that will ultimately limit the rotation rate. One can also imagine other interesting mechanisms and we hope that future experiments will be able to conclusively distinguish between them.

((WN)) Press coverage has focused on the fact this is the fastest spinning manmade object ever created, but the aim of the experiment was to research quantum physics. How did you end up with this unusual record — was it by accident?

MM: From the beginning we wanted to go for a very fast rotating sphere to test the limits of transfer of angular momentum of light. The motivation was to explore if we can see [if] any anomaly arose as we rotated the particle faster and faster. The hope was to develop an experimental platform that would allow testing the boundary between classical and quantum physics. That this worked better than expected was a happy accident.

((WN)) How was the sphere manufactured, and how long did it take?

MM: The spheres are produced by mixing three chemical compounds together (CaCl2, MgSO4 and K2CO3) until the mixture becomes transparent. This happens in about 5 to 10 minutes and results in birefringent spherical vaterite crystals of 4.4 micrometer in diameter.

((WN)) How long did the sphere take to reach 600 million revs per minute and break up?

MM: The whole process takes about 10–20 minutes. It all depends on how fast we evacuate the vacuum chamber. If we do it too fast we risk [losing] the micro-gyroscope from the trap. With regard to the sphere breaking up: This is a working hypothesis that we are not able to prove yet. What we observe is that the signal corresponding to the rotating sphere disappears at 600 million RPM. We need further measures to verify if the sphere breaks up or if its motion is perturbed and it escapes in some slingshot or other motion.

((WN)) Could the high speeds attained be taken as evidence against quantum friction, as the sphere simply kept getting faster until it broke apart?

MM: This is a very interesting question. The particle keeps getting faster and faster until the signal disappears, however, just before this happens we observe that the slope of the acceleration changes. This could be seen as a signature of “quantum friction” but we need to look more closely. Alternatively, it might be a consequence of the sphere deforming at such high rotation rates.

((WN)) The experiment failed to conclusively prove quantum friction, but did it provide any evidence to support the theory?

MM: The main goal of the experiment was not to prove or disprove quantum friction but to develop a tool that might be useful to carry out these studies in the near future. Though the micro-gyroscope that we studied sounds like a simple system its behaviour and interaction with the laser beam is very complex. In order to use this experiment to prove or disprove quantum friction it is first necessary to completely understand and model its complex behaviour. We need therefore more extensive experimental studies and more precise simulations.

((WN)) How challenging is research of this sort? What kind of difficulties are encountered?

MM: One of the challenges in this experiment is that it brings together many different parts of physics such as vacuum science, optical micro-manipulation, thermodynamics and potentially quantum mechanics. The main difficulty experimentally and theoretically is to combine all these fields simultaneously and make them work together to create a “clean” system that can test ‘friction’ or other theories.

((WN)) Previous research on the boundary between conventional and quantum physics has used atoms and individual molecules. Why was a sphere in excess of a million atoms appropriate for this experiment? Would that not move further away, rather than closer to, the boundary between the two?

MM: Quantum physics should not just be the remit of the world of atoms or molecules but should apply at all scales in some way. One of the main drives in present quantum technology is to create what is called mesoscopic or macroscopic quantum states, that is quantum states that can be see in a microscope. It is in the hope to achieve this that we chose to work with the micrometer sized vaterite crystals. The other reason for the size of the sphere is that we experimentally found that smaller spheres are presently more difficult to levitate.

((WN)) How likely is this result to be an anomaly? Might a similar ball break up more quickly, or be unable to spin as fast?

MM: With respect to the sphere break-up, these are interesting questions. One can expect that, depending on the mechanical failure property of the sphere, it would breakup sooner or later. Optically, we can make the sphere rotate at any speeds smaller than the maximum speed. So it would be very interesting to fabricate a series of spheres that have same optical properties but different mechanical failure points.

((WN)) Where would you like to see the research go next? More spheres?

MM: Indeed, two or more spheres would bring an additional degree of freedom to the experiments that would allow the study of the rotation rate as a function of the distance between them. Some theoretical predictions suggest that quantum friction effects might be enhanced in this case.

((WN)) If confirmed, what applications might quantum friction have?

MM: It is relatively easy to dream up applications for an effect that has not been observed yet! In general, friction dissipates energy and is seen as a detrimental effect. However, there are applications that use friction in a useful way. Indeed, velocity dependent friction could also be used to slow down microscopic objects to the point where these objects would reach what is called the quantum ground state for their centre of mass. Creating these states on demand would bring quantum technology a step closer and might lead us to “couple” quantum mechanically [macroscopic] objects — a phenomenon more accurately termed entanglement.

((WN)) One follow-up question for publication: You said you found smaller spheres more difficult to levitate. Why is that?

MM: I have double checked the sphere size problem. While it might be more difficult to use smaller sphere in the experiment due to the trapping geometry, as it turns out this was a sphere synthesis problem. With our present method we were not able [to synthesise] smaller spheres.

Friday, July 23, 2021

With five active cases of the Delta variant of COVID-19, South Australia begun a one-week lockdown on Monday. Announcing the lockdown, state Premier Steven Marshall declared “we have no alternative but to impose some fairly heavy and immediate restrictions”.

The first case out of South Australia’s active cases was presented to Modbury Hospital on Sunday night, having returned from Argentina earlier this month. The fifth, which Premier Marshall noted as “far more worrying”, visited The Greek on Halifax restaurant at the same time as someone who was later confirmed to be carrying the virus. Chief Public Health Officer for the state Nicola Spurrier said “if anyone has been at The Greek on Halifax they need to get into quarantine and get tested”.

In accordance with new regulations, there are only five reasons for South Australians to leave home: essential work, shopping for essential goods such as food, exercise, but only with people from the same household and within 2.5 kilometers (2 mi) of home, medical reasons (which includes testing and vaccination against the coronavirus, but excludes elective and cosmetic surgery), and caregiving.

Schools have closed for all but children of essential workers, with online learning having begun on Thursday. Face masks are also be mandated for those who leave home. ABC News reported that “support for businesses is expected to be announced…”, with all non-essential retail required to close under the new regulations.

Monday, September 24, 2007

Russ Aegard is running for the Green Party of Ontario in the Ontario provincial election, in the Thunder Bay-Atikokan riding. Wikinews’ Nick Moreau interviewed him regarding his values, his experience, and his campaign.

Stay tuned for further interviews; every candidate from every party is eligible, and will be contacted. Expect interviews from Liberals, Progressive Conservatives, New Democratic Party members, Ontario Greens, as well as members from the Family Coalition, Freedom, Communist, Libertarian, and Confederation of Regions parties, as well as independents.

Tuesday, May 29, 2007

War protestor Cindy Sheehan, the mother of fallen soldier Casey Sheehan who was killed in Iraq 3 years ago, wrote on what has been published by the Daily Kos as a personal web journal on Monday morning, a day in observance of Memorial Day in the United States, that “This is my resignation letter as the ‘face’ of the American anti-war movement.”

Her son Casey would have been 28 years old Tuesday. In what she writes are meditations upon developments in Sheehan’s life after she began a war protest that led her and a following of people to Camp Casey, beside the Texas ranch of President Bush in August 2005, included the notion that, “The most devastating conclusion that I reached this morning, however, was that Casey did indeed die for nothing. His precious lifeblood drained out in a country far away from his family who loves him, killed by his own country which is beholden to and run by a war machine that even controls what we think.”

In the text of Sheehan’s diary she is unable to reconcile herself with the Democratic Party that on Thursday, May 24, succumbed to the Bush administration on language for a troop funding bill that at one time tied funding to a time limit for U.S. involvement in Iraq. The presidential veto of that legislation to set a deadline for withdrawal of U.S. troops from Iraq resulted in the U.S. Congress caving to executive branch over the issue of war funding, and may have been the final straw for Sheehan.

“I am deemed a radical because I believe that partisan politics should be left to the wayside when hundreds of thousands of people are dying for a war based on lies that is supported by Democrats and Republican alike,” wrote Sheehan.

Sheehan said that she has spent every bit of money that she has received as compensation for the loss of her son from the U.S. government, and as a person who garnished speaking fees from the national attention on her campaign against the Iraq war, on trying to bring peace.

“I am going to take whatever I have left and go home. I am going to go home and be a mother to my surviving children and try to regain some of what I have lost,” wrote Sheehan.

Tuesday, January 29, 2008

Mauritanian refugees stuck in Senegal for nearly two decades after fleeing ethnic clashes in their home country have begun returning to Mauritania under a U.N.-sponsored program. But many do not want to return.

There were goodbye ceremonies and welcoming ceremonies attended by officials on both sides of the Senegal River as more than 100 former refugees were ferried on motorized pirogues.

A spokesman for the United Nations refugee agency, Alphonse Munyaneza, explained international funding will help pay for resettlement.

“Each refugee returning back to Mauritania will receive a piece of land equivalent to 140 square meters for establishing a house. UNHCR and the government of Mauritania will provide construction material so that they can build a house,” explained Munyaneza. “We will provide three months of food ration. We will provide a tent also.”

Mauritanian refugee children broke out in song and laughter when officials arrived at their camps close to the border to get the process going.

There are more than 20,000 Mauritanian refugees in Senegal. Officials say the return program will extend over 18 months.

One of those happy to go is Haddy Sy. She says she left Mauritania after she was beaten up. This took place during a wave of ethnic violence that began in Arab Moor-dominated Mauritania in 1989 and escalated into border clashes, forcing tens of thousands of black, mostly ethnic Fula, Mauritanians into exile.

In the late 1990s, more than 30,000 refugees returned by their own means and some U.N. assistance.

Sy says she is leaving behind many good things in Senegal, including a peaceful setting, but that she is still happy to return to her home country.

Since taking office last year, the government of the elected, post-coup President Sidi Ould Cheikh Abdallahi has been making efforts to bring home the refugees, including several thousand more in Mali.

But many in Senegal do not want to return home, like Yaraah Sow, who lives in the Dagana refugee camp about 400 kilometers northwest of Dakar.

He says he is still very bitter about what happened nearly 20 years ago. He said his father, who was a civil servant, was attacked by a mob and died of internal bleeding at the gates of a hospital after doctors refused to treat him.

Sow accuses the military of seizing all his family’s property. He says that two of his younger brothers died on the trip to Senegal. He says his children are now going to school and that they are better off in Senegal.

One of the refugee leaders, Mohamed Ali Sow, who left when he was 10, says he is studying at a university in Senegal to become a lawyer to defend the rights of chased out Mauritanians.

He says the return program has been rushed, because he says people who had their property seized, houses burned, and jobs taken away, should have guarantees these will be restored. He says until then, he does not think it is wise to go back.

Thursday, September 6, 2012

London, England— Tuesday, following her team’s 62–37 win over Mexico in the quarter-finals at the North Greewich Arena, Wikinews interviewed Amber Merrit of the Australian women’s national wheelchair basketball team.

In their next match, the Gliders will face the victors from the United States versus Canada, having suffered their first loss of this year’s Games to Canada on Sunday night by seven points.

((Laura Hale)) I’m excited to see you in London, because you were so fantastic in that interview.

[Wikinews previously interviewed Merrit, and teammates in July. —Ed.]

Amber Merrit: Thank you.

((WN)) Which state are you from?

AM: I’m from WA. [Western Australia —Ed.]

((WN)) You wheel change! What was wrong with your wheel?

AM: I smashed out three spokes. Someone hit me, and I lost three spokes in my chair.

((WN)) was that because you were playing really aggressively against Mexico?

AM: Yeah, or they were playing really aggressive against us.

((WN)) Watching that game it didn’t seem that they were playing that aggressive, in terms of they came in with set pieces; they weren’t doing the full-court press; they didn’t seem prepared for your offensive and defensive tenacity. ((Hawkeye7)) You kept on all holding them out, where they weren’t even getting across the centre line

AM: I think we have a really physical style of basketball where we’re going to press, and when we press we try to stop chairs and make sure they don’t get over that halfway line. They’re going to come out and play as hard as they can against us and sometimes there is that odd mishap where they might smash a few spokes cause they hit us. It happens.

((WN)) You tipped a lot in previous games. You haven’t tipped so much in this series.

AM: No, I’ve managed to keep my balance this time. Or maybe they haven’t hit me hard enough to put me down on the floor.

((WN)) Part of the appeal of wheelchair basketball, and I feel guilty admitting it, it watching you guys tip.

AM: And fall out. It’s embarrassing but I like it.

((WN)) You’ve got your next game coming up, which is going to be against the winner of the United States or Canada later today

AM: We’re not 100% sure yet who that’s going to be.

((WN)) Looking forward to meeting them?

AM: Yeah! Looking forward to coming up against them.

((WN)) Who would you prefer?

AM: I don’t know if I have a preference, to be honest. Whoever its going to be, we’re still going to go out there and play as hard as we can and take it to them as a team.

((WN)) Do you think you’ve been adequately prepared coming in to this, with your tournament in Sydney, your tournament in the Netherlands?

AM: Yeah, I think we’ve come in very well prepared for this tournament. We’ve been together for a while now as a team. Of course we had the Gliders and Rollers world challenge. We also went to Arnheim in the Netherlands for a pre-tournament, and we’ve trained together in Cardiff. And then after Cardiff we came in to London; so we’ve had that time together as a team and we’re doing really well.

((WN)) Does that give you an advantage over other teams?

AM: I’m not sure, because I don’t know what other teams have been doing behind the scenes as their training.

((WN)) Thank you very much.

AM: No worries!

Thursday, September 6, 2012

London, England — Wheelchair rugby got underway yesterday at London’s Basketball Arena with four games being played: the United States versus Great Britain, Sweden versus Belgium, Australia versus Canada, and Japan versus France.

Before a full house at a game that was the first one to sell out in the lead up to the start of the London Paralympics, the United States national wheelchair rugby team defeated Great Britain national wheelchair rugby team by a score of 56–44. While the game got off to a slow start for the United States, once the team found its rhythm, they dominated the home team and appeared to score at will. Despite this, the crowd supported their side, even when they were down by eight points. When the United States bench started a chant of U-S-A! U-S-A!, the crowd soon drowned them out with a chant of Team G-B! Team G-B!

The United States came to London as defending gold medalists and ranked first in the world. Coming into the game, the team’s assistant coach James Mate told the media regarding this game, “To be truthful we have played the home team a couple of times, but you have to play the game in that moment and it can give the hosts the edge. […] In Beijing, Great Britain gave us our best game, and the semifinal was a three-goal game. We had something similar in June (at the Canada Cup). […] They (Great Britain) play some like us and some like Canada, and are one of the teams that have a lot of good players, so we can’t focus on just one player, but on the team as a whole.”

Ranked sixth in the world, Great Britain came to London as the home town favorites. Their roster included club players from across the country including David Anthony who plays for the Cardiff Pirates, Andy Barrow, Bulbul Hussain and Steve Brown who play for the Kent Crusaders, Jonathan Coggan and Mandip Sehmi who play for the Stoke Mandeville Storm, Mike Kerr who plays for the North West Bulls, Myles Pearson who plays for the West Coast Crash, and the team’s only female player Kylie Grimes who plays for the London Wheelchair Rugby Club with teammate Ross Morrison.

Before the game, first time Paralympian Great Britain wheelchair rugby player Mike Kerr told the media regarding his squad selection, “I felt I’d never been given a chance to get noticed, so I got myself some court time at big tournaments like Knock and Roll in 2010 (a USA national tournament) and Bernd Best (the biggest wheelchair rugby tournament in the world, held in Germany). I played well and I think people finally took notice.” Regarding the wait to play, Kerr said, “It’s hard. I hate waiting around. I’m here to do a job and the sooner I get started the better. But it’s been a great experience so far. The crowd and support have been amazing. […] I’m really confident. We took confidence from how we played against them at the Canada Cup (in June). If we play our game we can shock them.”

The United States meets Japan while Great Britain meets France later today in their second games in pool play.

In the second wheelchair rugby match of the London Paralympics, Sweden defeated Belgium by a score of 52–42.

Sweden, the current European champions, came to London with a relatively new coach, who only took over the side in late 2011. Belgium’s coach Bob Vanacker also plays on the team. He and Peter Genyn and Lars Mertens play their club wheelchair rugby in the United States.

In the first game for both teams since the London Paralympics began, Australia national wheelchair rugby team defeated Canada by a score of 64–52. Australia and Canada both had their flag bearers from the opening ceremonies represented by this sport, Greg Smith for Australia and Garett Hickling for Canada.

Beijing silver medalists Australia came to London ranked second in the world. Their last major competition before the Paralympics was the Canada Cup, where they lost to the United States by a single point. The Australian side included flag-bearer Greg Smith at his fifth games, Nazim Erdem who is at his third Paralympics, Ryley Batt and Ryan Cott who competed at the 2004 and 2008 Games, Cameron Carr who competed at the Beijing Games, Chris Bond, Cody Meakin, Ben Newton, Andrew Harrison, Josh Hose and Jason Lees who made their Paralympic Games debut.

Canada came into their match against Australia as returning bronze medalists. Their roster included Ian Chan who was on the team that finished first at the 2002 World Championships, the former ice hockey player Jason Crone from Owen Sound, Ontario, debut Paralympian from Embrun, Ontario Oarice Dagenais, 2002 World Champion Jared Funk from Manitoba, five time Paralympian Garett Hickling, Trevor Hirschfield who is decribed by the Canadian Paralympic Committee as one of the world’s best low point players, Athens silver medalist and Beijing bronze medalists Fabien Lavoie, eighteen-year-old Zak Madell, University of Arizona alumnist Travis Murao, 2010 World Championships All Star Ten player Patrice Simard, former recreational hockey player David Willsie and Harrow, Ontario native Mike Whitehead.

Australia meets Sweden later today while Canada will take on Belgium.

In the last match of day yesterday, Japan defeated France 65–56. France qualified for the tournament despite the national team only being five years old. Japan came to London having beaten the top ranked United States in this year’s Canada Cup.