Confirmed: Hubble 3D will be awesome

February 3, 2010 | 6:55 pm

The word “awesome” has been over-used. It is now jokingly assigned as a term employed by people who can’t come up with more specific adjectives (or who surf). But it seems that looking down on Earth, from 350 miles above it, should reclaim the right to the word that means “inspiring awe.” An IMAX movie is the closest that many of us will get to seeing this wonderful sight, so it’s good to know that the new Hubble 3D movie, which documents the journey of space shuttle STS-125 to repair and upgrade the Hubble Space Telescope in May 2009, is looking truly awesome.

The film, set to be released on March 19, was made by the same crew that produced Space Station 3D in 2002, and the eye-feast Deep Sea 3D.

The movie documents the space shuttle crew’s preparation, the rocket launch, and Hubble itself. The crew brought an IMAX camera and eight minutes of film into space, plus took additional non-IMAX footage through helmet cameras and via satellite. Those images are not as detailed as IMAX, but are still mesmerizing.

STS-125 Mission Specialist Michael Massimino came back to his home state of New York this week to appear at a pre-screening of about 15 minutes of footage from the film.

Every time I’ve had the pleasure of hearing a former astronaut talk, they say that looking down at the Earth from above is one of the single greatest things they’ve ever experienced, and Massimino was no exception. He said he remembers thinking, “this is what heaven must look like.” The only sadness he felt at that moment came from realizing that he couldn’t share it with everyone. The film might not be quite as good as taking a space walk, but I could stare at the shots of Earth all day.

Note that the film is not a collection of images produced by the Hubble, although the trailer suggests there will be a little bit of that sprinkled in. But rest assured that the images of the actual telescope are also jaw dropping. The massive instrument responsible for all of that incredible beauty and knowledge is laid bare on the screen. In the grandeur of IMAX and 3D, Hubble looks like a sleeping beast; both colossal and vulnerable as the crew operates on its insides.

Talkative and excited, Massimino opened up with the audience after the film, saying that it made him teary to look at the footage and remember his time in orbit. He answered a question about the infamous bolt incident, where a single bolt holding a door in place refused to come unscrewed, and with time running out, the engineering crew on the ground told Massimino to rip the door off. He succeeded without further incident, and everything worked out all right. Massimino says his helmet camera was running during the incident, but he’s not sure if the footage will show up in the film.

The impromptu stunt wasn’t the only time Massimino worried about whether or not he and the crew could get everything done, and done right. But despite the ominous music and gritty voice-over in the trailer, Massimino reminded the crowd that “this is a success story.”

No kidding. Images from the updated Hubble have already been released, along with data analyses that might identify the most distant galaxies ever seen.

Massimino also returned to New York to deliver the American flag that he and the crew brought with them into space. They are donating it to the 9/11 memorial museum.

Calla Cofield

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New MINOS results “strongly disfavor” sterile neutrino, neutrino decay

February 2, 2010 | 10:24 am

Finding the truth, whether that means solving a crime or describing the nature of fundamental particles, is just as much about eliminating the wrong answers as it is about finding the right ones. The same way that ruling out an alibi for a suspect is an important step toward finding the bad guy, disproving a theoretical prediction is necessary in order to find the correct theory that explains the whole story.

In the search for a better understanding of neutrinos, the Main Injector Neutrino Oscillation Search, MINOS, recently put forth results that help rule out a theorized fourth neutrino and strengthen the case against the hypothesis of neutrino decay. MINOS co-spokesperson Rob Plunkett says the results “really start to close the loop” on some major theories that neutrino experiments set out to investigate.

The MINOS experiment begins at Fermilab, in Batavia, Illinois, where a neutrino beam is generated, and its composition measured by the MINOS near detector. The beam then travels 735 kilometers to the Soudan mine in northern Minnesota, where the MINOS far detector catches it.

MINOS examines the neutrinos primarily through a process called charged current interaction. This method reveals the flavor of a neutrino–muon, tau, or electron–observed in a detector. But, from detection of charged current interactions, MINOS only has the capability to identify the muon and electron neutrinos in the beam. However, the experiment also detects what’s called neutral current interactions, which count all neutrinos, but do not reveal their flavors.

The first theory examined in this paper is the prediction of the existence of a fourth neutrino–known as the sterile neutrino. The standard model comprises only three neutrinos, which interact with ordinary matter via the weak nuclear force. But scientists know that the standard model isn’t perfect. It predicts that neutrinos have no mass, yet experiments like MINOS tell us that they do. Hence there could also be a fourth type of neutrino that has eluded experimental detection so far, especially one like the sterile neutrino, which is immune to the effect of the weak force.

The sterile neutrino didn’t have a strong case going into the MINOS analysis. Results from the indirect observation of neutrinos at experiments at the European laboratory CERN pinned the number of light neutrinos at three, and so far only three neutrino flavors have been observed. Then, in 2001, an experiment at Los Alamos known as the Liquid Scintillator Neutrino Detector, LSND, published some puzzling results that seemed to indicate the presence of a sterile neutrino. Since then, no one has been able to reproduce the LSND findings. A few years ago, data from the MiniBooNE experiment (Booster Neutrino Experiment) at Fermilab seemed to refute most of the LSND results.

Still, the ghost of a sterile neutrino continues to wander among scientists, and MINOS is looking for either its fingerprint or evidence that it does not exist.

“[Our result] strongly disfavors the existence of a sterile neutrino,” Plunkett said about the analysis presented in the recent MINOS paper.

But the same way that it is difficult to put the rumors about ghosts to rest, ruling out the existence of a sterile neutrino is nearly impossible.

The MINOS paper strengthens the constraints on the sterile neutrino’s existence. Past analyses have shown that if muon neutrinos are oscillating into sterile neutrinos, only 68% of the disappearing neutrinos can do so. The new analysis shrinks that percentage to 50%, and more data will most likely reduce it further.

The second hypothesis up for investigation is the process of muon neutrino decay. Scientists know that the three neutrino flavors can oscillate among themselves. So, for example, a muon neutrino can turn into a tau neutrino. The transformations take place when neutrinos travel long distances, such as the 735 kilometers from Fermilab to Soudan. When scientists use neutral current detection techniques to analyze the beam, they find that the total number of neutrinos detected in Soudan agrees with expectations, given the measured number of neutrinos leaving the Fermilab site. But the composition of the beam changes dramatically. While the beam traversing the near detector at Fermilab consists almost entirely of muon neutrinos, the fraction of the beam that arrives at Soudan as muon neutrinos, as determined by their charged current interactions, is way down. The accepted interpretation is that the total number of neutrinos remains the same and that the missing muon neutrinos oscillated into tau  (and possibly electron) neutrinos.

An alternative theory says that the missing muon neutrinos may have decayed. The MINOS scientists looked at two scenarios: first, the possibility that only decay and no oscillation takes place. Second, the situation when both decay and oscillation contribute to the observed effect.

In both analyses, the MINOS collaboration found its data  to be inconsistent with neutrino decay. Plunkett said the results provide strong evidence against the existence of neutrino decay.

“This paper is really a terrific summary of a lot of stuff that’s going on [in neutrino physics] right now,” said Plunkett. “The paper shows the consistency of the whole picture. At the same time, it explores ways that the picture might be wrong or puts limitations on how wrong it might be.”

The paper has been submitted to Physical Review D, and is available on the physics website arxiv.org. The analysis was lead by Alexandre Sousa of Harvard University, Brian Rebel of Fermilab, and Anthony Mann of Tufts University.

Calla Cofield

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CERN’s new LHC plan: Two years at 3.5 TeV

February 1, 2010 | 5:53 pm

CERN’s new plan for the next phase of the Large Hadron Collider: run the accelerator for up to two years at an energy of 3.5 TeV per beam. The run, expected to start at the end of this month, would end no later than December 2011 and be followed by a long shutdown to prepare the accelerator to run at its full energy of 7 TeV per beam.

The goal for the next two years is for the LHC experiments to collect a certain amount of data – one inverse femtobarn – at 3.5 TeV per beam. With that amount of data at that energy, the LHC experiments would be competitive with the experiments at Fermilab’s Tevatron in the hunt for the big physics discoveries on the horizon: the Higgs boson and supersymmetry. If this goal is reached before December 2011, the accelerator and experiments may shut down earlier to begin the long process of readying the machine to run at the energy it was originally designed for.

The new schedule differs from that announced in August 2009 in two main ways: the length of the lower-energy run and its maximum energy. In August, it was announced that the LHC would begin its first run at 3.5 TeV per beam, perhaps increasing as high as 5 TeV per beam by the end of 2010. The accelerator would then shut down in 2011 in preparation for running at the full energy of 7 TeV per beam. The lower maximum energy decided on last week, and the longer running time at that lower energy, are a consequence of the problematic connections between superconducting LHC magnets. One such connection melted in September 2008 and led to one year of repairs,  and during the long shutdown in 2012, virtually all such connections will be re-made.

This news was first reported Friday by John at Cosmic Variance, following the conclusion of the LHC Performance Workshop in Chamonix, France. The annual workshop provides the team operating CERN’s accelerators a chance to retreat from the hustle and bustle of everyday work at the laboratory and focus on the near- and far-term future of the accelerator complex.  All of the presentations from last week’s workshop are available online. A summary of the workshop will be presented at CERN on February 5.

Update, February 3: CERN has officially confirmed the new LHC schedule.

Katie Yurkewicz

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