We’re all waiting for the LHC to restart. Current plans call for collisions later this year, but at lower energies than originally hoped.
Why is it so hard to say for sure? Here’s a nice article in the CERN Bulletin that lays out some of the difficulties.
Due to the huge amount of inter-dependency between different areas of work in the LHC, even a small change can necessitate a complete overhaul of the schedule. For example, something as simple as cleaning a water cooling tower - required regularly by Swiss law to prevent Legionella - has a huge impact on the planning: “When you clean the water tanks it means we don’t have water-cooling for the compressors, that means we can’t run the cryogenics, so the temperature starts to go up,” explains Myers. “If a sector gets above 100 K, then the expansion effects of heating can cause problems, and we could have to replace parts.”
That may be cold comfort (get it? cold comfort!), but it’s the real world. I have no strong opinions about the job CERN is doing, except to recognize that this is the most complicated machine ever built, so patience is probably called for. The particles and interactions are going to be the same next year as they were last year. (Or if they’re not, that would be even more interesting.)
Looking back at old data allows physicists to place new constraints on physics beyond the standard model and propose a new approach to uncovering evidence of new physics.
The Large Hadron Collider is still going through a painful commissioning process—coming online in time for the winter shutdown is probably not what researchers had in mind when they broke it the first time. So, what is a physicist to do when the shiny toys are still being polished? Sit around at the pub and gossip about old experiments, of course.
One such session has ended with Jorg Jaeckel, from Durham University, taking a new look at 40-year-old data from a classical electrostatics experiment. He found that this data provided the strongest constraints on a particular set of particles so far, thus proving that some experiments age very gracefully indeed.
The official kilogram is kept locked inside a secured vault at the International Bureau of Weights and Measures near Paris. Scientists are so paranoid that they’ve only taken it out on three occasions: in 1889, 1946 and 1989. Each time, they’ve compared it to a set of copies. In 1889, the copies and the kilogram weighed the same, but by 1989, they had drifted apart. Based on the data, the kilogram appears to weigh slightly less than the copies.
The real crux of this problem is that it’s impossible to tell what has changed over the past 120 years. The copies may have grown heavier over time by absorbing air molecules. But it’s equally possible that the kilogram is getting lighter. Periodic washings, for example, may have removed microscopic quantities of metal from its surface.
Or it could be that both the copies and the kilogram are changing, but at different rates. There is no way to tell what’s happening because mass is always calibrated against another mass, says Peter Mohr, a theoretical physicist at NIST who is working on the kilogram problem.
Recently, several astronomical experiments have revealed mysterious components of elementary particles. But up until now, the origin of electrons and positrons is unknown. Is dark matter the actual origin of this radiation, as some physicists speculate?
Now an international team of astrophysicists, including the Bochum junior professor Dr. Julia Becker and the Dortmund physicist Prof. Dr. Dr. Wolfgang Rohde, have found a simple explanation: giant stars, at least fifteen times the mass of our sun, emit elementary particles in a final explosion when they die. The flux of the electrons and positrons calculated on the basis of this theory fits in with the enigmatic signals observed during these astronomical experiments.
Argonne is opening its gates to the community Saturday, Aug. 29, from 9 a.m. to 4:30 p.m. — rain or shine. Nearly 100 engaging exhibits, demonstrations, tours and presentations are being planned for a day of fun and education for the entire family.
OMG! If you’re in the Chicago area please go to this.
Physics students, for the most part, are eternally insecure. Physics has sort of a cult of intelligence, where we worship the “heroic” figures of the past, pass on mythologies of their other-worldly brainpower, and glorify their acts of intellectual arrogance. It is no surprise, then, that every student is secretly afraid that s/he isn’t really smart enough to do physics as a career, and that if they talk too much they will reveal their secret. So in our conversations we stick to the math and the precise “formalism” left for us by other smart people, and it is only with great hesitancy and trepidation that we attempt to discuss the ideas behind all the math. Almost as a bluff, we act sometimes as if all the equations were self-explanatory, or that writing an equation is of itself a sufficient explanation. It isn’t.
I found this blog today and it is one of the best physics blogs I’ve seen in a long, long time. I hope this guy writes a book and I really hope he teaches, because this is physics made interesting.
NASA’s space shuttle program is winding down. With only about half a dozen more flights, shuttle crews will put the finishing touches on the International Space Station (ISS), bringing to an end twelve years of unprecedented orbital construction. An act of Congress in 2008 added another flight to the schedule near the end of the program. Currently scheduled for 2010, this extra flight of the shuttle is going to launch a hunt for antimatter galaxies.
The device that does the actual hunting is called the Alpha Magnetic Spectrometer—or AMS for short. It’s a $1.5 billion cosmic ray detector that the shuttle will deliver to the ISS.
In addition to sensing distant galaxies made entirely of antimatter, the AMS will also test leading theories of dark matter, an invisible and mysterious substance that comprises 83 percent of the matter in the universe. And it will search for strangelets, a theoretical form of matter that’s ultra-massive because it contains so-called strange quarks. Better understanding of strangelets will help scientists to study microquasars and tiny, primordial black holes as they evaporate, thus proving whether these small black holes even exist.
All of these exotic phenomena can make their presence known by the ultra-high energy cosmic rays they emit—the type of particles AMS excels in detecting.
"For the first time, AMS will measure very high-energy cosmic rays very accurately," explains Nobel laureate Samuel Ting.
Antimatter galaxies, dark matter, strangelets—these are just the phenomena that scientists already know about. If history is any guide, the most exciting discoveries will be things that nobody has ever imagined. Just as radio telescopes and infrared telescopes once revealed cosmic phenomena that had been invisible to traditional optical telescopes, AMS will open up another facet of the cosmos for exploration.
"We will be exploring whole new territories," Ting says. "The possibility for discovery is off the charts." … "For the first time we could find out what dark matter is made of."
I’m Kevin (check out my other tumblr), and I’m going to take over here and start contributing to Fuck Yeah Physics. Now Foobarnacle will still be contributing and involved, but not as often. Don’t worry, we’ll keep the great physics posts coming.
Also, you can now send all your tips for great physics articles/pictures/links to me with the tipline link in the sidebar now.
So you may have (and by “may have” I mean “definitely haven’t”) noticed that I haven’t been posting, well, at all. Now that I’m spending most of my day reading and thinking science, and soon maybe finally doing some science, I don’t find myself wanting to read and think about science in my off hours. HOWEVER, Tumblr needs physics! Would anyone like to take over?
NEW YORK (CNNMoney.com) — Math majors don’t always get much respect on college campuses, but fat post-grad wallets should be enough to give them a boost.
The top 15 highest-earning college degrees all have one thing in common — math skills. That’s according to a recent survey from the National Association of Colleges and Employers, which tracks college graduates’ job offers.
“Math is at the crux of who gets paid,” said Ed Koc, director of research at NACE. “If you have those skills, you are an extremely valuable asset. We don’t generate enough people like that in this country.”