Friday, December 14, 2012
Geminid Meteor Shower
If it's clear where you live, take a look at the Geminid meteor shower tonight, starting around 10 pm but especially after midnight. The peak was last night (Dec. 13/14), but tonight (Dec. 14/15) should be quite good as well. You can look anywhere in the sky. For more information, check out the EarthSky site.
Monday, November 12, 2012
Supersymmetry dealt a blow
The popular physics theory of supersymmetry was dealt a blow by the publishing of a crucial paper by CERN. Physicists who work at the Large Hadron Collider (LHC) look at specific particles, which are unstable. This just means that they split into smaller particles as they decay. Of course, there are many different kinds
of smaller particles into which the larger particle can split. Some of the
decays rarely happens.
According to the standard model, the decay in the question only happens in three out of 109 B-decays (A B-decay is a decay where a B-meson decays. A B-meson is a particle consisting of a anti-bottom quark and an up, down, strange, or charm quark). The fraction of all decays that lead to a particular final result is also called the branching ratio. So of all the possible decays that the B-meson can do, only 3 x 10-9 of the decays lead to the decay in the paper. Actually, they treat two different B-decays, but the branching ratio of both of them is in the order of magnitude ~10-9 - 10-10. According to Supersymmetry, the branching ratio of these decays is much higher.
What this all comes down to is if we have a billion of the large particles, only one of them splits into a certain combination of smaller particles. Thus, we say that the chance for that certain decay is one in one billion. The article is about one particular kind of decay.
Now, different theories have different chances for that particular decay of happenings. In the standard model, that is one in one billion. In super symmetry, it's maybe one in one million. That means it happens a thousand times more often.
Sometimes, scientists don't know whether a decay actually happens at all. But down at LHC, they've found the decay, so they know it happens. But they've only found it once out of maybe a billion other decays.
While this decay happens rarely, it happens many times in LHC. What's new with this publication is that they are now fairly certain that the amounts of decays they detect aren't some kind of freak accident or a problem with the test. The probability that background processes can produce the observed number of decay candidates is 5x10-4 and corresponds to a statistical significance of 3.5 sigma. That is that if they did the same experiment 5x104 times, one of them would be wrong.
This all comes down to that the standard model predicts that one in one billion decays is that particular decay, but super symmetry predicts maybe a thousand in one billion decays is that particular decay. So, according to SUSY, this decay should have happened many more times than this single one they've found. This means that right now, the standard model seems correct and super symmetry has something wrong.
According to the standard model, the decay in the question only happens in three out of 109 B-decays (A B-decay is a decay where a B-meson decays. A B-meson is a particle consisting of a anti-bottom quark and an up, down, strange, or charm quark). The fraction of all decays that lead to a particular final result is also called the branching ratio. So of all the possible decays that the B-meson can do, only 3 x 10-9 of the decays lead to the decay in the paper. Actually, they treat two different B-decays, but the branching ratio of both of them is in the order of magnitude ~10-9 - 10-10. According to Supersymmetry, the branching ratio of these decays is much higher.
What this all comes down to is if we have a billion of the large particles, only one of them splits into a certain combination of smaller particles. Thus, we say that the chance for that certain decay is one in one billion. The article is about one particular kind of decay.
Now, different theories have different chances for that particular decay of happenings. In the standard model, that is one in one billion. In super symmetry, it's maybe one in one million. That means it happens a thousand times more often.
Sometimes, scientists don't know whether a decay actually happens at all. But down at LHC, they've found the decay, so they know it happens. But they've only found it once out of maybe a billion other decays.
While this decay happens rarely, it happens many times in LHC. What's new with this publication is that they are now fairly certain that the amounts of decays they detect aren't some kind of freak accident or a problem with the test. The probability that background processes can produce the observed number of decay candidates is 5x10-4 and corresponds to a statistical significance of 3.5 sigma. That is that if they did the same experiment 5x104 times, one of them would be wrong.
This all comes down to that the standard model predicts that one in one billion decays is that particular decay, but super symmetry predicts maybe a thousand in one billion decays is that particular decay. So, according to SUSY, this decay should have happened many more times than this single one they've found. This means that right now, the standard model seems correct and super symmetry has something wrong.
Monday, November 5, 2012
Hunting for the Higgs Boson
If you're in the East Bay tonight, you should check out the 2012 Segre Lecture at UC Berkeley. Peter Jenni, a CERN Scientist and former ATLAS Spokesperson, will present "Hunting for the Higgs Boson and more at the LHC."
This annual lecture was conceived as a way for the Physics Department to honor and bring the work of an experimental physicist to the general public. Many renowned experimental physicists have been hosted. The observation of the Higgs Boson at the LHC was easily the biggest science story of the year, so this should be an excellent lecture. It will begin at 5PM in the Pauley Ballroom and is an lecture that any budding astronomer or science enthusiast won't want to miss! Click here to say you're going.
The lecture abstract is as follows:
For the past three years, experiments at the Large Hadron Collider (LHC) have begun exploring physics at the high energy frontier. A rich harvest of initial physics results has been obtained that allows us to test the Standard Model (SM) of elementary particles and to make searches Beyond the SM (BSM), at the highest energy level ever reached in a laboratory. Most exciting is the recent discovery of a new particle that may well be the long-awaited Higgs Boson. This discovery would also establish the postulated electro-weak symmetry breaking mechanism in the SM. Other far-reaching results can be reported for BSM physics searches like Supersymmetry (SUSY) and its implication for Dark Matter in the Universe, Extra Dimensions, and the production of new heavy particles. Besides these physics results, the history and technical challenges of the LHC project, its status, future physics prospects, as well as Cal and LBNL’s prominent role in them will also be covered briefly in this talk.
This annual lecture was conceived as a way for the Physics Department to honor and bring the work of an experimental physicist to the general public. Many renowned experimental physicists have been hosted. The observation of the Higgs Boson at the LHC was easily the biggest science story of the year, so this should be an excellent lecture. It will begin at 5PM in the Pauley Ballroom and is an lecture that any budding astronomer or science enthusiast won't want to miss! Click here to say you're going.
The lecture abstract is as follows:
For the past three years, experiments at the Large Hadron Collider (LHC) have begun exploring physics at the high energy frontier. A rich harvest of initial physics results has been obtained that allows us to test the Standard Model (SM) of elementary particles and to make searches Beyond the SM (BSM), at the highest energy level ever reached in a laboratory. Most exciting is the recent discovery of a new particle that may well be the long-awaited Higgs Boson. This discovery would also establish the postulated electro-weak symmetry breaking mechanism in the SM. Other far-reaching results can be reported for BSM physics searches like Supersymmetry (SUSY) and its implication for Dark Matter in the Universe, Extra Dimensions, and the production of new heavy particles. Besides these physics results, the history and technical challenges of the LHC project, its status, future physics prospects, as well as Cal and LBNL’s prominent role in them will also be covered briefly in this talk.
Wednesday, October 31, 2012
Adventures with America's Cup
AC45 boats race during qualifying rounds this year
(AP Photo/Eric Risberg; The Big Story)
In honor of all the America's Cup excitement here in the Bay Area, it's important to understand how these massive boats work.
One of the fundamentals of sailing is tacking into the wind. This translates into forward motion for a sailboat, when you might otherwise think that the boat would list or sail backwards. In fact, sailing ships have a keel that stops them from being just pushed sideways. Therefore, they can only go forwards or backwards.
When the ship faces into the wind at an angle instead of head on, it's possible to set the sails so that the force of the wind
is pushing a little bit back and a lot sideways. So let's say the wind is coming from the north and the ship is facing
northwest. A good sailor can set up the sail
so that the force on the sails is a little bit south and a lot west.
Since the ship can only go forwards or backwards, the western force overcomes the southwards force, and the ship goes a lot west and a little north. If you then turn the ship northeast, you can go a lot east and a little north. Now you're farther north than you started, even though the wind is blowing from the north. If you turn your bow directly into the wind however, you will go backwards as your sails cannot catch the wind. This is an excellent way to cut your speed.
The sailors competing in America's Cup all possess incredibly precise intuition—built from years of practice—regarding the degree they should be to the wind. It is thrilling to watch them compete and race towards their goal. Although the excitement is over for the year, they'll be back next year for an intense competition that promises to be exhilarating!
Since the ship can only go forwards or backwards, the western force overcomes the southwards force, and the ship goes a lot west and a little north. If you then turn the ship northeast, you can go a lot east and a little north. Now you're farther north than you started, even though the wind is blowing from the north. If you turn your bow directly into the wind however, you will go backwards as your sails cannot catch the wind. This is an excellent way to cut your speed.
The sailors competing in America's Cup all possess incredibly precise intuition—built from years of practice—regarding the degree they should be to the wind. It is thrilling to watch them compete and race towards their goal. Although the excitement is over for the year, they'll be back next year for an intense competition that promises to be exhilarating!
Wednesday, October 24, 2012
Bay Area Science Festival
The Bay Area Science Festival is a week-long celebration of science that kicks off later this week. UC Berkeley and Science@Cal are involved in a number of exciting events, beginning with not one, but two star parties on Friday (one at the Lawrence Hall of Science for everyone, and a second teen-exclusive event at the YMCA Teen Center in downtown Berkeley).
You can also hike the Hayward Fault with UC Berkeley seismologists, explore what you eat at local farmers' markets, learn about the amazing things plants can do, enjoy the chemistry of brunch, investigate the intersection of art and science at a two-night exclusive gallery gala in downtown Berkeley, and join 25,000 others for the big finale at AT&T Park on November 3rd.
Many of these events are free. For a few of them, a small fee applies and / or registration is required.
Details of Science@Cal's participation in these events can be found on their website here.
The main festival webpage, featuring other events taking place across the Bay Area, is at Bay Area Science.
Also, save the date for the next Science@Cal lecture, November 17th, featuring Prof. Rosemary Gillespie, Director of the Essig Museum of Entomology, talking about evolution on remote islands.
Science Education Kickstarter
Wonderfest, the nonprofit San Francisco Bay Area Beacon of Science, has just begun a Kickstarter campaign to support a new, online, video series called "Radical Physics." Alex Filippenko, one of the world's most highly cited astronomers and a professor at UC Berkeley, will be part of the series.
You can take part by contributing as little as $1. And if you want a tangible reward, you can pledge $10 or more. All contributions (including big ones!) will be very welcome, and are tax deductible.
To appreciate this campaign -- and the educational need for Radical Physics -- please see the following web page. If you wish, watch the short-and-fun video and check out the various rewards of the Energy Radical Physics Video Series.
Wednesday, September 12, 2012
Pi Art in the Sky
If you look up into the sky today in the SF Bay Area, you will see skywriting planes creating an art installation called "Pi in the Sky." What is this? Why pi?
This artistic presentation of sky calligraphy will be the world's largest ephemeral art installation. Five synchronized planes will draw the first 1000 digits of the infinite sequence of pi (π, 3.14…), the ratio of a circle's circumference to its diameter.
Though created by an SF-based artist (ISHKY) as a community-building civic art experience, this event also provides an interesting educational opportunity, reminding us of the importance of math and science in our lives.
It is supported by piZone.org, a crowd-source resource that uses pi to educate and engage students and the public to become more interested in math and science with interactive games, educational videos, activities/demos, and pi art. For more information, see the press release here.
We invite you to pi-ticipate!
Share the pi with people in the Bay Area and beyond.
Estimated Flight Times and Cities
San Jose ~11:30
Oakland ~12:00
San Francisco ~12:10
Palo Alto ~12:30
San Jose ~12:40
This artistic presentation of sky calligraphy will be the world's largest ephemeral art installation. Five synchronized planes will draw the first 1000 digits of the infinite sequence of pi (π, 3.14…), the ratio of a circle's circumference to its diameter.
Though created by an SF-based artist (ISHKY) as a community-building civic art experience, this event also provides an interesting educational opportunity, reminding us of the importance of math and science in our lives.
It is supported by piZone.org, a crowd-source resource that uses pi to educate and engage students and the public to become more interested in math and science with interactive games, educational videos, activities/demos, and pi art. For more information, see the press release here.
We invite you to pi-ticipate!
Share the pi with people in the Bay Area and beyond.
Estimated Flight Times and Cities
San Jose ~11:30
Oakland ~12:00
San Francisco ~12:10
Palo Alto ~12:30
San Jose ~12:40
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