A couple of interesting studies on the effect that the gender of the instructor has on science students were recently released. The first takes a look at the perceptions high school students have of their science teachers, the second examines the effect the gender of a professor has on the female student's probability of continuation in a science, math or engineering major. Both fascinating studies speak to the power that perception and expectation have in determining our self-potential.
The first study, lead by Zahra Hazari, a Clemson University professor of engineering and science education, examined biology, chemistry and physics teacher evaluations by 18,000 high school students. They found that although there was no difference in the success in college of students taught by males and those taught by females, the women teachers were rated more poorly than their male counterparts. Interestingly, in biology and chemistry only the male students underrated their women teachers, but in physics both boys and girls perceived their female teachers as less effective. As Geoffrey Potvin, another Clemson professor said, these data suggest that students 'have developed a specific sense of gender-appropriate roles in the sciences by the end of high school'. We see this bias reflected in the number of female college majors in the sciences. In 2005, women made up 52% of chemistry majors, 62% of biology majors, but only 21% of physics majors in the top 50 research universities*.
The second study, by professors at UC Davis and the Air Force Academy, investigates the effect of professor gender on the probability a freshman woman will major in science. They looked at the records of all of the approximately 9,000 Air Force Academy students who graduated between 2000 and 2007 for correlations between the gender of the entry level science course instructors and the probability for a student to choose a science major. At the Academy all students have to take the same classes, so it's an ideal environment to study gender effects, modulo the fact that it is a military institution with a significant history of gender problems. They found that while for women in general gender did not make a difference, women who scored higher than 700 on their math SATs were 26% more likely to major in the sciences if all their intro science teachers were women than if they were all men. There was no effect seen on the male students.
In concert these two studies show that by high school students have developed gender bias in perceptions of scientific aptitude but that putting the female students into contact with professional women scientists (i.e. professors) could reverse some of that bias. It would be very interesting to see the results of the second study divided by major. Would the effect be present in the physics students? At Berkeley there are 5 women active faculty out of about 65 total (or 6 out of 100 including the emeritus professors). The probability that one of them will teach an introductory level class any given semester is low. As an undergrad I never took a class taught by a female physics professor and out of all the classes I took at Berkeley, only 2 were taught by female faculty, one in math and one in anthropology. But, I started doing research in 2001 and in all of the years since I have only spent 2 with male advisors, so I have not lacked for women role models. (I also had my dad, who always supported my interest in science and gave me a working example of what a scientist does). I strongly believe that having role models is vital to increasing the representation of women in the sciences. To that end, I've been doing some outreach to elementary school students, but I'll write about that in another post.
Some have claimed that the lack of women scientists might simply be due to the fact that women don't have the 'aptitude' for science. Those hypotheses infuriate me given the volume of research, such as these studies above, which show profound societal influences of both the success and the perception of success of women in science. The aptitude argument is the easy way out. We don't have to confront bias if it is dictated by biology. Luckily, people have realized that increasing the number of women in science and technology is in our national interest, and are working hard to see it happen.
* I should note that between 1996 and 2005 women recieved only 32% of chemistry PhDs and 46% of biology PhDs while 14% of physics PhDs went to women. In chemistry and biology there is a leaky pipeline--they loose women at every step of the ladder. In physics the pipeline problem is minimal, but we have a source problem--not enough women start in the first place.
Saturday, May 30, 2009
Thursday, May 28, 2009
New Web documentaries about Particle Physics
There is a new documentary series highlighting the people of the LHC that looks pretty good. Check it out!
Colliding Particles - Episode 1: Codename Eurostar from Mike Paterson on Vimeo.
Monday, May 25, 2009
Its been a while!
Fear not, I haven't abandoned the blog yet! I was sick last week with a nasty cold and have some catching up to do before any writing occurs, but expect some posts in the near future.
Monday, May 18, 2009
In which I get in touch with my inner pioneer woman: Peas and Parsley Risotto
Today I shucked peas. I sat at my kitchen table, a bowl at my right for the peas, a bowl at my left for the pods, and methodically tore off the ends, split the pods down the middle and slid my thumbs along the inside to release the little green orbs. I felt like I should have been wearing a muslin dress, playing out some storyline of a Laura Ingalls Wilder book, or an episode of Dr. Quinn, Medicine Woman. Dr Quinn was one of my favorite TV shows growing up. What's not to love about a strong female doctor making her way in the Wild West, saving lives and changing minds? But I digress...back to the peas. The peas came in our CSA box and, as with many things that come in the box, I did not know what to do with it. I turned to my trusty cookbook, Vegetarian Cooking for Everyone, by Deborah Madison and a recipe for risotto with peas caught my eye. It ended up being quite tasty. The peas made a satisfying pop when you bit into them which I've never experienced with frozen ones and the risotto was much creamier than I usually make it. I normally make risottos with little to no dairy, probably because the first risotto I ever made was for a vegan friend. This recipe, however, called for cream, and since I had some crème fraîche on hand I decided to go for the full dairy risotto experience.
Risottos are very labor intensive, but I think that's why I like making them. The continual stirring becomes hypnotic and you can almost loose yourself in the cooking process. Have fun!
For the parsley liquid:
2 bunches of parsley to yield ~ 3 cups of packed parsley leaves, discard the stems.
1.5 cups of water
.25 tsp salt
For the risotto:
2-3 tbsp of butter I used unsalted
1.5 cups Aborio rice pearl barley might work as well
.5-1 cup dry white wine the wine lends an acidity to the risotto which brings out the flavors. I sometimes even use a 1 to 1 ratio of wine to rice. Use anywhere from .5 to 1 cups depending on your taste, more would be overpowering for this risotto.
5 cups of broth or water I used water this time
One medium sized onion, or several shallots, or several spring onions, finely chopped
1.5 cups of shelled peas, fresh or frozen.
.5 cups of cream, marscapone cheese, or crème fraîche
.33-.5 cups of grated Parmesan, plus more for the table
salt and pepper to taste
1. Make the parsley liquid by bringing the 1.5 cups of water to a boil and then adding the parsley leaves and .25 tsp salt and cooking for 1 minute. Take the pot off the heat and let cook for 5 minutes. Purée in a blender or other instrument of your choice until smooth. Set aside.
2. Prepare to make the risotto by heating the 5 cups of stock or water to a simmer in a small pot. Have a ladle or measuring cup near by.
3. Heat the butter in a wide heavy bottomed skillet or sauce pan over medium heat. Add the onions and cook until translucent, about 5 minutes. Add the rice and stir constantly for about one minute, until the centers of the grains are white and the outsides translucent. Add the wine and stir constantly until absorbed. At this point I usually just start adding the broth/water 1/2 a cup at a time, stirring until each addition is absorbed. Deborah recommends adding 2 cups of stock and covering, stirring occasionally until the liquid is absorbed, about 5 minutes. I tried it her way and it worked fine. After the two cups is absorbed, continue to add the rest of the liquid in 1/2 cup increments, stirring constantly throughout the process.
4. When the rice is close to being done and you've gone through most or all of the liquid, turn up the heat a little and add the parsley liquid all at once, stirring furiously until its all absorbed. When its just about absorbed add the peas and the cream, then season with salt and pepper, remembering that you are going to add some Parmesan, so it better not be too salty. Take off the heat, stir in the Parmesan and serve.
Risotto with Parsley and Peas
Risottos are very labor intensive, but I think that's why I like making them. The continual stirring becomes hypnotic and you can almost loose yourself in the cooking process. Have fun!
For the parsley liquid:
2 bunches of parsley to yield ~ 3 cups of packed parsley leaves, discard the stems.
1.5 cups of water
.25 tsp salt
For the risotto:
2-3 tbsp of butter I used unsalted
1.5 cups Aborio rice pearl barley might work as well
.5-1 cup dry white wine the wine lends an acidity to the risotto which brings out the flavors. I sometimes even use a 1 to 1 ratio of wine to rice. Use anywhere from .5 to 1 cups depending on your taste, more would be overpowering for this risotto.
5 cups of broth or water I used water this time
One medium sized onion, or several shallots, or several spring onions, finely chopped
1.5 cups of shelled peas, fresh or frozen.
.5 cups of cream, marscapone cheese, or crème fraîche
.33-.5 cups of grated Parmesan, plus more for the table
salt and pepper to taste
1. Make the parsley liquid by bringing the 1.5 cups of water to a boil and then adding the parsley leaves and .25 tsp salt and cooking for 1 minute. Take the pot off the heat and let cook for 5 minutes. Purée in a blender or other instrument of your choice until smooth. Set aside.
2. Prepare to make the risotto by heating the 5 cups of stock or water to a simmer in a small pot. Have a ladle or measuring cup near by.
3. Heat the butter in a wide heavy bottomed skillet or sauce pan over medium heat. Add the onions and cook until translucent, about 5 minutes. Add the rice and stir constantly for about one minute, until the centers of the grains are white and the outsides translucent. Add the wine and stir constantly until absorbed. At this point I usually just start adding the broth/water 1/2 a cup at a time, stirring until each addition is absorbed. Deborah recommends adding 2 cups of stock and covering, stirring occasionally until the liquid is absorbed, about 5 minutes. I tried it her way and it worked fine. After the two cups is absorbed, continue to add the rest of the liquid in 1/2 cup increments, stirring constantly throughout the process.
4. When the rice is close to being done and you've gone through most or all of the liquid, turn up the heat a little and add the parsley liquid all at once, stirring furiously until its all absorbed. When its just about absorbed add the peas and the cream, then season with salt and pepper, remembering that you are going to add some Parmesan, so it better not be too salty. Take off the heat, stir in the Parmesan and serve.
Quick Hit: Awesome Space Shuttle Photos
Check out this link, it's got some amazing photos of Atlantis transiting the sun.
Sunday, May 17, 2009
APS Leftovers: I suppose this one's for you, Dad.
There are a few stories from APS that I wanted to write about but didn’t get around to doing so until now. This post is an observation and reflection that might come off as cheezy, but I don’t know how to make it not cheezy, so consider yourself forewarned.
At APS you expect to see talks, talks and more talks, interspersed with posters, coffee break conversations, and perhaps the consumption of a few too many beers at dinner. Something I did not expect to see at APS were children, especially children in sessions, but there they were.
In one of the sessions about the Pamela, Fermi and ATIC results I sat behind a fatherand his young daughter. Dressed from head to toe in pink and clutching a little pink purse, she must’ve been no older than nine or ten years old. She tucked her arm into her father’s and sat with her head on his upper arm as she listened to the talks. I was wondering why she was there when her dad got up to give a talk about the Fermi data. She sat up, clapping excitedly with a big smile on her face and listened attentively through out the presentation. When he came back to his seat after a well received talk she gave him a big hug and a little while later she left.
I saw another child at a session for one of the awards which are giving out at APS for lifetime achievements, thesis prizes, etc. In this particular session I heard featured talks by the winners of the the Sakurai Prize, which is given to people who have made important contributions to theory. When one of the speakers, Keith Ellis, was introduced, I heard whooping and cheering from behind me and turned to see his young teenage son cheering for his dad. When the talk was over the son again cheered loudly, amusing the audience.
Perhaps these observations made an impression on me because I am the child of a scientist. I remember how excited I was to go to the office on Saturdays with my dad and draw on his white board while he worked and how happy I was to see him come home from trips to overseas labs. To both Ellis’s son and the girl in the cosmic ray session, what their dads were saying probably seemed like gibberish, but it didn’t matter to them because they had been allowed into the world which claims so much of their dads’ time and energy. Of course, this desire for inclusion is not unique to children of scientists, it is probably true of the progeny of any workaholic. Scientists just tend to fall in that category.
At APS you expect to see talks, talks and more talks, interspersed with posters, coffee break conversations, and perhaps the consumption of a few too many beers at dinner. Something I did not expect to see at APS were children, especially children in sessions, but there they were.
In one of the sessions about the Pamela, Fermi and ATIC results I sat behind a fatherand his young daughter. Dressed from head to toe in pink and clutching a little pink purse, she must’ve been no older than nine or ten years old. She tucked her arm into her father’s and sat with her head on his upper arm as she listened to the talks. I was wondering why she was there when her dad got up to give a talk about the Fermi data. She sat up, clapping excitedly with a big smile on her face and listened attentively through out the presentation. When he came back to his seat after a well received talk she gave him a big hug and a little while later she left.
I saw another child at a session for one of the awards which are giving out at APS for lifetime achievements, thesis prizes, etc. In this particular session I heard featured talks by the winners of the the Sakurai Prize, which is given to people who have made important contributions to theory. When one of the speakers, Keith Ellis, was introduced, I heard whooping and cheering from behind me and turned to see his young teenage son cheering for his dad. When the talk was over the son again cheered loudly, amusing the audience.
Perhaps these observations made an impression on me because I am the child of a scientist. I remember how excited I was to go to the office on Saturdays with my dad and draw on his white board while he worked and how happy I was to see him come home from trips to overseas labs. To both Ellis’s son and the girl in the cosmic ray session, what their dads were saying probably seemed like gibberish, but it didn’t matter to them because they had been allowed into the world which claims so much of their dads’ time and energy. Of course, this desire for inclusion is not unique to children of scientists, it is probably true of the progeny of any workaholic. Scientists just tend to fall in that category.
Thursday, May 14, 2009
Meyer Lemon Martinis: This One's For You, Mom.
My mom is a martini woman. Not the spine-straightening vodka and vermouth type; that's my Uncle Frank's specialty. Jeweled, slightly sweet and tingly refreshing drinks like cosmopolitans are more her style. When I come home to visit we usually spend an evening sitting at the kitchen counter, sipping cocktails. It's always wonderfully relaxing. Here is a drink I think she'll like.
One of my best friends from college, Jasmin, lives across the bay in San Francisco. We try to get together a couple of times a month for dinner and drinks. This weekend I hosted and was trying to decide what to make for dessert. Our apartment building has a Meyer lemon tree in the backyard (pictured) which is currently producing copious amounts of lemons and consequently everything I am cooking lately features lemons. I decided that dessert should be lemon-centric but nothing I saw on the internet or in my cookbooks looked either appealing or easy enough to be worth making. Then an idea occurred to me: who needs dessert when you can make cocktails?! A visit to Google and a few clicks later I had a recipe for Meyer lemon martinis, which I've reproduced below. Mmmmm, Mmmmm, they were delicious!
Meyer Lemon Martinis
2 oz Vodka
.75 oz meyer lemon juice
.5 oz lemon-infused simple syrup (instructions below, increase to .75 oz if using normal lemons)
* a shot glass is 1.5 oz
Mix, shake, and pour, that's all there is too it! To serve I ran a squeezed lemon half around the rim of our flared-mouth wine glasses and then coated the rims with sugar.
Lemon-infused Simple Syrup
2 parts water
1 part sugar
lemon zest to taste (I put one lemon's worth of zest in 1.5 cups of water)
Put the water, sugar and lemon zest in a pot, stir until the sugar is dissolved and heat until just boiling. Take off the heat and let cool, strain and store in the fridge.
Tuesday, May 12, 2009
You know it's gone too far when...
You find the following in your inbox:
Update: In conversation with one of my colleagues we realized that a committee on meetings was the only logical course of action for the experiment to try to reign in the rapidly multiplying meeting agenda. And then we realized how sad it was that we found the committee to be natural. We are in too deep; we have been assimilated!
In order to optimize the number and organization of ATLAS meetings, we have put in place a "Meeting Optimization committee"I kid you not. Meetings to organize meetings. I am a physicist, right? Just checking....
Update: In conversation with one of my colleagues we realized that a committee on meetings was the only logical course of action for the experiment to try to reign in the rapidly multiplying meeting agenda. And then we realized how sad it was that we found the committee to be natural. We are in too deep; we have been assimilated!
Monday, May 11, 2009
Lift Off
The space shuttle Atlantis lifted off today on a mission to fix the Hubble Space Telescope. Hubble has been mostly blind for the past couple of years, loosing one of the cameras in January 2007 and another in 2008. The astronauts are trying to fix both cameras and put in a new instrument, new gyroscopes and remove some old cameras at the same time. Hopefully they get it all done!
Cosmic Variance has a nice report on the launch. It's amazing to watch the shuttle lift off and know that people are traveling into orbit. I saw Star Trek this weekend (it was good!) and while the everything in the movie is pure fantasy, watching a shuttle launch plants a little irrational thought that maybe someday we'll achieve a tiny piece of what the screenwriters imagined.
Cosmic Variance has a nice report on the launch. It's amazing to watch the shuttle lift off and know that people are traveling into orbit. I saw Star Trek this weekend (it was good!) and while the everything in the movie is pure fantasy, watching a shuttle launch plants a little irrational thought that maybe someday we'll achieve a tiny piece of what the screenwriters imagined.
Et Voilà, Baguette!
Friday evening I stumbled home and flung myself on the couch after seven straight days of talks. Yep, seven. APS had begun the previous Saturday at 8:30 am and lasted through Tuesday. I got on a plane back to Berkeley Tuesday afternoon, missing the last half day of APS talks, and Wednesday morning I was back at LBL for a 7:30am meeting. That meeting was followed by the start of a workshop which lasted until Friday evening. When I flung myself down on the couch my brain was so saturated I vowed to not think about physics for the entire weekend. My plan for the weekend included sleeping, bike riding, cooking, and attempting to bake a decent baguette. I am happy to report that I had a wonderful weekend accomplishing all four of the above activities and almost succeeded in not doing any physics!
This post is to detail the baguette making, which was just as satisfying, if not more so, than the bagel making. The baguettes are made pain à l’ancienne style, detailed in Peter Reinhart’s book, which involves letting the fridge do most of the fermentation work. The result was a wonderfully crusty, sweet and nutty baguette which I couldn’t quite believe came out of my oven. I was supremely happy the rest of the day. It’s funny how flour, yeast, water and salt can do that to you.
Baguettes à l’Ancienne from Peter Reinhart’s The Bread Baker’s Apprentice
6 cups unbleached bread flour (27oz)
2 1/4 teaspoons salt (fine sea salt)
1 3/4 teaspoons instant yeast (increase by 25% if using active dry)
2 1/4 -3 cups ice-cold water (needs to be as cold as possible)
Semolina or cornmeal for dusting
*you will need an oven-safe, heavy duty skillet and a spray bottle of water for the baking stage
Step 1: Mixing
Stand Mixer Instructions: Combine the flour, salt, yeast and water in the bowl of the electric mixer with the paddle attachment and mix for 2 minutes on low speed. Switch to the dough hook and mix for 5 to 6 minutes on medium speed. The dough should be sticky on the bottom of the bowl, but it should release from the sides of the bowl. If not, sprinkle in a small amount of flour until this occurs (or dribble in water if the dough seems too stiff and clears the bottom as well as the sides of the bowl).
Hand Mixing: Standmixing is much preferred because it minimizes contact with the dough so it doesn’t heat up as much. However, I was using my stand mixer and didn’t realize that the dough had climbed up the dough hook and got a bunch of grease in it from the place where the hook attaches to the machine. I decided to start over and hand mix it with the following process. Combine the flour, salt and yeast in a large, wide mouthed bowl. Add the water and mix (by hand or spoon) until combined. Then, dip your hand in cold water and knead the dough inside the bowl by holding the bowl with one arm and using the other hand as a dough hook, folding and pressing the dough against the sides of the bowl. Do this for about 10 minutes. I think my dough got a bit too warm and wasn't quite sticky enough, even though I added more than the 2 1/4 cups of water. Next time I will add closer to 3 cups.
Step 2: Refrigeration
Lightly oil a large bowl and immediately transfer the dough with a spatula or bowl scraper dipped in water into the bowl. Mist the top of the dough with spray oil and cover the bowl with plastic wrap. Immediately place the bowl in the refrigerator and chill overnight, to retard fermentation.
Step 3: Final Fermentation
The next day, check the dough to see if it has risen in the refrigerator. It will probably be partially risen but not doubled in size (the amount of rise will depend on how cold the refrigerator is and how often the door was opened). Leave the bowl of dough out at room temperature for about 2 to 3 hours (or longer if necessary) to allow the dough to wake up, lose its chill, and continue fermenting.
Step 4: Shaping
Prepare the oven for hearth baking by putting a baking stone at the bottom and a heavy duty skillet on a rack near the top to function as a steam pan. Preheat the oven to 500 F, or 550 F if your oven goes this high. Boil ~4 cups of water and keep covered near by. Cover the back of two big sheet pans with baking parchment and dust with semolina flour or cornmeal. If you don’t have a baking stone you will just cook the bread on the back of the sheet pans.
When the dough has doubled from its original prerefrigerated size, liberally sprinkle the counter with bread flour (about 1/2 cup). Gently transfer the dough to the floured counter with a plastic dough scraper or spatula that has been dipped in cold water, dipping your hands as well to keep the dough from sticking to you. Avoid punching down the dough as you transfer it, to expel as little as possible of the carbon-dioxide gas that has built up in the dough during fermentation.
If the dough is very wet, sprinkle more flour over the top as well as under it. Dry your hands thoroughly and then dip them in flour. Roll the dough gently in the sprinkled flour to coat it thoroughly, simultaneously stretching it into an oblong about 8 inches long and 6 inches wide. If it is too sticky to handle, continue sprinkling flour over it.
Dip a metal pastry scraper into cool water to keep it from sticking to the dough, and cut the dough in half widthwise with the pastry scraper by pressing it down through the dough until it severs it, then dipping it again in the water and repeating this action until you have cut down the full length of the dough. (Do not use this blade as a saw; use it as a pincer, pinching the dough cleanly with each cut.) Let the dough relax for 5 minutes.
Take one of the dough pieces and repeat the cutting action, but this time cut lengthwise into 3 equal-sized pieces. Then do the same with the remaining half.
Flour your hands and carefully lift one of the dough strips and transfer it to an inverted parchment-lined pan, gently pulling it to the length of the pan or to the length of your baking stone. If it springs back, let it rest for 5 minutes and then gently pull it out again. Place 3 strips on the pan, and then prepare another pan and repeat with the remaining strips.
Score the dough strips as for traditional baguettes, slashing the tops with 3 diagonal cuts. Because the dough is sticky, you may have to dip the razor blade, serrated knife or scissors in water between each cut. You may also omit the cuts if the dough isn't cooperating.
Step 5: Baking
Take one pan to the preheated oven and carefully slide the dough, parchment and all, onto the baking stone (depending on the direction of the stone, you may choose to slide the dough and parchment off the side of the sheet pan instead of off the end); or bake directly on the sheet pan. I recommend wearing long sleeves and using oven mits or gloves and hot pads.
Make sure the pieces aren't touching (you can reach in and straighten the parchment or the dough strips, if need be). Pour 1 cup of the hot water you set aside into the steam pan and close the door.
After 30 seconds, spray the oven walls with water from the spray bottle and close the door. Repeat twice more at 30-second intervals. After the final spray, reduce the oven setting to 475 F and continue baking.
Meanwhile, dust the other pan of strips with flour, mist with spray oil, and cover with a towel or plastic wrap. If you don't plan to bake these strips within 1 hour, refrigerate the pan and bake later or the next day.
The bread should begin to turn golden brown within 8 or 9 minutes. If the loaves are baking unevenly at this point, rotate them 180 degrees. Continue baking 10 to 15 minutes more, or until the bread is a rich golden brown and the internal temperature registers at least 205 F.
Transfer the hot breads to a cooling rack. They should feel very light, almost airy, and will cool in about 20 minutes.
While these are cooling, you can bake the remaining loaves, remembering to remove the parchment from the oven and turn the oven up to 500 F or higher before baking the second round.
This post is to detail the baguette making, which was just as satisfying, if not more so, than the bagel making. The baguettes are made pain à l’ancienne style, detailed in Peter Reinhart’s book, which involves letting the fridge do most of the fermentation work. The result was a wonderfully crusty, sweet and nutty baguette which I couldn’t quite believe came out of my oven. I was supremely happy the rest of the day. It’s funny how flour, yeast, water and salt can do that to you.
Baguettes à l’Ancienne from Peter Reinhart’s The Bread Baker’s Apprentice
6 cups unbleached bread flour (27oz)
2 1/4 teaspoons salt (fine sea salt)
1 3/4 teaspoons instant yeast (increase by 25% if using active dry)
2 1/4 -3 cups ice-cold water (needs to be as cold as possible)
Semolina or cornmeal for dusting
*you will need an oven-safe, heavy duty skillet and a spray bottle of water for the baking stage
Step 1: Mixing
Stand Mixer Instructions: Combine the flour, salt, yeast and water in the bowl of the electric mixer with the paddle attachment and mix for 2 minutes on low speed. Switch to the dough hook and mix for 5 to 6 minutes on medium speed. The dough should be sticky on the bottom of the bowl, but it should release from the sides of the bowl. If not, sprinkle in a small amount of flour until this occurs (or dribble in water if the dough seems too stiff and clears the bottom as well as the sides of the bowl).
Hand Mixing: Standmixing is much preferred because it minimizes contact with the dough so it doesn’t heat up as much. However, I was using my stand mixer and didn’t realize that the dough had climbed up the dough hook and got a bunch of grease in it from the place where the hook attaches to the machine. I decided to start over and hand mix it with the following process. Combine the flour, salt and yeast in a large, wide mouthed bowl. Add the water and mix (by hand or spoon) until combined. Then, dip your hand in cold water and knead the dough inside the bowl by holding the bowl with one arm and using the other hand as a dough hook, folding and pressing the dough against the sides of the bowl. Do this for about 10 minutes. I think my dough got a bit too warm and wasn't quite sticky enough, even though I added more than the 2 1/4 cups of water. Next time I will add closer to 3 cups.
Step 2: Refrigeration
Lightly oil a large bowl and immediately transfer the dough with a spatula or bowl scraper dipped in water into the bowl. Mist the top of the dough with spray oil and cover the bowl with plastic wrap. Immediately place the bowl in the refrigerator and chill overnight, to retard fermentation.
Step 3: Final Fermentation
The next day, check the dough to see if it has risen in the refrigerator. It will probably be partially risen but not doubled in size (the amount of rise will depend on how cold the refrigerator is and how often the door was opened). Leave the bowl of dough out at room temperature for about 2 to 3 hours (or longer if necessary) to allow the dough to wake up, lose its chill, and continue fermenting.
Step 4: Shaping
Prepare the oven for hearth baking by putting a baking stone at the bottom and a heavy duty skillet on a rack near the top to function as a steam pan. Preheat the oven to 500 F, or 550 F if your oven goes this high. Boil ~4 cups of water and keep covered near by. Cover the back of two big sheet pans with baking parchment and dust with semolina flour or cornmeal. If you don’t have a baking stone you will just cook the bread on the back of the sheet pans.
When the dough has doubled from its original prerefrigerated size, liberally sprinkle the counter with bread flour (about 1/2 cup). Gently transfer the dough to the floured counter with a plastic dough scraper or spatula that has been dipped in cold water, dipping your hands as well to keep the dough from sticking to you. Avoid punching down the dough as you transfer it, to expel as little as possible of the carbon-dioxide gas that has built up in the dough during fermentation.
If the dough is very wet, sprinkle more flour over the top as well as under it. Dry your hands thoroughly and then dip them in flour. Roll the dough gently in the sprinkled flour to coat it thoroughly, simultaneously stretching it into an oblong about 8 inches long and 6 inches wide. If it is too sticky to handle, continue sprinkling flour over it.
Dip a metal pastry scraper into cool water to keep it from sticking to the dough, and cut the dough in half widthwise with the pastry scraper by pressing it down through the dough until it severs it, then dipping it again in the water and repeating this action until you have cut down the full length of the dough. (Do not use this blade as a saw; use it as a pincer, pinching the dough cleanly with each cut.) Let the dough relax for 5 minutes.
Take one of the dough pieces and repeat the cutting action, but this time cut lengthwise into 3 equal-sized pieces. Then do the same with the remaining half.
Flour your hands and carefully lift one of the dough strips and transfer it to an inverted parchment-lined pan, gently pulling it to the length of the pan or to the length of your baking stone. If it springs back, let it rest for 5 minutes and then gently pull it out again. Place 3 strips on the pan, and then prepare another pan and repeat with the remaining strips.
Score the dough strips as for traditional baguettes, slashing the tops with 3 diagonal cuts. Because the dough is sticky, you may have to dip the razor blade, serrated knife or scissors in water between each cut. You may also omit the cuts if the dough isn't cooperating.
Take one pan to the preheated oven and carefully slide the dough, parchment and all, onto the baking stone (depending on the direction of the stone, you may choose to slide the dough and parchment off the side of the sheet pan instead of off the end); or bake directly on the sheet pan. I recommend wearing long sleeves and using oven mits or gloves and hot pads.
Make sure the pieces aren't touching (you can reach in and straighten the parchment or the dough strips, if need be). Pour 1 cup of the hot water you set aside into the steam pan and close the door.
After 30 seconds, spray the oven walls with water from the spray bottle and close the door. Repeat twice more at 30-second intervals. After the final spray, reduce the oven setting to 475 F and continue baking.
Meanwhile, dust the other pan of strips with flour, mist with spray oil, and cover with a towel or plastic wrap. If you don't plan to bake these strips within 1 hour, refrigerate the pan and bake later or the next day.
The bread should begin to turn golden brown within 8 or 9 minutes. If the loaves are baking unevenly at this point, rotate them 180 degrees. Continue baking 10 to 15 minutes more, or until the bread is a rich golden brown and the internal temperature registers at least 205 F.
Transfer the hot breads to a cooling rack. They should feel very light, almost airy, and will cool in about 20 minutes.
While these are cooling, you can bake the remaining loaves, remembering to remove the parchment from the oven and turn the oven up to 500 F or higher before baking the second round.
Friday, May 8, 2009
A Standby: Spicy Leek and Tomato Sauce
I'd like to share a standby recipe that I use whenever I have leeks on hand and not much time to make dinner. I've adapted it from a 2007 Bon Appétit recipe which I found on Epicurious. What I'm going to suggest below is enough for 5 or 6 people, or dinner for 2 and lunch for a couple of days after. I used canned tomatoes, but when it's tomato season I use fresh ones. Also, all of the ingredient quantities are very approximate.
Linguine with Spicy Leek and Tomato Sauce
Linguine with Spicy Leek and Tomato Sauce
- 1/4- 1/2 cups extra-virgin olive oil
- 4 chopped garlic cloves, or 3 green garlic bulbs(?), white parts only, split lengthwise, sliced crosswise
- 1-1 1/2 teaspoon dried crushed red pepper
- 1 1/2 teaspoon fennel seeds
- 3-4 medium leeks (white and pale green parts only), split lengthwise, sliced crosswise
- 2 large cans diced tomatoes, 2/3 of the juice removed
- 1 cup dry white wine
- 2 tablespoons white wine vinegar * can be left out if you don't have any
- 1 box of linguine or pasta of your choice
- 2 cups of Parmesan
Meanwhile, cook pasta in large pot of boiling salted water until tender but still firm to bite. Drain, reserving a cup or so of the pasta cooking liquid.
Back to the large sauce pan which is still on medium heat: Add the pasta and a drizzling of oil and toss. Add ~1 cup cheese and toss until mixed, add some of the cooking liquid if the sauce seems dry. Season with salt and pepper. Serve with a sprinkling of extra cheese and a drizzle of nice olive oil to finish. The olive oil drizzle is key, it makes the flavors pop!
Tuesday, May 5, 2009
APS: Fermi Results
I am on my way back from the 2009 American Physical Society (APS)’s April meeting (in May). It was an exciting, well run conference and I thoroughly enjoyed myself.
The big news of the conference was the high energy electron+positron cosmic ray spectrum that the Fermi telescope released during the first talk of the meeting. As I mentioned in my previous post, cosmic rays are particles which are constantly bombarding the earth’s atmosphere. They consist of a mixture of protons, electrons, positrons (positively charged electrons), photons and a mix of heavier elements. They originate in a variety of sources ranging from astrophysical accelerators such as pulsars, supernovae remnants and active galactic nuclei which can accelerate particles to high energies to the sun. It is also believed that the cosmic ray flux could contain the decay products of dark matter annihilation. Dark matter comprises 25% of the known energy density in the universe, 5% goes to the normal matter that you, I and the stars are made of, and 70% percent goes to something so mysterious that we call it dark energy. Sounds spooky, right? There are many theories of what the dark matter could be made of but all we know for sure is that it interacts extremely rarely, giving it the property of ‘darkness’.
Eluding detection, dark matter has been a persistent thorn in the side of particle physicists and astrophysicists alike since Fritz Zwicky proposed it in 1933 after observing the rotational velocity of stars in galaxies. Stars orbit the center of their galaxy at a speed that is dependent upon the mass inside their orbits. We can measure the speed of the stars using the doppler effect and we can determine how much mass we think is there by measuring the amount of light we see. However, once you compare the mass in the galaxy and the velocity of the stars you find that you need many more times the mass that you see to generate the speed of the stars. Dark matter was proposed to fill this gap and has been verified in diverse and numerous observations.
There are a number of experiments investigating the flux of cosmic rays to try to find evidence of dark matter annihilation. In the past 6 months or so there have been several exciting yet unconfirmed measurements published. The ATIC experiment found an excess of electrons+positrons at high energy and, in a different energy range, the Pamela experiment found an excess of positrons relative to the number of positrons+electrons. Fermi, a state of the art satellite telescope designed to look at gamma rays and other cosmic rays, was supposed to clarify the situation. They released the results of electron+positron flux on Saturday morning and rather than clearing up the picture, it is now fuzzier. They do not see the same excess that ATIC sees, yet their data does not agree with the standard simulations of galactic cosmic rays. Looking at their data you could see an excess if you wanted to but if you don’t you can convince yourself its not there as is often the case with ambiguous results.
My concern with all of these experiments is that the signal is very small compared to the flux of protons, their main background, and their background rejection efficiency decreases in the region where the excess grows. A mis-measurement of the efficiencies, resolutions or the errors could make a big change in the results. I’m not yet convinced that these results are evidence for dark matter, and I think there are many who would agree with me.
It's important to note that there is a simple astrophysical solution which could explain the data. People have proposed that there is one or more nearby pulsars that are creating the excess that we haven’t found yet. However pulsars are mundane to particle physicists so that explanation was mostly ignored, especially by the theorists. It was amusing to see how quickly they showed plots comparing their favorite models to the new data.
A composite image of the pulsar containing Crab Nebula showing the X-ray (blue), and optical (red) images superimposed. The size of the X-ray image is smaller because the higher energy X-ray emitting electrons radiate away their energy more quickly than the lower energy optically emitting electrons as they move.
The experiments are in the process of further investigating their data. Fermi should release their high energy gamma ray data soon and Pamela will release their positron+electron flux measurement which can be directly compared to the Fermi data. If either of these signals confirm what we’ve seen already the case for dark matter will become more convincing. Until that time, however, I like the suggestion of a commenter in one of the sessions: “Members of each experiment should be locked in a room without weapons...and not let out until they figure this mess out”.
The big news of the conference was the high energy electron+positron cosmic ray spectrum that the Fermi telescope released during the first talk of the meeting. As I mentioned in my previous post, cosmic rays are particles which are constantly bombarding the earth’s atmosphere. They consist of a mixture of protons, electrons, positrons (positively charged electrons), photons and a mix of heavier elements. They originate in a variety of sources ranging from astrophysical accelerators such as pulsars, supernovae remnants and active galactic nuclei which can accelerate particles to high energies to the sun. It is also believed that the cosmic ray flux could contain the decay products of dark matter annihilation. Dark matter comprises 25% of the known energy density in the universe, 5% goes to the normal matter that you, I and the stars are made of, and 70% percent goes to something so mysterious that we call it dark energy. Sounds spooky, right? There are many theories of what the dark matter could be made of but all we know for sure is that it interacts extremely rarely, giving it the property of ‘darkness’.
Newly released Fermi results (red) of the electron and positron flux compared with the conventional diffuse model of cosmic ray flux (blue). For more information Physics has a technical article about it.
Eluding detection, dark matter has been a persistent thorn in the side of particle physicists and astrophysicists alike since Fritz Zwicky proposed it in 1933 after observing the rotational velocity of stars in galaxies. Stars orbit the center of their galaxy at a speed that is dependent upon the mass inside their orbits. We can measure the speed of the stars using the doppler effect and we can determine how much mass we think is there by measuring the amount of light we see. However, once you compare the mass in the galaxy and the velocity of the stars you find that you need many more times the mass that you see to generate the speed of the stars. Dark matter was proposed to fill this gap and has been verified in diverse and numerous observations.
There are a number of experiments investigating the flux of cosmic rays to try to find evidence of dark matter annihilation. In the past 6 months or so there have been several exciting yet unconfirmed measurements published. The ATIC experiment found an excess of electrons+positrons at high energy and, in a different energy range, the Pamela experiment found an excess of positrons relative to the number of positrons+electrons. Fermi, a state of the art satellite telescope designed to look at gamma rays and other cosmic rays, was supposed to clarify the situation. They released the results of electron+positron flux on Saturday morning and rather than clearing up the picture, it is now fuzzier. They do not see the same excess that ATIC sees, yet their data does not agree with the standard simulations of galactic cosmic rays. Looking at their data you could see an excess if you wanted to but if you don’t you can convince yourself its not there as is often the case with ambiguous results.
My concern with all of these experiments is that the signal is very small compared to the flux of protons, their main background, and their background rejection efficiency decreases in the region where the excess grows. A mis-measurement of the efficiencies, resolutions or the errors could make a big change in the results. I’m not yet convinced that these results are evidence for dark matter, and I think there are many who would agree with me.
It's important to note that there is a simple astrophysical solution which could explain the data. People have proposed that there is one or more nearby pulsars that are creating the excess that we haven’t found yet. However pulsars are mundane to particle physicists so that explanation was mostly ignored, especially by the theorists. It was amusing to see how quickly they showed plots comparing their favorite models to the new data.
A composite image of the pulsar containing Crab Nebula showing the X-ray (blue), and optical (red) images superimposed. The size of the X-ray image is smaller because the higher energy X-ray emitting electrons radiate away their energy more quickly than the lower energy optically emitting electrons as they move. Friday, May 1, 2009
Hi From Denver
I’m in Denver for the 2009 American Physical Society (APS) April Meeting. You might be saying, Wait! It’s not April anymore! And you would be correct. This meeting, which consists of particle physicists, astrophysicists and nuclear physicists, is traditionally in April. There is another yearly APS meeting, the March Meeting, which is for everything else. To distinguish the two they call them by the months in which they’ve traditionally been held.
This meeting consists of 4 days of 10 minute talks mostly by graduate students and post-doc, interspersed with longer plenary style talks from important invited speakers. I’m giving a talk tomorrow morning in the Instrumentation in High Energy Physics session. I’ll be talking about ATLAS’s tracking performance with cosmic rays. Even though the LHC is not running, the ATLAS detector is, and luckily Mother Nature provides us something to look at. (Actually, it's not running this Spring in order to do some maintenance.) The earth’s atmosphere is constantly being bombarded by particles from space which we call cosmic rays. Hundreds are passing through you right now. Modern particle physics was founded on the study of these particles, which can reach much higher energies than we can create in accelerators. ATLAS is 100 meters under the ground, so we see only one type of cosmic ray, the muon, which is created when a primary cosmic rays hits the Earth's atmosphere and decays. Particle physicists love muons. They are heavy and only interact via the electromagnetic and weak forces so they pass through most material relatively unhindered. Last fall ATLAS used these particles to start understanding how the detector works. It is such a massive machine that it takes an immense amount of calibration work before you can start doing physics. The cosmic rays give us a perfect opportunity to do that calibration in a simple environment since we usually see only one of them at a time. In a proton collision like what the LHC will deliver we will see hundreds! I’ve been looking at the performance of our Inner Detector, a set of 3 tracking detectors which work together to measure a particle’s trajectory and momentum. The conclusion of the study is that it is performing very well!
The picture is an artist's rendition of the showers of particles produced when ultra high energy cosmic rays interact in the atmosphere.
There is word that some exciting results will be released tomorrow. I’ll probably write about that and I’ll be writing posts through out the rest of conference as interesting topics come up!
This meeting consists of 4 days of 10 minute talks mostly by graduate students and post-doc, interspersed with longer plenary style talks from important invited speakers. I’m giving a talk tomorrow morning in the Instrumentation in High Energy Physics session. I’ll be talking about ATLAS’s tracking performance with cosmic rays. Even though the LHC is not running, the ATLAS detector is, and luckily Mother Nature provides us something to look at. (Actually, it's not running this Spring in order to do some maintenance.) The earth’s atmosphere is constantly being bombarded by particles from space which we call cosmic rays. Hundreds are passing through you right now. Modern particle physics was founded on the study of these particles, which can reach much higher energies than we can create in accelerators. ATLAS is 100 meters under the ground, so we see only one type of cosmic ray, the muon, which is created when a primary cosmic rays hits the Earth's atmosphere and decays. Particle physicists love muons. They are heavy and only interact via the electromagnetic and weak forces so they pass through most material relatively unhindered. Last fall ATLAS used these particles to start understanding how the detector works. It is such a massive machine that it takes an immense amount of calibration work before you can start doing physics. The cosmic rays give us a perfect opportunity to do that calibration in a simple environment since we usually see only one of them at a time. In a proton collision like what the LHC will deliver we will see hundreds! I’ve been looking at the performance of our Inner Detector, a set of 3 tracking detectors which work together to measure a particle’s trajectory and momentum. The conclusion of the study is that it is performing very well!
The picture is an artist's rendition of the showers of particles produced when ultra high energy cosmic rays interact in the atmosphere.There is word that some exciting results will be released tomorrow. I’ll probably write about that and I’ll be writing posts through out the rest of conference as interesting topics come up!
Subscribe to:
Posts (Atom)