(Almost) Wordless Wednesday: Most beautiful hydrograph in years March 20, 2012
Posted by mareserinitatis in Fargo, geology, science.Tags: fargo, flood, red river
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Scientist, with kids February 19, 2012
Posted by mareserinitatis in career, education, engineering, family, feminism, grad school, homeschooling, older son, personal, physics, research, science, societal commentary.Tags: feminism, gender equity, kids, parenting, role models, sexism
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FSP has a post asking about the Local Mom Effect. That is, she wonders if being in a department with more women professors who have kids affects the outlook of younger women in the field. I find this post interesting…but also, I hate to say it, irrelevant.
Let’s put it this way: what women?!
When I started school at Caltech, I knew of two women professors out of all of math, physics, and astronomy. I only ever met one of them, knew she had no kids. I knew nothing about the other professor. When I decided to go back to school a few years later, I ended up in a physics dept. where the professors were all men. Later, I ended up in an electrical engineering department where the professors were all men.
I guess that, in my mind, the notion of being one of the few women in the department was no different than being one of the few women with kids in the department. When I went back to school, I had a kid already, so it wasn’t like I really had a choice about whether or not to be a childless woman in physics or engineering.
I will say that when I originally got pregnant as an undergrad at Caltech, I was told by my advisor that women couldn’t do calculus while pregnant and that I should drop out. Of course, he was a guy, so I seriously doubted he understood how women’s brains work while pregnant. (And it turns out that I can do calculus great while pregnant…I just can’t speak a full sentence coherently.) However, I guess I never took it as a message that women with kids don’t belong in science…I inferred that he meant it more personally, and that I myself was not a good fit for science. (Fortunately, major hopping got boring after a while, I ended up back in physics.)
When I went back to school, however, I felt that being the only woman or one of a few was very advantageous for several reasons. First, if I was the only woman or one of a very small number, I was already an oddity. A woman with kids is probably not much more odd than a woman without, and there was really no one to compare myself to (or say that I was doing it wrong). Second, I went back to school in North Dakota, and it really seems like people here more or less expect you to have kids no matter what you’re doing. I know that grates on some people, but for me, it was a blessing: having kids is just another part of life, and most people here learn to do their jobs while having them. (Also, I can’t recall anyone having a fit if I said I couldn’t make it to something because of kid-related issues.) Third, I was older than the average undergraduate or even grad student, so I think people assumed that it was pretty normal for someone my age to have kids. The fact that the younger students didn’t have kids was simply a function of age and never made me feel self-conscious that I did have kids. Finally, when I started my MS, my advisor was fine with the fact that I was homeschooling the older boy and would only be doing my degree part-time. He said this was really no different than other students in the department who were working full-time and pursing their degree part-time, as well.
I have been told, especially when doing my PhD classes, that it was “really cool to see a woman in science with kids”, especially by some fellow grad students. Until I started my PhD, I really hadn’t expected it to be a big deal. It had never occurred to me that I might be a “role model”…but I keep hearing it more than I ever expected to. I also suspect it’s because I often had kids with me or family issues that were more apparent to fellow grad students. Many professors try to maintain a more professional relationship with their students, and it doesn’t surprise me that many grad students don’t see how having kids affects the lives of the professors or that they don’t realize some professors have kids at all.
Realistically, I only got here because I didn’t really know that what I was doing was unusual in any way. If I had been surrounded by women who had kids but never let it on or didn’t have kids, I might have felt self-conscious about being a mom already. With no one to compare to, however, I just assumed that it wasn’t any more abnormal than a woman without kids.
My theory on the Big Bang Theory January 30, 2012
Posted by mareserinitatis in humor, physics, science, science fiction, societal commentary.Tags: Big Bang Theory, physics, stories, suspension of disbelief, TV
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I really don’t watch much TV, but I do own all of the Big Bang Theory that’s available on DVD. Most of my friends really enjoy it, too, and I have a theory why that is: I think that it’s one of the few TV shows that nerds can stand to watch because it is far more factually correct than most TV shows.
Most of the nerds I know are the ones who annoy everyone else at movies by making commentary throughout about the impossibility or improbability of what they’re witnessing. (In particular, my older son is this way. Of course, he also likes to tell you what’s going to happen next, so he’s been banned from speaking during movies.) Suspension of disbelief becomes a little harder when you’re faced with something you know cannot possibly happen.
I think this became obvious to me in where Sheldon was waxing (un)poetic about how great Isaac Newton was. Leonard made some comment meant in sarcasm, and Sheldon’s response was to say that Leonard disputed Newton’s claim that he invented calculus so Leonard wanted to put Leibniz at the top of the Christmas tree.
Most people who have no clue about calculus would probably laugh at this scene because Sheldon missed the point of the sarcasm. On the other hand, those of us who know anything about calculus might have been laughing because we knew exactly to what he was referring. And it made me ponder…would I want Newton at the top of my tree, or Leibniz? For the record, I would have been fine with Newton at the top of the tree because he did a lot more than invent calculus…but I still am glad for Leibniz’s wonderful notation. Either way, you couldn’t have just thrown any mathematician or physicist’s name out. It HAD to be Leibniz because the rivalry is so historic and well-known among mathophiles.
As I go through the show, I find little details like that a lot, and I really enjoy them. Whether or not I want to, I tend to pay attention to those points and letting them go is tough. Sometimes they even draw me in more than just the storyline does. In the episode where Sheldon is attempting to teach Penny physics, I kept thinking, “There’s better ways to explain that.” And when she was supposed to answer a question, it felt like sitting in a classroom and wanting to blurt out the answer.
It’s a real treat to watch a show that doesn’t use science as some sort of nifty backdrop to the story, where the science actually is important to the story or at least makes it more fun. And better yet, it still manages to entertain all the non-physicists out there, too.
Am I missing something here? January 27, 2012
Posted by mareserinitatis in education, engineering, science, teaching.Tags: grades, homework, teaching
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Like everyone else, I came across the article on why college students leave engineering.
I was reading it with my jaw hanging open. Specifically this:
The typical engineering major today spends 18.5 hours per week studying. The typical social sciences major, by contrast, spends about 14.6 hours.
My first thought was: Where the heck can you go to school and study for 18.5 hrs/wk and still manage to pass enough classes to get an engineering degree?!
My second thought was that it explained something that has been puzzling me. Last semester, my students complained about the amount of homework I assigned for my 1-credit class. There was about 1 homework assignment per week, and I figured this meant they’d be spending an average of 1-2 hours outside of class on assignments.
When I started school, the rule of thumb was that 3 hours per week outside of class PER CREDIT was required for an A, two for a B, one for a C. This meant that if you planned to go to school full time (which was 12 credits per semester) and get an A average, you needed to be spending about 36 hours per week just on homework in addition to your 12 hours of seat time in a classroom.
I also learned that, for some classes, this was a significant underestimate (usually math, engineering and physics classes) while for other classes, it was an overestimate. I remember one senior-level sociology class that I took where I spent, on average, three hours per week on homework and still came out with one of the highest grades in the class. This is why I always felt it was a good idea to have a nice balance between technical and non-technical classes: it would even out the homework load a bit.
My understanding of a typical homework load is obviously a couple decades behind. (Although I am not sure I plan to change my tune any time soon.) However, I did feel good about one point in the article:
STEM fields (science, technology, engineering, mathematics) have also had less grade inflation than the humanities and social sciences have in the last several decades.
Apparently you can study less in engineering than you used to have to obtain a degree, which I have to admit bothers me a bit. However, it’s still harder than humanities and you’re more likely to actually have to earn those grades. Despite the fact that we’re probably pushing STEM fields more than we really need to, I do hope employers take that into consideration. STEM students have to be more committed to make it through their fields, which are also more technically challenging. I’d think that should be worth something.
When you think of a scientist… January 26, 2012
Posted by mareserinitatis in science, societal commentary, younger son.Tags: science, women in science, younger son
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On the way to school yesterday, the younger boy started telling me that Dr. Frankenstein wasn’t a real scientist. I asked him what he thought of when he heard the word scientist. He was very quiet, and I started feeling anxious that this was going to end up in a “dude in a lab coat with beaker”.
I interjected, “You think of your mom, right?”
“No,” he paused for a few moments more. ”I think of someone who is already dead.”
Oh great. So to be a scientist, you can only be recognized post-mortem, right? I wondered if it was someone crazy like Tesla.
“Already dead?”
“Yeah, she discovered radium, I think.”
I was kind of stunned. He wasn’t thinking of guys in lab coats – he was thinking of Marie Curie. Upon conversing further, it turned out that he knew quite a bit about her. There was a Magic School Bus book on science fairs at his classroom, and he had read about her in there.
I had to admit that I was hugely relieved that not only did he suffer from a common misconception about what a scientist is but that his first thought of a scientist was actually a very accomplished female scientist.
Although I’m still a tiny bit sad he didn’t think of me.
Pinewood derby: What a drag! January 16, 2012
Posted by mareserinitatis in engineering, physics, science, younger son.Tags: air resistance, cub scouts, drag, energy, energy conversion, friction, gravitational energy, physics, pinewood derby
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My husband son competed yesterday in my son’s his scouting group’s pinewood derby race. For those of you who have never had a kid in cub/boy scouts, they hand out these blocks of wood that you get to make into a car. The idea isn’t to win the race: it’s supposed to be that dads and their boys spend some time bonding over manly things like woodworking.
(One year, Mike was out of town during this whole thing, so I got to be manly and help the older boy build his car. All I can say is that Dremel tools are awesome.)
If you look on the web, you’ll find a lot of advice on how to prep pinewood derby cars and make them faster. One thing that consistently bugs me is that one should pay attention to aerodynamics of the car and give it a low profile.
This makes me nuts.
To understand the following, you might want to know what a track looks like. So here you go:
Let’s start out with the specifications. Most pinewood derby tracks have a height of about 4 feet and a length of 32 feet. I also will note that the ones we’ve raced on were wood, not aluminum.
Most of the pinewood derby cars I watched made it the whole 32 feet, though not all did. So let’s say that, on average, they travel 32 feet. The *fastest* ones traveled at an average speed of 10 ft/s (or 3 m/s). The maximum they can weight 5 oz. or 140 g.
What we’re going to do here is look at how much energy the system puts into overcoming air resistance versus friction. It’s very hard to figure out exactly how much goes into friction simply using equations, so we’re going to figure out the total energy and the energy lost to drag forces. Once we have those two quantities, we can subtract the drag forces from the total energy and assume that the difference is equal to the frictional losses. Finally, we can compare the drag and frictional losses.
First things first: what is our total energy? It starts out entirely as potential energy as the cars are placed at rest on the top of the ramp. Potential energy is, fortunately, very easy to calculate. It is simply the product of the height of the object, its mass, and the gravitational acceleration. In other words,
We know the mass of the car (0.14 kg), the height is approximately 1.22 m, and the graviational acceleration is 9.8 m/s2. This results in a total potential energy of approximately 1.67 J.
The potential energy is equal to the total energy in the system since the cars start with no other kind of energy. In a frictionless and drag-free system, all of this energy would be converted to kinetic energy and the cars would drive forever at the same speed once they reached the bottom of the ramp. Obviously, however, that’s not what happens. Eventually, all of the energy is converted to friction and drag, and the cars stop.
Now we need to determine the drag on the cars. The drag equation is:
The drag force is proportional, therefore, to the density of the fluid (ρ), velocity (v), drag coefficient (CD), and cross-sectional area (A).
The density of the fluid (air) is approximately 1.2754 kg/m3, and the velocity is 3 m/s. The cross-sectional area of the car, at maximum, is 2.75 x 3 in. In real *ahem* units, this is 0.00532257 m2.
The drag coefficient for a long cylinder, according to Wikipedia, is 0.82. Given the cars are all sorts of different shapes, I think this would probably be the closest approximation, although for some cars, this will be high.
All of this put together gives us a force of 0.025 N. Over a distance of 32 feet (or 9.75 m), this gives an energy of 0.24 J.
If we assume that all of the potential energy is converted to either drag or friction, that means 0.24 J is converted to drag while 1.43 J goes into friction. This means that roughly 14% of your energy losses are due to drag while the other 86% are due to friction.
My advice, therefore, is to not worry so much about drag and the aerodynamics of the car and to worry far more about the ways to reduce friction.
What should you do to help your pinewood derby car to be fast? There are three things:
1) You want to maximize your potential energy, so being as close to the 140 gram maximum weight is good. You can get all sorts of weights commercially to assist with this. Some people have argued that putting the weights near the back of the vehicle helps even more. I wouldn’t doubt this as you’re putting the weight at greater height, giving the car more initial energy to start with.
2) The biggest issue is reducing the friction between the wheel and the axle, and there are a few easy ways to do that: sanding and polishing the axles as well as using graphite or teflon as a lubricant. (Our troupe doesn’t allow graphite because it marks the floors, but teflon is allowed.)
3) Reduce the friction between the car and track. The best way to do this is to make sure your wheel alignment is as straight as possible as this will keep it from rubbing against the center of the track.
The winner of our pinewood derby actually had a very blocky car designed to look like a platypus. I’m guessing the winner didn’t spend much time focusing on aerodynamics and instead chose to minimize their frictional losses.
I have converted January 9, 2012
Posted by mareserinitatis in computers, research, science, solar physics.Tags: igloo, matlab, programming, scilab
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Because of the vagaries of my status at UMN (that is, I am an enrolled student, but I don’t pay tuition and therefore do not get some of the perks), I found out that I could no longer get access to Matlab. This is a bummer because, well, I need it for my thesis.
I’m trying to prove out some code and it’s easier to see what’s going on in Matlab because of the plotting functions. The idea is that I would like to write it up in there, see what’s going on, and then translate it to the dreaded Fortran.
Alas, I guess I’m having to break up with Matlab. Instead, I’m learning Scilab. I find this somewhat funny given how I was explaining to my engineering students last semester that once you know a computer language, it’s often easier to learn another. (Sadly, most chose not to learn a first one.) This is doubly so moving from Matlab to Scilab (or, I imagine, the reverse order) because they are so similar.
I like Scilab because it seems to me like a cleaned up version of Matlab. I don’t consider myself a master in the art of Matlab Kung Fu, but I’m passable. I have written a small program to solve the Boltzmann equation in the presence of an electromagnetic field and later solved the intractable igloo problem. However, there are some of the subtleties of matrix operations in Matlab which have always proved problematic for me, mostly dealing with conditional statements to indicate matrix indices, leaving me to fall back on loops. Not efficient, but it works. So far, it appears that these operations are more straightforward in Scilab. I also like the use of the % to indicate prenamed variables. I am all too guilty of using i as a counter and then being frustrated because it wouldn’t work as an imaginary value later in the program. And of course, I really like the price tag.
I haven’t yet gotten to some of the plotting I need, however, and as I understand it, that is where Matlab excels. We shall see.
Have you used both programs? If so, how do you think they compare?
Diffusion in the presence of nerds January 7, 2012
Posted by mareserinitatis in engineering, feminism, humor, science, societal commentary.Tags: humor, jokes, meetings, sexism
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If only life were as simple as mathematics. Unfortunately, people to act like molecules. That is, they’re not easily quantifiable and logical.
Earlier this week, I had to do an experiment in diffusion of the human variety.
I went into a meeting where I was the only woman (as usual), and it began with someone telling me a somewhat sexist (as well as old and lame) joke. At least I think it is. Either way, it definitely had nothing to do with the topic at hand.
How many men does it take to change a roll of toilet paper? They don’t know…it’s never happened.
My first inclination was to respond that obviously the investigators had never been to my house. One of the things you probably don’t need to know about me is that I tend to be lazy and pull TP out of the closet and just put it on the back of the toilet. My dear, patient husband gets horribly annoyed with this particular quirk of mine. However, he’s never actually told me he’s annoyed, but he will make a show of picking it off the back of the toilet and putting it on the roller in front of me. When he does so, I tend complain that he has put it on backwards and that I will have to fix it. (We’ve both engaged in these practices for at least ten years, so I don’t see them changing any time soon.)
I also had the inclination to say that I’d heard it before…or even that I thought I was inappropriate. The problem is that there were other people in there, and I got the feeling that most of them were both thinking also that the joke was inappropriate and not sure how I would react. The overall sense I got (which may or may not have been incorrect) was that everyone was a bit uncomfortable and not sure how to respond. Hence, I needed a way to diffuse the situation.
I did none of these things (pointing out the inappropriateness of the behavior seems rather useless with certain individuals). I’d heard a joke the day before and had shared it online with several people. I decided to not acknowledge the joke the colleague had just told other than to say, “And now I have a joke for you.”
A photon walks into a hotel. The concierge asks, “May I help you with your bags?” The photon says, “No, thanks. I’m traveling light.”
Given I was with a bunch of engineers and scientists, this was a great way out of it. I didn’t have to look like a jerk for calling the person out nor did I make anyone uncomfortable, even though I don’t think anyone would have faulted me if I had. And better yet, I think those present appreciated my sense of humor than my colleague.
What would you have done in that situation?
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The Brain Drain March 22, 2012
Posted by mareserinitatis in education, Fargo, grad school, research, science, societal commentary.Tags: fargo, higher education, north dakota, politics, universities
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Yesterday, I was getting into my car when I noticed something on my windshield.
My neighbor had seen the article about me in yesterday’s paper and left me a message about it. In fact, it hit three of major newspapers in the state. (If you care to read it, one copy is located here.)
When I was asked by the public relations person at NDSU if she could feature my research as part of an effort to promote the supercomputing facilities on campus, I was certainly glad to do so. First, from a simply pragmatic point of view, it’s not a good idea to bite the hand that feeds you. (Although, to be honest, they have a lot of other projects they could’ve featured.) Second, and more important in my mind, is that this type of thing counters some of the negative attitude about the state universities in the western part of the state.
People from out of state (probably the 4 of my 5 readers) are probably not aware that there is a bit of a divide in state politics, and it can be roughly framed by drawing a vertical line down the center of the state. The eastern part of the state has the major universities and sees the benefits of having them. The western part of the state thinks the universities are sucking all of their hard-earned money, and worse yet – children, away from them.
Growing up in the 80s and 90s all I heard about was the ‘brain drain’ that the state was suffering: all of those bright, hard-working, born-in-North-Dakota kids were being educated at a low cost and then leaving the state. The people in the western part of the state seemed to think we just ought not to spend so much money educating them. I don’t think they understood that the likely result of that would not be to prevent brain drain but to accelerate it as those students would end up leaving for colleges out of state. On the other hand, the eastern part of the state was asking for more and more money to fund already seriously underfunded universities which were teaching a lot more kids than they could realistically accommodate. And we won’t even talk about research. The universities are supposed to be there to serve the students from the state…what does research have to do with anything?
I was one of those kids that left straight out to go to college, and I really had no intention of returning. I wanted to do research, and I knew that coming out of high school. I knew that because I’d gotten involved in research through a state-sponsored program at NDSU as a high school student, and I also knew that I likely couldn’t do what I wanted here. And why should I, when I could go someplace better?
If you fast forward to about 2000 (when I came back to return to school), there were some significant changes happening. Great Plains software was bought out by Microsoft, making it the second largest Microsoft campus in the world. There were companies in town doing engineering. There was a way to stay in North Dakota with a technical degree. And about that same time, NDSU started to make some aggressive moves to increase the size and reputation of its campus.
In the past ten years (even before the oil boom in the western part of the state), this significantly slowed the population loss the state was suffering. However, the western part of the state was still shrinking, and this was probably aggravating the divide. The eastern part of the state is right, though, IMO. If you want to keep people from leaving, you need to find a way to create jobs, and not just any jobs: they have to be jobs that bright, educated people will want to do. Universities are very often centers of creativity and entrepreneurship, and so bringing in more money to the universities will likely do a lot to create jobs and businesses. Bright, educated people will start businesses to hire those that may not necessarily have the advanced degrees but are still hard workers. The state is finally starting to see that, and they’re also using some of the money from the oil and gas taxes to create incentives for businesses to operate here.
Going back to the article, I was excited to do this as I see this as a way to communicate to the skeptics that the universities are good for the state. Here is a project that I would likely have to do somewhere else if it weren’t for the fact that we have the facilities here and they are easily accessible. Part of the reason I think my research was featured is not only the coolness factor, but the fact that I’m a native of the state and one of the people who, ostensibly, you don’t want leaving for a better job elsewhere. So yes, the universities are doing something to keep people here, even if not in the western part of the state. (On the other hand, it sounds like they have more people there now than they really know what to do with, which is another story altogether.)
My only disappointment in all this is that my hometown paper, the Bismarck Tribune, didn’t run the story. I can’t help but wonder if that is a result of the fact that the divide still obviously exists.