Untitled

[sixpenceee]

This is too real.

[frogsandgoats-blog]

LOL..some truth here.

[fuckyeahfluiddynamics]

When we think of resonance, we often think of it in simple terms: hit the one right note, and the wine glass will shatter. But resonance isn’t always about a one-to-one ratio between a driving frequency and the resonating system. Especially in fluid dynamics, we often see responses that occur at other, related frequencies.

One of the simplest places to see this is with a droplet bouncing on a bath of fluid. Above you see a liquid metal droplet bouncing on a bath of the same metal. At low amplitude, the pool surface moves at the driving frequency and a droplet bounces simply upon that surface, with one bounce per oscillation. Increase the amplitude, though, and the droplet’s bounce changes. It bounces twice – one large bounce and one small bounce – in the time it takes for the pool surface to go through one cycle. This is called period doubling because the bouncing occurs at twice the driving frequency.

Turn the amplitude up further, and the system undergoes another change. Faraday waves form on the surface. They resonate at half the driving frequency, and a droplet’s bouncing will sync up with the waves. That means the droplet returns to a one-to-one bounce with the waves, but the waves themselves are no longer reacting at the driving frequency. It’s this kind of complexity that makes fluid systems fertile grounds for studying paths toward chaos. (Image and research credit: X. Zhao et al.)

[frogsandgoats-blog]

Yep.  In differential equations, the driving function need not be periodic to induce resonance; in fact even a decaying function (e. g. a Bessel Function of the first kind) can induce resonance. 

[frogsandgoats-blog]

Opportunity vs. “being likely to succeed”

This is really an issue for us. On one hand, there is a great deal of statistical data that yields a correlation between performance on our “skills assessment exams” (plus the math part of the ACT/SAT exam) and success in our freshman calculus courses. On the other hand, students from underserved educational districts in our state tend to do poorly on said exams and are thereby excluded from starting with calculus. The reality appears to be that our university really can’t make up for the poor start that many students get prior to arriving here. And yes, aptitude matters. Aptitude is a factor of genetics and the environment in which the student was raised (having great genes for math aptitude could well be overridden by poor nutrition, a polluted environment and a lack of exposure to proper grade school education).  And there is some research which suggests that if some ideas are not learned by a certain stage of childhood, they are unlikely to ever be learned. No answers here; just a lot of frustration with trying to be as fair as possible to everyone while giving the prepared students the course that they deserve. 

[back-to-the-stars-again]

Cone Nebula NGC 2264.

Credit: NASA, H Ford, G Illingworth, M Clampin, G Hartig, the ACS Science Team and ESA

[frogsandgoats-blog]

This reminds me of the time when I was a kid and my parents bought me a small telescope. I thought that when I looked through the scope, I’d, well...see things like this. ROTFLMAO.  I had a bit to learn. 

[frogsandgoats-blog]

Social media under your own name

Yes, I do have a non-anonymous blog and HAD a non-anonymous pinterest page. One of the things I found out is that some students WILL look you up and find you and, well, “stalk” you.  And yes, after 15 years I got my first official complaint.  And THAT was the end of my “say/post anything” under my own name blogging/posting career. A word to the wise: view anything that you post non-anonymously as something that you are yelling from the town square, off of campus.  If you do something as careless as to, say, post “Big Bertha’s Big Booty Twerking Video” to your Pinterest or lectures by a female economist who takes off ALL of her clothes while lecturing (saying that she wants to normalize the female body and make a point about Brexit...just google her)...well, you are likely to find yourself in the Dean’s office very quickly.  The students ARE looking through any window that you don’t firmly shut...like it or not. Expect it.    I am going to keep private things private.  I will talk about controversial ideas under my own name, but that is a hill I am willing to fight for and even “die” on.  But I don’t want to make my life harder in this “the customer is always right” atmosphere, even though I’d probably win a case in court. 

[frogsandgoats-blog]

Why I am here (academia)

I am here for the anonymity.  I anticipate talking about academic issues, relating to life at a non-R1, “sort of selective” (ACT 24-26) type university that does have some “we need to keep our tuition stream coming” pressures; we aren’t at the “parents would want to spend 500K to get our kids into our school” caliber. Because I am staying anonymous, I will NOT be identifying my university by name nor will I call out specific people. That would be beyond cowardly, at least in my case.  I honestly believe that our upper administration (Dean, Provost) operate in good faith and are competent. However they are often torn between legitimate issues: e. g. need to revenue, need to maintain academic standards and the need to give of lesser academic preparation (due to going to poorer high schools) a shot at earning a degree.  So, I want to keep things about, well, “principles and not personalities”, as some might say. 

And when I talk about student behavior, I’ll keep it general and attempt to make it clear that I am talking about “a certain subset of students.” and not “all students.”  Frankly, some of our students are a pleasure to work with; most are fine to work with and a few, well, really aren’t.