On this day, I learned that cloves (blacks) are actually made in Indonesia. I wonder if Yoga has ever smoked them. (hi yogie!)

I learned that when dealing with non-homogeneous equations like I mentioned on Wednesday, you can use some simple guesses to find y_p. If it’s a sine/cosine function, try y_p = Asin(x) + Bcos(x). However, if you already have that in your y_c, you won’t be able to get an actual solution (it’s jus tlike multiplying y_c by a constant), so instead, use y_p = Axsin(x) + Bxcos(x). The same thing goes for if you’re using e^x. X x x X x!

I also learned that my Diff E professor is largely hilarious. There was a dead roach on the floor at the front of the class that I noticed when he stood near it, but he didn’t seem to notice it then. A few minutes later, he looked down and said suddenly “Hello you, are you registered?” and I laughed but everyone further back in the room must have been going “WTF?” because they couldn’t see the roach on the floor xD Then he said “Well, I guess since you’re being quiet, you can stay”. Then, several minutes later, he must’ve kicked it with his foot or something because it skidded across the floor and he apologized to it xD

I learned that you should use enthalpy (h) for energy content (m*h) when your mass is moving, flowing, changing. Use internal energy (u) for when it’s just sitting there. Apparently this encompasses a surge of energy when the mass changes its position/state without even delving into its kinetic energy. Well, it made sense at the time xD

I learned that the WOW! Japanese Bistro on Dickson St. is offering some of its sushi for half off. This enticed me to go, so I drug Stu along and got cucumber rolls and a beef and rice dish. And it was really good! I was kinda surprised at first because the rolls were room temperature and the nori or whatever on the outside was really really chewy, but I liked it.

I learned that wasabi is really dang hot, even if it’s just fake wasabi (probably) that is horseradish mixed with mustard. I almost made the mistake of putting a large clump on one of my rolls, but luckily I sniffed it before I put it in my mouth and realized what a bad idea that would be. Eek.

On this day, I learned that you can use Indirect proofs to prove a statement. One method of indirect proof is Contradiction, where you presume your statement is false and proceed from there until you reach a tautology or a contradiction. Then by inverting the truth value of your presumption, you get the truth value of the original statement!
Proof by Contraposition works in a similar vein; you take the contrapositive of your original statement and try to prove it instead.

I also learned that there are 2544 Btu/hr per horsepower.

I learned that clove cigarettes(blacks) are cheap, compared to cigars for example.

I learned that Amazon’s Kindle is cool. I kept imagining myself with one just reading all the time and it was wonderful. Especially since I like to read books that are a couple of inches thick.

I learned about an interesting book series called Wicked Lovely. Apparently it involves tattoo fairiesxD

I learned that the French word “foudre” means a strike/bolt/lightning. Now I just have to decide if my friend who said he was struck by lightning seven times in the last week was using it in a literal or metaphorical sense. . . (Think of the Godfather when Michael falls in love in Sicily. in the book, they call it being struck by the thunderbolt. I don’t remember if they mentioned it in the movie).

On this day, I learned that to solve a non-homogeneous upper level linear ODE (isn’t that a mouthful?), if it’s equal to some constant, then you pretend it’s homogeneous, find the general solution y_c and add to it the particular solution y_p where y_p happens to be none other than the constant.
if it’s equal to some function of x, set y_p equal to some function of the same power of the form Aⁿ + B^n-1 . . . + C, take derivatives of it to match the form of your ODE, subsitute it in, set it equal to the function of x, and solve for A, B, . . . C.

The example we did was y” – y = x². You take y_p = Ax² + Bx + C, y_p‘ = 2Ax + B and y_p” = 2A

Substituting in, we get 2A – (Ax² + Bx + C) = x². Solving for coefficients, we see B = 0 (there are no x terms on the right hand side), we see 2A = C, and -A = 1. Solve, substitute, and voila!

I learned that the Carnot Cycle is an example of a totally reversible thermal process. A totally reversible process is one where you can take heat and get work, but also use that work to get back your original heat. It’s easier to think of this in terms of what it isn’t. An irreversible process would be adding cold milk to your hot coffee and expecting to be able to extract your cold milk back out or your hot coffee back out. A temperature differential means that any process you perform won’t be reversible, it will require work to move the heat back the way it came.

I learned that the Non Adventures of Wonderella are pretty dang funny.

I learned that on Réunion, over a dozen different species of birds have gone extinct, and just as many on Guam :( Sadtimes. The extinctivity on Guam is largely due to the introduction of the brown tree snake during WWII.

On this day, I learned that tattoos will fade with exposure to sun and moisture. I learned that you should either demand a parlor uses an autoclave or disposable needles.

I learned that you can draw a reasonable graph of a piecewise position function by taking its velocity function and drawing smooth quadric or linear segments from one point to another depending on what the velocity functions were. Not particularly helpful or accurate, but it was kinda fun.
(of course, if you want to be specific, you should just integrate piecewise, but that takes too long for graphing desires ;))

I learned that the workers at Late Nite in the Union really get into their Mardi Gras. I saw a couple of masks and an alligator hat. Exciting.

I learned that 3D movies are a blast. Stu and I watched Coraline and it was my first 3D movie. I kept taking my glasses off to judge by the offset of the images just what kind of depth of field we were being subjected to.

I learned that if cops commit murder in the name of the law, sometimes they will be subject to some sort of justice. Kathryn Johnston was shot 39 times by police, who have been sentenced to a collective 21 years in prison.

I learned that having the right ratio of omega-3 to omega-6 fatz in your body might just stave off a slew of nasty things. Research isn’t conclusive (when is it ever?) but it’s pretty exciting all the same.

On this day, I learned that the government body in control of such things as gauging appliance efficiency has a very unusual unit set for thermal efficiency (?), that being (Btu/hr)*(1/Watt), which means that it essentially is a Btu (British Thermal Unit) per Watt hour. Some of you may have realized from reading your electric meter that electricity is measured in watt hours. More simply, this is a watt times a second, or a Joule. The interesting part in this is that a Btu and a Joule are both measures of energy, so this “Energy Efficiency Ratio” does not really have any units. It only has numerical factors used to convert from Btu/hr to Watts (3414Btu per kWhr or something like that). I imagine the reason they did this is because Watt Hour is used for electric meters and Btu is used for the amount of heat an air conditioner can remove or a heat pump can put out. That’s just my theory.

I learned that an angular impulse has almost the same units as a moment of a force, just off by a factor of time. Which makes sense, as moments are basically forces applied at an angle to some support or axis. Where it gets fun is angular momentum which can be referred to as “Momentum of a Moment”. Ahahaha. My book uses weird notation though. I thought P was typically momentum, but we’re using some other variable. They also changed kinetic energy from KE to T and Potential from U to V. It doesn’t make a lot of sense to me, but whatever.

I finally learned how to parse Buffalo buffalo Buffalo buffalo buffalo Buffalo buffalo.

I learned that being an outspoken Anti-Twilite is a dangerous occupation. *shudder* It’s kinda scary how a small population is so prepared to force their opinions and tastes on the majority.

On this day, I learned the difference between phrenology and phenology. Phrenology is the study of the head and where different kinds of wisdom lie, like this. Phenology is the study of plants and when they grow, like Project Budburst. Everytime I walked past the flower buds outside, I kept thinking the word “phrenology” and when I finally looked it up tonight, sadly it was not what I wanted!

I learned that “recidivism” essentially means what the Baptists call “backsliding”, or a return to a previous [bad] state of [usually criminal] behavior.

I learned that there is a guy who will repair your Real Doll.

In a similar vein, I learned that some men are desperate to regain their foreskins, and that you can boost your testosterone by working out, intaking some zinc and magnesium, and losing weight. This improves your depression and libido, supposedly.

I also learned that Fayetteville Farmers Market will be back in business in April! Hurray spring!

On this day, I learned that Russell Crowe is both from Oceania and played the lead in A Beautiful Mind. (I also learned that I really liked this movie and found I could relate to his character!)

I learned that a kid shot his dad’s pregnant girlfriend and will be tried as an adult, since Pennsylvania’s laws require homicides committed by anyone over 10 years old to be tried that way.

I learned that Hugh Jackman uses Skype.

I also learned about a heart-warming Missourian dog, named Jim the Wonderdog.

On this day, I learned that there are 550 footpounds/second to one horsepower. I learned that Elastic Spring Potential is equal to .5kx² where k is the spring constant and the x is displacement from the free length.

I learned that when you have homogeneous ODE with constant coëfficients, in the form am² + bm + c = 0, you can get a solution in the form e^mx. Since this is a quadratic equation, the real solutions to this will number 2, 1, or 0. Since the order of the ODE was 2, ideally, we’d like two solutions. If we glean 2 solutions, sweet. If there’s only one, we can use the Reduction of Order method to get some more.

Reduction of Order is solely for homogeneous ODEs, but the idea is you take your first solution, y1 and multiply it by some u so that y2 = u*y1. Take derivatives of y2 so that you have all the necessary derivatives. For y”, you’d need two derivatives.

Separate the derivatives in terms of u, u’, and u”, and note that thanks to the homogeneous nature, the u terms will equal 0. Set some w = u’, so then it’s easy to solve for w, then u, and then y2! (x_X)

I learned that there is a pretty sweet restaurant in Fayetteville on Mission and Crossover called Bizys. It’s the kind that has specials of the day, crayons and paper on the table, and I just really enjoyed it!

On this day, I learned that Pac Man is waaaaaay more complicated than you’d think! You can even make the ghosts pass right though you :O

I learned that NASA has an open poll for naming the next node of the ISS. Guess which entry is winning.

I learned that d|n means “n divides d evenly”. (And had the insight that my discrete professor chose those letters for “denominator” and “numerator”)

I learned that you can’t adjust the size of an array, you have to remake it (omg).

On this day, I learned that Facebook decided to rescind a very troublesome change to their ToS. This signals to me, that even if they only superficially appear to be considerate of their userbase’s whims, they at least act the part, which is a lot more than some other companies can claim.

I learned that the mass flow rate of a system is equal to the area the flow is passing through times the specific volume (or divided by the density, they are inverses of each other) times the velocity through the area. This is pretty cool!

I learned that finding the fundamental solution set of a linear homogeneous ODE is kinda similar to finding a basis for a vector space in Linear Algebra! You have to make sure all your solution functions are linearly independent (via Wronskian). You also have to have the right number to span it, although this is a lot easier to deal with at the moment, because we are given all the solutions! (I’ll keep you posted as we learn to find the fundamental solutions sets ourselves)

I learned that PepsiCo is planning a spectacle involving cane sugar. Scary!

I learned that Arkansas is home to several poisonous snakes, including Water Moccasins and Copperheads (these I knew) but also Rattlers and Coral snakes. SCARY. I kept kinda shaking when I looked through this site! (Apparently in Southern Arkansas, they also have alligators. I thought those were just in Southern Louisiana.)