Questions for Callaway

[Triste]

If I pour a cup of bleach into 8000 gallons of water, how long will it take for the bleach to evenly disperse?
(This is a need-to-know question, not theoretical)

[Callaway]

Do you know the temperature of the water?

Is the water still or being stirred?

[Triste]

It is my drinking water tank, so is the ambient temperature which these days is around 80 degrees or higher.
And unstirred, which is the reason for the question.  You're supposed to take an oar and stir the bleach, but I'm wondering if there's a way to avoid stirring (have you ever stirred 8000 gallons of water?)

[Callaway]

I am working on gathering the information necessary to give you an answer to this question, Triste.

My gut reaction is that it will disperse many times faster if you stir it than if you rely solely on molecular diffusion to disperse it, so I would recomend stirring it, even though it is a pain to do.  Even if you do not stir it perfectly, it will greatly speed up the rate of dispersion.

[Triste]

Right.  Because I figured you'd know about rates of molecular diffusion.

[Triste]

Okay, here's another one (take your time):
When making homemade yogurt, why do you have to heat the milk to just below boiling, then cool it down to lukewarm (100 to 110 degrees)?  This makes no sense to me since the milk we all use is already pasteurized.

[McGiver]

callaway,

what is your level of education?

[Callaway]

Okay, here's another one (take your time):
When making homemade yogurt, why do you have to heat the milk to just below boiling, then cool it down to lukewarm (100 to 110 degrees)?  This makes no sense to me since the milk we all use is already pasteurized.

Milk is pasteurized to reduce the bacterial content to 0.00001 of the number of bacteria in unpasteurized milk.  If you wanted to make yogurt from raw milk, you would need to pasteurize it first by heating it to 161.5 degrees Fahrenheit and holding it at this temperature for at least 15 seconds.  Heating the milk to just below boiling changes the structure of the milk protein so that that it does not coagulate and make curds and whey instead of yogurt.  You have to cool it off to lukewarm before you inoculate it with the yogurt culture so you won't kill the bacteria.

Sorry, but the molecular diffusion question is difficult for me to get a good answer for.  Molecular diffusion of the chlorine bleach into still water in the water tank would happen very slowly and that is why stirring it is recommended.  Actually, if the water tank is subject to temperature fluctuations between day and night, you would get convection currents from the colder and warmer water and also if you use water from the tank and add water to the tank periodically, that would mix the water more quickly than molecular diffusion.  I don't know how to calculate these effects in closed form, and a computer model would require a lot more information. 

McJagger, I have a Master's degree in Chemical Engineering.

[Triste]

(Bows down before Dr. Callaway)
Thank you!  Beautiful answers.

Question:  My master's program advisor is so disorganized and incompetent that both my learning and grades are at risk.  I have to take at least 6 classes taught by her.  Should I change tracks to get out of her realm; should I drop out of school entirely; or should I stick it out with her, complaining and documenting everything?

[Callaway]

Tell me more about her.  What are your problems with her?

Why is she your master's program advisor?  Did you choose her?  What are her responsibilities as your advisor?

If the classes are required for graduation, then can you take them from someone else, or is she the only person who teaches them?

[Triste]

Tell me more about her.  What are your problems with her?

Why is she your master's program advisor?  Did you choose her?  What are her responsibilities as your advisor?

If the classes are required for graduation, then can you take them from someone else, or is she the only person who teaches them?

In a nutshell, the class expectations are extremely unclear.  Also confusing is how assignments are graded. She has written 3 different explanations of the syllabus and assignments, and they all contradict each other. She mixes up her terminology so it's impossible to tell even how many papers are due.  Despite my repeated questions to her about this, she still hasn't clarified anything.

She is my program advisor because of the track I selected.  She is the only person who teaches the classes - it is a small department.

[Callaway]

Would you still need to take these classes if you chose a different track?

[Triste]

If I chose a different track, it would take an extra year of school, but then she wouldn't be my advisor, and I'd only have to take 2 of her classes instead of 6.

[Callaway]

Can you afford another year of school?  Why did you choose this track?  What about it appeals to you?  Is there another track that appeals to you as much as this one does, given that this person's teaching style is incompatible with your learning style?

[Triste]

Sigh.  My age is the thing holding me back from adding another year to the program.

But I can see where you're going.  I'll see about changing later today. (From nursing administration to nursing education, btw)
side note:  you'd think somebody who teaches management and administration WOULD HAVE A FUCKING CLUE as to how to organize a  class, now wouldn't you.  I'm pissed but that's good - I DO need to change.