Friday, August 1, 2008

English Major?

Erachet: I wanna derive equations
Bad4: Good. So, if i give you the following equation: A(t) = (εdCd + εs1Cs + εs2Cs)b Where A(t) stands for UV absorbance with respect to t (temperature) and epsilon-d stands for the extinction coefficienct of the duplex strands. Cd is unknown Epsilon-s stands for the extinction coefficient of the single MO strand Cs is unknown Epsilon-s2 stands for th extinction coefficient of single DNA strand Cs again is unknown b = 1 and I give you all the epsilons for the given temperature of, say, 35 degrees celsius can you find Cs and Cd for me?
Erachet: er maybe?
Bad4: It's theoretically simple. Define the two variable in relation to each other and plug in. I think.
Erachet: okay
what are the epsilons?
Bad4: the funny e-shaped things.
Erachet: no, I know THAT
you said you would give me them
Bad4: They stand for extinction coefficient
oh, right. hold on: I'm going to email it to you. I wrote it all down, but I discovered that two of the epsilons are inaccurate. Theoretically, in terms of deriving the equations, it doesn't matter. But I'd like to get them right before I proceed because I'm a bit OCD like that.
Erachet: okay :)
...I'll get back to you after I eat some pizza bagels

6 comments:

badforshidduchim said...

The relationship is Cd/4 = Cs+Cs, for reasons I keep forgetting, but my postdoc says so and I trust him.

so it proceeds quite simply from there (using E to stand for epsilon):

A = (Cs(E1+E2) + EdCd)b
A = (Cs(E1+E2) + Ed8Cs)b (replacing Cd with its equivalent, 4(2Cs)
Then, factor out Cs:
A = (Cs((E1+E2)+8Ed))b
then divide A by everything except Cs:
Cs = A/((b)((E1+E2)+8Ed))
Ta-da!

Only problem - it doesn't yield the right answer. Oh well. It's days like these that make me wonder why I stopped being an English major.

Of course, sometimes bad math is fun...


1) X=Y ; Given
2) X^2=XY ; Multiply both sides by X
3) X^2-Y^2=XY-Y^2 ; Subtract Y^2 from both sides
4) (X+Y)(X-Y)=Y(X-Y) ; Factor
5) X+Y=Y ; Cancel out (X-Y) term
6) 2Y=Y ; Substitute X for Y, by equation 1
7) 2=1 ; Divide both sides by Y

Ezzie said...

I always loved that last one from Bad4. :)

SJ said...

Um, Erachet...WUAT?????

::Head...hurts...many...numbers..::

D2 said...

Alright bad4...

I get your whole proof, but I know that one of those steps is erroneous. I think its step number five, but I'm not sure why. Can you explain it to me?

D2 said...

Never mind - I figured it out.

Bad4 said...

It's dividing by zero.

Zero is a big black hole in the mathematical universe.

When you divide by it, everything collapses.