what's your favorite equation?

[Modelworks]

Life = Life /0

 

[RallyMaster]

Ic = B Ib

 

[keird]

PAO2 = FiO2(Pb-PH2O)-R(PaCO2)

Alveolar Gas equation

 

[Leros]

Originally posted by: RallyMaster
Ic = B Ib

bipolar junction transistor!

 

[chuckywang]

Quadratic reciprocity:

p, q odd primes

(p/q) (q/p) = (-1)^((p-1)(q-1)/4)

 

[herm0016]

http://xkcd.com/55/

 

[Tiamat]

Simplified Fowler-Nordheim Equation, the backbone of my thesis.

ln (I/V²) = ln ? - ?(1/V)

where:
? =1.56E-6 * (Aß²)/(d²F)
? = 6.87E9 * (d*F^1.5)/ß


I = Measured Current (mA)
V = Applied voltage (V)
A = Emitting area (cm²)
ß = Field Enhancement Factor = E*d/V
E = Electrical Field (V/cm)
d = Distance (m) between anode and cathode
F = Work function of the emitter

If the plot I/V² vs. 1/V yields a straight line with negative slope, the electrons traverse the vacuum between anode and cathode by quantum tunneling; also known as Fowler-Nordheim emission.

 

[eLiu]

Navier-Stokes Equation YEAH!

Also, exp(i*pi) = -1 comes in a very close second.

 

[Tiamat]

Originally posted by: eLiu
Navier-Stokes Equation YEAH!

Also, exp(i*pi) = -1 comes in a very close second.

The undergrad version of NS or the real version?

 

[Oil]

OOIP = 7758*phi*h*acres*So

 

[JohnCU]

Originally posted by: Tiamat
Simplified Fowler-Nordheim Equation, the backbone of my thesis.

ln (I/V²) = ln ? - ?(1/V)

where:
? =1.56E-6 * (Aß²)/(d²F)
? = 6.87E9 * (d*F^1.5)/ß


I = Measured Current (mA)
V = Applied voltage (V)
A = Emitting area (cm²)
ß = Field Enhancement Factor = E*d/V
E = Electrical Field (V/cm)
d = Distance (m) between anode and cathode
F = Work function of the emitter

If the plot I/V² vs. 1/V yields a straight line with negative slope, the electrons traverse the vacuum between anode and cathode by quantum tunneling; also known as Fowler-Nordheim emission.

holy fuck that's awesome!

 

[bobsmith1492]

I1 = I2 + I3 + ... (KCL)

(Va-Vb)/Ra + (Vb-Vc)/Rb + ... = 0 (KVL)

You can describe just about any system with these. Kirchoff was a genius.

 

[udneekgnim]

Black-Scholes Equation

http://en.wikipedia.org/wiki/Black-Scholes

 

[us3rnotfound]

Originally posted by: bobsmith1492
I1 = I2 + I3 + ... (KCL)

(Va-Vb)/Ra + (Vb-Vc)/Rb + ... = 0 (KVL)

You can describe just about any system with these. Kirchoff was a genius.

And all of that stuff goes back to Ohm.

 

[Shadow Conception]

I never understood Kirchoff's voltage stuff. I ended up screwing the stuff up completely on the end of year exams for our Digital Electronics course, but I still averaged an A for the year. Having a teacher that pretty much took the course over the summer a year beforehand didn't help, either.