This one takes the cake as the best so far. Short, eloquent and yet da-yum funny. And special mention to GrizzRich’s Tethys joke, 'cause that was always my favourite moon.
Yo mama is so fat when she took a step Darth Vader felt a tremble in the force halfway across the galaxy!
Yo momma’s so fat, when she spends 20 minutes in the Marianas Trench, she spends 20 minutes in the Marianas Trench!
Yo mama’s so fat, when she come back, she eat pie!!
Yo’ mama’s so fat that when she put on the Van Allen belt, she had to let it out a notch.
Your Mom is so dumb that she tried to minimize a 12 variable function to a minimal sum of products expression using a karnaugh map instead of the Quine-McCluskey Algorithm.
The moon landing was a hoax, they landed on your mother’s backside by mistake and planted the flag 'tween her arse cheeks.
Yo Mammas so fat even God can’t move her.
Yo grandmomma’s bones are mistakenly on display as a newly discovered dinosaur fosil.
Yo momma’s so fat, the US Geological Survey called her in to recalibrate their seismographs, because in addition to being so fat, she also has a PhD in geological sciences!
Yo mama’s so ugly, yo daddy is still in the garage working on the flux capacitor in the Delorean.
Yo mama’s so ugly, Klingons think she’s hawt!
Yo momma’s so dumb she got a liberal arts degree from a state college.
Yo momma’s so dense light can’t escape from her (pies niether).
Yo momma’s so dim that photons/in^2 of surface area can’t even be measured with theoretical data let alone test data.
Yo Mama so fat, the Earth-Yo Mama system barycenter is outside the surface of the Earth.
Yo Mama so fat, her interior is theorized to be metallic hydrogen.
Yo Mama so fat, when she jumps in the ocean she doesn’t get wet, instead the ocean gets yo Mama.
Yo Mama so fat, the Hubbert peak had to be recallibrated to take into account her oil reserves.
Yo Mama so fat, that when God created a burrito so big even He could not eat it, she could.
Yo mama so fat, the friction from her thighs rubbing together when she walks burning your dog.
Yo mama’s so fat she posts on the straight dope!
Oh yeah? Well, *yo *mama’s so fat, she thought the Kuiper Belt was too tight.
And when she put it on, she turned around and said “Does this make my asteroid look big?”
Yo mama’s so fat, they had to created a distributed program called weighing@home to calculate her weight!
Yo’ mama so fat, she don’t have weight and height, she got declination an’ azimuth.
Yo’ mama so fat, non-terminating decimals gotta go around.
Yo’ mama so big, she still ain’t seen “Star Wars” because the light hasn’t got there yet.
Yo’ mama so fat, when she logs on to City of Heroes, Hamidon gets lag.
Yo’ mama so fat, she insulates against Ice-9.
Yo’ mama so fat, she crosses two state lines. An’ I’m talkin’ about Boolean states!
Wow, Fish, those are good ones! Especially the Ice-9. I actually laughed out loud, which I don’t do very often.
Thanks, pinkfreud. I laughed out loud at most of this thread, partly in acknowledgement of how geeky I must be to get so many of them. 