A Solar Calculator, a Game Ball, and a Cheerleader's Bosom - S1-E5
Factual error: In this episode we see George throwing a ball against his bedroom wall. On the wall is a picture of Axl Rose wearing shorts in the pattern of the USA flag. This photo is from the Guns N' Roses appearance at Rock In Rio 2 festival in Jan 1991. The show is set in 1989. 2 years prior to the photo the poster is made from is taken.
A Baby Tooth and the Egyptian God of Knowledge - S3-E20
Factual error: Georgie removes his stash of cash from the air vent in his bedroom (envelope with a photo of a mustang taped to it) and the cash ($20 bills) have a serial # starting with the letter "C" which is a series of bills that were not printed until 2001. (00:15:14)
A Solar Calculator, a Game Ball, and a Cheerleader's Bosom - S1-E5
Factual error: The commentary suggests that Sheldon had the correct solution to problem 1 and merely lost points on the quiz because he didn't show his work. In reality he did the first problem incorrectly. Taking the derivative of (x+2) ^2+ (y+1) ^2 = 13 with respect to x yields: 2* (x+2) +2* (y+1) * (dy/dx) = 0 which implies that: dy/dx = - (x+2) / (y+1) and at the point (0,2) this means that the slope dy/dx is actually equal to - (2/3), not 2/3. It is correct that when using the form y=mx+b at the point 0,2 reveals that 2=m*0+b, or that b=2. So the correct equation for the tangent line is y = - (2/3) x + 2, not y = (2/3) x + 2 as shown in the episode. (00:13:55)
A Suitcase Full of Cash and a Yellow Clown Car - S5-E16
Factual error: In the closing shot of this episode, a pile of cash is down close up. The bills are current circa 2000s and the show is set in the late eighties. The bills didn't have the current security markings that we have now.
White Trash, Holy Rollers and Punching People - S5-E21
Factual error: When Georgie goes to the doctors office with Mandy, when he walks in you can see a modern covid-19 safety poster behind his shoulder. (00:11:00)
A Patch, a Modem, and a Zantac - S1-E6
Factual error: At the start of the episode when someone is talking at the podium, there's a a periodic table behind him on the wall. On the left of barium, 'Sc' for scandium is there instead of 'Cs' for cesium. (00:00:40)
Answer: Some people just have a dislike for someone that can't be explained. Could be as simple as the way he's dressed.