Factual error: Aetius' troops don't look anything like 5th century Roman soldiers. They are carrying a large rectangular shield, a pilum (a spear which was used for throwing) and a sword (gladius) on their right. This was typical for the Roman army until about the 3rd century A.D. In Aetius' time, the soldiers would have had smaller oval shields, a hasta (a lance used for stabbing and for fending off cavalry attacks) and a sword (spatha) on their left. Also, there would be an enormous amount of "barbarian" mercenaries in the Roman army (Goths, Vandals, even Huns.), so it was hardly a Roman army anymore. And where's Aetius' cavalry?
Factual error: Aphrodite's son and Psyche's husband is Eros, not Cupid. Venus's son is Cupid. (Eros is Greek and Cupid is Roman).
The King of Knaves Affair - S1-E13
Factual error: Supposedly engraved on a ceremonial sword is the wrong date - 1443 - for the fall of Constantinople. That happened in 1453. (00:33:15)
Factual error: Tru arrives "more than three hours late" for the MCAT and then begins the test. Firstly, it would be pointless for her to even bother going at that time, since she'd have already missed the entire Verbal Reasoning section and possibly the Physical Sciences as well (depending on how much more than three hours she was late). Secondly, that's really a moot point since late arrivals to MCAT testing centers are not permitted to take the test.
Factual error: A 250-year-old sea chest recovered from the ocean floor is opened, and all its paper items are perfectly dry: the log book can be opened and read, and the letters can easily be unrolled. Highly unlikely. The chest's wood and pitch would deteriorate (salt water is extremely corrosive), and the paper should be damp and crumbly, at the very least. Even more likely, it would have become a lump of unreadable sludge.
A Nice Place to Visit - S1-E14
Factual error: When the team is in uniform for their friend's funeral, Smith and Peck (both commissioned officers) have their Special Forces insignias on their berets when they should have their rank insignia.
Epiphanies - S2-E13
Factual error: Early in the episode a damaged Viper makes its way back to Galactica with its port-side gun trailing smoke as if in an atmosphere. But in a vacuum, the smoke wouldn't trail. It would build upon itself much the way shaving foam does when slowly leaking from a damaged can, unless the ship changed course and/or speed and then the smoke would appear to do the opposite - ship turns right, smoke moves off to the left because it remains on its original course regardless of what the ship does. The gun is not propelling the smoke rearward. The ammo inside is simply burning. (00:05:15)
Children of the Gods (1) - S1-E1
Factual error: The escort for Colonel O'Neill is wearing both Major and Staff Sergeant rank insignia. Probably what the writers thought was a "Sergeant Major", which does not exist in the Air Force. Major is a commissioned officer, sergeants are non-commissioned officers.
Factual error: When Klaus and Ben visit Dave at the hardware store in November 1963, they arrive in a 1965 Imperial. (00:32:48)
The Big Tick - S2-E2
Factual error: When Gwen and Grandpa Max use the shell plates from the tick to ward off it's corrosive secretions, their fingers should have been eaten away since they were grabbing the rims of the plates when the acid came raining down.
Factual error: Tarrant fails Astronomy 101 here, just as Travis did in the first season. He tells the clerk, "I'm surprised you've heard of it (the FSA), if you're from another galaxy." The Tharn and his minions were not extragalactic; they were from other planets in our galaxy. (00:35:10)
A Sour Note - S2-E2
Factual error: Gino commits a murder using a six-shooter with a silencer attached, and his shot doesn't make any noise. But it should have. Though it's a long-standing Hollywood cliché, a revolver with a silencer wouldn't be silent at all. Unlike automatic weapons, revolvers are open-chambered, which allows sound to escape. They can't be muffled with a silencer. (00:34:00)
Carbon Creek - S2-E2
Factual error: Part of this episode takes place in the 50s, during a previously-unknown incident of Vulcans crash landing on earth. Modern twenty and fifty dollar bills are visible in the tip jar.
The Return of Wonder Woman - S2-E1
Factual error: When Steve gets attacked by the bad guys and Wonder Woman shows up, the lady in the car pulls out a camera and films the event. She sits still, the car isn't moving, and she does all the filming from the same position. However when she watches the playback, the film shows footage from multiple angles and varying distances, which is impossible because she and the camera were in the same spot the whole time.
Factual error: When they first assault the city, the Greeks construct catapults. Only problem: catapults were invented at 400 - 300 BC, i.e. about 800 years later; and the first models looked similar to giant crossbows. The one-armed onager and similar types (as seen here) were a later Roman invention.
Factual error: Looking at a nuclear explosion that close will burn your retinas irreparably. One can be blind 30 miles away, just by seeing the flash. The little girl at the start is looking directly at the explosion when it hits, and continues to watch.
Factual error: When the missile intersects with the asteroid, and nothing happens right away, Arturo mentions to Bennish that light travels at over 186,000 miles per second, implying that the light from the explosion will take a moment to become visible. The problem is that by the time the missile is about to hit the asteroid, the light from the missile itself will have just as much lag time as the asteroid's explosion. The explosion should therefore have appeared immediately upon seeing the missile hit the asteroid.
Helping Hands, Iron Fist - S1-E4
Factual error: When Bruce Banner sees the Hollywood sign reflected in the puddle of water, the reflection is backwards.
Factual error: There is a periodic table shown in the background of the lab, showing an accurate periodic table as of now. During 1945, at least 21 elements had not been discovered. (00:17:40)
Seeds + Permafrost + Feather - S3-E17
Factual error: Bozer and for that matter I would assume all of the team went to a spycraft academy. A basic subject in any of such academies is surveillance, including proper techniques to follow and stake out someone. Bozer being so inept at tracking MacGyver's father is inconceivable given their training.