Factual error: In chapter 11, when different types of liars are described, one of those listed is High Machiavellians, and it is said this name comes from "the ruthless Italian prince". But Niccolo Machiavelli was never a prince, but a diplomat and politician. His most famous book is called "Il Principe" (the Prince), but he himself did not hold that title.
Factual error: In the end of chapter 7, Foaly provides Butler with a moonbelt. From its name and what the book tells us, the moonbelt will reduce the weight of its attachments to the same ratio as the Earth's gravity to the moon's gravity. That means the moonbelt should reduce the weight of its attachments to one sixth of the Earth norm, but in the book it states that it only reduces to one fifth of the Earth norm.
Factual error: When Firestar, Ravenpaw and Greystripe are helping Mistyfoot, Featherpaw and Stormpaw escape the Tigerclan camp, it says: "the whites of his [Greystripe] eyes bright in the half light" but cats' eyes don't have whites. Their eyes are all one colour eg: orange, yellow, green. with a black pupil in the middle.
Factual error: The young Augustus is called Octavian, however his name was actually Octavius. Octavian is short for Octavianus, which means "of the Octavius family" and was added to his name after Caesar's death. Augustus never acknowledged the name himself.
Factual error: Ayla can mimick a horse's whinny, a lion's roar and a bird's song so well that the animals themselves confuse her for the real thing. Ayla would not have the physical ability to produce those sounds, no matter how hard she practiced. A human simply cannot whinny or roar and sound just like the real animal.
Factual error: (CONTAINS SPOILERS) Detective Coogan finds an important clue by looking at the photo of Remembrer House, which appears to have been doctored. He is told by the photographer that someone else has the negative, but that the photographer made a "duplicate negative" and can give Detective Coogan a copy. However, this was in the days before digital cameras - and negatives are what happens when you take the actual film in the camera and develop it. It is impossible to make more than one - and even a beginning photography student would know that.
Factual error: At one point Rudi points at The Beano and asks who Desperate Dan is. But Desperate Dan is from the Dandy.
Factual error: When Claire tends to Roger's injured foot, the book refers to the bones in them as "metacarpals." Metacarpals are bones in the hand. The book should have referred to "metatarsals."
Factual error: On the first page, it compares the differences between a dad and a mom's relationship with a baby, saying that it starts with the dad in the delivery room, but for the mom with conception. It says that in the delivery room, that is Day 1 for dad. But mom is on day 462. But a woman only carries a baby for 9 months. That is 270 days approximately. If it was 462 days, that would mean she was pregnant for 15 months.
Factual error: Harry et al. are captured by Death Eaters in March (it's mentioned part way through chapter 22 that Ron was unable to find Potterwatch on the radio until one night in March; they are captured shortly after the program ends). Greyback and the other Snatchers take Harry and his friends to Malfoy Manor, and Narcissa states that, if this is indeed Harry Potter, her son, Draco, will recognize him. She says he is home on Easter break. However, this is 1998 (Harry turned 17 near the beginning of the book, which would've made it 1997, and this was the following March), and Easter was April 12th that year. Draco would still be at school.
Factual error: The arms dealer tells Special Branch detectives that Charles Calthrop - wrongly suspected to be The Jackal - barely escaped with his life when Rafael Trujillo, the dictator of the Dominican Republic, was assassinated in 1961. "The whole regime collapsed within hours." He tells them, relating how Calthrop was with the Police Minister at the time and had to flee, bribing a fisherman to take him off the island in order to escape the angry mobs of partisans who were rioting in the streets, indiscriminately killing anyone they thought had collaborated with Trujillo's regime. What cobblers. There were no partisans and no riots. Trujillo's regime continued uninterrupted. His brother Hector immediately took power and ruled absolutely and ruthlessly for another eight years. Calthrop would have nothing to worry about unless Trujillo himself had signed his pay cheque. Calthrop's alleged involvement in the assassination is a hugely important plot point as it inadvertently leads to the discovery of the false passport obtained by the Jackal and the uncovering of his false identity, and his name was only placed on file because of his rumoured involvement in events which simply did not take place.
Factual error: Any invisible man would be blind. This is because if your retina in the eye is as transparent as an invisible man's, any image that can form on it will pass right thorough it without generating any vision signal via optic nerve. Thus your brain gets no visual signal if you are invisible.
Factual error: When the Australian astronaut is describing the Battle of Dehli, he says "Just like the limeys used to do in the colonial days." Limeys is just an American term. In Australia, Englishmen are referred to as pommies.
Factual error: The author says that Rachel and Michael (as well as Corky) are rescued by a Coast Guard MV-22 Osprey. The Coast Guard does not fly Ospreys.
Factual error: In Chapter 14, Cato is being awarded a grass crown for saving his centurion and the standard of his company. The grass crown was only given to generals or other higher officers, for rescuing an entire legion or army, and it had to be acclaimed by the entire legion he rescued. As an optio, Cato would be ineligible for a grass crown, his actions would not qualify for it, and he is said to be unpopular with his company, so a unanimous vote is highly unlikely.
Factual error: On page 204, Eelektrik is said to weigh 22 pounds or 48.5 kilograms when it is actually 48.5 pounds or 22 kilograms. Also, Eelektross is said to be 6 feet and 1 inch when it is actually 6 feet and 11 inches. Additionally, Emboar and Emolga are said to be 1.1 metres and 1.6 metres respectively when they are actually 1.6 metres and 0.4 metres respectively. Furthermore, they weigh 30 kilograms and 150 kilograms respectively when this is actually the reverse.
Factual error: The book mentions Bilbo's sword as being originally made as a dagger for an elf. The problem is, proportional to the wearer, that doesn't work, weapons and tools have to be made with the user's exact size always in mind. The blade or handle would be too thick, or something else would be off. I know this from trying to use a figurine sword to open envelopes.
Suggested correction: The origins of Sting are largely unknown. Even though it was made by elves doesn't mean that it was meant for elves. The book doesn't say it was a dagger for elves, just the size was comparable to one. It's only said that it was very small for Elf standards and that means it has a small handle perfect for a Hobbit hand.
Factual error: The main character, a WWI U-boat captain, mentions his vessel as having chemical air regenerators, an underwater airlock for divers to leave by, and of course dive suit(s), but I don't believe such craft of that era had any of those.
Factual error: On page 512, line 10, there is a mistake in the "voice over" when dealing with the killing of Desi, "the feel of his own blood spurting between his fingers with each pulse." The jugular vein was cut, and veins don't spurt with each pulse; they ooze. Arteries do the spurting with each pulse.
Factual error: Numerous times in the series cabins are said to have wood stoves. Wood burning stoves were not actually invented until well after the medieval period.