Goofs

The type of aircraft used to drop the nuclear weapon changes between the arming scene (B-1) and the flight scenes (F-16).

When Jacob first uses his camera at Stonehenge it is a Canon. In the next shot, a few seconds later, it has changed into a Nikon.

When Jacob talks to people who call into his radio show near the beginning of the movie, his headset disappears and reappears between shots.

The primary school the scientists base themselves at on Salisbury Plain is called an "Elementary School" (written on the side of the school), a term which does not exist in the UK.

Major Peatman has three 'pips' on his shoulder, this actually denotes a captain in the British Army, a major would have a single crown instead of the 'pips'.

None of the supposedly British military vehicles used by the British Army security forces around Stonehenge are actually used by the UK. The 8-wheeled armoured car is Canadian as is the Iltis jeep and the 2.5 ton truck. The HMMWV (Humvee) is American, as was the M151A1 Mutt seen in desert tan. The only British vehicle was the Land Rover, which was a mid 50s-60s variant that has been long out of active service.

The meters shown during periods of magnetic activity have a red zone starting at "500 milligauss" which Jacob describes as an extremely intense level of magnetic energy. In fact, the Earth's natural magnetic field at the surface varies from 0.31 to 0.58 gauss. In "milligauss" terms, this would be 310 to 580; in similar terms, an ordinary refrigerator magnet has a strength of 50,000 "milligauss" and an MRI machine's field varies from 600,000 to 70,000,000 "milligauss", but neither have brought the planet to the brink of destruction.

The opening sequence of the film features a guide walking tourists through the middle of "Stonehenge" - the real Stonehenge has had a perimeter fence around it for years and no-one is allowed near the stones.

Characters in and around the fake Stonehenge all drive vehicles with the steering wheel on the left. This being England the steering wheel should be on the right.

When Jacob first goes into the fake Stone Henge area, he passes a sign that says 'authorize'. Being in England, this should be spelled "authorise".

In the newspaper article in the opening sequence "Mayan Calendar" is spelled as "Mayan Calander". Also when the radio guy is looking at websites at the beginning "Salisbury" is spelled as "Salsbury" on one site.

At one point, the military leader requests that a 100-mile evacuation zone be declared around the nuclear bomb-targeted Stonehenge site, yet near the end of the film, he and his troops are shown standing unconcernedly less than a quarter mile away from it.

The British use a U.S. B-1 bomber to deliver their nuclear weapon. The RAF does not operate this type of aircraft and has its own airplanes which are quite capable of delivering nuclear bombs.

In the background scenery in the scenes showing Stonehenge there are some rather large mountains - not a general feature of Salisbury Plain in Wiltshire.

Considering all of the scenes set in England, all of the cars are left hand drive. (English cars are right hand drive)

At the beginning of the movie Jacob reports on picking up an electro-magnetic burst from Maine to England, but the line he follows ends in the North East of England, not the South West - some 270 miles away from Stonehenge.

The volcano and earthquake occur on the island of Java in Indonesia. The lines on Glaser's map are shown going to the island of Sumatra.

The visitor center is located close to the stones and would certainly have been seen in the shots had the real Stonehenge been used.

Jacob greets the British soldiers approaching him at Stonehenge with "top of the morning to you" in an attempt to speak the local lingo but that's an Irish greeting not a British one.