Image caption The native South American engineers devised a mechanism that collapsed the temple when Indy stole the idol, but were unable to make a door to keep him out in the first place

On 8 October Paramount Pictures releases the Indiana Jones films in the UK on Blu-ray, more than three decades after the premier of Raiders of the Lost Ark. So is it still possible to enjoy those absurd action sequences without adult reason spoiling the fun?

In the third scene of Raiders of the Lost Ark, two men from "Army intelligence" despatch Indiana Jones on a quest to find the lost Ark of the Covenant before the Nazis do.

The mission is critical to US national security and is funded by the government. So why does Indy travel alone with no security team, wield no weapons heavier than a bull whip and a revolver, and have no intelligence or logistical support?

Action and adventure films require what theorists call the suspension of disbelief. To enjoy the film, the audience must let go that sense of "nah, that could never happen".

But upon repeated viewings, the audience already knows the plot and the scenes and is free to reflect on just how ridiculous the action is, says Brad Chisholm, a professor of film studies at St Cloud State University in Minnesota.

Raiders, the first film in the Indiana Jones cycle, was released in 1981. It has been a television staple in the US and Britain since.

We watched Raiders recently and had a blast. But here are five scenes where the gleeful child inside us was shouted down by the rational adult. Spoiler alert!

Temple of broom

Image caption Indiana Jones beat a team of local thugs - probably hired by the German consulate in Kathmandu - and escaped Marion Ravenwood's burning pub

Scenario: Raiders opens as Indy enters a temple deep in a South American jungle. He's after a golden idol still worshipped by the Jovitos Indians.

Implausible moment: The pre-Columbian civilisation that built and outfitted the temple were master engineers.

They built spiked booby traps triggered by optical sensor, like a supermarket door ("stay out of the light").

They engineered devices that shoot poison darts when an intruder steps on the wrong paving stone. And their system destroys the entire temple when the idol is disturbed.

The temple and its mechanisms obviously undergo regular maintenance: Its floor has been recently swept, and those booby traps need frequently to be oiled, cleaned and tested, moving parts replaced.

Yet the administrators in charge of keeping up the temple fail to post a guard at the front. If they are such brilliant builders, why didn't they make a better door?

Possible solution: By 1936, when the action takes place, the Jovitos had begun moving out of the jungle into urban settlements and lacked the man-power to post a full-time guard.

Indy's expedition coincided with a staff furlough.

Snakes in a tomb

Image caption Lucasfilm and Paramount restored the original 1981 print frame by frame before the 8 October UK Blu-ray release

Scenario: Indy and his sidekick Sallah drop into the Well of Souls to retrieve the Ark. But first, they must deal with hundreds of snakes crawling around on the floor.

Implausible moment: The Well of Souls is a ruined temple long-buried in the middle of the Egyptian desert. How did all those snakes get in there? Where did they come from? What do they eat and drink?

Possible solution: ?

Superhuman strength

Image caption Archaeology aficionado Indiana Jones would have to save the sightseeing tour for a later trip

Scenario: The Nazis seal Indy and Marion in Well of Souls to die.

Implausible moment: Indy finds an exterior wall. He pushes a loose block from the wall and they escape.

The block appears to be about 3ft by 3ft by 4ft, or 36 cu-ft (1 cu-m). A limestone block that size weighs more than 6,000lb (2,721kg).

Possible solution: ??

Submarine stowaway

Image caption On a U-boat, there's nowhere to run and nowhere to hide. Unless the stowaway is Indiana Jones

Scenario: Indy and Marion smuggle the Ark out of Egypt on a tramp steamer.

A German submarine intercepts the ship. The Nazis capture the Ark and kidnap Marion while Indy hides below decks.

Implausible moment: Indiana Jones swims over open water to the U-boat and stows aboard it just as it is about to dive. How does he break into the sub? Where does he hide from the crew? Anyone who has ever seen Das Boot knows how claustrophobic those craft were.

Why, for that matter, didn't the US government exfiltrate them on a military plane or naval vessel?

Possible solution: Indy's hair and clothing are wet in the next scene. By 1936 the Mediterranean had not yet become a theatre of naval combat, so the U-boat only underwent a shallow dive as an exercise. Indy clung to the gunwale until it resurfaced, rode in the conning tower and leapt off when the crew disembarked.

And Indy was working on Mission: Impossible rules. The US government needed plausible deniability should he be captured.

Uniform switcheroo

Image caption In 2008, Harrison Ford (Indiana) and Karen Allen (Marion) starred in Kingdom of The Crystal Skull

Scenario: On a secret Nazi island base, Indy joins the rear of a detachment of soldiers sent to open the Ark. He is clad in a German uniform pilfered from a soldier he knocked unconscious without raising a commotion.

Implausible moment: The detachment includes about two dozen men, yet none notice two of their comrades are missing and have been replaced by a poorly-shaven stranger with no rifle. Didn't the German army have non-commissioned officers to enforce discipline?

Possible solution: A closer look reveals Indy is wearing a different uniform from the rest of the troops in the column. Amid the unusual circumstances, the enlisted men assume he's a high-ranking officer sent in for the special operation.

Forget disbelief and enjoy the fun

Even if you spend the film's 115 minutes picking apart the many incongruities, Raiders remains terrific fun.

"There's an understanding from the outset that he's a mythical character," says Michael Lindley, a film student at American University in Washington DC and Indiana Jones fan.

"You understand that no normal person could do this - but he's not a normal person."