Interstellar goofs

At the baseball match, immediately after Donald grumbles about the lack of hot dogs, Murph's spoken lines do not match her lip movements when she speaks to Cooper.

(at around 44 mins) Cooper empathises with Dr Brand, saying, "It's hard, leaving everything." Although not sharply in focus, his mouth can be seen moving before he delivers the line.

During one scene in which the older Murph removes the watch from its box in her room, a boom microphone is visible reflected in the watch's glass.

During the docking crisis, CASE analyses the Endurance's rotation at 67–68 RPM, which equates to just over one revolution per second for the entire station. However, what viewers actually observe is much slower, roughly 20 RPM (about one rotation every three seconds).

While manoeuvring to dock with the Endurance, Cooper gives distance readings in feet. Since NASA employs the metric system, those measurements should have been expressed in metres. Given that he had not worked at NASA for a while, such errors were to be expected.

During the drone pursuit through the cornfield, Cooper claims the solar cells on its wings could "power an entire farm." Even a theoretically 100% efficient solar panel wouldn't produce anywhere near 100 watts per square foot.

When at Cooper Station, sitting on the porch outside the farmhouse, TARS asks Cooper if "this is how it really was?" — presumably referring to life back on Earth. However, TARS was on Earth when they first met, and, by implication, had been there for quite some time. He would surely have possessed first-hand knowledge of what life on Earth had been like.

Cooper suggests that, in order to slow sufficiently to reach Miller's planet, the Endurance might "swing around that neutron star." However, to obtain the necessary change in velocity via a gravitational slingshot around a neutron star, the Endurance would have to come so close that the neutron star's tidal forces would tear it apart. A preferable alternative would be to use an intermediate-mass black hole.

Dr Brand argues that Miller's and Mann's planets would be inhospitable because Gargantua had diverted incoming objects like asteroids that might otherwise have struck them. In fact, this claim is mistaken — a world orbiting a black hole would more likely encounter a higher frequency of such impact events.

At Murph's parents' evening the teacher dismissed the Moon landing as not genuine and said other pupils didn't believe it either; yet the film presents space travel as an established fact, so the Moon landing itself would not be implausible.

Two characters suffer a fall from an ice plateau, down a steep icy ramp onto a shadowy ice platform. A moment later, a panoramic shot shows them fighting in a very different location.

When Cooper enters Murph's room to bid her farewell, his watch shows roughly 9am. In the following scene, when he hands Murph a watch, it shows roughly 8.20am.

Cooper sketches a schematic on the drawing board to illustrate a landing on a planet near the black hole. Two scenes on, the sketch differs from the version shown earlier.

The drone Cooper and his children are chasing has an aerial on its top, but the one they catch does not.

After they touch down on Miller's planet, with the time dilation there running at seven Earth years for every hour, viewers can observe the receding wave that has just passed. The sequence plays out in real time and lasts only a few minutes. By the time the next wave is noticed it is almost upon them and, given how rapidly it arrives, far too much occurs between that moment and the impact — when realistically they should have had only seconds. The crew also do not display the expected level of panic for self-preservation; Doyle, for instance, lingers unnecessarily and dies. As the ship climbs out on the far side of the first wave we can already see the subsequent swell approaching in the background as the landing struts extend. The action and dialogue continue uninterrupted between the waves and again cover only a few minutes, yet the lines imply that three quarters of an hour have passed while they wait for the engines to drain. In context, the time experienced on Miller's planet amounts to roughly 10–12 minutes, equating to just over a year of Earth time — broadly in line with initial expectations — whereas Romilly endures 23 years aboard the mothership.

As Cooper perches on the bed beside Murph, attempting to say "Goodbye" before he departs, her necklace alternates between lying on the outside of her T-shirt and being tucked inside, as the camera's angle shifts.

When Cooper is sitting in Murph's room after the sandstorm, pondering whether gravity caused the streaks of sand on the floorboards, he flicks a coin onto the floor; it comes to rest at the end of a line of sand, almost adjacent to the seam where two floorboards abut. In the very next shot the coin has shifted much further along the sand streak and away from the butt joint, having moved by at least the width of one floorboard.

Within the tesseract, whilst Cooper is poised to transmit data from the black hole to Murphy, his spacesuit becomes mirrored — his name is shown on the right rather than the left.

During the initial dust storm, Cooper drives the lorry directly up to the house. As the family leave the lorry and enter the house, the wind and dust are blowing from left to right on the screen. When Cooper and Murph come out after the storm, the dust has collected on the wrong side — the right-hand side — of the lorry.

During their fight, Cooper and Mann's shoes repeatedly switch between white and orange, even though the sequence is presented as continuous. In the struggle both are shown with orange spikes on their trainers, yet later in the film their footwear appears completely white.

While she's travelling in the lorry, before the tyre blows out, Murph has a pencil tucked into her hair. Shortly after the blowout her brother remarks 'Murphy's Law', and Murph replies angrily — by then the pencil is no longer in her hair.

Towards the end of the film, after Murph throws the papers and shouts "Eureka", there is a close-up of several people with a yellow robotic arm descending. In the following shot centred on Murph, the arm in the background is fully raised.

At 1 AU from Gargantua, Miller's planet would be travelling at approximately 0.99c. In the companion book, Kip Thorne notes that Cooper utilised Intermediate Black Holes (IMBHs) of roughly 10,000 solar masses to attain this speed. However, using a maximum speed of 0.3 AU per month (the rate at which the Endurance travelled to Saturn), it would have taken at least three months of Cooper's proper time for the ranger to travel from an IMBH situated just 1 AU from Miller's planet to Miller's planet. Given the time dilation in the neighbourhood of Miller's planet, about 15,000 years of Earth time would be required for this leg of the journey. A further three months from Miller's planet back to another IMBH yields a best-case total of 30,000 years (Earth time) for a return trip to Miller's planet.

The rocket launching from the underground facility is depicted as a three-stage Saturn V booster. The concentric rings of office windows in the silo would have been blown out during liftoff. The static test firings of the Saturn V's Rocketdyne F-1 engines at NASA's George C. Marshall Space Flight Centre (MSFC) in Alabama were known to routinely blow out windows in downtown Huntsville well over five miles away.

That would be the case if the glazing were ordinary window glass. However, Professor Brand explains that the launch chamber also served as a centrifuge and a space station, meaning everything would be designed to withstand the extreme conditions of launch. Combined with the likelihood that NASA would have been aware of the history of windows being blown out, one can reasonably assume the windows around the launch chamber were almost certainly blast-proof.

The film's title is not strictly accurate. "Interstellar" refers to travel between stars within the same galaxy, yet Professor Brand states the three candidate planets, labelled Miller, Edmunds and Mann, lie in another galaxy. That means both Cooper's Endurance mission and the earlier Lazarus mission would have had to cross from our galaxy to a different one — which would properly be described as intergalactic travel.

After Cooper decides he is leaving for the mission, during ascent in the Ranger TARS announces first that he is "beginning roll pro-grade" then goes on to say "prepare for stage 1 separation... Stage 1... there it is, Mach 1." In reality, TARS should have announced reaching Mach 1 well before Stage 1 separation. At the point of first-stage burnout in this phase of ascent they would already be travelling far faster than Mach 1 — roughly 2,300 m/s, closer to Mach 7. This becomes possible because, as the vehicle climbs, air density falls, cutting aerodynamic drag and permitting much higher speeds than at sea level. The Apollo programme made use of the same approach: the first main ascent stage (S-IC) could carry the vehicle to the edge of the upper atmosphere, but without the horizontal velocity required for orbit it would still re‑enter, so the second stage (S-II) was then ignited to develop the sideways velocity needed to achieve LEO (Low Earth Orbit). Staging is arranged this way deliberately (by calculation) and is vital for saving fuel — arguably the most important resource in space aside from life support. The rocket shown launching the Ranger in the film closely resembles the Saturn V’s first two stages with a Ranger mounted on top. No operational launch vehicle has ever exceeded the Saturn V in height, mass, total impulse or payload capability. Since these are NASA missions rather than those of a private space firm, it is reasonable to assume they would reuse proven, effective older designs with slight modifications (the payload now being a Ranger) to save time and development cost. Saturn V and Apollo programme details per Wikipedia, and from experience with KSP and FAR.

On departing Earth, a three-stage rocket is used to launch the Ranger with four people aboard (and a robot). On leaving the water planet, where gravity is 1.3 times Earth's, the Ranger's thrust is only sufficient to lift two people (and the robot). The combined weight of the other two crew members would not be enough to counteract the increased gravity.

During the emergency attempt to dock with the spinning Endurance, CASE informs Cooper that the vessel is penetrating the stratosphere of the planet below, and Brand adds that the Endurance has no heat shield. As the atmosphere appears sufficiently dense to support "frozen clouds" (sic), the Endurance would have long ago been burnt up before ever nearing the stratosphere.

The Dodge Ram pickup Cooper drives is fitted with a six-speed manual gearbox. When young Murphy is changing gear and grating the gears as they are called out, she is told "second" then "third" — neither of which matches the position she actually shifts into.

After Dr Mann detonates part of the Endurance and sets it spinning, there is no reason for the ship to rotate precisely about its original axis — it could be tumbling in a completely different orientation, even at right angles to the initial axis. Even if it were rotating in the same direction, the axis of rotation would not lie through the centre of the docking bay, because the Endurance’s centre of gravity would have shifted away from the blown-away sections. Therefore, docking would most likely be impossible.

The surface of Miller's planet would remain unlit. No light would be emitted by the black hole, as it is not accreting matter. Were it accreting material from other bodies, an intensely hot ring of plasma would produce a luminous ring of light and would likely destroy Miller's planet or leave it hot, dry and barren.

The newer-model Dodge truck seen throughout the film shows rust on the chromed plastic trim around the radiator grille. Rust can only form on metal surfaces — for example, the large chromed bumpers.

When the shuttle enters Miller's atmosphere and starts to shake, the reflections on the astronauts' helmet visors remain perfectly still. In reality, those reflections ought to be moving too — the images would be bouncing and jittering as the craft vibrated.

Around 1 hour 30 minutes into the film they enter Dr Mann's shelter. It's freezing and their breath is visible, yet they remove their gloves and Brand operates the metal latch on Dr Mann's cryopod — her skin would have frozen to the latch. Some scientist.

Dr. Mann's planet's atmosphere would not have been dense enough to sustain ice clouds. Although some phenomena might resemble ice clouds, they would not be solid enough to walk on.

Modern satellite systems can map not only wave patterns and surface topography but do so at very high resolution. It’s reasonable to assume the Endurance would have carried comparable — if not more advanced — sensors, so they ought to have detected the enormous, rapidly moving waves on Miller's planet well before beginning the landing. However, because time aboard the Endurance passes at roughly seven years for every hour on the planet — over 61,000 times faster — the motion of those waves would have been effectively invisible from the ship. Even so, it still seems odd they didn't appear to consider that conditions in the planet’s own timeframe might be drastically different from what they observed from the vessel.

In the convoy leaving the village, at the moment when conditions on Earth reach rock bottom, you can clearly make out the radiator grille of a Mercedes 190, complete with the Mercedes badge. That point in time is set about two generations in the future, which would make that car — a model produced until the early 2000s — roughly 74 years old, so it appears to be an anachronism. It is, however, reasonable to imagine that, as in the Great Depression and World War II, people would keep things running far longer than they otherwise might. The car is not in the 'Rust Belt', and Mercedes are well built and long-lasting; their diesel engines would likely be carefully maintained in a farming area. Even now, seventy-year-old cars are still used every day in Cuba, despite a generations-long embargo on importing spare parts from the United States.

When he meets the NASA team, Cooper says the nearest star is 1,000 light‑years away. Although the closest star, in the Alpha Centauri system, is about 4.4 light‑years distant, Cooper was referring to the fact that, with the technology available at the time, a spacecraft would take roughly 1,000 years to reach it.

At 0:18:20, as they're getting out of the car and hurrying straight to the front door because of the dust storm, another person suddenly appears to help them into the building. He doesn't go in with them; he simply walks off to the left-hand side of the house.

Before Cooper's departure, Cooper and Donald sit on their veranda, drinking what looks like beer, even though, apart from corn, no other crops — including hops and barley, the typical ingredients in beer — can be cultivated.

At 2 h 9 min, during the rotating docking sequence, the G-forces seem to push the two pilots in opposite directions rather than the same way. This is correct: the spacecraft is rotating about its central axis, and the centripetal force acts on the pilots in that manner.

When Cooper and Murphy arrive at NASA in the lorry, Cooper wakes her and tells her it's the end of the road. Murphy, still drowsy, asks whether he brought the wire-cutter and then dozes off again. The instant Cooper climbs out of the lorry, she sits bolt upright with wide eyes and moves into the driver's seat. The abrupt shift is peculiar and seems to indicate a discrepancy in either the acting or the direction.

When Cooper initiates the spin of their lander to match the Endurance, which was damaged by Dr Mann's incomplete docking, Cooper's neck bends laterally in the opposite direction to Brand's. Once their rotations are synchronised there is rotational velocity but no acceleration, so their bodies should not be pushed sideways, only away from their seats by the remaining centripetal force directed radially outwards as their lander spins about the centre line of the Endurance's docking hatch.

When Dr Mann tries to open the Ranger's airlock whilst attempting to board the Endurance, in reality mechanical, electrical and electronic interlocks would prevent the outer hatch from being opened if the airlock still contained atmosphere and the docking interfaces were not fully engaged. Such safety features in airlocks became standard practice during the 20th century.

By 2074, NASA would require substantial industrial capability to construct the Endeavour and the other spacecraft needed for the Lazarus missions. All signs indicate that most of Earth's industrial base, especially its high‑tech sector, is no longer operational by then, as shown by people driving vehicles at least sixty years old and by the ageing drone Cooper and his family accidentally caused to crash near their home.

When they find the NASA facility, they're told that "nobody" knows it exists. Yet the site houses dozens upon dozens of people living and working in a purpose-built complex, building huge rockets and spacecraft, eating proper meals and drinking whisky. The place is well supplied with machinery, materials and foodstuffs for "nobody" to be aware of it.

When Brand clambers onto CASE to hurry her back to the Ranger, she's lying the other way round as they start to head back.

When Cooper initially gives the watch to Murphy, the time is about 8:20. Later, when Murphy throws the watch onto the floor, the shot is clearly mirrored — it now reads 3:30, and the clasp is oriented the opposite way to that of typical watches.