Goofs

When Adam is explaining the ripple effect of their time travel, the series of circles he draws on the chalkboard change shape from shot to shot.

The 2nd time Daivd goes to Lollapalooza, while talking with the girl his backpack keeps disappearing and appearing. I assume it's because they used the footage from the first time they've been to Lollapalooza.

The entire basis of not having enough money to attend MIT appears to be a goof, based on the fact that MIT gives all admitted students whose family income is under $75,000 free tuition. They also state that, "If admitted to MIT, we will make sure that you can afford to come to MIT." The premise of immediately needing to sell the house because of only a $5,000 scholarship does not appear to be realistic based on MIT's published averages on their website.

The opening minutes of the movie are shown to be recorded on a mobile phone camera, and records the characters finding and activating their fathers handy-cam, yet in the closing minutes of the film this same scene is shown with the alternate time-line camera, which now has the mobile phone footage of the siblings finding the original camera.

Nitrogen isn't explosive by itself and by itself reacts minimally to temperature changes.

When the group first discovers the schematics for the time machine, they incredulously spout a bunch of tech-terms contained within the documents trying to understand what the machine is used for. Two of the terms they read, back to back, are "Engine Pressure Ratio" and "Course Deviation Indicator," which are aviation terms (to do with turbine engine thrust and airway navigation, respectively); neither phrase seems to have anything to do with how the time machine works.

"The motion sensors are routed through my smart phone with an 802.11g, 64 gigahertz wireless." IEEE 802.11g-2003 is an old Wi-Fi standard that uses the 2.4GHz radio band.

Part of the plot revolves around not having enough hydrogen. Hydrogen and Oxygen can be easily made from water and electricity. It's one of the most basic high school science experiments. So hydrogen should never be scarce to these wiz kids.

When Adam is testing the backpack camera in the mirror, he turns to walk away in one direction, but the camera view rotates in the opposite direction.

Even though the camera abruptly stops and then starts recording over a hundred times throughout the movie, the various songs that play throughout the movie are almost never affected. In the found-footage genre, a dubbed soundtrack tends ruin the suspension of disbelief.

There is a frame near the end of the movie where David is talking to his father and mid-way he is putting items into a trash bin to destroy them. One looks like documents for the time-machine but the date is marked AUG 14 2025. This doesn't make sense since his father made the plans with DARPA in the past before David's seventh birthday in 2004. Unless they made a working prototype and also went into the future alongside the past this is improper prop use here.

When David looks at the plane crash footage on his notebook alone in his room, you can see the reflection of the green screen from his notebook's screen in his face.

Allen draws circles on the board to explain the ripple effect on the plane crash. Later, David goes back in time to fix it. When he comes back, we see the board still has circles drawn on it though they shouldn't be there considering the plane crash never happened.

When the team travels back in time to change Quinn's outcome in the chemistry presentation they have to move Quinn's "past-self" out of the way. Which makes David's time travel attempt to kiss Jessie not possible since he would have to get rid of himself in that time line, in that exact moment and then somehow remember it.

David goes back to the concert to try his chances again with Jessie. This establishes that if you go back in time again, you will see yourself from your first trip back. Based on this, when they have to go back so Quinn can pas the exam and they go back more than a dozen times, there should have been more than a dozen of them there.

As David goes back in time to get more hydrogen the movie continues its ''found footage'' style. Yet no-one traveled back with David and he is seen, running through corridors, not holding the video-camera. Thus it is impossible for this footage to be filmed.

While building the time machine, the friends chatter about becoming "Doctor Who" - but that is the title of the TV series, its hero is known as "the Doctor".