Cobb and Mal might have spent decades in limbo, but that’s equal to less than a day in the waking world, according to the rules of Inception.
How long Cobb and Mal were in Limbo remains unclear to many who’ve seen Inception, which is just one of the movie’s biggest mysteries. Indeed, the mind-bending Christopher Nolan movie raises a lot of questions about the nature of time and space, but one of the biggest is about how many hours pass in reality as opposed to in a dream. As Cobb explains to Ariadne, time stretches in a dream; seconds turn to minutes, minutes turn to days, and days turn to years.
The length in which time stretches for a dreamer depends on where they are in Inception‘s dream levels. Typically, a dreamer’s perception of time lengthens exponentially the deeper they are inside a shared dream. This effect happens from the first until the last level of dreaming, Limbo, the shores of the subconscious – where Cobb and Mal grew old together before the events of the movie. Here’s everything else viewers need to know about how time works in dreams in Inception.
How Inception Explains Dream Time
During Inception, Cobb and his team of dreamers use several different compounds to create and enter shared lucid dreams. At the start of the movie, Cobb and Arthur use a version of Somnacin that turns five minutes in reality into about an hour of dreamtime – making the dream 12 times longer than reality. Later in the film, however, Cobb and his team use a specialized compound to complete inception. That drug turns 10 hours on the surface into about a week of dreamtime – 20 times as long. How long Cobb and Mal were in Limbo can be inferred from these increments in time.
As Cobb explains, the amount of time spent in a dream is compounded with each level. On the first level, a 10-hour job is about a week. On the second level, it’s six months; and on the third, it’s 10 years. Limbo, the purgatory of dreamspace, is the rarely seen fourth level, a place where time stretches out for eternity. It’s on this level that Cobb and Mal were trapped in for 50 years, eventually reawakening to find their physical bodies still young in reality.
Cobb And Mal Were In Limbo For 21 Hours
The thing is, Cobb’s calculations in the movie are a little imprecise, complicating the answer to how long Cobb and Mal were in Limbo. Using the 1:20 ratio, 10 hours of reality actually equals 8.3 days of dreaming on the first level, 5.47 months on the second, and 9.1 years on the third, as experienced by Cobb’s team in Inception during their mission.
It’s tempting to also use the 1:20 ratio to calculate how much time might have passed for Cobb and Mal on the surface when they were trapped in Limbo. But according to the timeline of the film, the lovers became trapped before Yusuf’s specialized Somnacin was ever developed or used. The first time for any dreamer to use the sedative-laced compound is during the events of Inception.
Cobb says he and Mal were experimenting with dreaming when they got lost, so it’s possible he was also experimenting with Somnacin. If Cobb did use a similar compound with the 1:20 ratio, he and Mal would have been asleep for only 2.7 hours as 50 years passed in Limbo. What’s more likely, however, is that Cobb and Mal were using the standard compound with a 1:12 ratio and experimenting with the depth of Inception‘s shared dreaming technology. Using that math, Cobb and Mal would have been asleep for 21 hours, which translates to dozens of lifetimes inside Limbo.
How Long Saito Was In Limbo Before Cobb Found Him
Unlike how long Cobb and Mal were in Limbo, the exact amount of years Saito was never made clear, but can be estimated from several clues. In Inception‘s ending, Cobb and Saito would’ve been trapped in Limbo for 182 years – if they hadn’t been kicked out of the dream. However, Saito’s time in Limbo likely lasted just around 50 or more years.
This is based on how much time passes between Saito’s death in Level 3 – the fortress in the snow – and when Cobb lands on the shores of the subconscious, as well as the extent of how Saito is older than Cobb in Limbo. It can’t have been any longer than that, as Saito enters Limbo near the end of their mission, and the plane ride ends shortly after Cobb and Saito wake up in reality – just before the final scenes of Inception.