In the movie "In Time" a person stops aging when they hit 25. At that point their "clock" starts ticking, and the person no longer ages, instead they suddenly die when their time runs out.

How does this technology work? How does it stop a person from aging? Also: (Since it has to do with not aging, and is most likely connected) What kills a person when their clock runs out?

  • It's never discussed in the film. Jul 26, 2012 at 0:24

2 Answers 2


It doesn't happen because of the implant (the device implant - the clock), the device only ends their life (stops their heart).

It happens because of genetic alteration that allowed humanity to stop aging at 25. What this genetic alteration is has not been explained in the movie. It's probably some kind of genetic-chemical-electronic combination.

Since the device stops their heart, it probably stops blood flow through their heart, resulting in no oxygen supply to the heart, followed by death. It can also be explained by a heart attack that causes death or an instant electric shock through their heart - a frequency that causes the heart to stop beating.

  • Thanks for the answer. I didn't realize the anti aging was due to a genetic modification. I actually thought it had to do with the time keeping device.
    – onewho
    Jul 26, 2012 at 15:36
  • Speaking in broad, very simple terms, "aging" is simply the slowdown (and eventual cessation) of cell division/replacement. It seems plausible that a genetic "enhancement" could simply keep division/replacement taking place at its normal rate, thereby preventing aging (since the humans in the movie are otherwise mortal). Jul 26, 2012 at 16:07
  • There would also have to be some methodology in place to fix transcription errors, but that's about as likely as the idea of avoiding the division slowing problem.
    – FuzzyBoots
    Sep 22, 2014 at 13:33
  • I haven't seen the film, so I'll ask here. If you remove the implant, do you become immortal?
    – Petersaber
    Mar 26, 2017 at 21:52

This is addressed in the film's original script (back when the film was called I'm.Mortal) which offers a number of 'info-dumps' about the clocks that don't seem to have made it into the final cut of the film.

All of humanity has been genetically engineered.

In the not-too-distant future the aging gene has been switched off. (NB: The minor variation in the biological age of adults is due to the differing time of life an individual matures. Full maturation triggers the aging gene to switch off and the "body clock" to begin ticking.)

"Time" can be moved from person to person.

Time is transferred from person to person by way of a unique handshake. The right wrists are held together - the time conveyed by the electricity in the pulse. The one who has their hand on top of the other - who literally has the "upper hand" - is the one extracting the time. Both parties monitor the amount of time exchanged by watching the body clock on their left wrist.

Running out of time causes a heart attack.

In this world, the genetically rewired circuitry of the body that keeps you young is also what kills you. Suddenly Rachel suffers an irreversible shock to the system - a massive heart attack. She is hurled off her feet, dead before she hits the ground.

The clocks are biological, not technological.

Greta proudly shows off her newborn's wrist with its tiny but perfectly-formed unticking clock.

GRETA There it is.

We FOCUS on the digits indicating years - "1".


BOREL: Shame we've got to wait twenty years - we could use that year right now.

GRETA: It's a miracle, isn't it - how our bodies know when to switch it on? Nature sure is beautiful.

BOREL: Except it's not nature. We don't even know any more how our bodies do it. Why a year? Why are we even born with this clock?

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.