My protagonist, a victim of a similar accident from my previous question, looks and acts the same on the outside, while being very different on the inside. In this question however, the main informations are: his nervous system and body allow him to react and function normally at Mach 50 (his body can take the consequences of doing so and has a much longer potential lifespan, so he ages at what'd be considered normal rate, additionally his nervous signals travel at much faster speeds than in a normal human). The main issue with this however is that functioning all the time at that speed makes him essentially incapable of functioning normally by human standards, moving will cause destruction and interaction with others is almost impossible due to how slow they seem.

Based on this and to solve such an issue, is there a biological way for my character to be capable of slowing down his overall perception of time caused by his speed?. Though his different biology could allow me to stretch a "yes", I'd like to know if one can actually, to some degree, slow down their processing and reaction speed. My original approach was having him naturally function at a slightly slower speed and grant him certain control over his metabolism, since this was the best natural response I've found, with the reduction in brain activity as a byproduct of a lower metabolism, but it doesn't quite match what I need, as it wouldn't really slow down his processing speed (it does somewhat reduce the brain's capacity overall, but it also has a fair share of unwanted side-effects, including headaches, concentration problems and others, and a hypermetabolism didn't turn out to be a good approach either).

  • $\begingroup$ What do you mean by "slow down his perception of time"? We all move through time at exactly one second per second, and there is no way to make it slower or faster. Why would interaction with a slow peripheral device be a problem? I would understand the difficulty in interacting with a very fast peripheral device, but slow peripherals have never been a problem. He asks a question, then waits for the slow human to respond. While waiting he can do something else -- compose a poem, consider natural ethics, contemplate the things in themselves etc. $\endgroup$
    – AlexP
    Commented May 21, 2020 at 12:36
  • $\begingroup$ @AlexP here's the problem: per my previous question's conclusions, he perceives a second as ≈30 minutes, so if someone takes 4 seconds to write an answer, he'll need to wait 2 hours for it. Additionally, it's problematic to live if you can't move without constantly causing sonic booms, especially if you already perceive yourself as moving slower (and that's only consider going at Mach 1, Mach 50 has many more problems, especially heat). Essentially I need a way for him to slow down (reducing mainly his nervous system's processing speed) so that he can move and react at speeds below Mach 1. $\endgroup$ Commented May 21, 2020 at 13:05
  • $\begingroup$ Slowing down your body and perceiving time slower may be 2 different things, think of slow motion cameras and their high frame rate, so you nerve speeds would need to increase to react with a slower perception of time. $\endgroup$
    – user69935
    Commented May 21, 2020 at 13:34
  • $\begingroup$ There is absolutely no problem with waiting for an answer; before e-mail, people actually corresponded via physical letters carried by physical couriers. There used to be even a special genre of novels, epistolary novels (for a well-known example, Dangerous Liaisons by Choderlos de Laclos), where everything proceeds at the speed of physical mail correspondence. $\endgroup$
    – AlexP
    Commented May 21, 2020 at 14:36
  • $\begingroup$ @AlexP I don't think you understand what I mean. It's not simply waiting. His whole concept of time is shifted by his perception. Gravity seems to almost not work for him. He sees the period of a year as over a millenia (1700 years to be precise) and needs to force himself to move at a rate that, to him, is beyond slow (to get a better image of his situation, think of the quicksilver scene, but slower, lasting until your death, and you can't move like he does, because doing so will shatter windows and make some people go deaf). That's essentially why I need him to be able to slow down. $\endgroup$ Commented May 21, 2020 at 15:01

2 Answers 2


Yes, or - not really.

Yes, since hey, that's your story. You don't even need to explain it too much. For example in the Safehold series, the main character is almost in the position you describe, and they has "governors" embedded in their body so that it can mimic normal human reflexes. What these governors are, or how they might work (do they queue pseudo-nervous impulses? Do they slow down proportionally? Do they...?) is not covered in the slightest.

Otherwise, no. Just try moving in really slow motion, like you do to avoid triggering a PIR sensor. You'll succeed maybe two times out of three, and that with much practice. That's a macroscopic fault. Then try moving in slow motion, film yourself and project the film at accelerated speed. What you will see is definitely not a natural motion; that's a microscopic fault, much more difficult to eliminate.

The main problem is that when you change the time scale at which you move, your perception of gravity and acceleration changes. You cannot, for instance, run in slow motion. Move too fast, and turning a corner becomes awkward due to centripetal force. Walk, and friction becomes a problem long before sonic booms do. And when you are in the air, you can wait subjective eternities for gravity to bring you back, and you can do nothing to accelerate the process.

"Accelerating" a body's perception and speed is not enough to allow "normal movement but at higher speed", even if novels consistently ignore this fact (from Wells' The New Accelerator to Frank Herbert's Heretics of Dune). A more realistic version I found in Douglas Richards' Infinity Born (or was it Amped?), and there, the long-term cost of shifting into an accelerated time frame is insanity.


Not quite sure if this is what you are looking for, but, in theory, you could increase the characters “maximum rate of temporal information processing in the visual system.” You can look at this website here -


Just replace "small animals" with your character :)


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