Saturday, April 04, 2009

How it's possible for a 22 year old to have lived for longer duration than a 23 year old person

This thought is based on the idea of more effective / productive time utilization, the way we use it in the context of work.


7 hours of optimized sleep per day has the same amount of desirable effect as 8 hours of usual sleep (which can be reasonably assumed to be unoptimized in most cases), without involving any compromise with one's physical or mental health. The basis of this (unproven) hypothesis is real-life observation on myself, among some other observations.

  • Amount of desirable effect: Sleep has some purposes (related to both the physical and the mental health), and these purposes are the desirable effects of the activity of sleeping on our body and mind. These effects can vary in extent depending upon sleeping conditions and its duration
  • Optimized sleep: When sleep takes place in such conditions as to maximize the desirable effects obtained per hour, the sleep is called optimized sleep. Posture, noise, lighting, time, type of bed, and many other factors affect the quality of our sleep
  • Usual sleep: The way most of us sleep each day. The conditions we sleep in are not the best possible, and hence almost all of our sleeps are not optimized. The desirable effects we obtain per hour are lower than the maximum possible amount achieved during an optimized sleep
Sleeping like a baby


If a 22 year old person has been having 7 hours of optimized sleep each day for the last 10 years of his life, then he has been awake for about 3,651 hours more than a similar-aged friend who has been having 8 hours of usual sleep, without making any compromise with his physical and mental health (this follows from my hypothesis).

Assuming that the average number of productive hours (the hours which are utilized each day for work - these hours do not include eating, entertainment, bathing, etc.) per day for any person who takes 8 hours of usual sleep per day is 10, a 23 year old person X has had 40,170 productive hours in the last 11 years of his life (3,650 hours per year; 2 days have been added to account for the minimum number of leap years that must be traversed during 11 consecutive years).

Using the same methodology, a 22 year old person Y - who takes 7 hours of optimized sleep per day and hence has one extra productive hour per day - has had 40,172 productive hours in the last 10 years of his life (4,015 hours per year) - a total of 2 hours more than person X. This difference will increase as person X and Y age.


Assuming that most of the learning / living occurs during the productive hours (the definition of productive hours can be broadened to include entertainment, since a lot of social learning takes place during entertainment activities), the 22 year old person Y has effectively lived slightly more than the 23 year old person X - without making any compromise, and without accumulating any sleep debt.

If this hypothesis is proved to be true, it will make education about effective sleep all the more important for inclusion in the syllabus of school children. Also, optimized sleep will become another productivity-enhancing weapon in the arsenal of organizational CxOs (CEOs, COOs, CTOs, CFOs, CIOs, CMOs, etc.), and other high-ranking individuals.

Finally, it must be remembered that optimized sleep is just one out of many possible methods by which a 22 year old can have practically lived for more duration than a 23 year old. Also, this idea assumes that the situations faced by person X and person Y (while they're in their productive hours) are the same. In real life, it's more likely that these 2 individuals shall face very different situations, resulting in learnings that vary not only in extent, but also in type.

Update: Forgot to mention that person Y also has a full extra calendar year ahead of him, compared to person X, since he's only 22 yet (that's 4015 more productive hours by the time he turns 23!).

My Thoughts About Human Memory


  1. I thought that it was a puzzle and I solved it like this.
    Two people named X and Y borne on same day (let us suppose 10th oct 1985) but on different places on earth. Let us assume that time gap between these places be 6 hrs. Also assume that X borne at 11 am and Y borne at 1am at their respective places (that means X borne 4 hrs later than did Y borne, according to GMT). Now imagine on exactly the same date when 23 years are about to complete imagine earth taking usual axial rotation and it is about to strike 12'o clock midenight at X's place and date become 10 dec 2008 at 12o clock, so logically speaking X turns 23 but Y is till 22 years old. Now this is the period we can say that X though has turned 23 but has lived lesser than a 22 year old Y.

    Plz corect me if I am wrong.......

  2. Interesting way to look at the post headline... but I'm sorry to inform you that your solution is flawed.

    Since X was born 4 hours later than Y, when the clock was about to strike 12'0 clock midnight at X's place, it would also be ready to strike 4 AM at Y's placing, meaning that Y has already turned 23 (exactly 4 hours before X did).

    More importantly, seconds are getting added to the age of both simultaneously, and hence the symbolic representations we use to indicate our age (years, months, etc.) cannot affect the exact count of the number of seconds we've lived so far.

    I also want to add that I believe that midnight is just a convenient "rounding off" prevalent in the real world. Personally I prefer a system in which the unit's place is not used as the least count to define a person's age in years, but rather at least two places of decimal are used (preferably based on the exact time at which a person was born).

    As an example, right now it is May 24, 2009 at my place, and Wolfram Alpha tells me that my chronological age as of now is 22.89 years

    Hence your solution is a case of a rounding-off error.

    Hope that helps

  3. Really appreciate you Rishab for your analysis, but it has gone wayward in the haste for answering.

    First of all there is a time gap of 6 hrs, between X and Y's place. so if clock has struck 12'o clock at X's place then simultaneously it should be 6 pm of 9th oct 2008 at y place , not 4 am as you said (because OO.OOhrs on 10oct 2008 minus 6hrs=6pm of 9 Oct 2008 )

    Second thing - throughout the world there is a convention that year is considered complete when clocks strike 12 pm at night and not that people wait to for that last mini second of exact time of birth. Just 00:00 hrs is significant for them. This reasoning can be exemplified with by taking example of New Years day.
    Everyone celebrates new year at oo.oo hrs of 1st jan each year and not by taking into account extra 6 hrs each year which should be added each year after every leap year to make it a complete year, its not like that people just wait for 12'o clock.

    Your saying that "seconds are getting added to the age of both simultaneously, and hence the symbolic representations we use to indicate our age (years, months, etc.) cannot affect the exact count of the number of seconds we've lived so far. what you are saying is correct but then answer this question -- would you say that X has not turned 23 at 10 oct 2008 at 12o clock just like all the people in world would say or you would say " No x will be 23 only when clock comes exactly at 11 am on 10 oct 2009.

    Also i want to mention that x place was in east compared to y place

    and last but not least - I hope that it should remain as an intellectual argument rather than a tiff for self-ego.

    take care!!!

  4. Hi Tim

    Apology if you felt that my reply was out of self-ego. It wasn't meant to be.

    Now, I realize that I had misinterpreted your solution (though it was not out of a haste to answer), because when I re-solved your solution just now, it turns out that when the clock is about to strike 12 midnight at X's place, it's about to be 6 PM at Y's place (6 hours behind).

    Agreed so far.

    Also agreed that throughout the world there is a convention of considering a year complete when the clock strikes 12 midnight. However, I the problem is to identify a way by which a particular 22 year old person *actually* lives longer than a 23 year old person.

    X may be tagged as a 23-year old according to the norms followed by most of the world, but fact remains that he has not *lived* longer than Y. Just because an erroneous method is a norm followed by the public doesn't mean that it should be used as the reasoning behind mathematical or logical problems, especially by professionals.

    The duration of X's life is Q-P, where Q is the date and time of measurement, and P is the date and time at which P was born. Similarly for Y. Everything else kept same, X will always have lived 4 hours less than Y.

    I personally would not consider X turning 23 when the clock strikes 12 midnight. For me, he turns 23 at 11 AM of October 10, 2008.

    I'm an engineer and I do not like rounding-off errors :)

    I hope you read my reply in the good spirits, and don't find ego in it.

    Let me know your thoughts!

  5. Well, I was just curious, how someone might have lived longer, though senior in age. The post is brilliant (I will try to follow it from now on). I think the comments from both Tim and Rishabh are very analytical too... Good :)

  6. Update (15-Sep-10): I now feel that Optimized Breathing (or Optimized Respiration) can be another potent method to increase activeness or fitness, and to even prolong one's life.