According a recent biography of Henri Poincaré,
Poincaré … worked regularly from 10 to 12 in the morning and from 5 till 7 in the late afternoon. He found that working longer seldom achieved anything …
Poincaré made tremendous contributions to math and physics. His two-hour work sessions must have been sprints, working with an intensity that could not be sustained much longer.
I expect most of us would accomplish more if we worked harder when we worked, rested more, and cut out half-work.
Update: To be clear, the quote above refers to Poincaré’s most intellectually demanding work. Poincaré carried on his administrative duties outside the four hours of concentration mentioned above.
Now that I’m working on my own startup I’m beginning to think the same way. After working for a period of time (much less than 8 hours) you don’t produce the same quality of work.
It is the Tabata theory of work. =)
When I travel on business, I find that I can get a surprising amount done in short sprints of remote work.
Advice from Yoda along these lines: http://www.youtube.com/watch?v=BQ4yd2W50No
This reminds me of Bertrand Russel`s essay In Praise of Idleness, in which he proposes halving the working hours.
“All this is only preliminary. I want to say, in all seriousness, that a great deal of harm is being done in the modern world by belief in the virtuousness of work, and that the road to happiness and prosperity lies in an organized diminution of work.”
http://www.zpub.com/notes/idle.html
Well. It really depends on what you call “work”.
I think that truly creative work cannot be done for 8 hours a day. It is maybe closer to 4 hours for me as an upper bound (which means that some days, I cannot do more than 2 hours).
But most of my work does not require high creativity. For example, grading or reviewing papers is not highly demanding. So I tend to mix highly creative work with lots of busy work that I have to complete no matter what.
I agree with Daniel Lemire, with the added caveat that my productive days are the ones where I successfully recognize when I can be creative and when I cannot. There’s nothing worse than wasting a day trying to do something clever, then realizing that you would have been better off cleaning your desk or filing papers instead.
This question’s being explored rather interestingly by Dr. Cal Newport, a theoretical computer scientist, at Georgetown University. His blog is at http://calnewport.com/blog/about/
A probably interesting question is what Poincaré did the rest of the time.
It would be interesting to see statistics from a large population of academics, scientists, or similar, which observes the total contributions produced at e.g. 4 ,8, 12 hr. work days.
TW: I agree that would be interesting, but I doubt you could get honest numbers. Also, even if people were honest, it’s hard to say what counts as a work hour. As Daniel pointed out above, some people may work hard for a couple hours a day and take care of chores the rest of the day that don’t require great concentration.
I don’t remember the details, but I read somewhere that Fields Medal winner Stephen Smale lost his grants for a while after making some remark about doing his work on a beech. It’s best to keep your mouth shut about unusual work habits.
Just because you are idle, doesn’t mean your mind isn’t working on a problem. This may be especially true if you are trying to be creative.