In the summer of 1997, NASA's Pathfinder spacecraft landed
on the surface of Mars, and began transmitting incredible,
iconic images back to Earth. But several days in,
something went terribly wrong. The transmissions stopped. Pathfinder was, in effect,
procrastinating: keeping itself fully occupied
but failing to do its most important work. What was going on? There was a bug, it turned out,
in its scheduler. Every operating system has something
called the scheduler that tells the CPU how long
to work on each task before switching, and what to switch to. Done right, computers move so fluidly
between their various responsibilities, they give the illusion
of doing everything simultaneously. But we all know what happens
when things go wrong. This should give us, if nothing else,
some measure of consolation. Even computers get overwhelmed sometimes. Maybe learning about the computer science
of scheduling can give us some ideas about our own
human struggles with time. One of the first insights is that all
the time you spend prioritizing your work is time you aren't spending doing it. For instance, let's say when you check
your inbox, you scan all the messages, choosing which is the most important. Once you've dealt with that one,
you repeat. Seems sensible,
but there's a problem here. This is what's known
as a quadratic-time algorithm. With an inbox that's twice as
full, these passes will take twice as long and you'll need to do
twice as many of them! This means four times the work. The programmers
of the operating system Linux encountered a similar problem in 2003. Linux would rank every single
one of its tasks in order of importance, and sometimes spent more time
ranking tasks than doing them. The programmers’ counterintuitive solution
was to replace this full ranking with a limited number
of priority “buckets.” The system was less precise
about what to do next but more than made up for it
by spending more time making progress. So with your emails, insisting on always
doing the very most important thing first could lead to a meltdown. Waking up to an inbox three times fuller
than normal could take nine times longer to clear. You’d be better off replying
in chronological order, or even at random! Surprisingly, sometimes giving up
on doing things in the perfect order may be the key to getting them done. Another insight that emerges
from computer scheduling has to do with one of the most prevalent
features of modern life: interruptions. When a computer goes
from one task to another, it has to do what's called
a context switch, bookmarking its place in one task, moving old data out of its memory
and new data in. Each of these actions comes at a cost. The insight here is that there’s
a fundamental tradeoff between productivity and responsiveness. Getting serious work done
means minimizing context switches. But being responsive means reacting
anytime something comes up. These two principles
are fundamentally in tension. Recognizing this tension allows us to decide where
we want to strike that balance. The obvious solution
is to minimize interruptions. The less obvious one is to group them. If no notification
or email requires a response more urgently than once an hour, say, then that’s exactly how often
you should check them. No more. In computer science, this idea goes by
the name of interrupt coalescing. Rather than dealing with
things as they come up – Oh, the mouse was moved? A key was pressed? More of that file downloaded? – the system groups these
interruptions together based on how long they can afford to wait. In 2013, interrupt coalescing triggered a massive improvement
in laptop battery life. This is because deferring interruptions
lets a system check everything at once, then quickly re-enter a low-power state. As with computers, so it is with us. Perhaps adopting a similar approach might allow us users
to reclaim our own attention, and give us back one of the things
that feels so rare in modern life: rest.
This is why I hate Ted now, flashy animation and then a pitch to sell you something. There was no substance or suggested action from this video.