I'd go further and say it's dangerously untrue. What I advise people is that your results are constantly decaying. Only a rate of progress that exceeds the rate of decay will get you out the door. Decay happens for a number of reasons:
* Your records are never good enough to completely replace your memory of what you did. The longer it takes, the more studies, readings, etc., that you will have to repeat.
* In physical and biological sciences, equipment breaks down, gets taken away, facilities get moved, etc. This stuff happens at a constant rate, and is a pure time cost.
* Technological progress gradually raises the bar for the minimum quality of some results, e.g., in computation. Even "theory" is highly computational these days.
There are also risks of career-ending accidents that can be treated as a constant risk per unit time:
* Your advisor dies, retires, gets promoted to administration, loses funding, changes jobs, gets embroiled in ethical / legal issues, etc.
* Some unexpected new result from another team or industry erases the relevance or novelty of your work.
* You get sick, have family crisis, etc.
* Burnout
Results are the wrong unit of measure. A better KPI is results per unit time. The people who look like they fucked around for 4 years then submitted a brilliant thesis were either working hard all along, or were just brilliant, which I certainly wasn't.
My then-fiancee and I were both grad students. We made a pact to meet at 7:00 every morning in the cafe across from the research building for coffee, to force both of us to stay on a work schedule.
This is the kind of advice I give incoming graduate students. The sooner you start to treat grad school like a full-time job, the better. I was in a similar boat: my wife and I were both in grad school at the same time. We worked 9-5 every day, even if we weren't going in to the office. We both finished on time, and generally didn't have a difficult time with our degrees.
* Your records are never good enough to completely replace your memory of what you did. The longer it takes, the more studies, readings, etc., that you will have to repeat.
* In physical and biological sciences, equipment breaks down, gets taken away, facilities get moved, etc. This stuff happens at a constant rate, and is a pure time cost.
* Technological progress gradually raises the bar for the minimum quality of some results, e.g., in computation. Even "theory" is highly computational these days.
There are also risks of career-ending accidents that can be treated as a constant risk per unit time:
* Your advisor dies, retires, gets promoted to administration, loses funding, changes jobs, gets embroiled in ethical / legal issues, etc.
* Some unexpected new result from another team or industry erases the relevance or novelty of your work.
* You get sick, have family crisis, etc.
* Burnout
Results are the wrong unit of measure. A better KPI is results per unit time. The people who look like they fucked around for 4 years then submitted a brilliant thesis were either working hard all along, or were just brilliant, which I certainly wasn't.
My then-fiancee and I were both grad students. We made a pact to meet at 7:00 every morning in the cafe across from the research building for coffee, to force both of us to stay on a work schedule.