[guylhem]

I disagree.

Take a military analogy - if you're not doing something "shippable" (ex: fighting), you are training to maintain or raise your potential for when you will have to get in action - or at least to maintain discipline.

I'm not into physics, but if I had to place my bets between a team of physicists who loves to redo the world with the help of beers during long lunch hours, and a team of physicist who is into laser cutting a table from an aluminum sheet, I'd place my bet on the latter.

You may not be "shipping" physics at the moment, but you are maintaining your knowledge, training doing something that might seem pointless but will help you keep your skills or even develop new ones (ain't there a place for physics to decide how to best laser cut aluminum? Can you write an equation for the precise minimal laser power required to cut, depending on the metal and its depth?)

[ISL]

I agree.

Play is incredibly important. I only wanted to point out that 'awesome' alone may be insufficient as a hiring criterion.

[lifeisstillgood]

Brilliant catch there.

And adding in a quote I heard recently supposedly from a Navy SEAL

  Under pressure you don't rise to the occassion, you sink 
  to the level of your training.

As a rough rule bet on the girl with a large number of working github repos - she is used to shipping working code