mrogers writes "New Scientist Space is reporting that the health effects of microgravity can be reproduced by staying in bed. Inclining the bed at an angle of 6 degrees with the head at the lower end produces bone and muscle loss, decreases in cardiovascular activity, and reduced capacity to exercise similar to those produced by prolonged spaceflight. (Valeri Polyakov was not available for comment at the time of going to press.)"
egrep patterns are full regular expressions; it uses a fast deterministic
algorithm that sometimes needs exponential space.
-- unix manuals