One of the interesting things about getting bigger is that you can’t see it happening. Growth is invisible. You can only see it after it’s happened. For example sometimes you need to measure a person’s height or weight to tell if he or she has gotten taller or heavier since the last time you looked. That’s not watching growth that’s just measuring results. This is true of life in general. Things are getting bigger all the time but so slowly you can’t see it happening. Watching the grass grow can be pretty boring. This is why scientists studying plant growth don’t shoot movies of plants getting bigger; they take photos maybe once a day to chart the growth. Only by examining pictures in sequence or by speeding up a film can they “watch” something grow.