If we could slow light down and see what it does in those trillionths of a second, we could answer more questions with regards to our existence itself. What exactly happens with photosynthesis and how do lasers go through glass? This video shows the answers.
What's really amazing is the fact that it's now possible to slow the travel of light down to a visible rate, and the research with regards to the technology is only at the beginning. If I could change the time of anything, I'd love to see a closeup video of hair growth, skin shedding, and bloodflow through the body in a realistic way. If I could slow things down, I'd love to see how plants react when light is first emitted in the morning, and I'd love to see the movement of cells with regards to the growth of something, or the change of one state into the next, and what happens between.
It seems we're expanding the limit to what we can see. I am not able to even think what a femtosecond is, but it seems as if this technological development is pushing our knowledge to another level.