Well, I don’t rightly know or comprehend the explanation. But they’re in the news because of the Noble Prize award in Physics for work generating laser light pulses as short as that. An Attosecond is a billion billionth of a second. A very short pulse of light. What I found fascinating was the fact that an Attosecond is a time period compared to a second is shorter than a second is compared to the creation of the universe 13.7 billion years ago. Another fascinating thing I saw was in a MIT video shot 11 years featuring a short laser beam slowed down with a “camera” capable of 1 trillion frames per second. It turns out that speed has improved dramatically since this video was made. But what got my attention was the statement that in comparison a fired bullet slowed down the same amount would take 3 years to traverse that soft drink bottle.