Questions for “Physicists have clocked the shortest time span ever”

hydrogen molecule

The shortest time span ever measured is 247 zeptoseconds. That’s how long it takes light to cross a hydrogen molecule. / Getty Images Plus

To accompany “Physicists have clocked the shortest time span ever


Before Reading:

1.  What units do we use to measure time?

2.  How do we tend to measure time? If something were happening fast, how would you go about measuring just how fast it was? How would you do it if it happened faster than one second?

During Reading:

1.  What is the new time span measured? And what did it measure?

2.  What is a zeptosecond?

3.  What is a quantum of light?

4.  How does light move?

5.  What was important about have a two-atom molecule for measuring the path of light here? What would have made it harder if it were a single atom?   

6.  What is an attosecond and how does it compare to a zeptosecond? 

After Reading:

1.  Did you notice that the new time span is written as a singular unit — second — in part of the second sentence, but as a plural — zeptoseconds — toward the end of that same sentence? It’s not a mistake. Explain why it’s appropriate for one to be singular and the other plural.