[填空题]
An atomic spectrum conkm ;ferhu(/n *tains a line with e p n09d o7n9n7ohp/o et5om6xa wavelength centered at 488 nm. Careful measurements show the line is really spread out between 487 and 489 nm. Estimate the lifetime of the excited state that prxdome9/9eon7 nt7op pn5h06 ooduced this line.
$\Delta t = $ $\times 10^{-14}\ \text{s}$
