Weather Talk: Measuring length of full day with high accuracy possible
An atomic second is defined as the duration of 9,192,631,770 periods of the radiation corresponding to the transition between two hyperfine levels of the ground state of cesium 133 atoms.
Are you a newspaper subscriber but you don't have a Digital Access account yet? Activate your account.
You will need your subscription account number and phone number. Not sure if you have an account? Email us or call (800) 274-5445 and we can help you.