Originally Posted by **Jameson**

I'm doing my physics homework online, and this unit conversion problem is getting to me. Here it is along with my work.

Time standards are now based on atomic clocks. A promising second standard is based on pulsars, which are rotating neutron stars (highly compact stars consisting only of neutrons). Some rotate at a rate that is highly stable, sending out a radio beacon that sweeps briefly across Earth once with each rotation, like a lighthouse beacon. Suppose a pulsar rotates once every 1.342 806 448 872 75 6 ms, where the trailing $\displaystyle \pm$ 6 indicates the uncertainty in the last decimal place (it does not mean $\displaystyle \pm$6 ms).

Now my thoughts:

It rotates one time every 1.342806448872756ms, so I need to convert this to one # of times per 30 days.

$\displaystyle {1.342806448872756ms} \times \frac{10^3ms}{1s} \times \frac{60s}{1min}$$\displaystyle \times \frac{60min}{1hour} \times \frac{24hours}{1day} \times 30 days$

which equals 3480554315 times, which is incorrect. I know I'm having a brain fart. Someone tell me what it is.