Chapter 03 of 5
A Billionth of a Second
Why GPS depends on atomic clocks and timing measured in nanoseconds.
- The Speed
Light's Speed Limit
Light travels about 30 centimeters in one billionth of a second, a nanosecond.
- The Stakes
A Tiny Error, a Real Miss
A timing error of just one nanosecond puts your position out by about 30 centimeters.
- Bigger Errors
A Few Millionths
A timing error of a few millionths of a second would put you about a kilometer off.
17 more cards in this chapter
Could you answer this?
How far does light travel in one billionth of a second?
🛰️ Why Your Phone Needs Einstein
- 01Beeps From SpaceHow listening to Sputnik led to satellite navigation.
- 02Four Satellites and a StopwatchHow a phone works out where it is by timing radio signals.
- 03A Billionth of a SecondWhy GPS depends on atomic clocks and timing measured in nanoseconds.
- 04Einstein in OrbitThe relativity corrections that keep your blue dot on the right street.
- 05Lost in the CityUrban canyons, jamming and how your phone fills the gaps.