HPS 0410 | Einstein for Everyone |

What Happens at High Speeds

According to special relativity, rods and clocks are affected by their motion. If a yardstick is moved rapidly along the direction of its motion, it contracts. If a clocks ticks once per second when it is at rest, it will tick more slowly when it is moving.

Velocity | Fraction of Lightspeed | β factor (see below). |
Contracted length of yardstick = β yards |
Time between ticks of clock = 1/β seconds |

100 mph | .000000149 | .99999999999998885 | .99999999999998885yd (Earth's diameter 7,926 miles loses 5.6 millionth inch) |
1.00000000000001115 sec (One year loses 0.35 microseconds) |

10,000 mi/sec | ||||

26,200 mi/sec | .141 | .99 | .99 yd | 1.01 sec |

93,000 mi/sec | ||||

.866 | .5 | .5 yd | 2 sec | |

.99 | .141 | .141 yd | 7.1 sec | |

.995 | .10 | .10 yd | 10.0 sec | |

.9999 | .014 | .014 yd | 70.7 sec | |

1.0 (impossible) | 0 | 0 yd | infinity sec |

Calculate β factor =√(1-(fraction of
lightspeed^{2})).

i.e. *Square root* of (1 - *square* of fraction of lightspeed)

The speed of light is 186,000 miles per second.