Question

A second of time is defined as x oscillations of a cesium atom's resonant frequency, and is commonly measured in atomic clocks. If an atomic clock is propelled at near the speed of light (or at any speed), wouldn't that definition of a second be distorted? If so, shouldn't we add a longitude and latitude to the definition since all places on earth travel at different speeds?

Asked by: Ryan Gallagher

 Answer

A second of time can only be defined relative to the observer. Whether you determine the passage of one second of time with a stopwatch or a Cesium 133 atom, you want the source of that measurement to be in your own inertial frame. What you are measuring is the passage of LOCAL time. There is no universal inertial frame of reference that can determine an 'absolute' second to correct for.

Answered by: Paul Walorski, B.A. Physics, Part-time Physics Instructor

Search

Loading



Sponsors

USC University of Southern California Dornsife College Physics and Astronomy Department McMaster University Physics and Astronomy Department

Science Quote

'We should take care not to make intellect our god; it has powerful muscles but no personality.'

Albert Einstein
(1879-1955)

Deal of the Day

Image of Shark Tooth Fossil in Matrix. Click on this image for more info. Shark Tooth Fossil in Matrix
Regular Price: $39.95
Today's Price: $15.00
Superb shark fossil specimen for the science classroom! Buy it now! Deal ends at midnight!

Top Selling

Here are our physics & astronomy bestsellers:
Mini Plasma Ball
Slide Making Kit
Top Secret - Spinning Top
Wood Grain Newtons Cradle
Deluxe 3D Mirascope
Solar Radiometer
Periscope
Solar Science 4M Kit
Ultimate Chemistry Set CHEM C3000
3D Magnetic Field Tube