# Can I measure my time dilation displacement **URL:** \ **Category:** Factual Questions\ **Created:** [December 16, 2023, 4:23pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696 "2023-12-16T16:23:56Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Crane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crane/32/3495_2.png) [@Crane](https://boards.straightdope.com/u/Crane)\ **Post date:** [December 16, 2023, 4:23pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/1 "2023-12-16T16:23:56Z")
I have traveled over a million miles as a passenger in jet aircraft. According to GPT4 that produces 2 microseconds of time displacement. I’d like to use that as a science project with my great grand daughter. We both have oscilloscope software that can easily handle 2 microseconds. We could build oscillators or pulse generators if necessary or travel to a location with an accurate time reference. So, is it possible to measure the time dilation between us? ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [December 16, 2023, 4:45pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/2 "2023-12-16T16:45:08Z")
Sure; it’s easy (and been done: > **[Hafele–Keating experiment](https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experiment)** > > The Hafele–Keating experiment was a test of the theory of relativity. In 1971, Joseph C. Hafele, a physicist, and Richard E. Keating, an astronomer, took four caesium-beam atomic clocks aboard commercial airliners. They flew twice around the world, first eastward, then westward, and compared the clocks against others that remained at the United States Naval Observatory. When reunited, the three sets of clocks were found to disagree with one another, and their differences were consistent with t Ac... ) Not cheap, though; you need a bunch of plane tickets, and some atomic clocks (+ power). Today you can get those accurate rack-mounted ones; will also need power, a laptop to interface with it and, I assume, coordination with the airline to get their permission to set up your gear. ---
**Author:** ![Crane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crane/32/3495_2.png) [@Crane](https://boards.straightdope.com/u/Crane)\ **Post date:** [December 16, 2023, 4:50pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/3 "2023-12-16T16:50:03Z")
I already did that part by traveling on jet aircraft. My great grand daughter can substitute for the other clock. So one of us is displaced given the same reference. Now how do I measure it. ---
**Author:** ![Telemark](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/telemark/32/372_2.png) [@Telemark](https://boards.straightdope.com/u/Telemark)\ **Post date:** [December 16, 2023, 5:07pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/4 "2023-12-16T17:07:01Z")
> [@Crane](#): > > Now how do I measure it. I think the only way that makes sense is to start the measurements before you travel. ---
**Author:** ![Chingon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chingon/32/17645_2.png) [@Chingon](https://boards.straightdope.com/u/Chingon)\ **Post date:** [December 16, 2023, 5:07pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/5 "2023-12-16T17:07:06Z")
I think you might be confused, or missing something. Unless you were both actually actively measuring something while you were flying and she was not, it’s irrelevant what your previous flights were. ---
**Author:** ![Chingon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chingon/32/17645_2.png) [@Chingon](https://boards.straightdope.com/u/Chingon)\ **Post date:** [December 16, 2023, 5:09pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/6 "2023-12-16T17:09:19Z")
I should also comment that’s it’s (relative) speed that’s important, not distance travelled. You’re missing a denominator. ---
**Author:** ![Crane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crane/32/3495_2.png) [@Crane](https://boards.straightdope.com/u/Crane)\ **Post date:** [December 16, 2023, 5:15pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/7 "2023-12-16T17:15:17Z")
The aircraft traveled over a million miles at 500 miles an hour. That is a rate. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [December 16, 2023, 5:39pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/8 "2023-12-16T17:39:12Z")
Time = space according to Einstein. So, “500 miles per hour” can directly be expressed as a kinematic time dilation factor; that was the measurement. However, now you are off the 'plane; it is not a residual effect or anything like that, like radiation exposure. ---
**Author:** ![Crane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crane/32/3495_2.png) [@Crane](https://boards.straightdope.com/u/Crane)\ **Post date:** [December 16, 2023, 5:52pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/9 "2023-12-16T17:52:13Z")
So, the guys in SF novels who return to earth after travelling around the galaxy and find everything different due to time dilation just have to jump out of their ship and it will spring back to ‘real’ time. Oh yeah, if it’s not a property then the clock experiment would not have worked. ---
**Author:** ![DPRK](https://avatars.discourse-cdn.com/v4/letter/d/4491bb/32.png) [@DPRK](https://boards.straightdope.com/u/DPRK)\ **Post date:** [December 16, 2023, 5:57pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/10 "2023-12-16T17:57:40Z")
No more than I expect to “spring” back to LA after I fly from LA to New York and alight at JFK. ---
**Author:** ![Crane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crane/32/3495_2.png) [@Crane](https://boards.straightdope.com/u/Crane)\ **Post date:** [December 16, 2023, 6:03pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/11 "2023-12-16T18:03:17Z")
Right, so is there a way that I can measure the time dilation between me and my great grand daughter. ---
**Author:** ![Chingon](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chingon/32/17645_2.png) [@Chingon](https://boards.straightdope.com/u/Chingon)\ **Post date:** [December 16, 2023, 6:04pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/12 "2023-12-16T18:04:05Z")
Not feasibly with any current methods. ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [December 16, 2023, 6:04pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/13 "2023-12-16T18:04:33Z")
You measure the time dilation by bringing a clock with you. Now, your own metabolic processes provide a clock of sorts, but it’s an extremely low-precision clock. A wristwatch is better, but still not nearly good enough. If you want to measure it, then you need to bring a really good clock with you. If you didn’t do that on your previous flights, then it’s too late now: You can’t measure those previous flights. ---
**Author:** ![Crane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crane/32/3495_2.png) [@Crane](https://boards.straightdope.com/u/Crane)\ **Post date:** [December 16, 2023, 6:05pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/14 "2023-12-16T18:05:25Z")
Why not? There are accurate references available and 2 microseconds is no big deal for any oscilloscope. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [December 16, 2023, 6:06pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/15 "2023-12-16T18:06:31Z")
Oscilloscopes can’t do anything with events that happened in the past. ---
**Author:** ![Crane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crane/32/3495_2.png) [@Crane](https://boards.straightdope.com/u/Crane)\ **Post date:** [December 16, 2023, 6:06pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/16 "2023-12-16T18:06:59Z")
The clock is just a measurement device and is not required. Time dilation works on the thing in motion. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [December 16, 2023, 6:07pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/17 "2023-12-16T18:07:24Z")
Or, earlier, the [Pound–Rebka experiment](https://en.wikipedia.org/wiki/Gravitational_time_dilation) where they measured the difference between clocks at the top and bottom of a tower. Cheaper than taking a plane. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [December 16, 2023, 6:07pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/18 "2023-12-16T18:07:58Z")
> [@Crane](#): > > The clock is just a measurement device and is not required. Time dilation works on the thing in motion. But you specifically asked about measuring it which, by definition, requires a measurement device. ---
**Author:** ![Crane](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/crane/32/3495_2.png) [@Crane](https://boards.straightdope.com/u/Crane)\ **Post date:** [December 16, 2023, 6:08pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/19 "2023-12-16T18:08:48Z")
But with time dilation one oscilloscope is 2 microseconds in the past compared to the other. ---
**Author:** ![Whack-a-Mole](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/whack-a-mole/32/141_2.png) [@Whack-a-Mole](https://boards.straightdope.com/u/Whack-a-Mole)\ **Post date:** [December 16, 2023, 6:10pm UTC](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696/20 "2023-12-16T18:10:18Z")
I read somewhere (ages ago now) that a cosmonaut who had been in space for six months was 2-seconds off from those on earth when he returned. [Next page](https://boards.straightdope.com/t/can-i-measure-my-time-dilation-displacement/994696.md?page=2)