4 ms·
Is time dilation measurable between the two (due to gravity differences between locations)?
by madengr 10y ago
Is time dilation measurable between the two (due to gravity differences between locations)?
- eeZi 10y agoYes it's in the article. Pretty exciting.
- madengr 10y agoThanks; I glossed right over it. "Also, the apparent rate of a clock depends on the local gravitational potential: comparing two clocks measures the gravitational redshift between them, and thus yields their height difference. Such measurements provide data points for the geodetic reference surface, the so-called “geoid”. This research approach is pursued jointly by physicists and geodesists in the Collaborative Research Centre 1128 (“geo-Q”) of the German Science Foundation (DFG)."
- foota 10y agoI don't think this would be solely due to the height difference that the article suggests, but also the composition of the Earth beneath the facilities.
- cmdrfred 10y agoAnd the weight of the operator in the office next door, but we probably can't measure that yet.
- foota 10y agoI wonder if the position of the moon is significant enough to have a noticeable effect.
- grogers 10y agoThey can measure height differences of less than a meter, so I would guess they could measure the contribution of the moon. But this particular link currently seems to measure time differences between two fairly nearby clocks, so the moon position should have almost no effect on that.
- foota 10y agoI'm not so sure about that. The distance between the two locations is ~.25% of the distance from the Earth's surface to the moon, while one meter is only 0.000016% of the Earth's radius. So if the moon were on the side of the Earth such that it were closer to one of the locations than the other it would probably matter.
- jkot 10y agoEvery GPS receiver has to calculate time dilation of satellites.