Comment on The young centre of the Earth (2016)parentComments−mehrdadn6yWe have clocks which can measure it over just a few feet of height differenceWait, seriously? Do you have a link??−colechristensen6yMeasuring the height of a mountain with a portable atomic clock (1000m accuracy) https://www.nature.com/articles/s41567-017-0042-3NIST measuring speed differences < 10 m/s and height < 1 m with a pair of atomic clocks https://science.sciencemag.org/content/329/5999/1630.long−raattgift6yTests of gravitational time dilation are also within the reach range of enthusiastic amateurs using second-hand atomic clocks:Part 4 (starting pdf page 44) of http://web.stanford.edu/group/scpnt/pnt/PNT18/presentation_f... (slides)Or if you prefer non-PDF:http://leapsecond.com/great2005/http://leapsecond.com/great2016a/−mehrdadn6yAmazing. They observe fractional frequency changes of around 4.1E-17. Thanks for sharing the links!−ta12345678906yCouldn't see that number in the info at the link above, is that from the full article?−mehrdadn6yYeah: "The two measurements consist of approximately 100,000 s of low-height data and 40,000 s of high-height data, and the clocks exhibit (Fig. 3) a fractional frequency change of (4.1 ± 1.6) × 10^−17."
Comments
Wait, seriously? Do you have a link??
Measuring the height of a mountain with a portable atomic clock (1000m accuracy) https://www.nature.com/articles/s41567-017-0042-3
NIST measuring speed differences < 10 m/s and height < 1 m with a pair of atomic clocks https://science.sciencemag.org/content/329/5999/1630.long
Tests of gravitational time dilation are also within the reach range of enthusiastic amateurs using second-hand atomic clocks:
Part 4 (starting pdf page 44) of http://web.stanford.edu/group/scpnt/pnt/PNT18/presentation_f... (slides)
Or if you prefer non-PDF:
http://leapsecond.com/great2005/
http://leapsecond.com/great2016a/
Amazing. They observe fractional frequency changes of around 4.1E-17. Thanks for sharing the links!
Couldn't see that number in the info at the link above, is that from the full article?
Yeah: "The two measurements consist of approximately 100,000 s of low-height data and 40,000 s of high-height data, and the clocks exhibit (Fig. 3) a fractional frequency change of (4.1 ± 1.6) × 10^−17."