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A comment on Large crack in East African Rift is evidence of continent splitting in two. Parent comment

Re:Large crack in East African Rift is evidence of continent... by marshray on Wednesday April 04, 2018 @02:51PM (#16757718)
I love this idea, but the speed of separation is just a couple of cm per year. Unless the cable had absolutely no temperature expansion, weather changes would probably have a far greater effect on cable length than the imperceptible drift of the endpoints (which suggests another crazy idea interesting in its own right).

One might build this deep underground to minimize temperature changes and provide the hard rock anchor points necessary for the forces involved.

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Re:Large crack in East African Rift is evidence of continent... by sannee on Wednesday April 04, 2018 @04:16PM (#16758591)
> weather changes would probably have a far greater effect on cable length than the imperceptible drift of the endpoints (which suggests another crazy idea interesting in its own right)

There is a clock running for over a century based on a similar idea: https://en.wikipedia.org/wiki/Beverly_Clock

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Re:Large crack in East African Rift is evidence of continent... by userbinator on Wednesday April 04, 2018 @11:07PM (#16761463)
...and the commercial version, which is still in production:

https://en.wikipedia.org/wiki/Atmos_clock

Not cheap (few k$), but not as expensive as some other high-end timepieces either.

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Re:Large crack in East African Rift is evidence of continent... by NegativeLatency on Wednesday April 04, 2018 @03:46PM (#16758286)
Go deep enough and you might as well just build a geothermal power plant.
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Re:Large crack in East African Rift is evidence of continent... by theandrewbailey on Wednesday April 04, 2018 @04:33PM (#16758755)
Kenya is way ahead of you:

https://www.nytimes.com/2018/02/23/business/geothermal-energ...

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Re:Large crack in East African Rift is evidence of continent... by nojvek on Thursday April 05, 2018 @08:47PM (#16770087)
Kenya generates 47% of power from geothermal and 35% from hydro. For a third world country, it’s quite greener than most developed nations. https://mobile.nytimes.com/2018/02/23/business/geothermal-en...

I do hope Kenya gets a electric car boom, because all of it’s fuel is imported. Solar + other methods could power the whole economy with relative ease. Being on equator means plenty of sun throughout the year.

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Re:Large crack in East African Rift is evidence of continent... by deadmetheny on Wednesday April 04, 2018 @03:52PM (#16758366)
Which would have the side effect of actually generating power!
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Re:Large crack in East African Rift is evidence of continent... by avz on Wednesday April 04, 2018 @04:22PM (#16758644)
> Unless the cable had absolutely no temperature expansion...

One might be able to get a composite with very close to zero thermal expansion coefficient by linking stages made of materials with positive and negative [1] coefficients.

[1] https://en.wikipedia.org/wiki/Negative_thermal_expansion

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Re:Large crack in East African Rift is evidence of continent... by jmharvey on Thursday April 05, 2018 @12:44AM (#16761837)
You don't even need to use exotic materials with negative thermal expansion: instead, you can use a combination of materials with different coefficients of thermal expansion pointed in opposite directions. This was one of the innovations that John Harrison made that allowed him to make precision timepieces.

https://en.wikipedia.org/wiki/Gridiron_pendulum

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Re:Large crack in East African Rift is evidence of continent... by z3t4 on Thursday April 05, 2018 @04:26AM (#16762942)
You could use a couple of anchors so that when it only moves 1mm the end attached to the gear would move several meters. Where the gear is really huge which makes the small gear spin faster. But it might still be too slow.
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