3 ms·
A portable vacuum chamber. Pretty cool. So unlike a pressure altimeter, this could also work in space. And unlike a radar altimeter, you don't need a direct lin
by programmarchy 9y ago
A portable vacuum chamber. Pretty cool. So unlike a pressure altimeter, this could also work in space. And unlike a radar altimeter, you don't need a direct line of sight to the surface.
Although seems like the measurement could also be distorted by large masses like the moon...
- deleted 9y ago[deleted]
- mikeash 9y agoUnfortunately, you still need some communication with the outside world. To the local observer, the clock will run at the same rate no matter where you are. Only distant clocks will change.
- 7952 9y agoI wonder if you could measure the difference between two clocks on the same craft at a distance from one another. The strength of gravity follows the inverse square law so presumably the difference in time between the two points will change also.
- mikeash 9y agoThat should work, and give you the local gravitational gradient, which would correspond to the altitude. You might want four arranged in a tetrahedron so you don’t need to orient them.