Our land moves like the interest rate curve (PHYS 6/5/2010)

Progress in Physics World: June 4 2010

Observations of Random Walk of the Ground in Space and Time Vladimir Shiltsev Phys. Rev. Lett. (to be published) "arXiv:0905.4194v1 (2009).

Our land is moving everyday under the affection of earthquake, weather change, moon gravity and even human activity. However, there exists one magic component of factor, random walk, which is discovered by Vladimir Shiltsev. With the usage of the micron-scale moving detection sensors in Fermi Lab, Vladimir have found that the variance <(ΔD)^2> ~ ΔT * D as the distance is D and ΔT is the time interval. Usually the normal random walk has only <(ΔD)^2> ~ ΔT. In this case, the variance behaves like one kind of interest rate model which is called as CIR model where dr_t= alpha(t,r_t)dt+sigma*sqrt(r_t)dW_t if alpha(t,r_t) can be neglected. The reason for this random motion is still a mystery. Shiltsev argue that it might come from the fractal nature of the ground as the ground can be regarded as a collection of blocks that vary over a wide range of sizes.

Comment: This is a very interesting finding. Our ground is moving randomly! Because the ΔT * D "law" here, it also tells us the extra information that this random walk has well organized origin, otherwise it will not proportional to D!