Month: September 2022

SPEAKING SPIDER. “We're beginning to perhaps be able to speak the language of a spider.Scientists at the Massachusetts Institute of Technology have turned spider webs into music -- creating an eerie soundtrack that could help them better understand how the arachnids spin their complex creations and even how they communicate.” https://lnkd.in/dzyYUP5 View in LinkedIn

FRAGMENT FROM NATURE continues and concludes this weekend on the wonderful article that leaps from jammed sand to black holes. It is rare to find such bold leaps and interesting connection of the dots. It is this spirit of raw enquiry which stimulates debate, opens vistas, and regardless of the eventual truth, contribute to the dialogue. Truth is slippery and gets overprinted with new data, but the process of enquiry is the Shackleton drive that opens new territory. View in LinkedIn

PUSHING THE ANALOGY. “Thus, θ(τ) < 0 for every τ may be proposed as the signal of jamming in this analogue gravity formulation of granular matter.” https://lnkd.in/dusKMKM View in LinkedIn

IMAGINATIVE CONNECTION. “Isotropic jamming would correspond clearly to a situation with spherical symmetry. In this case, with Tμν = 0, the vacuum Einstein equation reduces to Rμν = 0 which admits the Schwarzschild solution.” https://lnkd.in/dusKMKM View in LinkedIn

THE BLACK HOLE. “The length scale rS characterizing this solution is called the Schwarzschild radius; r = rS is identified with the event horizon, and represents the boundary between events connected to asymptopia and those that are confined to the region r ≤ rS - the black hole region.” https://lnkd.in/dusKMKM View in LinkedIn

FRAME BY FRAME. “The spatial symmetries of granular interactions are manifest in every frame of the gravity analogue.” https://lnkd.in/dusKMKM View in LinkedIn

BLACK HOLE FORMATION. “A more realistic situation for appearance of trapped surfaces is gravitational collapse. Here, the stress-energy tensor vanishes outside the boundary of the collapsing body (assumed spherical for simplicity).” https://lnkd.in/dusKMKM View in LinkedIn

GRANULAR SAND. “Granular media are known to exhibit a richer variety of density fluctuations under externally applied stress, especially a shear stress.” https://lnkd.in/dusKMKM View in LinkedIn

SHEAR STRESS. “Clearly, the shear stress has been applied on an already spontaneously jammed isotropic state, to show that anisotropic structure formation results because of this external stress perturbation. This implies that, in the gravity analogue as per the Rachaudhuri equation, θ(0) < 0, so that we have a convergent geodesic congruence.” https://lnkd.in/dusKMKM View in LinkedIn