04-19-2017, 11:34 PM
I hope Rob forgives me for something not really Hawaii related, but couldn't help myself.
"How not to make astronomy interesting to anyone else"
This is recent research about Keplerian disks. These are basically disks of gas and dust that are often seen around young stars. The disks typically obey the physical laws Kepler and Newton came up with and they're where planets form. Then it becomes much less interesting:
"In the project, the authors suppose that Keplerian flow breaks into a turbulent state at the Reynolds number not yet attained in the research. As turbulence cannot exist in the absence of growing perturbations of velocity and pressure, they consider in detail how large the growth factor of transiently growing perturbations can be. Generally, those perturbations arise in the form of spirals being unwound by the differential rotation of the bulk flow.
Viacheslav Zhuravlev says, "We've managed to show for the first time that such perturbations are able to sustain turbulence also at scales significantly exceeding the disc thickness. Additionally, we predict a value of the Reynolds number corresponding to transition to turbulence both in Keplerian and super-Keplerian flows."
The researchers have been solving the linearised Navier-Stokes equations both numerically and analytically. Moreover, for the first time in astrophysical scientific literature, they have employed a so-called variational approach in order to determine the optimal perturbations that demonstrate the highest possible growth of amplitude."
https://phys.org/news/2017-04-scientists...erian.html
I'm not certain, but I think what they are saying is that they may be coming up with an idea about how planets may form around young stars.
"How not to make astronomy interesting to anyone else"
This is recent research about Keplerian disks. These are basically disks of gas and dust that are often seen around young stars. The disks typically obey the physical laws Kepler and Newton came up with and they're where planets form. Then it becomes much less interesting:
"In the project, the authors suppose that Keplerian flow breaks into a turbulent state at the Reynolds number not yet attained in the research. As turbulence cannot exist in the absence of growing perturbations of velocity and pressure, they consider in detail how large the growth factor of transiently growing perturbations can be. Generally, those perturbations arise in the form of spirals being unwound by the differential rotation of the bulk flow.
Viacheslav Zhuravlev says, "We've managed to show for the first time that such perturbations are able to sustain turbulence also at scales significantly exceeding the disc thickness. Additionally, we predict a value of the Reynolds number corresponding to transition to turbulence both in Keplerian and super-Keplerian flows."
The researchers have been solving the linearised Navier-Stokes equations both numerically and analytically. Moreover, for the first time in astrophysical scientific literature, they have employed a so-called variational approach in order to determine the optimal perturbations that demonstrate the highest possible growth of amplitude."
https://phys.org/news/2017-04-scientists...erian.html
I'm not certain, but I think what they are saying is that they may be coming up with an idea about how planets may form around young stars.