Tuesday, May 10, 2022

Black hole Annoucements on May 12th

Garching bei München, European Southern Observatory, see ESO Media Advisory (15:00 CEST) - Live streaming at ESO Website and ESO YouTube Channel

Mexico City, CONACyT, see CONACyT Media Advisory (08:00 CDT) - Live streaming at CONACyT YouTube Channel

Santiago de Chile, Joint ALMA Observatory, see ALMA Media Advisory (09:00 CLT)

Shanghai, Shanghai Astronomical Observatory, see Shanghai Astronomical Observatory Media Advisory (21:00 CST)

Taipei, Academia Sinica Institute for Astronomy and Astrophysics (21:00 CST), see YouTube Live Streaming.

Tokyo, National Astronomical Observatory of Japan (22:00 JST), see YouTube Live Streaming.

Washington D.C.,  National Press Club, see National Science Foundation Media Advisory (09:00 EDT) - Live streaming at NSF Webpage and NSF Facebook

Madrid (15:00 CEST, see CSIC YouTube streaming)

South Korea (22:00 KST, see YouTube Live Streaming

How to Understand the Black Hole Image

Saturday, December 05, 2020

The Sound of the Perfect Fluid


 The sound of the perfect fluid


Perfect Fluid

Perfect fluid

From Wikipedia, the free encyclopedia
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The stress–energy tensor of a perfect fluid contains only the diagonal components.

In physics, a perfect fluid is a fluid that can be completely characterized by its rest frame mass density and isotropic pressure p.

Real fluids are "sticky" and contain (and conduct) heat. Perfect fluids are idealized models in which these possibilities are neglected. Specifically, perfect fluids have no shear stresses, viscosity, or heat conduction.

In space-positive metric signature tensor notation, the stress–energy tensor of a perfect fluid can be written in the form

where U is the 4-velocity vector field of the fluid and where is the metric tensor of Minkowski spacetime.

In time-positive metric signature tensor notation, the stress–energy tensor of a perfect fluid can be written in the form

where U is the 4-velocity of the fluid and where is the metric tensor of Minkowski spacetime.

This takes on a particularly simple form in the rest frame

where is the energy density and is the pressure of the fluid.

Perfect fluids admit a Lagrangian formulation, which allows the techniques used in field theory, in particular, quantization, to be applied to fluids. This formulation can be generalized, but unfortunately, heat conduction and anisotropic stresses cannot be treated in these generalized formulations.[why?]

Perfect fluids are used in general relativity to model idealized distributions of matter, such as the interior of a star or an isotropic universe. In the latter case, the equation of state of the perfect fluid may be used in Friedmann–Lemaître–Robertson–Walker equations to describe the evolution of the universe.

In general relativity, the expression for the stress–energy tensor of a perfect fluid is written as

where U is the 4-velocity vector field of the fluid and where is the metric, written with a space-positive signature.

See also


External links

Monday, November 23, 2020

Solar Panel Revolution in the Wind?

           By AleSpa - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=29290121


 I am encouraged by some research that is currently going on that is improving the efficiency of solar panels up and coming. This encouragement is based on designs I have seen in corollary manufacturing processes that could created a whole new industry.

It is a whole new research path that could greatly improve the energy retention otherwise seemingly at a standstill,  although these manufacturing processes for solar panels are currently inexpensive.

I have been pondering these ideas for sometime now and since the move to electrics for transportation is now more important then ever as I open the door to the studious and bright innovators who wonder about these potentials.

New solar panel design could increase efficiency by 125%

 Dr. Christian Schuster, researcher from the Department of Physics, told The Week news “We found a simple trick for boosting the absorption of slim solar cells. Our investigations show that our idea actually rivals the absorption enhancement of more sophisticated designs, while also absorbing more light deep in the plane and less light near the surface structure itself. Our design rule meets all relevant aspects of light trapping for solar cells, clearing the way for simple, practical, and yet outstanding diffractive structures, with a potential impact beyond photonic applications.” He added, “This design offers potential to further integrate solar cells into thinner, flexible materials and therefore create more opportunity to use solar power in more products.”



 See also: Frogs, Foam and Fuel: UC Researchers Convert Solar Energy to Sugars