Fluid dynamics is an ongoing topic with many surprising aspects. One of these is the Leidenfrost effect. It comes from the name of the German scientist who described it for the first time: Johann Gottlob Leidenfrost. It occurs when a liquid, in contact with an object significantly warmer than the liquid's boiling temperature, produces a vapor layer which surrounds the object and thus isolates it from the direct thermal exchanges with the object.
Like many fluid dynamic aspects, this phenomenon is poorly understood and yet it has important implications for the thermodynamics of evaporation – and could also have a range of applications in water cooling microchips or moving chemical molecules.
In Russia, Researcher Oleg A. Kabov from Institute of Thermophysics and his team have also been studying this interesting effect . In particular, they looked at levitating droplets of liquid condensate and their organization into ordered arrays.
By: BRANDON A. WEBER
There is a new radio telescope up and running based in Karoo, South Africa. The MeerKAT (Karoo Array Telescope), as it’s named, operated by the South African Radio Astronomy Observatory, is already producing brilliant images of the super massive black hole that is at our galaxy’s center, 25,000 light years away.
That center is obscured from view when using traditional methods of observation; it’s behind the constellation Sagittarius, where clouds of gas and dust hide it from view. However, MeerKAT's radio wavelengths penetrate the obscuring dust and open a window into this distinctive region and its black hole.
Taken by MeerKAT, this shot shows a 1,000 x 500 light-year area of the center of the Milky Way. The brighter the spot, the more intense the radio signal. Image by Square Kilometer Array, South Africa.
The “filaments” that you see in the image above are not yet fully understood, after being first...
The neurocomputational paradigm is the predominant model of explaining cognitive functioning of the brain – the generation of subjective qualia comprising a state of awareness, phenomenological experiences, as well as learning and memory. As indicated by the name, the neurocomputational model is based on the theory that the brain is analogous to a computer, and therefore mental activity arises from computational operations of neurons, specifically the synaptic connections among them.
This standard model of cognitive biology has faced significant challenges in constructing a coherent and viable explanation by which consciousness, particularly agents with free will, would arise from computational behavior. Leading some, one of the most notable of which is physicist Dr. Roger Penrose, to posit that some “intrinsic” behavior of neuronal activity is operating beyond a...
When a massive astrophysical object, such as a boson star or black hole, rotates, it can cause the surrounding spacetime to rotate along with it due to the effect of frame dragging. In a new paper, physicists have shown that a particle with just the right properties may stand perfectly still in a rotating spacetime if it occupies a "static orbit"—a ring of points located a critical distance from the center of the rotating spacetime.
The physicists, Lucas G. Collodel, Burkhard Kleihaus, and Jutta Kunz, at the University of Oldenburg in Germany, have published a paper in which they propose the existence of static orbits in rotating spacetimes in a recent issue of Physical Review Letters.
"Our work presents with extreme simplicity a long-ignored feature of certain spacetimes that is quite counterintuitive," Collodel told Phys.org. "General relativity has been around for a bit more than a hundred years now and it never ceases to amaze, and exploring...