3.10.2006

Physics graphics


At first, I thought Physics News Graphics was a joke because of the text that accompanies this cool image:

New experiments and simulations show that large-scale fluid circulations drain energy from smaller-scale vortices to sustain themselves, akin to a hostile takeover of smaller corporations. The figure shows a visualized flow from a laboratory experiment of a thin salt-water layer driven by magnetic forces. One can see vortex structures on a range of scales.

But if you look at the other images, you'll see that the other text is serious, such as this:


Sketch of an acoustic lens based on a two-dimensional sonic crystal and a map of the resulting sound level (in dB). The sketch is drawn to scale. The lens-like sample measure 1.2 m of width. In this experiment, the researchers use a sonic crystal consisting of a triangular lattice of 4-cm-diameter cylinders, the pitch being 6.35 cm. The sound pressure map
has been taken at a frequency of 1700 Hz, which is well below the first acoustic gap that starts at 2300 Hz.

So I'm assuming the site is serious. BTW--I have no idea what that means, or much else on the site. Mahndisa probably understands, since I found out about it from her. But visit the site--you'll be looking at the images all day, like this one:



Scary!

3 comments:

Mahndisa S. Rigmaiden said...

03 10 06

Hey MJ: hahahahahha I am so happy you have posted these images. The picture that sort of looks like a Van Gough painting is called a contour map. -Well in a general sense. It maps three dimensional flows onto a two dimensional surface, much like weather maps that you have seen on the news. The concept is pretty much the same. And the color differences show various properties of the vortices, so it is a serious pic!

The pic you have below is of the Sandia Z pinch device. What you are seeing is the machine discharging which is insane. Basically, it has to hold a bunch of charge that it uses to create electrical energy in the form of a voltage. the voltage is like 20Million VOLTS too! So whenever there is voltage, there is also current and the current is the flow of the electrical energy-more accurately a flow of charge carriers (e.g. electrons). That picture shows a device that exists nowhere else in the world! They were able to generate a temperature hotter than a SUN in that thing. Yeah it is pretty but scares me to high heaven!!!

Regarding frequencies and lattices etc. Well a fair amount of the elements on the periodic table are arranged in lattice structures. For the simple case, imagine an atom in the center of a line and to his left he has another atom, and to his right he has another atom. Both companions are equal distances away from the center atom. This is called a one dimensional chain or lattice. In two dimensions, imagine a square with atoms on the corners of each square. This is a simple square lattice. Certain lattices are objects that has symmetries with respect to rotation angles too. These are called Bravais lattices and Silicon, Diamond, Table Salt and a whole host of other elements and compounds have Bravais lattice structures.

This means that if I have a Bravais lattice, if I rotate it through a specific angle, it will look the same as it did BEFORE I rotated it.

Next thing, vibrations through a lattice occur at various frequencies and at low temperatures, there is a special frequency called the Debye frequency that contributes to the specific heat of the object. The specific heat is the amount of energy required to raise the temperature of an object by one degree.

Okay, I hope I haven't rambled too much. I always pleases me when someone is remotely curious about physics!

Mahndisa S. Rigmaiden said...

03 10 06

And for a better and more precise explanation of this stuff, check out this link:)

mj said...

Thanks for the explanation--I actually understand it. But the whole physics thing is beyond me.

I agree that the first pic looks like a Van Gogh. But what made me think it was fake was the description of it: "scale vortices to sustain themselves, akin to a hostile takeover of smaller corporations." I thought it was some kind of societal commentary.