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APOD: Orange Sun Oozing (2011 Nov 06)

Posted: Sun Nov 06, 2011 6:51 am
by APOD Robot
Image Orange Sun Oozing

Explanation: The Sun's surface keeps changing. The above movie shows how the Sun's surface oozes during a single hour. The Sun's photosphere has thousands of bumps called granules and usually a few dark depressions called sunspots. The above time-lapse movie centered on Sunspot 875 was taken in 2006 by the Vacuum Tower Telescope in the Canary Islands of Spain using adaptive optics to resolve details below 500 kilometers across. Each of the numerous granules is the size of an Earth continent, but much shorter lived. A granule slowly changes its shape over an hour, and can even completely disappear. Hot hydrogen gas rises in the bright center of a granule, and falls back into the Sun along a dark granule edge. The above movie and similar movies allows students and solar scientists to study how granules and sunspots evolve as well as how magnetic sunspot regions produce powerful solar flares. A few days ago, the largest sunspot group in recent years rotated into view.

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Re: APOD: Orange Sun Oozing (2011 Nov 06)

Posted: Sun Nov 06, 2011 9:13 am
by jimmy

Re: APOD: Orange Sun Oozing (2011 Nov 06)

Posted: Sun Nov 06, 2011 1:05 pm
by orin stepanek
Reminds me of this! :wink:
Click to view full size image

PRATTLE number

Posted: Sun Nov 06, 2011 2:35 pm
by neufer
------------------------------------------------------------------------------------
*PRATTLE*, n. Trifling or childish tattle; empty talk; loquacity on trivial subjects; prate; babble.
------------------------------------------------------------------------------------
__ Othello, The Moor of Venice Act 1, Scene 1

IAGO: unless the bookish theoric,
__ Wherein the toged consuls can propose
__ As masterly as he: mere *PRATTLE*, without practise,
__ Is all his soldiership.
------------------------------------------------------------------------------------
The *PRANDTL* number Pr is a dimensionless number; the ratio of momentum diffusivity (kinematic viscosity) to thermal diffusivity.
Image
http://en.wikipedia.org/wiki/Lorenz_attractor wrote: <<The Lorenz attractor, named for Edward N. Lorenz, is an example of a non-linear dynamic system corresponding to the long-term behavior of the Lorenz oscillator. The Lorenz oscillator is a 3-dimensional dynamical system that exhibits chaotic flow, noted for its lemniscate shape. The map shows how the state of a dynamical system (the three variables of a three-dimensional system) evolves over time in a complex, non-repeating pattern.

The attractor itself, and the equations from which it is derived, were introduced in 1963 by Edward Lorenz, who derived it from the simplified equations of convection rolls arising in the equations of the atmosphere.

In addition to its interest to the field of non-linear mathematics, the Lorenz model has important implications for climate and weather prediction. The model is an explicit statement that planetary and stellar atmospheres may exhibit a variety of quasi-periodic regimes that are, although fully deterministic, subject to abrupt and seemingly random change.

From a technical standpoint, the Lorenz oscillator is nonlinear, three-dimensional and deterministic. For a certain set of parameters, the system exhibits chaotic behavior and displays what is today called a strange attractor. The strange attractor in this case is a fractal of Hausdorff dimension between 2 and 3. Grassberger (1983) has estimated the Hausdorff dimension to be 2.06 ± 0.01 and the correlation dimension to be 2.05 ± 0.01.

The system also arises in simplified models for lasers (Haken 1975) and dynamos (Knobloch 1981).

The equations that govern the Lorenz oscillator are:
  • Image

    Image

    Image
where σ is called the Prandtl number and ρ is called the Rayleigh number. All σ, ρ, β > 0, but usually σ = 10, β = 8 / 3 and ρ is varied. The system exhibits chaotic behavior for ρ = 28 but displays knotted periodic orbits for other values of ρ. For example, with ρ = 99.96 it becomes a T(3,2) torus knot.>>
----------------------------------------------------
__ Troilus and Cressida Act 2, Scene 1

THERSITES: I shall sooner rail thee into wit and holiness: but,
__ I think, thy horse will sooner con an oration than
__ thou learn a prayer without book.
----------------------------------------------------
__ King Henry VI, Part i Act 3, Scene 1

GLOUCESTER: No, prelate; such is thy audacious wickedness,
__ Thy lewd, pestiferous and dissentious pranks,
__ As very infants *PRATTLE* of thy pride.
__ Thou Art a most pernicious usurer,
__ Forward by nature, enemy to peace;
__ Lascivious, wanton, more than well beseems
__ A man of thy profession and degree;
----------------------------------------------------
__ Measure for Measure Act 5, Scene 1

DUKE VINCENTIO: Silence that fellow: I would he had some cause
__ To *PRATTLE* for himself.
----------------------------------------------------
__ King Richard II Act 5, Scene 2

DUKE OF YORK: As in a theatre, the eyes of men,
__ After a well-graced actor leaves the stage,
__ Are idly bent on him that enters next,
__ Thinking his *PRATTLE* to be tedious;
----------------------------------------------------

Re: APOD: Orange Sun Oozing (2011 Nov 06)

Posted: Sun Nov 06, 2011 2:55 pm
by Beyond
neufer wrote:IAGO: unless the bookish theoric,
__ Wherein the toged consuls can propose
__ As masterly as he: mere *PRATTLE*, without practise,
__ Is all his soldiership.
Neufer, THOU Art Oozing with practise.^^

Re: APOD: Orange Sun Oozing (2011 Nov 06)

Posted: Sun Nov 06, 2011 3:34 pm
by biddie67
To the neufer ~~

Such a good man but who can not, although stone cold sober, think a simple straight line ...

3 cheers to this good ol' gipper !!!!

Re: APOD: Orange Sun Oozing (2011 Nov 06)

Posted: Sun Nov 06, 2011 5:16 pm
by Ann
I assume that the sunspots are somehow obeying the Lorenz equation.

Thanks, Art, I feel ever so slightly more enlightened now.

Ann

Re: APOD: Orange Sun Oozing (2011 Nov 06)

Posted: Sun Nov 06, 2011 5:39 pm
by ulao
Nice video of Sun but I want a copy of the picture of Super Kitten that I got on my desktop in its stead.

Re: APOD: Orange Sun Oozing (2011 Nov 06)

Posted: Sun Nov 06, 2011 5:57 pm
by neufer
Ann wrote:
I assume that the sunspots are somehow obeying the Lorenz equation.
Not the sunspots...the granules.

Ordered chaos (...much like the Starship Asterisk*).
Ann wrote:
Thanks, Art, I feel ever so slightly more enlightened now.
There'll be a pop quiz shortly.

Re: APOD: Orange Sun Oozing (2011 Nov 06)

Posted: Sun Nov 06, 2011 7:48 pm
by orin stepanek
APOD Robot wrote: and falls back into the Sun
ulao wrote:Nice video of Sun but I want a copy of the picture of Super Kitten that I got on my desktop in its stead.
It's a plane; it's a bird; it's Super Kitten! 8-)
Click to view full size image

Re: APOD: Orange Sun Oozing (2011 Nov 06)

Posted: Sun Nov 06, 2011 9:10 pm
by NoelC
My first thought was: I wonder how far these features have "oozed" in an hour. What's the scale of this video?

Betcha they're not really oozing all that slowly*, but rather blasting across the surface at unbelievable rates.

-Noel


*To me the term "ooze" implies "slowly". Thick liquid oozes. Water does not ooze over a waterfall.

Re: APOD: Orange Sun Oozing (2011 Nov 06)

Posted: Sun Nov 06, 2011 9:16 pm
by NoelC
Just as a SWAG, it seems to me we're talking about numbers in the vicinity of 10,000 to 100,000 miles/hour here.

-Noel

Re: APOD: Orange Sun Oozing (2011 Nov 06)

Posted: Sun Nov 06, 2011 10:31 pm
by Ulao
Thanks Orin