PDA

View Full Version : Discussion: Solar Astronomers Getting Better ...



Fraser
2005-May-20, 07:36 PM
SUMMARY: Researchers have discovered that the structure of the Sun's lower atmosphere, or chromosphere, can be used to predict the speed and intensity of solar winds - the stream of electrified gas constantly blowing off the Sun. This was unexpected, because the solar wind comes from the corona, or outer layer, while the chromosphere is much deeper into the Sun. By learning how to predict the strength and speed of the solar wind, scientists will be able to protect electrical equipment, satellites and space explorers.


View full article (http://www.universetoday.com/am/publish/predicting_solar_wind.html)

What do you think about this story? Post your comments below.

om@umr.edu
2005-May-20, 09:04 PM
This is really great news, Fraser!

The original Southwest Research Institute news release refers to the surprisingly deep roots of the solar wind.

The lead author, Dr. Scott McIntosh, says "It's like discovering that the source of the river Nile is another 500 miles inland."

The solar wind (SW), and the magnetic fields that bring SW material up to the surface of the Sun, in the quiet solar wind as well as in solar eruptions, likely hold the key to our understanding of:

a.) the solar cycle,
b.) solar eruptions,
c.) the source of solar energy, and
d.) the internal workings of the Sun.

The solar wind is mostly Hydrogen. Each year the Sun discards 50,000,000,000,000 metric tons of SW Hydrogen in this manner.

Here are two key issues to be resolved:

1. Is SW Hydrogen a by-product of heat producing reactions inside the Sun ?

Antoine Lavoisier, the father of Chemistry, coined the name Hydrogen for the gas pouring from the top of a beaker when heat is produced as a metal like Zinc reacts with an acid like Sulfuric Acid:

Zinc + Sulfuric Acid -> Zinc Sulfate + Heat + Hydrogen

Heat from chemical reactions is too low to explain solar luminosity, but some nuclear reactions produce Heat + Hydrogen.

2. How deep are the magnetic fields that we see projecting through the solar surface in solar eruptions and in the 11-year solar cycle ?

Could they, for example, originate in the core of the Sun ?

Again, thanks for publishing news of this discovery in Universe Today. The paper is published in the 10 May 2005 issue of Ap. J.

With kind regards,

Oliver
http://www.umr.edu/~om

om@umr.edu
2005-May-22, 01:11 PM
There was a related press release from the Max Planck Society concerning the "Magnetic Nature of Solar Wind Sources" (http://www.mpg.de/english/illustrationsDocumentation/documentation/pressReleases/2005/pressRelease20050421/index.html) on April 22, 2005.

This research by Professor Chuanyi Tu et al. was more concerned with the fast solar wind pouring from coronal regions with open magnetic field lines, the so called coronal holes.

Closed magnetic fields at the solar surface generate the slower, more dense solar wind, traveling at about 750,000 miles per hour.

Open magnetic fields at the solar surface produce coronal holes where faster, less dense solar wind departs the solar surface at speeds up to 1,500,000 miles per hour.

The news release from the Southwest Research Institute (SWRI),
"Deep Roots of the Solar Wind" (http://www.swri.org/9what/releases/2005/Solar.htm), notes that there are permanent coronal holes at the Sun's poles, in addition to those that appear sporadically closer to the Sun's equator.

Measurements with mass spectrometers have accumulated a backlog of data over the past 2-3 decades showing that lightweight isotopes of elements are more abundant in the slow solar wind (ssw) than in the fast solar wind (fsw), i.e. mass fractionation is more severe in (ssw):

(Ne-20/Ne-22)-ssw > (Ne-20/Ne-22)-fsw

(Mg-24/Mg-26)-ssw > (Mg-24/Mg-26)-fsw

(Ar-36/Ar-38)-ssw > (Ar-36/Ar-38)-fsw

The SWRI news release has this excellent "Image of Magnetic Fields at the Solar Surface" (http://www.swri.org/press/2005/solarwind.htm).

Material ejected slowly along trajectories represented in this image by the short red arrows is more severely mass fractionated than material ejected rapidly along trajectories represented by the long red arrows.

Secrets of the
a.) solar cycle,
b.) solar eruptions,
c.) solar luminosity, and
d.) internal workings of the Sun
may be recorded in these findings.

With kind regards,

Oliver
http://www.umr.edu/~om

suntrack2
2005-May-22, 04:16 PM
the image is much better and never seen before, are these been call after solar cyclones and their directions?

om@umr.edu
2005-May-22, 05:20 PM
Originally posted by suntrack2@May 22 2005, 04:16 PM
the image is much better and never seen before, are these been call after solar cyclones and their directions?
Hi, Suntrack.

Lengths of the red arrows show the relative speeds of solar wind ejecta leaving the solar surface.

Short red arrows represent slower moving Solar Wind (slowSW) ejecta coming from regions with closed magnetic fields. Lightweight atoms are more enriched in this slow moving solar wind material, i.e., it is more mass-fractionated.

Long red arrows represent faster moving Solar Wind (fastSW) ejecta coming from open magnetic fields in coronal holes. Lightweight atoms are less enriched in this fast moving solar wind material, i.e., it is less mass-fractionated.

These measurements contain intriguing information about the internal composition of the Sun.

(Ne-20/Ne-22)-(slowSW) > (Ne-20/Ne-22)-(fastSW)
(Mg-24/Mg26)-(slowSW) > (Mg-24/Mg26)-(fastSW)
(Ar-26/Ar-38)-(slowSW) > (Ar-26/Ar-38)-(fastSW)

You may be able to see the open and closed magnetic fields better in this drawing from the 22 April 2005 issue of Science.

Open and Closed Magnetic Fields at the Solar Surface (http://www.universetoday.com/am/uploads/2005-0422wind-full.jpg)

With kind regards,

Oliver
http://www.umr.edu/~om

lswinford
2005-May-23, 05:26 PM
Well outside my current memories, someone described an idea that the sun may have zones, spots, or regions of fusion activity. It was described as a jet engine with its combustion 'pots'. Others, however, using a simple hydrogen model, conjectured that all the fusion was in the core and the energy simply took a century or two rise fairly uniform to the surface where the result was to boiled off the surface material as ejecta and solar wind. Forgive me if I ignite an old conflict, but one almost might see that the irregularities lend credence to more 'shallow' and diverse fusion reactions than for deep ones.

antoniseb
2005-May-23, 07:33 PM
Originally posted by lswinford@May 23 2005, 05:26 PM
one almost might see that the irregularities lend credence to more 'shallow' and diverse fusion reactions than for deep ones.
No one can make a good physical case for Solar fusion happening in any meangful quantity outside the core of the Sun. The temperature and pressure are simply too low anywhere else.

Such great quantities of energy roiling out from the center are apt to cause some irregularities, perhaps similar to the irregularities in the surface of a pot of boiling water.

VanderL
2005-May-23, 07:51 PM
No one can make a good physical case for Solar fusion happening in any meangful quantity outside the core of the Sun. The temperature and pressure are simply too low anywhere else.

As long as you don't expect fusion to be a power source it can even be accomplished at room temperature (http://www.nature.com/news/2005/050425/full/050425-3.html), alas you would need another way to power the Sun, but all it takes to get fusion to happen at the solar surface is a strong electric field.

Cheers.

Nereid
2005-May-23, 08:54 PM
all it takes to get fusion to happen at the solar surface is a strong electric field
That may be so.

However, to get fusion to happen at a [within ~0.1%] constant rate, for several billion years on end [variation ~<10% over this time, OOM], you need considerably more than just &#39;a strong electric field&#39;.

Just on the energetics (total output, OOM, in joules), what must the (DC) current be to give the Sun&#39;s (energy) output for (say) 4 billion years?

om@umr.edu
2005-May-23, 11:39 PM
I know its unpopular to say it here, but

Many, many measurements show that nuclear reactions have been making isotopes of Li, Be and N near the surface of the Sun over geologic time.

I gave references to the original papers in the Iron Sun thread.

With kind regards,

Oliver
http://www.umr.edu/~om

VanderL
2005-May-24, 12:21 PM
all it takes to get fusion to happen at the solar surface is a strong electric field


That may be so.

However, to get fusion to happen at a [within ~0.1%] constant rate, for several billion years on end [variation ~<10% over this time, OOM], you need considerably more than just &#39;a strong electric field&#39;.

If the Sun isn&#39;t powered by fusion, it doesn&#39;t need to be constant over billions of years.


[Just on the energetics (total output, OOM, in joules), what must the (DC) current be to give the Sun&#39;s (energy) output for (say) 4 billion years?

The same as it is now and then for 4 billion years?

Cheers.

om@umr.edu
2005-May-24, 12:44 PM
Originally posted by VanderL@May 23 2005, 07:51 PM
. . . all it takes to get fusion to happen at the solar surface is a strong electric field.

How strong?

How does it compare to the electric component of the magnetic fields seen at the solar surface?

With kind regards,

Oliver
http://www.umr.edu/~om

antoniseb
2005-May-24, 02:15 PM
Originally posted by om@umr.edu@May 23 2005, 11:39 PM
Many, many measurements show that nuclear reactions have been making isotopes of Li, Be and N near the surface of the Sun over geologic time.
Yes, they have, but the process creating these isotopes was neutron capture, and the quantity generated is microscopic compared to what would be needed to be counted as a significant source of energy for the Sun. This is completely independent of what the main energy source is (fusion as mainstream scientists, and almost everyone else believe, or anything else, as our alternative friends consider).

VanderL
2005-May-24, 08:31 PM
Oliver:


(VanderL @ May 23 2005, 07:51 PM)
. . . all it takes to get fusion to happen at the solar surface is a strong electric field.

How strong?

How does it compare to the electric component of the magnetic fields seen at the solar surface?

I can only answer the question by looking at the strength of the electric field in the crystal (article I linked to earlier).

"The electric field at the end of the tungsten probe tip is so high (25 V/nm) that it strips electrons
from nearby deuterium atoms."

I&#39;m not sure if these strengths can be found at the solar surface, but of course conditions there are very different, and it doesn&#39;t necessarily involve hydrogen/deuterium atoms as is expected in the solar core.

Cheers.

Nereid
2005-May-25, 12:53 AM
If the Sun isn&#39;t powered by fusion, it doesn&#39;t need to be constant over billions of years.
Hmm ... then we would need to &#39;unexplain&#39; results obtained from geology, both terrestrial and lunar (and possibly martian), as well as what the asteroids and meteorites have to say about the Sun&#39;s constancy.

[Just on the energetics (total output, OOM, in joules), what must the (DC) current be to give the Sun&#39;s (energy) output for (say) 4 billion years?The same as it is now and then for 4 billion years?
And that number is .... ?

Nereid
2005-May-25, 12:57 AM
Originally posted by VanderL@May 24 2005, 08:31 PM

Oliver:


(VanderL @ May 23 2005, 07:51 PM)
. . . all it takes to get fusion to happen at the solar surface is a strong electric field.

How strong?

How does it compare to the electric component of the magnetic fields seen at the solar surface?

I can only answer the question by looking at the strength of the electric field in the crystal (article I linked to earlier).

"The electric field at the end of the tungsten probe tip is so high (25 V/nm) that it strips electrons
from nearby deuterium atoms."

I&#39;m not sure if these strengths can be found at the solar surface, but of course conditions there are very different, and it doesn&#39;t necessarily involve hydrogen/deuterium atoms as is expected in the solar core.

Cheers.
Well, I guess that rules out electric currents of that magnitude, does it not?

High resolution spectoscopy of the Sun gives clear estimates of the (local) electric and magnetic fields (via the Stark and Zeeman effects).

Maybe we should move all these posts to the EU thread?

Duane
2005-May-25, 01:40 AM
VanderL and Doc O, you are both aware of how we here at UT look at discussions of alternative theories here in the Story forum. End this now, as any further posts on the issues of EU ot IS will be deleted without explanation.