6 comments

• Phill O

  May 10, 2016 at 5:54 pm

  The forefront of astrophysics should be solar dynamics. This is becoming quite important with the changes in the sun spot cycles that are being observed.
• Edward

  May 12, 2016 at 3:31 pm

  I worked, for a while, for a solar astrophysics group. They were working on understanding the sun. Sun spots and magnetic fields were important, but they were also watching the wave action on the sun’s surface after large masses followed field lines to crash back onto the surface. They believed that the surfacing of shock waves might help them determine the densities of the interior.

  The big mystery still seems to be how the corona can be so hot (1 million degrees) when the sun’s surface is so cool (ten thousand degrees) — relatively speaking. The latest that I heard is that magnetic reconnection, and the sudden acceleration of the ions caught in the magnetic fields, does not adequately explain the temperature difference.
  https://en.wikipedia.org/wiki/Magnetic_reconnection
• Max

  May 13, 2016 at 3:05 am

  I just checked Wikipedia, is says the Corona is at 1,000,000 to 2,000,000 kelvin.(1,700,000 Fahrenheit to 3,500,000°F )
  I have other books that say it ranges from 8 million to as high as 30,000,000°. Wikipedia also admits that they do not know why.

  In the late 90s, after the launching of the Soho satellite, one of the British scientists on the project printed a book called “our Manic Sun” (or “The Manic Sun”)
  I remember being so captivated by the new observations that would revolutionize the way we think of the sun that I went on the way back machine a few years later on my dial-up computer to listen again to the BBC broadcast of his interview. He was talking about electric arcs and micro flares, that were only in theory, now seen under high magnification.
  For years, Wikipedia would only mention it without explanation. Now it has an entire segment dedicated to nano flares. Here is a small example of what is catching on from old observations.

  “The theory of nanoflares then supposes that these events of magnetic reconnection, occurring at nearly the same time on small length-scales wherever in the corona, are very numerous, each providing an imperceptibly small fraction of the total energy required in a macroscopic event These nano flares might themselves resemble very tiny flares, close one to each other, both in time and in space, effectively heating the corona and underlying many ofl the phenomena of solar magnetic activity.”

  Shortly after this interview, I remember that announcement by NASA that satellite data would no longer be available directly to the public, but will pass through a third party first.
  I know they say there are good reasons for this, I’ve always thought it was to keep the truth from the public and to protect themselves. Also to sell potential profit making discoveries and to Funnel research papers to the proper universities as favors.
  As for the chromosphere, it is the source of the solar wind, heat, and light from the sun. The light spectra, when broken down, is nearly identical to lightning or / and electric arc through hydrogen gas. Must be just a coincidence….
• Wayne

  May 13, 2016 at 5:44 am

  Edward/Max:
  Interesting discussion!
  You might find this recent talk enlightening:
  “Surprises in solar physics from the point of view of Newton and Maxwell”
  presented by Dr. Phil Judge
  [High Altitude Observatory, National Center for Atmospheric Research]
  https://youtu.be/CF4f49SyDFY

  Academic talk, rather than a public lecture, and with lots of good (and current) info on magnetic fields & sunspots.
  (I can’t vouch for the Dr.’s academic/research standing, but he appears to be well-versed in his subject matter & with zero detectable political-bent or agenda other than science.)

  Tangent– are we studying any nearby Stars that do not rotate?? (differential rotation of our Sun appears to play havoc with the idealized-diagrams concerning magnetic-fields, dynamo-action, and heat-transport.)

  [Edward: “WAY COOL” working on solar astrophysics stuff!! And to repeat– most excellent commentary, on a wide range of topics the past few weeks. I’m ready to Vote for You, for any number of Office’s! or we can just appoint you Science Advisor to President Cruz in 2021.]
• Edward

  May 13, 2016 at 2:49 pm

  Max,
  I don’t know why NASA would filter their data. They are rather adamant that data taken on the ISS be made available after 5 years, giving the researching company a little time to get a jump on competitors.

  Wayne,
  Nice lecture.

  I don’t know about finding any non-rotating stars, though. I have not heard of any, and it seems unlikely that one would form without rotation. The problem with non-rotating stars is that there would have to be no net angular momentum in the cloud of gas that collects to make the star, and that seems unlikely, to me. This would also suggest that there would be no planets, as there would not be enough net angular momentum for the matter that would form them to avoid falling into the star.
• Wayne

  May 13, 2016 at 4:43 pm

  Edward:
  Thanks, ref non-rotating stars— like Unicorn-hunting eh!
  >It finally dawned on me, it was a solar-physic’s joke. (POOF, right over my head.)