09 April, 2012

A-Z Blogging Challenge: Helioseismology

P mode waves. Public domain image. SOURCE.
Helioseismology is the study of wave oscillations in the Sun. The word comes from the Greek helios, which means "Sun" or "light"; seismos which is Greek for "tremor"; and logos, for "reasoning" or "discourse".

Helioseismology is used to determine the inner structure of the Sun. The aforementioned wave oscillations are generated by convection, which is when cooler matter (in the case of stars, gas) moves downwards and the hottest matter moves upwards. The waves become visible because of the movement of gases, which appear as shifts of light along the spectrum (a process called redshift).

There are three types of waves: acoustic waves (which generate p modes), gravity waves (g modes), and surface gravity waves (f modes). The length of a wave oscillation is around five minutes, and modes have lifetimes from hours to months. These waves "resonate" in the Sun due to increases in the speed of sound, which then cause the wave to be reflected back toward the surface. The back-and-forth behavior creates what are called "standing waves".

By monitoring the waves, processes such as nuclear energy generation, energy flows, magnetic fields, and particle acceleration can be observed, and theories of stellar structure and evolution ("solar models") can be tested. Furthermore, helioseismology can show the temperature, density, composition, and motion in the interior of the Sun.

The Sun, seen in UV light. Public domain image. SOURCE.
Notable Helioseismologist/Heliophysicist:

Ilia Iankov Roussev

Ilia Roussev got a Master's Degree in Physics and Astronomy from Sofia University, Bulgaria, in 1995. In 1999 he studied solar events in Belfast, Northern Ireland at the Armagh Observatory. In 2001, he completed Ph.D. studies in Solar Physics and became a Research Fellow at the Center for Space Environment Modeling at the University of Michigan. He is currently a Associate Astronomer at the Institute for Astronomy in Hawaii, and a member of the American Geophysical Union, the Committee on Space Research, and the American Astronomical Society.

His research has included the solar atmosphere, solar magnetic fields, and waves and turbulence in space plasma.

Video of Ilia Roussev explaining helioseismology:





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Sources:
http://ast.phys.au.dk/helio_outreach/english/engHA0.html
http://c2h2.ifa.hawaii.edu/Pages/people.php
http://gong.nso.edu/info/helioseismology.html
http://www.ifa.hawaii.edu/users/iroussev/
http://physics1.usc.edu/solar/project.html
http://soi.stanford.edu/results/heliowhat.html
http://solarscience.msfc.nasa.gov/Helioseismology.shtml
http://www.stat.berkeley.edu/~stark/Seminars/Aaas/helio.htm

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Do you think we'll ever control energy from the Sun?

And since it's been a week after the start of the A-Z Challenge . . . are you getting tired of all the science yet?


-----The Golden Eagle

33 comments:

Old Kitty said...

Loved this clip esp the "aaahhhhhhhhhhh" (ping/lightbulb/penny drop) moment! when the Prof explained what Heliosiesmology is! LOL! take care
x

Bob Scotney said...

An interesting topic but the video was disappointing.

Nick Wilford said...

The sun is certainly a fascinating entity. You must have put a whole lot of research into these posts!

shelly said...

Dear Golden:

I love science stuff when it comes to the topics you've chosen so far. Space is a wonder and for some reason when in trouble we look upward for God like our anscestors did.

Shelly
http://secondhandshoesnovel.blogspot.com/

Kimberlee Turley said...

I was just thinking you'd need some incredible type of filter to look at the sun and notice these patterns. The UV image is incredible.

running4him said...

Hey, great blog!! Nice set up and pictures!! Keep up the good work!! You are invited to check out or follow my blog anytime!!! Have a great day!!

The Golden Eagle said...

Old Kitty: Glad you liked the clip!

Bob: I was just glad to find a video that anything to do with helioseismology. There aren't really any big names in the field, like there is for, say, physics. :P

Nick: I tried to do that! Didn't want to get something wrong, of course.

Shelly: I'm glad you've enjoyed the topics I've written about!

Kimberlee: I knew I had to post that one when I saw it. :)

Running4him: Thank you for coming by The Eagle's Aerial Perspective!

Jack said...

I'm reading through many of the A-Z challenge blogs and yours, by far, has been the most interesting one! Kudos! :)

Murees Dupé said...

Wow! This is really a great piece of information. I can always trust in you to deliver the good stuff. Thank you for teaching me something new. The sun is definitely very powerful and would be a great energy source.

S. L. Hennessy said...

I always wondered how we know anything about the sun, being as we can't exactly go up and take a few measurements. This makes more sense haha. Great post!

Susan Gourley/Kelley said...

Not even a little tired of the science. I wish we would do with the energy we get from the sun now. When we will have an affordable means to collect solar energy/

Clarissa Draper said...

I don't think we'll ever find a way other than solar powered things we have now but what do I know. We would be smart to harness the sun.

Heather said...

Definitely not tired of all the science, I love it! I always feel smarter after reading these posts. ;) I think some day we might learn how to harness the sun's energy.

Erin M. Hartshorn said...

I think there are a lot of interesting applications of solar energy, including recent attempts at collecting it in batteries to use as power during the night. I'm also very impressed with all that NASA does with solar energy to power vehicles, although I'd still like to see more solar sails.

As for helioseismology, I've never heard this term before. Thanks for educating me!

Erin

Pat Hatt said...

I'm sure if we don't blow ourselves up one day we may control the energy from the sun or at least some portion of it.

Belle said...

I never get tired of science. I learned a lot here today.

Carrie Butler said...

I love these posts! I feel like I'm sitting in the back of a class taught by Professor Eagle. ;)

Nicki Elson said...

I'm so happy there are people out there to figure these things out. If it were let up to me, I'd probably still be operating under the assumption the world is flat.

DeniseCovey_L_Aussie said...

Hi Golden. If we ever could harness the energy from the sun, our energy problems would be solved.

Denise

Jemi Fraser said...

I don't know if we could ever have the technology to control such a massive entity! And we could never tire ofyour science :)

Leon Kennedy said...

cool stuff, and topical with the recent coronal mass ejections we had earlier this year

Theresa Milstein said...

The UV light sun picture is amazing. It's hard to believe we could ever harness the sun's energy. But then again, there was a time when people didn't believe there'd ever be a flying car.

Emily R. King said...

I find this fascinating. I wonder what scientists will be able to do in twenty-five years. Amazing!

Jaye Robin Brown said...

Okay - you win. Today's science is WAY over my head.

Jay Noel said...

Wow. Fascinating.

I remember when the media was all abuzz about the solar flares. Turns out it wasn't as bad as they thought, but the "Northern Lights" show was pretty amazing.

Peggy Eddleman said...

Wow! Interesting! I was reading a book about the parts of the sun with some fourth graders the other day, and I was thinking, but HOW do they know this? Eagle to the rescue.

Rob and Lisa said...

What an interesting theme for the a-z challenge. Good luck.

Lisa
http://livethemoment09.blogspot.com

Duncan D. Horne - the Kuantan blogger said...

You have chosen a really intriguing theme for your challenge and I'm not at all getting tired of it! It's all very simply explained too :)

This is me, Duncan D. Horne, visiting you from the A-Z challenge, wishing you all the best throughout April and beyond.

Duncan In Kuantan

Paul Tobin said...

Fascinating stuff, I am learning a lot from this challenge.

Hilary Melton-Butcher said...

Hi Golden .. no not tired at all of your science.

This is fascinating .. I don't think for a while we'll be able to control the sun's energy or harness it - who knows in the future .. we are learning lots very quickly.

Interesting that Ilia came out of Bulgaria ..

Cheers Hilary

The Golden Eagle said...

Jack: Thank you! :)

Murees: You're welcome. And the sun certainly would be!

S. L.: Thanks!

Susan: Well, that's good to hear. I've still got plenty of science posts to come. :)

Good question.

Clarissa: We would.

Heather: Awesome!

It would be interesting if we did.

Erin: I recently read a book that incorporated solar sails--The Last Theorem by Frederik Pohl and Arthur C. Clarke. It was fascinating.

You're welocme!

Pat: Yup. Hopefully, we won't go through the "blowing up" part of it, though. :P

Belle: Great. :)

Carrie: I'm glad you like them!

Nicki: From the perspective of someone on the ground, it seems awfully unlikely that the world is anything but.

Denise: Probably!

Jemi: It would certainly be a dangerous operation.

Leon: I heard about those--wasn't there a lot of talk about disruption of communications?

Theresa: We're still a bit far from that, though. :P Planes, yes; but small things individuals with relatively little training can fly don't really exist. (Just so far as I know, of course.)

Emily: It's interesting to think about!

Jaye: Er, I had hoped to make the subject accessible for readers . . .

Jay: I really want to see Aurora Borealis someday. There are so many gorgeous images of it.

Peggy: Glad I could explain something you'd been wondering about. :)

Lisa: Thank you!

Duncan: Thanks--and I'm glad you think it's simply explained!

Paul: Excellent. :)

Hilary: Most of the scientists I found through Google searches, so some are/were fairly random choices. He was actually the only person who really came up in relation to helioseismology.

Jamie Gibbs said...

Sounds intense - I'd just assumed the inside of the sun was "hot stuff" and "more hot stuff". Thanks for the ingo :)


Jamie
Fellow A-Z Bloggy Buddy
Mithril Wisdom

Deniz Bevan said...

It boggles my mind how people study things they can't *see*. Amazing.