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Kavli Day 4

May. 18th, 2007 | 12:55 am

First, I'd like to thank Randy Landsberg, the Director of Education and Outreach, for inviting me out here and setting up the interviews. It is his work that got us interviews with people like Michael Turner, Jim Cronin and all the other "cosmology rock stars". And thanks to the Kavli Institute for Cosmological Physics for sponsoring this trip.

Today's big news was Michael Turner's interview getting on the front page of Slashdot. That's the first time it has happened to us (we've been on the Science page once before). Of course, it slashdotted our server for an hour or so until I setup a redirect to a plain html page. It wasn't bandwidth that killed us but rather CPU cycles spent on processing the php. Once the html holding page was setup we were pretty good.

This morning I interviewed Dr. Stephan Meyer. Like Dr. Turner, he had a welcoming personality that made it not only easy, but fun to talk to. His story of how our knowledge of the structure of the CMB came about is mostly first hand - so he can tell it like it is a narrative.

In the afternoon, the Second Life chat with Dr. Thom went well. He enjoyed it and has offered to do it again sometime this summer. I liked how he answered the questions directly and how he was willing to use hard science. The transcript will go up on our home page this weekend.

I also got a tour of the deep sub-basement with Dr. Juan Collar, where he and his graduate students are assembling a kick *** piece of equipment to look for WIMPs as a possible source of dark matter. I took video of this tour and home to turn it into a video podcast in the next couple of weeks.

Finally, the evening ended with a dinner at Randy's house with a bunch of graduate students, postdocs and fellows. After dinner, I threw a mic out on the table and e recorded the first edition of a new segment we hope to include in future Slackerpedia Galactica episodes. We'll call it the Kavli Cosmology Nugget, or Kavli Cosmology Minute, or something else entirely. But the idea is to include a short cosmology segment in each episode. You guys asked for more cosmology, so you're going to get it! :)

I had a break through today, technically. I discovered that the iRiver has a sensitivity setting for the line in. I turned it down 15% and the difference is night and day. No more air conditioning, computer fans, jack hammers, etc!! My apologies for the rough quality of the first interviews. I believe that was the problem and it's fixed now. These last few interviews were much better.

Tomorrow I fly home. After resting Friday evening and catching up on work Saturday, I'll start to edit together the leftover shows. The rest of the SG team is planning to record a regular episode Sunday night. So send in any questions to info@slackerastronomy.org. I also would like to do another Light Bright Tutorial in the coming weeks.

The next of these type of intensive meeting reports, interviews and blogs will occur in mid-July, when I head to Astrobiology 2007, a week long convention in Puerto Rico. Can't wait to bring you tons of stuff on the cutting edge field of astrobiology!

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Day Three

May. 17th, 2007 | 12:26 am

Today's treat was the interview with Dr. Turner. I was more nervous about meeting him than anyone else on this trip and he put me at ease the moment I saw him in the hallway. He is such a nice guy with a gentle air about himself. And his summary of basically everything in cosmology was a great tour of where things stand and how we got there. I really do hope we can do it again in 11 years. :)

Dr. Kravtsov kindly supplied me with a list of resources he recommends for some more detailed reading about dark matter:

  • Dan Hooper, 2006, "Dark cosmos: in search of our Universe's missing mass and energy"
  • Mario Livio, "The accelerating universe"
  • Pedro G. Ferreira, "State of the Universe: primer in modern cosmology" (2006, London)
  • "Scientific American", February 2004 issue (it is a special issue on
  • Recent strong evidence for existence of dark matter - "The Bullet"
    cluster of galaxies. Wikipedia contains info and links to additional resources.

He also is going to help us make a video podcast out of two of his animations that illustrate the evolution of structure of the Universe. However, that will probably take a few weeks to produce. Stay tuned!

I spent the evening talking with staff at the Adler Planetarium, one of the largest planetariums in the United States. They have an active group of researchers, historians and educators. They recently built an awesome 3D visualization lab to begin producing 3D activities for the rest of the museum. It's an amazing place. If anyone is ever visiting Chicago, definitely take a day out to visit the Adler. They also have podcasts!

One thing I forgot to mention yesterday is that recorded a round-table discussion of cosmologists talking about stuff over beers, like we did at the Minneapolis AAS meeting. Unfortunately it was in a pub which has bowling lanes, so it quickly got too loud. I'm not sure if I can save the audio, but I'll try.

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Day Two

May. 15th, 2007 | 10:08 pm

Its only 9pm and I'm exhausted. I had to take a shower to stay awake. The tub here at the International House at the U of Chicago drains poorly. So when the shower is done, you have a good foot of water in the tub. This evening I noticed the water is blue, as in Tidy-Bowl Blue. Nice.

I interviewed three people today and have most of their shows online. All three people were ace and very helpful. Andrey did a superb job of explaining dark matter and Clem did an exquisite job at explaining where we go from here regarding the Big Bang theory. It's tough predicting the future and almost as tough to even identify problems of the present. I knew the basics of these areas before coming here but felt like I really didn't "get it". Of course, no one does! But now I feel like I can see all the pieces that the cosmologists are working with.

It was an honor, and the first time for me, to interview the winner of a nobel prize, Dr. Jim Cronin. I originally intended to ask many questions about it. But as the day wore on it felt wrong and at the advice of Randy Landsberg, my host and the person who is supporting all this new content for you, I cut them out. That was 27 years ago and I'm sure Dr. Cronin's sick of being asked about it now and has bigger fish to fry: cosmic rays. One embarrassing moment: I arrived an hour early for the interview as my watch was still on East Coast time! He was very cool about it.

Overall, the thing that strikes me today is how energized this field is right now. I didn't realize how close it is to answering some more questions and, just as importantly, open the doors to new questions not yet asked. This is a very exciting time in cosmology. To all the math-whiz undergraduate physics geniuses out there: consider this field for graduate study. It's hoppin'. And it seems like it may last for a bit.

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Kavli Day 1

May. 14th, 2007 | 09:11 pm

The Kavli Institute For Cosmological Physics really impressed me so far - and the effect seems to stem from the top down. Dr. Carlstrom is a talent at what he does. Not only has he been in on a number of the most important cosmological discoveries of our time, but he also truly believes in the collaborative effort. You can hear that in the interview, where everything was the result of someone else's work and participation. From talking to the others here I can tell that he really feels that way and he has the respect of everyone around. I've been to lots of astro centers in my time and I have run into only a few which have such a positive energy as this place. Usually, it seems the more that cutting edge work is being done there, the more stuffy and political it is. Here people work hard and just get things done. Probably what NASA was like decades ago?

Another striking thing about this place is its immense size! They have office and lab space galore. Back east real estate is at a premium. No one has enough and everyone has to be very territorial about what they do have. This isn't only inherent to Kavli, the entire University of Chicago and the city itself seems to be immense. The museums look like something from ancient Europe. Perhaps it all stems from the immense body of water that is Lake Michigan. Boston has the Atlantic, which is even bigger, but most of the city itself is separated from the coastline by docks and stuff. Not here, the city goes right up to the water and STOPS.

Tomorrow I hope to get into more of the cosmological stuff with three interviews planned. Should be a busy day and I have a ton of studying to do tonight so I don't ask completely idiotic questions. I'll edit them as fast as I can and get them online. But I can't promise I'll get it all done in one night.

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Fare the well, Seattle

Jan. 10th, 2007 | 09:11 pm

Welp, the meeting is officially over. The final talk by Michael Brown was very good. He spoke at that perfect level that was informative yet not overwhelming and with plenty of good natured humor. His topic was Kuiper Belt Objects. Some notes:

+ He showed the latest pics of Eris from HST and said they are likely the best we'll get any time soon. It covers only 1.5 pixels in the camera at its current distance of around 97 A.U. He talked a lot about its high albedo (87%, second highest in the solar system after Enceladus - a moon of Saturn). When Eris is closer the Sun in its orbit, at 36 A.U., it probably has an atmosphere of methane and hydrogen. But it is frozen out at its current distance and temperature. It has a surface mantle of a layer of methane that is 1.5 microns thick beneath a 1mm layer of frozen hydrogen. Talk about skating on thin ice! There is no rotation in the Eris light curve, meaning the surface is pretty homogeneous.

+ It's moon is in a pretty circular 15.7 day orbit. Most KBO object moons are in eccentric orbits. Moons created by collisions usually end up in circular orbits, but this one is moving too fast to have been caused by a pure collision. So it's likely that the moon came from a glancing blow sometime in Eris' past.

+ Brown's favorite object is not Eris, but 2003 EL61. He calls it "the coolest thing in the Universe", tongue somewhat planted in cheek. It has a two hour period in its light curve and varies by a third of a magnitude. This is too fast for regular rock (unless it is made of titanium or uranium!). So they think that it is oblong shaped and rotating along our line of site, so it is closer to a 4 hour period. It also has two moons, one of which also orbits along our line of site. The other orbits in a different plane, which is unusual for a moon. It has a high density of 2.6 gm/cm3, suggesting that it is almost entirely made of rock - not a rock/ice mixture like Pluto. It has a thin veneer of water ice on its surface.

+ There is a small class of comets that don't have dust. He suggests the possibility that they are pieces of KBO objects that were broken off during collisions. So by studying these comets in detail we may be able to learn much about KBO objects which are too far away for careful study.

So that's it for this meeting. Overall it was very productive for me personally from a networking perspective. But there weren't as many amazing science discoveries announced as there were a year ago in D.C. Still, these meetings are a blast. You can come too. The public can purchase passes to the meeting (but they aren't cheap) by the day or for the entire meeting. Also, there is usually a free public talk on the first or second evening. Check out www.aas.org for info on future meetings. Upcoming ones are in Hawaii (May 07), Austin (Jan 08), and St. Louis (Jun 08).

We hope you enjoyed this meeting blog. We'll do it again at future meetings. The next likely one will be a meeting on Astrobiology in July, unless someone wants to sponsor one of us to attend the Hawaii meeting in May. (hint! hint!)

Thanks to Swinburne Astronomy Online for travel funds to attend this meeting.

p.s: Here are a list of podcasts we have recorded for this meeting. All are on the feed, or will be soon. They are linked to the files so you ca view/listen directly by clicking on them.

Dirty Rotten Astronomers
AAS recap Days 1-2
AAS recap Day 3
Interview With Dr. Pamela Gay

Neil deGrasse Tyson on famous astronomers
AAS Meeting Nonsense (Asking Smart People Stupid Questions)
Poster wanderings I
Hot astronomers
Doug interviewing a science visualizer with Gemini/NOAO
The Moon is a trip

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Update Day 4

Jan. 10th, 2007 | 03:23 pm

It's pretty slow but not quite deserted. Posters were supposed to be up until 4pm but the booths had to be broken down by 1pm. So the posters were moved to a lobby in the convention center. I feel sorry for the poster authors. Today is delegated to "late posters" (that came in after the deadline), so I guess they can't look a gift horse in the mouth. I went through them and found a few tidbits:

+ There were many posters about JWST updates. JWST is supposedly the successor to Hubble. But, as expected, it is late and over budget. It had been cut back once already (many years ago) but I won't be surprised to see it cut back again. But I sure hope not, it will be a beast once in flight. I believe these "status of JWST" posters are to help build confidence in the project.

So construction of its primary instrument, NIRCAM, has begun. They are making two models: one for testing and one for flight (a lesson learned after Hubble). The test instrument will be completed in Nov. '08 and the flight instrument in Dec. '09. So far they expect it to be more sensitive than the specs due to better than expected quality in the optical coatings. It's going to have a 6.6m primary mirror assembly. The facilities to manufacturer the many smaller mirrors that make up the larger assembly have been built and all the mirror blanks fabricated. Ten mirrors are in various stages of grinding and one mirror has already passed the first level of launch stress tests. The material that will make up the large sun shield has been designed and tested for radiation, micrometeorite, abrasion and tearing damage. It also has undergone 2,200 test deployments (in space it will fold out after launch - a critical operation to the success of the telescope). Integration of the JWST components will begin in 2009 with launch currently set for 2013. (Although no one thinks it will actually happen then.)

+ A small study of the unique star KH 15D was presented. This is known as the Winking Star because every 48 days it dissapears from view for 1/2 of an orbit. The young binary system has two stars orbiting each other with a disc of dust and gas around them. When the disc eclipses the stars, it fades from view. However, there are subtle changes in the light curve around the eclipse. The poster's authors suggest that forward scattering of light through the cloud actually brightens it a bit before eclipse. This is similar to the halo effect around the Moon when it is seen through thin clouds.

+ Edplum is a wikipedia style resource for educators. The site will promote the sharing of "plums" (small nuggets of teaching material) which teachers can mix and match. They want to keep it simple, relevant, reliable and growing. It sounds a bit like our own Slackerpedia Galactica, except aimed at teachers. I think it is a great idea and look forward to helping when they finally launch in early 2007.

+ The Long Wavelength Array (LWDA) has seen its first light. I hadn't heard of this system before but I like it because it is novel, simple and builds on existing technologies. It will utilize a large array of small dipole antennae (about the size of a person) to collectively have about a square kilometer of observing area. They are operating at 10-88Mhz, which is a very loud band that carries TV and radio signals so is very rarely studied in astronomy. Good luck to them!

There is a talk this afternoon by Michael Brown, he of Eris fame. I'll do my best to attend and report back later today.

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Slow Day

Jan. 10th, 2007 | 11:17 am

It's going to be a slow day today. The meeting peters out in the afternoon as people break down booths and such. I think only one more press conference is scheduled and there won't be many posters. Most people leave before the last day, so I feel sorry for those who have posters the last day (it happened to me once). We have a total of six videos in various stages of production and one more audio podcast. We hope to get one or two more of each today. We'll put them online slowly over the next week. You definitely want to check them out, we have some pretty wild ones (one is titled "hot astronomers") along with some pretty serious ones. Michael has left and Travis and I are editing like mad this morning in the hotel room. Then we'll head over to the convention center and I'll try to make one last blog post this afternoon covering the science from today.

Yesterday I did an audio interview with Pamela Gay. It is on the podcast feed or you can click here to download it. -Aaron

Update: Last night's roundup show will be on the feed later (or but you can download it directly now via this link). We chit chat about the day's events, rumors and press releases and end with a pretty neat experiment with hot chocolate physics.

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AAS Missteps

Jan. 9th, 2007 | 06:25 pm
location: Seattle, WA USA

OK, this meeting has been great and the AAS, in general, does a great job. But I am a malcontent and I have to bitch about something, don't I? Here goes...

1. Security has been too tight. There are not national security secrets at this meeting. They have been policing the badges big time. I'm not sure what the point is. I saw a nice young man get turned away who just wanted to take a peak at the posters. What's the big deal? Trying to wring out a few bucks? This reached a hilarious but unfortunate apex when they didn't let the general public in to the public talk! There was almost no on there because they turned away the public from a public talk. WTF. Someone has to tell these folks to relax a bit.

2. No afternoon coffee. At every other meeting I've gone to they bring out coffee in the morning and then again in the afternoon. This year, no afternoon coffee. C'mon, guys, we are in Seattle, the home of Starbucks. I think they should serve coffee all day long but at least give us our afternoon fix. Plus the stupid Starbucks in the convention center closes at 4pm or something even though the conference goes into the evening. DO NOT PUT BARRIERS BETWEEN US AND OUR COFFEE!

3. No booze. Again, at every other AAS meeting I've been to they have a cocktail hour at 5pm or so where you can wander through the posters with a beer in your hand. Not this year. As a result, most people leave at 5pm instead of hanging out. I don't understand. It was a cash bar, so it wasn't like it cost the AAS anything.

There were a few good improvements at this meeting, though, too. Registration was super quick and easy. They also let us use the computers/printers to print our boarding passes. The nice folks also gave me a second free umbrella today when it started raining and I had left mine at my hotel. The wireless Internet was also not as bogged down as past meetings.

So only 3 bitches. That's not too bad!


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VY CMa in 3-D

Jan. 9th, 2007 | 01:23 pm
location: Seattle, WA USA

I went to a press conference yesterday that was somewhat near and dear to my heart, because two of the people presenting it are professors at the University of Minnesota, where I am a student. In fact one of them, Dr. Roberta Humphreys, is someone I work closely with.

The press conference was about VY CMa (link is to AAVSO article from 1999), an "extreme red supergiant". It is a star 300,000 times more luminous than the sun and extremely massive. It has a large, circumstellar nebula, created by episodic mass loss events. So it looks like a big mess when viewed in 2-D -- a large blob of knots, filaments and ejecta:

The cool results at the press conference was, using radial velocities from spectra combined with polarimetry, a 3-D map of the ejecta can be determined, unraveling the mess to a large degree.

Here is a QuickTime movie showing this in motion.

This star is relatively close and already quite bright and will someday go supernova.


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Late morning press conferences - destroying the Eagle!

Jan. 9th, 2007 | 10:33 am

Quick notes from some late- morning press conferences:

The first press release was about determining the type of the supernova that Kepler saw (and created the Kepler nebula). They determined it was a Type IA that was more massive than expected. If so, this has important implications for cosmology. Type IA supernovae are important standard candles for measuring distances to other galaxies. They are standard candles because we assume they are all the same. If some are more massive, then they would explode sooner and have different light curves. This also would seed the Universe with Iron 10-20 times sooner than current estimates, affecting models of stellar populations and galaxy formation. (Steven Reynolds? NC State)

Updated 14:53 PST: The second press release was about the famous SN 1987A. Prevailing wisdom suggested that the progenitor of the supernova was a blue giant, not a red giant as predicted by current models of stars of that size (20Msun). This is based on pre-outburst imagery and spectra. However, it also had a circumstellar nebula with spectral properties consistent with that of a red supergiant. So the two red supergiants merged, temporarily and formed a blue supergiant (a.k.a. luminous blue variable -LBV) and then went supernova. However, that would be quite rare and would not have been detectable had it happened earlier than it did (due to the technology being available to image the progenitor). So it seems often lucky that something so unique would just happen to be the best observed supernova in history. OTOH, the Universe is a big place. :) I appreciated the astronomer offering this "aesthetic worry", as he put it. There are other things that complicate this scenario, including the fact that two supernova echos have been detected around 1987A. So that means there would have to be two different major outbursts.

However, the astronomer (Nathan Smith - UC Berkeley) suggests that instead a Luminous Blue Variable (LBV - wikipedia) was the progenitor. This explains the shape of the circumstellar material, which is pinched at the waist. LBV winds may have shed a circumstellar disk, whose gravitational influence may have shaped the pinch. Smith has found other nebulae in the sky with similar shapes, all of which have LBVs in their center.

The third announcement (Nicolas Flagey - Institute Spatial Astrophysics France) was about the Pillars of Creation, the famous 1995 HST image of the Eagle nebula (M16). New images from Spitzer at 70 microns was able to measure the temperature of dust in a cavity around the pillars. The dust is far warmer than expected - too warm to be explain by warmth from star light. However, it can be explained by the passage of a shock front from a supernova. If it is a shock front, then the shockwave is instigating the star formation that we see. But it is also destroying the nebula. The time line presented estimates that the supernova occured in 6000BC and begin destroying the nebula in 4000BC. The light of the supernova shockwave reached Earth in 1000 AD and in 3000AD we'll begin to see te destruction of te crumbling regions in the nebula. Not content to wait a millenia for confirmation :), they are investigating ancient chinese astronomical records to see if the original supernova (in 4000BC) was seen and recorded.

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