Friday, March 25, 2011

Meeting Aftermath

I flew home to Louisiana from the LIGO-Virgo Meeting in California on Saturday.  The rest of this week has been a bit crazy for me since! 

I have been preparing for a talk I am giving at Rice University on Monday (the ad for it is here).  I love giving overview talks on LIGO and its potential so I am very much looking forward to it.  That being said, I don't do 'canned' talks (those are talks that are generic enough to be given with little notice and to varied audiences).  Well, I just lied a little - I do have a very basic talk that introduces LIGO to an audience that has little or no previous knowledge about gravitational waves.  I think that I have given that talk 4 times.  The talk I am giving at Rice is very different in that I am talking to other physicists (faculty and students) who are knowledgeable in physics, but are not experts on relativity or gravitational waves.  The most difficult part is figuring out how best to pitch the talk so that everyone stays interested but no one gets lost.  And then there is the issue of what cool things to talk about and what other things to leave out (I only have a 55 min slot and that includes time for audience questions).  Those are some of the hardest choices.

And then life always likes to make everything more complicated...

I was having an odd toothache since just before the I left for the meeting.  I got the first dentist appointment that was available to have it looked at.  I made a horrible mistake of taking some Advil before my appointment (it hurt) which made it difficult for him to figure out what was going on (since it didn't hurt anymore then).  Since there was something suspicious on my X-rays he was worried that I may need a root canal and that would need a specialist my roots on that tooth are curved irregularly.  So off to the root canal doctor the next day (no stress - it's not that I'm scared of a root canal, I just had so much work to do, a talk to polish and I didn't want to be recovering from a root canal while giving the talk).  GOOD NEWS!  It turns out that I brush my teeth with a little bit more enthusiasm than in healthy for my gums.  I have a little bit of recession which exposes a bit of dentin which causes sensitivity and repeatedly exposing those teeth to cold/hot/sweet/etc. was causing the ache.  I don't think the root canal doctor gets someone to smile as big to him as I did when he told me I needed some Sensodyne toothpaste and not a root canal!

<sigh>  It is a little odd writing my mundane blog posts after the post about the "Big Dog" blind injection got so much attention.  But the whole point of this blog is to let you see what it is like to be a LIGO scientist for real.  The bottom line is that there are some days where great and interesting things happen, but most days are just like everyone else's.  Right now, I need to clean up my house, I need to get groceries (I haven't gone for more than bread, etc. in a few weeks and I am out of everything), I have a pile of laundry with my name on it (and my husband's name since he helps out with that - I have a great man at my back) and a movie from Netflix that has been sitting by my TV for almost 3 weeks.  Yup.  This is my life and I like it just the way it is!

Here's a little LIGO fun to get you though the weekend.  This compilation of Beach Boys parodies was made by a group of LIGO REU (Research Experience for Undergraduates) summer students.  I guess we didn't keep them busy enough :)

Research experiences are priceless for physics students, especially those considering going on to graduate school.  If you are interested in the LIGO REU, you can find more information here.  It is too late to apply for this summer, but consider applying for next summer!  Most students end up working at Caltech (like the students in this video) but you may get to work/visit LIGO Livingston and meet me :P

Friday, March 18, 2011

Last Day at the LIGO-Virgo Meeting

Today is the last day I am at the LIGO-Virgo Meeting in CA.  While the main meeting is over, last afternoon and today is the Education and Public Outreach (EPO) retreat.  This is different from the education work I do at the LIGO Livingston Science Education Center (that is physically on-site at one of the LIGO observatories) since the EPO group seeks to serve the all of the public (not just those people geographically near the observatories) and this work is done by all of the collaboration, in this country and around the world.

One of the fun things that have been developed recently and used for education and outreach are computer games about gravity and gravitational waves!


SPACE TIME QUEST (created by the gwoptics group at the University of Birmingham, UK)

You are the principal investigator (PI) of an interferometric gravitational wave observatory like LIGO.  You select the location for your detector and design it to fit within the budget for your project.  At the end of the game, you turn on your detector and look for gravitational waves.  The deeper into space you can detect gravitational waves, the higher your score (and you can compare your score against others' high scores).  My first try at the game, I was able to detect gravitational waves from more than 29 Mpc (~94.5 million light years) away.


BLACK HOLE PONG (also created by the gwoptics group at the University of Birmingham, UK)

This is a new take on the classic game "Pong" except instead of paddles, you use black holes to gravitationally move and sling a mass into your opponent's half of the screen.  Every time the mass enters your opponent's space, you score a point.  This is currently a 2 player only game (you can't play against the computer yet) and you can even use your Xbox controllers!


SLINGSHOT (created by the RIT Center for Computational Relativity and Gravitation)

The goal of this strategy game is to shoot your opponent's spacecraft on the opposite side of the screen.  However, there are planets in between that attract your projectile gravitationally (they warp space-time) deflecting it from a straight path (the game name of Slingshot refers to the fact that stars, planets and moons can be used as a gravitational slingshot to speed up spacecrafts or other masses - NASA used this to get the astronauts from Apollo 13 back to Earth when they were low on fuel).  The strategy is to account for these deflections and still destroy your opponent's spacecraft.  This 2 player game can be very addictive!  Download it here.


Talk to you next week!  (Below is a picture of me at the LIGO-Virgo Meeting taken by my friend, Cristina Torres:)


Like I mentioned in a previous post, being at the LIGO-Virgo Meeting always overlaps with my sister's birthday.  That being said:  "Happy Birthday, Brie!"

This is Brie and me at her high school graduation last May (I am much older than her [don't you dare ask how much] and no, neither one of us is adopted).

Thursday, March 17, 2011

The LIGO-Virgo Meeting on Normal Days

Wow!  I can't believe the attention my last blog post got!  I was meaning to post everyday, but with the reception of the "Big Dog" post, I couldn't think of anything nearly as interesting to follow it immediately.

The rest of the LIGO-Virgo Meeting has been continuing on at its usual frenetic pace.  The meeting starts at 8:30 am and lasts until 6:30 pm (assuming we aren't running late).  Monday evening was the meeting dinner which is always nice to catch up with colleagues you don't get to see often (with more than 800 members of the collaboration spread across the country and around the globe, meetings are sometimes your only time to talk face-to-face).  On Tuesday morning I had the pleasure of organizing a Women's Breakfast for the collaboration and I believe this is the first time something like this was done (it was suggested and sponsored by the LIGO Lab Diversity Committee).  About 40 women from all levels of LIGO (student to professor, engineer to scientist) came and contributed to the discussion.  It was very informal and the conversation was productive!  I believe that this will become a regular event and I would like to move it from a breakfast event for two reasons:  First, we had a limited time to talk before the main meeting started and second, I am not a morning person!  The breakfast started at 7 am (don't you feel bad for me) and I prefer not to acknowledge that anything before that time exists :)

Today is the last day of the meeting proper.  This afternoon and tomorrow is a special EPO (Education and Public Outreach) meeting where all of us who are interested in doing outreach get together and organize our efforts.  There were also 2 days of informal meetings before the LIGO-Virgo Meeting started on Monday.  These meetings are by the individual search groups to discuss their data analysis.  There are 4 main sources of gravitational waves: continuous (long duration), inspiral (binary pairs merging into each other), stochastic (noisy background gravitational waves, perhaps the relics of the Big Bang), and burst (short duration gravitational waves from unanticipated sources or from sources that we aren't sure what to expect).  Each of the groups search the data looking for their special kind of gravitational wave and publish their search methods and results.

In closing, about 340 people attended the LIGO-Virgo Meeting and this was the view from near my seat this morning (my seat and computer is in the middle at the bottom):

Tuesday, March 15, 2011

The "Big Dog" in the Envelope

So, there has been a lot of excitement in the LIGO and Virgo Collaborations because we thought that we may have had a gravitational wave detection candidate from the early morning hours of 16 September 2010.  Because the potential source was localized in the vicinity of Canis Major constellation, the candidate event was informally dubbed the "Big Dog" (get it? we think we're cute).

I was especially excited since I was one of the first people to know about the event.  I mentioned in a previous blog entry that LIGO and Virgo have developed an effort to process the data that we collect rapidly so we can tell our traditional astronomy colleagues (those with actual telescopes) where to look for a potential optical signal component of the event.  I was one of about 25 scientists that were notified when a candidate event for observation was detected so that we can make sure that the event is valid before we send it out for observation.  While I wasn't the scientist on duty for this purpose at the time, I received the text message a little after 1 AM Central time (I couldn't sleep).  This was only 8 minutes after the data was collected!

It was sent out for observation and the entire collaboration began to get very excited.  This looked just like what we would expect from a neutron star-black hole binary (pair) system orbiting into each other (to make a bigger resulting black hole).  But one of the things that every scientist needs to learn is not to get overexcited and declare this to be the first direct detection of gravitational waves without making sure that this isn't a false alarm.  There are 2 ways this could be a false alarm:  1:  There is something in the environment that just so happened to make a coincident signal in all of the detectors (LIGO in Louisiana, LIGO in Washington state and Virgo in Italy) or 2:  This could be a blind injection (test).  Until we knew for sure, no one was allowed to discuss this event outside of the collaboration.  I've had to keep my lips sealed for 6 months (just like the over 800 other scientists who are in the Collaboration)!

A blind injection is a test the higher-ups in LIGO can do to make sure that the data analysis methods are doing what they need to be doing.  Basically, a very small subset of people in the collaboration (think like 2 or 3 people) inject a fake signal into the detector and this injection is not recorded anywhere like the other injections we regularly do to test things like detector calibration, etc.  The fact that a blind injection exists is sealed away (in what we metaphorically call an envelope) until all due diligence is done and the collaboration is ready to declare that the signal is a detection unless it is a blind injection (that it, we prove that it is nothing in the environment or and nothing was wrong with the detectors detectors that caused the signal).

Yesterday (14 March 2011) at the LIGO-Virgo Meeting was the big day when we opened the envelope (which turned out to be a flash drive with a PowerPoint presentation on it).  If the envelope was empty or if whatever injections were in the envelope were not the "Big Dog", then that would mean we made a detection.  The envelope was opened and, indeed, the "Big Dog" was inside and not a real gravitational wave detection.

I was not surprised - there had not been a blind injection in the run before this and everyone expected that there would be at least one.  However, there was also a big part of me that was hoping against hope that this was real.  My entire career has been dedicated to the effort of directly detecting gravitational waves and the development of gravitational wave astronomy.  If the "Big Dog" had been real, this would have been a fulfillment of the first part of my goals and the opening of the door of the second part.

Regardless, all of the effort that was put into validating the "Big Dog" up until it was revealed to be a blind injection has been a priceless exercise for the collaboration.  We even have a paper that was ready to be submitted for publication if it had been real.  Since this is something that we have never done before, we have developed skills for when we do make the first detection with Advanced LIGO

Below is a picture (from my seat) of the title slide in the presentation opening the envelope.  This just goes to show that even if you think that scientists are smarter than you, it all depends on how you define smrt :)

7 April 2011 - UPDATE:  Read more detail on the "Big Dog" blind injection here!

Monday, March 14, 2011

What Have I Been Up To?

It has been a long time since I've updated and I don't feel good about that!

This time of year is always very busy in the LIGO community since one of our yearly meetings always takes place during the 3rd week of March (and it has been that way for at least a decade since I ALWAYS miss my little sister's birthday).  During the weeks leading up to the meeting, there is always a rush to get final results for whatever project a person is working on done and, when the meeting takes place during or after a science run, mature results on what we did or did not see.  That is exactly what I have been doing since my last post.

Well, that and seeing the inside of more doctors' offices than I care to think about.  I've been stuck more than a few times and had the wonderful experience of being covered in electrodes for three weeks on a heart monitor.  There's nothing to get worried about but since I had my minor kidney crisis over the summer, I have been working to resolve other issues I've previously shrugged off. 

I will be attending the LIGO-Virgo Meeting this week and will try to blog on a daily basis about what goes on at meetings like this.  It really is interesting watching how a large collaboration works towards the same goal.  Let me tell you, it is no easy feat; scientists are very opinionated and we have to all work together in order to be productive.  I can think of a few instances where this was more contentious than others but as a whole the LIGO and Virgo Collaborations have some of the nicest people I've ever met in them.  And they aren't paying me to say that :)

Oh, one more thing...  I got to give a tour of the LIGO Livingston facility to a visiting scientist friend who had never been to the site before.  This gave me the opportunity to take her into some of the clean (think dancing Intel guys in those shiny suits - but ours aren't shiny) areas where assembly of the new parts for Advanced LIGO are being put together.  I rarely get to do this since I am a data analyst who spends most of her day working on a computer, but I enlisted my engineer husband to give a the grand tour.  I got a picture of us together in the clean gear (there is more that needs to be worn when you will be touching the materials, but we weren't):

Can you tell I'm smiling?

I will write more from the meeting!