On June 20, 2017, ESA's Science Programme Committee selected LISA as the third large mission in the ESA science program. LISA will now enter a detailed study phase, the first step in a long gestation culminating with launch around 2034.
One of the three LISA spacecraft, monitoring the distance to its two sisters by way of laser interferometry
On June 13-17, 2016, I had the privilege of lecturing on gravitational waves at the 2016 Summer School of Cosmology of the International Center for Theoretical Physics in Trieste, Italy. I met dozens of smart, enthusiastic students from all over the world, and I had a chance to re-learn the foundations of my very own subject. I short, I had a ball.
I'm happy to report that the Astrophysical Journal just published a letter authored by our JPL/Caltech pulsar-timing group, in which we discuss how soon gravitational waves from the cosmic population of supermassive black holes could be detected by radio telescopes. We conclude that, notwithstanding recent negative results from the Parkes Pulsar Timing Array, we expect to have clear and convincing evidence of low-frequency gravitational waves within the next decade.
In the 100th anniversary year of Einstein's prediction of gravitational waves, after a 50-year-long experimental pursuing, and after spending most of my scientific career devoting my personal effort to gravitational-wave science, I'm proud to join my voice to the chorus announcing and celebrating the first detection of gravitational waves from a binary system with LIGO.
I have been a member of the LIGO Scientific Collaboration since 2001, and it has been a privilege to witness (and help, if only modestly) the incredible improvement of the experiment, the growth of its community, and the exhilarating last few months of feverish work, culminating in today's announcement.
LIGO just released the data taken by the project's two gravitational wave detectors during their flagship sixth science run (S6), which took place from July 2009 through October 2010. While no gravitational-wave events were found during this run, open-data releases pave the way toward the coming of age of gravitational-wave astronomy.
I am proud to be part of the LIGO Open Science Center (LOSC) that put together this data release, and prepared detailed metadata, tutorials, and software tools that will help non-LIGO users play and work with these data. Some such experiments are also featured in my Computational Salon lectures on elegant and efficient scientific computing.
I am proud to be a member of the new NSF-Funded Physics Frontiers Center, the multi-institution North American Nanohertz Observatory for Gravitational Waves (NANOGrav). A $14.5-million, five-year award will support the research activities of 55 scientists at 15 institutions. Our JPL team will lead NANOGrav's efforts to develop the approaches and algorithms for extracting the weak gravitational-wave signals from the minute changes in the arrival times of pulses from radio pulsars that are observed regularly by these instruments.
I recount the "click in the night" that led to my Geometric TDI paper in my contribution to the excellent Birth of an Idea project by Vitor Cardoso and Ana Sousa Carvalho, a "catalogue of stories documenting the scientific process as it truly is: perplexing, difficult, painstaking, spontaneous, exciting and fun".
My postdoc Rutger van Haasteren and I recently completed two new papers that (we believe) represent significant steps forward in the quest to implement gravitational-wave searches that can ingest large pulsar-timing-array datasets, such as those assembled by the International Pulsar-Timing Array.
I spent the last week at the 10th LISA Symposium in Gainesville, Florida. The general mood of the conference was one of impatience—the European Space Agency will launch LISA Pathfinder next year, and it has formally approved a large mission (very probably eLISA) to detect low-frequency gravitational waves in space, but with a distant launch date of 2034. Space-based GWs are still a priority for NASA, but for the moment we don't have any concrete plans to join Europe or to fly our own mission. Personally, I have been doing no LISA-related work since last summer, a definite break after dedicating more than ten years to this mission; I attended the conference as a LIGO representative, giving a presentation about the up-and-coming LIGO Open Science Center (more about this soon).
Since the space-based gravitational-wave detection program has receded well into the future, and since the ground-based observatories are currently not taking data while they are being upgraded, I've being devoting more and more of time to the effort to detect GWs using pulsar-timing data. I'm very lucky to be aided in this work by my amazing postdocs Sarah Vigeland and Rutger van Haasteren, and by my colleagues Curt Cutler, Joe Lazio, Walid Majid, and Sarah Burke-Spolaor at JPL and Caltech. My last two papers to see the light (of arXiv) are indeed about pulsar timing.
It seems that I have been getting new papers out faster than I could blog about them, so let me catch up with this post. The first is a LIGO paper, the second may be my last LISA paper for a while, and the third is about the statistical theory of extracting information from gravitational-wave signals. All three will be published in 2013, and all three are... good stuff.
An excerpt from the Sep 24, 2012 performance of Andrea Centazzo and Michele's "Einstein's Cosmic Messengers", presented at the Jet Propulsion Laboratory to my fellow NASA scientists and engineers. The video includes my introduction and one of the music segments. See on video page.
I wanted to celebrate my birthday by posting a new preprint on the arXiv, but JPL wanted to make sure first that I wasn't giving away any big secrets (really), so I am a few days late. Nevertheless, I am happy that it's out now, and I think that it carries a useful result. Let me see if I can tell you briefly about it in this blog post. (That would be a nice tradition to start, wouldn't it?)
Today marks the debut of the new version of vallis.org. I loved the old design of connected boxes with a yellow background, but it was time for new. Most of the old content should have survived through the transition at the same URL. Please let me know if you're missing anything, or if anything looks strange.
The new website is carefully handcoded in HTML5/CSS, on the basis of Twitter Bootstrap, and it is generated by a custom static-site engine using Jinja2 templates. jQuery provides a little interactivity.
My own 1905.
Not quite, but I submitted three papers in January: a methods paper on computing the sensitivity of space based detectors (with Chad Galley), a long Astrophys. J. paper on GWs from Galactic binaries (with Samaya Nissanke, Tom Prince, and Gijs Nelemans), and a compressed version of the eLISA science case (with a bunch of other people, but the paper is my compilation and my lovechild). Now the question is how to keep this up...
Here's the video and slides of two seminars that I gave on my... Canadian tour of PI and CITA: "How Good is good enough for Gravitational-wave Templates?" (Nov 28, also a local mirror) and "Space-based gravitational-wave astronomy in the next decade, with a coda of statistics" (Dec 1).
The Oct 22 performance of Einstein's Cosmic Messengers was shot by rising film-makers Roberto Canuto and Xu Xiaoxi, and a live DVD is now available. Here's a short documentary feature about gravitational waves that I produced and that includes interviews with Andrea, with LIGO Executive Director Jay Marx, and with me. You may also be interested in the 30-min panel discussion that followed the concert, featuring K C Cole, Elena Pierpaoli, Andrea, and me. See all in my video page.
My contribution on gravitational waves is published in the Pars Foundation's Findings on Elasticity, which features "the work of 50 artists and scientists who shape the way we look at the world today [...] their findings range from the quirky, humorous and beautiful to the mind-bogglingly complex and disturbing."