Science & Technology
We live in a Universe of remarkable structure. From super-clusters of galaxies, tens of millions of light years across, to grand-design spiral galaxies and small rocky planets like Earth, structure exists on all scales. It wasn’t always this way: through the extraordinary advancements of observational cosmology of the last several decades, we now know the Universe was homogeneous at its beginning. While the physics which links the young and smooth Universe to its underlying Dark Matter skeleton is well-established, perhaps paradoxically we know very little about how the objects composed of regular matter – the stuff you and I are made of – assembled. In a general sense, cosmological structure grows hierarchically; small systems collapse first then merge to form progressively more massive objects. But this is a violent and energetic process, triggering bursts of star formation, feeding matter onto super-massive black holes, stripping galaxies of their interstellar medium, and fundamentally shaping the complex structure we see around us today.
Dr. Webb’s research centers on the growth of structure in the universe, and galaxies in particular. Her approach is to use data at many different wavelengths of light; each wavelength probes a different physical process and tells us something unique about galaxy formation. Because a lot of the physics in galaxies happens behind thick veils of dust, she focusses much of her research on submillimeter (~400-1200µm) and mid/far-infrared (~3-400µm) observations, which directly detect the dust and provide clues to what’s happening behind it. She primarily studies galaxies in the very distant and young universe (i.e., high-redshift); because of the finite speed of light we are seeing these systems as they existed 5-12 billion years ago and can literally watch them form! However, she is also beginning programs to study near-by galaxies since these systems can be studied in much more detail and will provide insight into the processes which formed the galaxies of today.
April 24, 2013 at 11:15 am
Guest: David H. Shoemaker (MIT). David is part of the advancedLaser Interferometer Gravitational Wave Observatory (LIGO), and we discussed gravitational waves and how LIGO is expected to detect these ripples in the curvature of space-time predicted by Einstein.
Duration: 21 minutes.
April 24, 2013 at 10:29 am
Guest: Lucy Fortson (U. of Minnesota). While Lucy’s initial research interest were focused on high-energy astrophysics, she joined the Zooniverse collaboration (initially the GalaxyZoo project), an online citizen-science project. We discussed what the project its challenges are, as well as some of the science that resulted from it. If you are interest in joining one of the projects of Zooniverse, visit their page and select a project.
Duration: 33 minutes.
April 24, 2013 at 10:26 am
Guest: Dan Stinebring (Oberlin College).
The discussion was focused on gravitational waves and the NANOGrav collaboration.
Duration: 17 minutes.
April 9, 2013 at 1:30 pm
Wonder why you keep hearing about so many new infectious diseases? How do we manage them? Come explore the perpetual arms race between humans and microbes as we both battle for survival in our modern world.
April 9, 2013 at 1:11 pm
Guest: Aaron Parsons (UC Berkeley). We talked about the PAPER experiment, which is hoping to shed light on the end of the “dark ages” of the Universe, just as the first stars and galaxies started to form.
Duration: 19 minutes.
March 22, 2013 at 1:50 pm
Guest: Maxim Lyutikov (Purdue University). We discussed how and why pulsars emit radiation at radio wavelengths, and at higher energies in the gamma-ray and X-ray bands.
Duration: 19 minutes.
February 18, 2013 at 3:03 pm
Special podcast with 2011 Physics Nobel laureate Brian Schmidt (Australian National University). We had the honor of receiving Brian Schmidt for a podcast interview, during which we talked about his discovery that the Universe was expanding. Brian Schmidt, Saul Perlmutter and Adam Riess received the Nobel Prize in Physics in 2011.
Duration: 27 minutes.
February 6, 2013 at 4:30 pm
Guest: Christian Ott (CalTech). We discussed the death of massive stars, called supernova explosions, and how we can try to understand them with computer simulations. Here is a link to the YouTube channel mentioned during the podcast: SXS Collaboration YouTube Channel.
Duration: 24 minutes.
February 6, 2013 at 4:29 pm
Guest: Joanna Rankin (U. of Vermont). In this episode, the discussion was focused on her work on the emission mechanism of pulsars, sometimes called “cosmic lighthouses”.
Duration: 20 minutes.
February 6, 2013 at 4:27 pm