Astronomer Rachael Livermore is finding the most distant galaxies in the universe. Because the galaxies are so far, the light from them has been traveling for a duration just short of the age of the universe. We're seeing back in time. This ability to look back in time allows us to ask the question, "How have galaxies changed in time?". Rachael describes the tools with which she has made discoveries- the biggest, best telescopes on Earth. Specifically Rachael uses the tremendous light collecting ability of the Keck telescopes and their powerful instruments, to gauge the distance (or redshift) of the galaxies based on the extent to which the spectrum of the object is stretched in wavelength. Dr. Livermore's most recent work has been on the Hubble Space Telescope (HST) "Frontier Fields". This special project combines HST's precision, with a special phenomenon of space called gravitational lensing. The frontier fields are revealing the most distant galaxies humans have ever detected- galaxies in the infancy of the Universe.
Elizabeth Milano, a PhD student in Integrative Biology at UT-Austin, joined us to talk about her research on the underlying genetic architecture of switchgrass (Panicum virgatum), a major candidate biofuel crop. Cellulosic ethanol derived from perennial feedstocks, such as switchgrass, produces higher returns on energy inputs and less greenhouse gases and is less damaging to ecosystems than corn-based ethanol. Additionally, switchgrass is native across most of the United States, requires less water and fertilizer, and can be grown on marginal land. Elizabeth, along with her colleagues in the Juenger group at UT, study the genetics of locally-adapted ecotypes of switchgrass that grow in different environments. In particular, their research focuses on finding genetic markers associated with high yield in certain areas so that breeders can grow more efficient grasses in these locations.
The cosmic dark ages is the name for an epoch in history 13 billion years ago, when stars did not yet exist. UT Austin theoretical astrophysicist Chalence Safranek-Shrader simulates the first stars in the cosmic dark ages. His tools include pen and paper, laptops, and the super computer "Stampede" at the Texas Advanced Commuting Center (TACC). Chalence's cosmological simulations are special because they enforce cosmological initial conditions of the Universe. The approach is to treat little lightyear-sized parcels of the universe as chunks of discretized gas. The specific technique Chalence prefers is called Adaptive Mesh Refinement, which can follow these discretized parcels of gas, with all the known laws of physics in a huge differential equation. The super computer can take up to months to crunch all the numbers, generating terabytes of data. Chalence is finding out behavior of the second generation of stars that formed the bulk of the heavy elements beyond Hydrogen and Helium, and how that led to the end of the cosmic dark ages. There is not much hope to observe the first stars with a telescope. However, the next generation James Webb Space Telescope, could detect clusters of first stars, their supernovae, or the first galaxies.
Dr. Joshua Tewksbury, the Director of the Luc Hoffman institute, joined us in the studio today to talk about the biggest challenges the world must solve in the next decade. Josh is a trained ecologist, natural historian, and conservation biologist and is the Walker Professor of Natural History at the University of Washington. His research group has worked on a broad array of research questions, ranging from the ecological and evolutionary consequences of climate change to the chemical ecology of chilis to the whole ecosystem consequences of bird loss. In 2013, he joined the World Wildlife Fund in Geneva to launch the Luc Hoffmann Institute, which is a global conservation organization operating at the science to policy interface. Josh discusses how the LHI bridges the gap between scientists and NGO's so that a more sustainable relationship between people and the rest of the planet can be fostered. The objective of the LHI international fellows program is not solely to solve immediate conservation questions but to develop scientific leadership in countries that need it the most. Josh also explains the roles he envisions for science and civil society in solving the most pressing issues in conservation and sustainable development. The biggest issues that impact biodiversity must be presented to decision makers in their terms, and we must create value for the natural capital societies use and embed this value in our economic systems.
Geophysicist Kaustubh Thirumalai (@holy_kau) explained so much about the world we live in, and how it has been changing in time. Over the last century, physical chemists like Harold Urey figured out that the relative abundances of isotopes were sensitive to the local temperature. Kaustubh has applied these so-called 'proxies' as ways to indirectly measure the temperature and salinity of the ocean. These measurements go back to the last 10,000 years (aka. the 'holocene' - in between glacial worlds). Why was it hotter or colder in the past? What will the climate be like in the next 100 years? About 56 million years ago the world had a period of enhanced warming, which gives us an imperfect analog to the modern climate. Kaustubh breaks down the fact that the vast majority of scientists are in accord about anthropogenic climate change.
Dr. Joel Green's vivid descriptions of the observations of young stars bring to life the details of the star formation process. Joel answers questions about how long it takes planets to form, and how to look for disks around stars. The disks around stars are hotter closer into the star, and colder farther away from the star. Using infrared-sensitive detectors connected to telescopes, astronomers like Joel and cohost DJ Gigayear discover properties of disks surrounding young stars. We break down the different classes and types of protostars. Joel describes his work with the Spitzer Space Telescope and the Herschel Space Telescope. One of the things Joel is trying to figure out is the effect of chaotic sudden burst events seen in stars like FU Orionis.
Astronomer Klaus Pontoppidan visited us in the studio this week from the Space Telescope Science Institute (STScI), in Baltimore, MD. Klaus is attacking questions about the origins of life, and how planets form around stars. He is one of the foremost experts in infrared astronomical spectroscopy and the detailed chemistry of the birth sites of planets. Specifically, he has detected water in the form of either gas (water vapor), or ice (frozen water). Back on Earth, there are still remnants of the 4.6 billion year old solar protoplanetary disk. These shards of pristine and processed rock (rarely) rain onto our homes in the form of meteorites. Klaus gives us advice on where to look for these meteorites so we can sell them on eBay. We wrap up with a discussion of the James Webb Space Telescope (JWST), and how this and other technologies will dramatically improve the detail with which we can examine distant planets.
Exoplanets are planets around stars other than the sun. We now know about thousands of exoplanets or candidate exoplanets, owing to advances in technology and space telescopes. The main space telescope used for discovery of exoplanets is the NASA Kepler satellite, which can indirectly detect the presence of exoplanets orbiting stellar systems through the transit technique. There is building evidence that most stars have planets. A new class of instruments employing "extreme adaptive optics" are emerging, and we highlight the Gemini Planet Imager's first light in November 2013. Astronomer and guest DJ Timber helps elucidate the challenge of exoplanet detection, and what it all means.
Dr. Roz Eggo joins us on the show to explain influenza (flu) pandemics, and how immunity works. What to the H and the N mean in the flu strains, like H1N1? What characterizes a flu pandemic? What is the difference between a pandemic and just a bad flu season? How do we predict what strains will be dominant for a coming flu season? Herd immunity helps to slow down transmission in everyone, not just those people who have been vaccinated. Roz's research involves how hospitalizations in Texas are related to infectious disease circulation. She uses population level models to inform the hospitalization rates. A key factor is the contact rate of students in- and out- of school, where students get colds more easily from others. Roz sorts out the sources of data and answers all our questions about viruses.
University of Texas at Austin Graduate Student Amanda Lea explains all about female mate choice in Tungara frogs. Frogs convey information about themselves to their potential mates by their characteristic calls. Working at the Smithsonian Tropical Research Institute, Amanda has done work in forests of Panama and in phonotaxis chambers. We can now directly learn the preferences of frogs by playing back recorded sounds and watching their movements. Amanda entertains us by replicating the characteristic "Tuunn-gara" calls. The decoy effect is all around us!