Starts With A Bang Podcast

Swarming through our own galaxy, we've detected quite a few bizarre objects: pulsars. These rapidly spinning neutron stars are only a few kilometers across, yet contain more mass than our entire Sun. They're denser than a uranium atom's nucleus, and some of them possess the strongest magnetic fields in the known Universe. The fastest-spinning one known rotates about its axis 766 times per second, and they can travel at up to ~65% the speed of light. And outside of the ones we've found, we fully expect there might hundreds of millions or even as many as a billion such neutron stars hanging out simply in our Milky Way galaxy. But they also emit their own light, and a good chunk of that light is polarized, giving us an incredible set of information. In addition, by coordinating the pulse times of many different pulsars, we can not only detect gravitational waves, but can detect the types of waves generated by objects that LIGO and even LISA will never see. I'm so pleased to welcome Haley Wahl, pulsar specialist

If you look out at the Universe and measure all the matter out there, including stars, gas, dust, plasma, black holes, etc., it simply doesn't add up. You can't explain the gravitational effects you see with the known particles of the Standard Model alone. But even if you add in the one extra ingredient of cold, collisionless dark matter, it only fixes everything to a certain extent. In particular, the small-scale structures of the Universe, on the scales of individual galaxies and below, have a large mismatch between what's observed and what's predicted. While there are many approaches we can take, and a few different possible explanations, perhaps the most compelling approach is to try and infer what particle properties might dark matter have to bring our observations in line with what our theories and simulations would predict? Here to talk to us about the latest progress on that front is PhD candidate and budding science communicator Sophia Gad-Nasr (a.k.a. @astropartigirl), who joins us for a fascinatin

Have you ever wondered what it's like to work as a small (but vital) part of a large collaboration, where hundreds or even thousands of experimental scientists get together to produce an experiment far larger or more complex than any one person could oversee on their own? Have you ever wondered where the line is between physics and astronomy, and whether it even makes sense to have a line at all in the case of astroparticle physics? And have you ever wished that people would be more honest about the recent toxic experiences that they had when they were starting out that are still relevant to young people in those shoes today? I'm so pleased to have such a remarkable discussion with astrophysicist Niko Sarcevic (pronounced "SHAR-chev-itch" when comes out of my mouth) that's was not only far ranging but incredibly enjoyable for me. I hope you like listening, and if you want to listen to me absolutely botch describing the XENON experiment (which doesn't use the lead shielding I described; that was a different d

You might have thought that if we were going to find life anywhere in the Universe, our best bet would be to look at stars like our Sun, on account of the tremendous success of Earth. It's a good bet, for sure, but did you know that the Sun is brighter and more massive than 95% of stars in the Universe? And that down at the low-mass end of the spectrum, the most common type of objects out there are ultracool dwarfs: low-mass red dwarfs and even brown dwarfs? They have rocky planets around them and could be our first candidate Earth-sized worlds for direct imaging, and are incredible scientific objects of study all on their own. What do you want to know about them? I'm so pleased to welcome PhD candidate Anna Hughes onto the Starts With A Bang! podcast, and to share her knowledge and wisdom and enthusiasm with all of you. Here's how we start 2021 with a bang, and I hope you enjoy it!

Over the past 2 years, an exciting development has finally arisen: scientists have measured a large number of small, diffuse galaxies exquisitely well, and have finally found their first candidate galaxies that appear to have no dark matter at all. Whereas large cosmic structures typically have dark matter-to-normal matter ratios of 5-to-1, smaller structures typically have higher ratios, as star formation will kick some of the normal matter out but leave the dark matter intact. However, there should be a second type of galaxy: stars without dark matter, as tidal interactions can rip the normal matter out and keep it out. But these structures are easy to destroy, and so shouldn't persist for very long. How, then, did we find a galaxy that both appears to have no dark matter and also appears to have not formed any new stars in ~7 billion years or more? While the science is still ongoing, I'm so pleased to welcome Dr. Mireia Montes onto the program, whose recent paper may have just solved the mystery. Have a l

Over the past 30 years, we've gone from zero exoplanets to thousands. With each new generation of telescopes, observatories, and scientists, we build upon our previous finds to make enormous advances that go beyond what any one person could ever produce. The ESA's Gaia mission has surveyed more than a billion stars, identifying the closest ones that would make potentially great targets for NASA's James Webb Space Telescope, if they had potentially habitable planets around them. NASA's TESS is doing the preliminary work of observing these stars, most of which are red dwarf (M-class) stars, to find which ones actually have interesting planets that transit across their parent star's face. So far, we've found some fascinating candidates, some of which just might be humanity's first discovery of biosignatures beyond our Solar System if we get lucky. This month, we're so fortunate to be joined by astronomer and TESS scientist Emily Gilbert, a Ph.D. candidate who specializes in exoplanets. (And who has the delightf

It was only back in the early 2000s that scientists were struggling to identify and weigh the small number of supermassive black holes that we'd been able to identify in the known Universe, but the past 15-20 years have led to a revolution in what we know about them. We've identified tens of thousands of active galaxies, pinned down the masses of some of the closest ones to us through a variety of techniques, and even observed the event horizon of our first black hole directly. These powerful advances were mainly enabled by superior observatories and instruments, and the spectacular Atacama Large Millimetre/Submillimetre Array (ALMA) of telescopes, which was indispensible to measuring the mass and imaging the event horizon at the core of the largest massive galaxy in our neighborhood: M87. I'm so pleased to welcome astronomer and Ph.D. Candidate Kyle Kabasares onto the show, where we talk about black holes, mass measurements, ALMA, and the future of black hole-related astronomy! Kyle is also passionate abou

When most of us think of astronomy, we think about two types of scientists: the observers who point their telescopes at the sky and collect data, and the theorists who put together the physical rules of the Universe to both make critical predictions for what those observational results ought to yield and to interpret the data that comes in. But in reality, there are other important types of astronomers that we don't talk about frequently: analysts who focus on dealing with these literally astronomical data sets and the people who work on (and with) the instrumentation itself. This includes telescope and instrument builders, telescope operators and system specialists, and many other vital roles. Additionally, the science of astronomy isn't just about the science itself, but also questions important for the interplay of science and society. Whose land are these telescopes on? What does responsible stewardship look like? Who has access to these facilities, and who has equal (and unequal) access to the career pa

When we look out at the Universe today, we see that it's full of stars and galaxies. And yet, we can only see those stars and galaxies because the space between those galaxies and ourselves doesn't block that starlight before it gets to our instruments, observatories, telescopes, and eyes. But early on, that's an enormous problem: there is light-blocking gas and dust, and the record-holder for most distant galaxy ever discovered is still not a pristine, first-generation galaxy at all. But there are new observatories and cutting-edge techniques that will reveal them, teaching us how the Universe grew up: from a collection of neutral atoms with no stars and galaxies at all to the structure-rich Universe we see today. Joining me on this special, bonus edition of the Starts With A Bang podcast (because don't we all need a bonus?) is extragalactic astronomer and PhD candidate Rebecca Larson from the University of Texas - Austin, in a rich conversation that takes us all the way back to the edge of the Universe as

When we look out at the galaxies in the Universe, almost all of them have supermassive black holes at their centers: millions or even many billions of times more massive than our Sun is. Most of the time, these black holes are relatively quiet, but every so often, a black hole can be spotted emitting enormous amounts of radiation over a large range of the electromagnetic spectrum. These "active galaxies" come in many different flavors, from blazars to AGNs to quasars and many others, but they're very closely tied to both the age of the Universe and how rapidly a galaxy forms stars. There's an awful lot that we've learned about these objects, and yet, still so many more mysteries to solve and uncover. This month, as the first of two podcasts, I'm so pleased to bring PhD candidate Alyssa Sokol, from the University of Massachusetts - Amherst, onto the program, as we enjoy a far-reaching conversation that takes us beyond the limits of what we know. (Image credit: X-ray - NASA, CXC, R.Kraft (CfA), et al.; Radio

When it comes to gravitational waves, our terrestrial laser interferometers have provided us with unparalleled success in terms of direct detection. But they have some strong fundamental limits: their laser arms are short; their sensitivity is limited to low-mass, small-radius objects; the signals they detect last for mere seconds, at most. Most importantly, seismic noise, and even the fact that we live on a planet with tectonic plates, place restrictions on how sensitive we'll ever be able to get. But in space, all of these stories change dramatically, and the upcoming European Space Agency mission LISA is aiming to open up our eyes to a realm of gravitational wave astronomy like we've never experienced before. On this edition of the Starts With A Bang podcast, we're joined by Dr. Ira Thorpe of NASA as we explore the future of gravitational wave astronomy in an entirely new realm: in space! (Image credit: EADS ASTRIUM)

Even today, the Universe is forming enormous numbers of new stars: from various nebulae throughout our galaxy to mighty starburst galaxies where the entire galaxy is an enormous star-forming region. A decade ago, we were still trying to figure out how, when, and where stars formed throughout the Universe; today, we have that nailed down, but a whole suite of new questions and puzzles have arisen as a result of what we learned. On this edition of the Starts With A Bang podcast, I'm pleased to welcome Indiana University astronomer Jennifer Sieben to the show, who specializes in the Universe's star-formation history and also works in astronomy outreach. She has a YouTube channel with astronomy vlogs: https://www.youtube.com/playlist?list=PLNgwz85_GjP_t2_HhUQ7BFj_S189sOPz1 Serves as her University's outreach coordinator for astronomy and is co-Editor-at-Large for a science blog: blogs.iu.edu/sciu/ And can be found here on Twitter: https://twitter.com/TARDISeeker Come enjoy the spectacular story of the Universe

Dark matter is often thought of as the glue that holds the Universe together. With five times as much gravity due to this unseen form of matter as compared to normal, atom-based matter, it affects how galaxies and giant large-scale structures form in a tremendous, truly epic way. But depending on what the properties of dark matter actually are, we should get a very different Universe on smaller scales. Is dark matter cold? Warm? Hot? And does it interact with itself, or is it truly invisible? Thanks to a fascinating new technique, we're learning more about this than ever before. Take a listen as we invite Dr. Anna Nierenberg onto the podcast to talk about how gravitational lensing is revealing dark matter substructure as never before, and how it might reveal these elusive properties of dark matter at long last as a result. (Additional information: https://www.forbes.com/sites/startswithabang/2020/01/10/eight-new-quadruple-lenses-arent-just-gorgeous-they-reveal-dark-matters-temperature/ ) (Image credit: NA

When you look up at the sky, most of the points of light we see appear to be fixed. On night-to-night timescales, the distant stars and galaxies, with the exception of a few notable variables, appear to be relatively unchanged. But every once in a while, a spectacular event will occur, giving off a transient signal that outshines a typical star's brightness by factors of many billions. These events fall into many classes: supernovae, gamma ray bursts, and even more exotic events, and part of the fun is uncovering exactly what's going on as we discover these new classes of objects for the first time. Scientist Anna Ho, PhD candidate at Caltech, is right on the cutting edge of that frontier, and brings us an insider's look at this exciting and rapidly evolving field. Come get the latest on what we know and what we're still learning about the cataclysmic deaths of stars! (Image credit: Bill Saxton (NRAO/AUI/NSF))

One of the great challenges for astronomy is to determine, in gory detail, how stars are formed from a mere cloud of molecular gas and dust. Although the general picture is simple, where gravitational collapse leads to protostars that ignite nuclear fusion in their cores, the actual environments where these stars are born have many competing factors at play. Gravitational collapse is only one of them, joined by thermal heating and radiative cooling, magnetic fields and hydrodynamics, as well as stellar winds, ultraviolet radiation, and feedback from a variety of sources. Here to help us disentangle what's important, where, and when is Ph.D. candidate Mike Chen, an astrophysicist specialized in the formation of stars at the University of Victoria. If you've ever wondered how we actually form stars in our Universe, this edition of the Starts With A Bang podcast is for you! (Image credit: ESA and the Planck Collaboration.)

How many planets are out there in the Universe? How many stars have planets, and what kinds of planets do stars of various types have? How close are we to doing direct imaging, finding whether some of our Earth-like planets are potentially habitable or even inhabited? Are Super-Earths a real thing, or are all of the ones larger than our world more Neptune-like than we care to admit? We've answered a whole slew of questions about exoplanets that we didn't even know to ask a decade or two ago, and there's so much more happening right now as well as on the horizon. Come get the scoop on the latest Starts With A Bang podcast, featuring the incredible Dr. Jessie Christiansen of NASA's Exoplanet Science Institute! (Image credit: NASA / TESS)

The history of astronomy is a history of receding horizons. As we improve our optics, our instruments, and our observing techniques, we can reveal progressively more of the Universe than we've ever seen before. As the 2020s dawn on us, we're preparing to jump from 10 meter-class observatories, which are presently the largest in ground-based optical telescopes, to 30 meter-class ones, with approximately thrice the resolution and ten times the light-gathering power. There's a tremendous suite of cosmic stories to discover, but the only one of the 30 meter-class observatories to be built in the Northern Hemisphere is facing a tremendous controversy that's been decades in the making. What are the next steps towards building the Thirty Meter Telescope? The latest edition of the Starts With A Bang Podcast features the TMT's vice president for external relations, Dr. Gordon Squires, and you won't want to miss it! (Image credit: Thirty Meter Telescope Collaboration)

Have you ever wondered what the first moments of our Universe were like? Not just going back towards the hot Big Bang, but at the very first fractions of a second that come after, during, and even before the Big Bang occurs? It was my pleasure to get to speak to Dan Hooper, astrophysicist, professor, and author of the new book At The Edge Of Time, which is my favorite popular science book of 2019. (Pick up a copy here: https://amzn.to/2XReiGG) In this fascinating hour+ conversation, we cover topics like dark matter, inflation, and what not only 21st century physics but even 30th century physics might hold. Don't miss it! (Image credit: Princeton University Press / Dan Hooper.)

What lies out there, in the outer Solar System, beyond the orbit of the last known planet? Up until 1992, you would have said Pluto and its moon (maybe "moons" if you were willing to speculate), but even the existence of the Kuiper belt was doubted by many. Of course, all of that changed with the discovery of many different objects, including the more-massive-than-Pluto world discovered in 2003: Eris. We quickly realized that Pluto was not unique, but one member of a distinct class of objects thoroughly different than the planets. In 2006, we created the "dwarf planet" classification for non-planetary objects that still were Pluto-like. But more recently, a compelling but controversial idea has emerged: the idea of a Planet Nine that is more massive than even Earth, but lies hundreds of times farther away that we are from the Sun. Both of these achievements, the theorizing of Planet Nine and the Pluto-killing discovery of Eris, come courtesy of the same planetary astronomer: Mike Brown. Dive into a fascinati

The Large Hadron Collider, located at CERN, is the most powerful particle accelerator and collider in human history, and the detectors that observe the collisional debris are the most sensitive and comprehensive ever constructed. With this powerful new tools, physicists discovered the Higgs boson earlier this decade, and continue to probe the frontiers of the known Universe. Currently undergoing upgrades, the LHC has only collected, to date, 2% of the eventual data it will wind up collecting. Meanwhile, physicists are already planning for the future, looking to build a next-generation collider capable of probing the frontiers beyond the LHC's reach. Yet many detractors, dissatisfied with the motivations for pushing these boundaries forward, are working to obstruct this tremendous, civilization-scale endeavor. My guest this month on the Starts With A Bang podcast is Dr. James Beacham, a scientist who works as a member of CERN's ATLAS collaboration. In a far-ranging discussion, we talk about the LHC and beyon