Workshop for Science Writers. Astrophysics and Cosmology

Europe/Stockholm
122:026 (Nordita)

122:026

Nordita

George Musser (Scientific American) , Sabine Hossenfelder (Nordita)
Description

Scope

Writing about science for the public is challenging. With deadlines looming, it's hard to carve out time to recharge your intellectual batteries, find distinctive stories, and get a broad overview of where researchers are headed. We've designed this workshop to give you the background material you need to cover astrophysics and cosmology, packing as much as possible into as short a time as possible for the busy working journalist.

Researchers will offer lectures on currently relevant topics with extensive question-and-answer sessions -- like a seminar class, minus homework and grades. They'll focus on topics that are either relevant for presently running experiments or are likely to increase in relevance in the soon future when experiments will deliver data. We hope that this meeting will be conductive to improve the flow of information about recent research in astrophysics and cosmology. We also hope, of course, that it will be fun.

Topics that will be covered are:

  • Dark Matter: What is this invisible stuff that fills the universe? We'll cover the evidence, theory, and experiments. Dark Energy: Why is the expansion of the universe accelerating and why does that trouble physicists so profoundly? We'll get into both theory and observation.
  • The Cosmic Microwave Background: How might the afterglow of the big bang reveal the deep structure of space and time? We'll cover novel effects such as tensor modes and non-Gaussianity and their relevance for testing quantum gravitational effects and the inflation scenarios in the early universe.
  • Gravitational waves: What's coming up with observations of ripples in the fabric of spacetime? We'll discuss theory, experiments, and implications.
  • Gamma Ray Bursts and Supernovae: How do the biggest explosions in the universe boggle the brain? We'll learn about observations, simulations, and the meaning of it all.
  • Solar Physics: How does our own star tick and why does it still perplex astrophysicists? We'll discuss theory, simulation, observation, and the relevance of understanding the physics of our sun and that of other stars.

Venue

The workshop takes place at Nordita, the Nordic Institute for Theoretical Physics, in Stockholm, Sweden. It is located at the AlbaNova University Center. More information about Nordita can be found on the Nordita website or in the information brochure (PDF).

Lecturers

Lecturers
  • John Barrow (University ofCambridge)
  • Stefan Hofmann (LMU Munich)
  • Patrick Sutton (Cardiff University)
  • Robert Nemiroff (Michigan Technological University)
  • Ray Jayawardhana (University of Toronto)
    • Slides part 1: PDF
    • Slides part 2: PDF
  • Anne Green (University of Nottingham)
  • Axel Brandenburg (Nordita)
Organizers:
  1. Hossenfelder, Sabine (Nordita)
  2. Musser, George (Scientific American)

Accommodation

Invited participants and lecturers will be booked in the BIZ apartments. For questions about the accomodation, please refer to the information on the Nordita website

Travel

The closest international airport to the conference venue is Arlanda (ARN), about 35 km North of the Stockholm City Center.

To get from Arlanda to Stockholm, you can either take the train, the bus, or a taxi. The train is called Arlanda Express, leaves every 15 minutes and arrives at the Central Station (T-Centralen) within 20 minutes. The price is SEK 240 one way, or 460 round trip. The busses are called Flygbussarna, leave every 10 minutes, and arrive at T-Centralen within 40 minutes. The price is approx SEK 120 one-way, you can save SEK 20 by buying the ticket in advance online. The busses also stop at other places before T-Centralen. The price for a taxi to the city center is about SEK 500.

Directions to the institute with maps can be found at this website. The closest subway station is Tekniska Högskolan on the red line direction Mörby Centrum. You find a subway map here.

Getting Around

Stockholm has a very well functioning public transportation system with subways and busses. You can get tickets at every subway station in stores called Pressbyrån.

Currency and Language

The Swedish currency is SEK (Sweden Krona), *not* the Euro. In most places you can pay with major credit cards or debit cards in the Maestro system. If you want to change foreign money, it is recommendable to do this already at arrival either at the airport or at T-Centralen.

Almost everybody in the Swedish capital speaks English.

    • 10:00 AM 10:45 AM
      The Expanding Universe and the Cosmological Constant 45m
      An introduction to the expanding universe and those questions that everyone asks about it –What is it expanding into? Are we at the centre of the expansion? What is expanding? We will then introduce the ‘cosmological constant’ and its effects on the expansion of the universe, see why was it invented by Einstein, and discover how it can be made to appear inevitably in Newton’s theory of gravity. Particle physics provided a new interpretation of the cosmological constant as the vacuum energy of the universe. We will then see why this meant that almost no one believed it existed before it was discovered.
      Speaker: John Barrow
    • 10:45 AM 11:15 AM
      COFFEE BREAK 30m
    • 11:15 AM 12:00 PM
      Why the Cosmological Constant turned into Dark Energy 45m
      We will begin with a brief introduction to the hot early stages of the universe and the background radiation and the differences between decelerating and accelerating universes. This leads to definition of ‘inflation’ which will look like the appearance of a temporary cosmological constant in the very early universe. We will look at some of its unusual consequences. We show how the concept of ‘dark energy’ generalises the simple idea of a cosmological constant and some of the candidates for it. We then summarise the different pieces of observational evidence for dark energy, including the simple anthropic bound, and the prospects for future discoveries. Finally, we draw together the big unexplained features of the dark energy, look at some attempts to resolve them, and conclude by seeing what dark energy may mean for the far future of the universe.
      Speaker: John Barrow
    • 12:00 PM 12:30 PM
      Q&A 30m
      Question and answer session to the topics of this morning's lectures.
      Speakers: George Musser, Sabine Hossenfelder
    • 12:30 PM 2:00 PM
      LUNCH BREAK 1h 30m
    • 2:00 PM 2:45 PM
      The CMB Bonanza, Part I 45m
      The lectures aim at explaining the basic mechanisms at work in the origin of the cosmic microwave background and at a global characterization of our Universe in accordance with the relic microwave background.
      Speaker: Stefan Hofmann
    • 2:45 PM 3:30 PM
      The CMB Bonanza, Part II 45m
      The lectures aim at explaining the basic mechanisms at work in the origin of the cosmic microwave background and at a global characterization of our Universe in accordance with the relic microwave background.
      Speaker: Stefan Hofmann (Nordita)
    • 3:30 PM 4:00 PM
      Q&A 30m
      Question and answer session to topics of this afternoon's lectures.
      Speakers: George Musser (Scientific American) , Sabine Hossenfelder
    • 4:00 PM 4:30 PM
      COFFEE BREAK 30m
    • 4:30 PM 5:15 PM
      Gravitational Waves: Whole Lotta Shakin' Goin' On 45m
      Gravitational waves -- ripples in the fabric of spacetime - - were one of the first major predictions of Einstein's General Theory of Relativity, and are the last to be directly measured. These waves are produced by some of the most violent phenomena in the universe, such as collisions of black holes, the explosive deaths of massive stars, and the big bang itself. Gravitational waves could provide novel probes of matter and gravity under extreme conditions, but they are so fantastically weak that they have so far eluded direct observation. A worldwide effort to detect gravitational waves has been building over several decades, and is approaching culmination with the upcoming operation of a new generation of detectors that are expected to finally catch these elusive signals. I will review the physics of gravitational waves, experimental efforts to detect them, and the scientific potential of this new window on the universe.
      Speaker: Patrick Sutton
    • 5:15 PM 5:45 PM
      Q&A 30m
      Question and answer session to today's topics.
      Speakers: George Musser (Scientific American) , Sabine Hossenfelder
    • 6:00 PM 7:00 PM
      RECEPTION 1h
    • 10:00 AM 10:45 AM
      Gravitational Lensing Boot Camp 45m
      What is gravitational lensing, what has it told us about the universe, and what more can it tell us about the universe? Lenses such as black holes, stars, galaxies, clusters of galaxies, and the universe as a whole will be covered. Concepts such as Einstein rings, photon spheres, image pair creation events, and shear will be defined and briefly discussed. The intersection of gravitational lensing with current research frontiers will be reviewed including how microlensing is being used to search for extra-solar planets, how radio telescopes are being used to probe galaxy-center black holes, and how weak lensing is being used to probe galaxy evolution in the early universe. Possible lensing signals in continuing and upcoming missions such as Planck, DES, LSST, Euclid, and WFIRST will be reviewed. Relevant parts of the lecturer's own research will also be briefly mentioned.
      Speaker: Robert Nemiroff
    • 10:45 AM 11:15 AM
      COFFEE BREAK 30m
    • 11:15 AM 12:00 PM
      Gamma Ray Burst Boot Camp 45m
      Gamma Ray Bursts (GRBs) are the furthest explosions known. As such they are valuable probes of energetic explosions and fluctuating beacons seen through nearly the entire intervening universe. Although almost every physical mechanism behind GRBs is debated, leading theories will be reviewed including expansion physics and candidate progenitor objects. The phenomenology of GRBs will be reviewed including prompt emission, afterglows, common light curve features, and candidate standard candles. Searches for GRB coincidences with detectors sensitive to neutrinos, gravitational radiation, cosmic rays, and extremely high energy photons will be reviewed. Searches for gravitational lensing by intervening dark matter and Lorentz invariance violations by intervening quantum foam will be reviewed, as will possible effects GRBs could have on the Earth. Relevant parts of the lecturer's own research will also be briefly mentioned.
    • 12:00 PM 12:30 PM
      Q&A 30m
      Question and answers to this morning's lectures.
      Speakers: George Musser (Scientific American) , Sabine Hossenfelder
    • 12:30 PM 2:00 PM
      LUNCH BREAK 1h 30m
    • 10:00 AM 10:45 AM
      Finding Exoplanets 45m
      Two decades ago, we knew of only one planetary system: our own. Since then, astronomers have found nearly a thousand confirmed planets and thousands more planet candidates around other stars. These discoveries --most of which have been made by measuring the subtle effects that planets induce on stars-- have revealed a remarkable diversity of worlds, from close-in super-Earths to far out super-Jupiters, blurring the very definition of what constitutes a "planet". They have challenged our preconceptions about the origins and architectures of planetary systems many times over. Now we stand on the verge of identifying the first crop of terrestrial worlds in the habitable zone where rocky planets could sustain liquid water on the surface. Our picture is far from complete, however, and more surprises are likely in store. I will review the emerging view of the planet population, highlight the strengths and limitations of different search techniques and discuss future prospects for extending their reach.
      Speaker: Ray Jayawardhana
    • 10:45 AM 11:15 AM
      COFFEE BREAK 30m
    • 11:15 AM 12:00 PM
      Characterizing Exoplanets 45m
      Remote sensing of distant worlds, across tens or even hundreds of light-years, to pin down their characteristics ain't no easy task. The whopping brightness contrast between the glaring suns and their faint planetary embers makes it particularly difficult. Yet, despite daunting hurdles, astronomers have begun measuring physical properties of alien worlds in earnest: in other words, the era of "comparative exoplanetology" is here. Planets caught in transit and those imaged directly are best suited for detailed characterization. I will review how we can determine not only the masses and orbital parameters of exoplanets but in some cases also learn about their bulk composition, day- and night-side temperatures, and upper atmospheres. I will discuss how we might adopt similar techniques to target terrestrial planets with a view to assessing their habitability and to search for biosignatures.
      Speaker: Ray Jayawardhana
    • 12:00 PM 12:30 PM
      Q&A 30m
      Question and answers to this morning's lectures.
      Speakers: George Musser, Sabine Hossenfelder
    • 12:30 PM 2:00 PM
      LUNCH BREAK 1h 30m
    • 2:00 PM 3:00 PM
      The Search for Dark Matter 1h
      Most of the matter in the Universe is invisible. This dark matter is also exotic, made of new elementary particles. I will briefly describe the observational evidence for dark matter, on scales ranging from individual galaxies to the entire Universe. One of the best dark matter candidates are WIMPs, Weakly Interacting Massive Particles. I will describe how WIMPs arise in particle physics models designed to unify the fundamental forces and are generically produced in the early Universe with the required abundance. WIMPs can be detected directly, via their rare interactions with conventional matter, or indirectly, via the gamma-rays and anti-matter produced when they annihilate. WIMPs can also be produced at particle colliders such as the LHC. I will conclude by describing the principles, current status and future prospects of these experiments.
      Speaker: Green Anne
    • 3:00 PM 4:00 PM
      The Sun's Enduring Mysteries 1h
      The realization that stars like the Sun are giant gas balls is less than 100 years old, and for much of this time, astrophysicists have remained deeply perplexed about our nearest star. For example, in the Sixties, our simple physical understanding was challenged, because it led to estimates for the rate of neutrinos that exceeded measurements by a factor of 3. This controversy took decades to put to rest. A crucial tool has been helioseismology, which allows scientists to peer beneath the Sun's surface and create a map of its interior structure. In solving one mystery, however, these measurements only created others. For instance, the Sun's surface was long known to rotate non-uniformly: faster at the equator and about 30% slower at the poles. Helioseismology was able to provide information about the Sun's internal angular velocity as well. Curiously, the lines of constant angular velocity do not lie on cylinders, as was predicted by simulations, but are spoke-like. This puzzles scientists, as there is still no good agreement between measurements and simulations. In addition, helioseismology provides crucial measurements about internal flow speeds and their temporal variation during the 11-year solar cycle. Theory and simulations suggest turbulent flow speeds of about 100 m/s, but new helioseismic measurements suggest much smaller values. Something must clearly be wrong somewhere. Theorists are also puzzled by what generates magnetic fields in the Sun. Understanding this is crucial for being able to predict space weather. This is now a major concern to airlines, who routinely reroute transcontinental flights to lower latitudes during times of strong magnetic storms.
      Speaker: Prof. Axel Brandenburg (Nordita)
    • 4:00 PM 4:30 PM
      COFFEE BREAK 30m
    • 4:30 PM 5:00 PM
      Q&A 30m
      Question and Answers to today's lectures.
      Speakers: George Musser (Scientific American) , Sabine Hossenfelder
    • 5:00 PM 5:45 PM
      Closing Discussion 45m
      Speakers: George Musser (Scientific American) , Sabine Hossenfelder
    • 6:00 PM 8:00 PM
      BBQ 2h