Hay Festival2013 June 1HEART OF DARKNESSUnraveling the Mysteries of the Invisible UniverseDr Simon MittonSt Edmund’s Colle...
The nature of the universe. What the ancients achieved, and why we should beimpressed• Plato and Aristotle taught that the...
ISAAC NEWTON
ISAAC NEWTONNewton’s universal law ofgravitation means each objectin the universe is attracted to allother objectsUniversa...
Thomas Wright puts the Sun as a star atthe center of the Milky Way
explores objects beyond the solarsystem1755 Immanual Kant proposes “island universes.”From 1782 – 1802 Herschel undertakes...
WILLIAM HERSCHELGravity shapes the nebulae, making them morecondensed over time
WILLIAM PARSONS, THIRD EARL OF ROSSE
WILLIAM PARSONS, THIRD EARL OF ROSSE1845, Discovery of spiral structure in the nebula M51
SIR JOHN HERSCHEL 1792-1871At the Cape of Good Hope he completes hisfather’s work on surveying the heavens
Vesto Slipher 1875 – 1969VESTO SLIPHER 1875-1969 – clocks the speeds of galaxiesLowell Observatory, Flagstaff, Arizona.Dom...
ALBERT EINSTEIN 1879-1955In1915 Einstein published theGeneral Theory of Relativity, atheory of gravity that includes the“t...
EDWIN HUBBLE 1889-19541920s, Hubble measures thedistances to nearby galaxies, hisgreatest achievementEdwin Hubble 1889 –1954
The data of Slipher and Hubble combinedThe velocity-distance relation (Hubble Law)SpeedSLIPHERDistance from us HUBBLE
GEORGES LEMAîTRE 1894-19661923-24. Georges Lemaître joinsEddington in Cambridge. Asmathematicians, they worktogether on ge...
The FIREWORKS UNIVERSE 19271927 Lemaître has an explanation for Hubble’s results.Publishes in 1927 a paper (in French) on ...
FRITZ ZWICKY 1898-19741933 Coma cluster, measuresinternal velocities, proposesDark Matter1935 Pioneers the use ofSchmidt c...
ALLAN SANDAGE 1926-2010Hubble’s successor at PalomarDevoted his career to a “searchfor two numbers”, the Hubbleconstant an...
BEATRICE TINSLEY 1941-19811966 Awarded PhD Univ Texas atAustin, and received a postdocFellowshipHer 1968 paper in Astrophy...
ARNO PENZIAS AND ROBERT WILSONArno Penzias and Bob Wilson1978 Nobel Prize Physics1964 This strange radiotelescope accident...
American Astronomical Society Meeting January 1992
Mapping the microwavebackground1992, Ripples in the background radiation show structurewhen the universe was 380,000 years...
2003 – 2012 Better maps of cosmic microwavesinterpreted to discover major properties of the universe
2013 European Space Agency Planck Mission:the most precise all-sky map of the oldest light in the universe
The distant universe imaged bythe Hubble Space Telescope
The Hubble eXtreme Deep Field (2012)5,500 galaxiesup to 13.2 billion light years away
Clusters of galaxies are weighed down by dark matterUnseen dark matter is ten times morecommon than ordinary matter
An enormous ring of dark matter surroundsa great cluster of galaxies
NOBEL PRIZE PHYSICS 2011Discovery of the accelerating universeSaul Perlmutter Brian Schmidt Adam Reiss
A great discovery:the expansion of the universeis accelerating!Distant galaxies - 10 billion light years away -are going m...
The universe: what’s in the pie?Just over one quarterof the universe isunseen dark matterLess than one-twentiethof the uni...
The Universe: What we know1. It is expanding, and the rate is speeding up2. It had a hot beginning - the Hot Big Bang3. It...
The Universe: How galaxies formed1. The microwave background radiation showsthat structure existed 380,000 years after the...
“Why is there something rather than nothing?”• The universe grew from a singularity, or quantum fluctuation, at the scaleo...
The Universe: What we do not know1. In cosmology, the current generation alwaysclaims to have the “right” model2. Can we r...
Books bySimon Mitton
Hay Festival2013 June 1HEART OF DARKNESSUnraveling the Mysteries of the Invisible UniverseDr Simon MittonSt Edmund’s Colle...
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The universe: why does it exist? Why is there something rather than nothing? Where and why did structure arise: galaxies, and clusters of galaxies. This slide show is a full history of enquiry into how structure arises in the universe. It goes from Plato and Aristotle to the Nobel Prize in Physics 2011. The title Heart of Darkness refers to a book that has the full story: Heart of Darkness, by Jeremiah P Ostriker and Simon Mitton, ISBN 978 0691134307

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  • Title slide
  • Expansion of Universe Our story begins almost a century ago, in the railroad town of Flagstaff, in northern Arizona. In 1913 VS made the first attempt to measure the velocity of a galaxy wrt Milky Way. Extremely difficult. 1917 announces that a dozen galaxies are distancing themselves from the MW. He had expected half to approach, half to recede. What could this mean he wondered?
  • Edwin Hubble used 100-inch Mt Wilson. First success M31, used star magnitudes. Then started on Slipher ’ s sample. A pattern slowly emerged in which galaxies at greater distances had higher velocities.
  • A few years later. Hubble law low redshift. With more data, astronomers accepted that the universe is expanding, our first great discovery. From the Hubble diagram it is possible to assign an age to the universe, 13.7 Gyr
  • Second discovery Telescope Holmdell, New Jersey, about 20 miles from NYC Penzias and Wilson noticed that the telescope always picked up a faint signal, no matter what. [Time step] They eliminated all local sources. [Time step] When they told colleagues of their strange discovery, one at Princeton University realised immediately that they had discovered the heat radiation released in the Big Bang, now weak and dilute Confirmed Hot Big Bang
  • Astronomers immediately realised that if they could observe this radiation in much greater detail they could understand some of the situation in the Big Bang. Thus this scientific satellite was launched with the sole purpose of mapping the sky in microwaves. [Time step] Here you see one of the results, as a colour coded map of the whole sky. The microwaves have a temperature: blue = cooler, red = hotter. [Time step] Shows structure emerging in the early universe.
  • WMAP 5 yr NASA 21st century This map brings us completely up to date Describe what people are looking at Results are highly technical. Give an accurate result for age of universe. [Time step], and reveal dark matter and dark energy
  • Planck March 2013 Three years ago the European Space Agency launched an even better microwave probe, named Planck. And a few weeks ago astronomers were enthralled with the all-sky image you see here. This is the most precise map ever made of the oldest light in the universe, emitted just 380,000 years after the start of the Big Bang. The grainy structure here took 15 months to analyse in order to measure just six numbers that specify the properties of our universe. One of those numbers is the Age of the Universe, which came out at 13.82 billion years, a hundred million years older than previously thought. The map also has solid evidence about dark matter and exotic dark energy.
  • Describe the picture - what people are looking at, and how this image was made - ten days of HST time There are more than one thousand galaxies, many of which are seen just 100 million years after their formation Demonstrate how small the area of sky is This image made such a big impact that it was repeated recently.
  • One click to bring up the comparison of XDF and Moon
  • Galaxy cluster CL 0024+117 HST More about dark matter Notice the distorted images of galaxies How galaxies move within the cluster depends on mass. These galaxies are moving sufficiently fast that the cluster should have dispersed long ago. But it is not flying apart. [Time step] Dark matter weighs it down.
  • CL0024+17 Ring of dark matter. Distance 5 bly. Diameter 2.5 mly. This stunning x-ray image shows hot gas as wisps. A ring of dark matter blocks our view to some of this gas.
  • Third great discovery - accelerating universe Explain
  • Inventory of the universe Astronomers are truly in the dark, only 5% of the universe is visible Speculate on dark matter and dark energy Mention LHC
  • Summary slide with time steps
  • Summary slide with time steps
  • Summary slide with time steps
  • Title slide
  • Heart darknesshay2013lite

    1. 1. Hay Festival2013 June 1HEART OF DARKNESSUnraveling the Mysteries of the Invisible UniverseDr Simon MittonSt Edmund’s College,University of CambridgeVice President, Royal Astronomical SocietyGuest Lecturer Astronomy, RMS Queen Mary 2Website www.totalastronomy.comEmail simon@totalastronomy.com
    2. 2. The nature of the universe. What the ancients achieved, and why we should beimpressed• Plato and Aristotle taught that the heavens can be subjected to rationalenquiry. Our book Heart of Darkness presents the full history of attempts tounderstand why the universe has structure• The Greek geometers changed the nature of that enquiry forever.Geometry became the key to understanding the mechanics of theuniverse. Geometrical argument remains at the heart of understandingstructure in the universe.• Hipparchus of Rhodes: first star catalogue (850 stars!); discoveredprecession of the equinoxes. Our narrative stresses the great importanceof astronomical surveys for revealing the structures within the universe.
    3. 3. ISAAC NEWTON
    4. 4. ISAAC NEWTONNewton’s universal law ofgravitation means each objectin the universe is attracted to allother objectsUniversal attraction of gravity meansthe solar system (and the universe) isunstable
    5. 5. Thomas Wright puts the Sun as a star atthe center of the Milky Way
    6. 6. explores objects beyond the solarsystem1755 Immanual Kant proposes “island universes.”From 1782 – 1802 Herschel undertakes sky surveysto catalogue and examine the nebulae.WILLIAM HERSCHEL 1738-1822
    7. 7. WILLIAM HERSCHELGravity shapes the nebulae, making them morecondensed over time
    8. 8. WILLIAM PARSONS, THIRD EARL OF ROSSE
    9. 9. WILLIAM PARSONS, THIRD EARL OF ROSSE1845, Discovery of spiral structure in the nebula M51
    10. 10. SIR JOHN HERSCHEL 1792-1871At the Cape of Good Hope he completes hisfather’s work on surveying the heavens
    11. 11. Vesto Slipher 1875 – 1969VESTO SLIPHER 1875-1969 – clocks the speeds of galaxiesLowell Observatory, Flagstaff, Arizona.Dome and 24-inch telescopeIn 1917 Slipher announced the measurement of the velocitiesof a dozen galaxies, all of them rushing away from our MilkyWay galaxy
    12. 12. ALBERT EINSTEIN 1879-1955In1915 Einstein published theGeneral Theory of Relativity, atheory of gravity that includes the“time” dimensionArthur Eddington in Cambridgeunderstands that GR can be used tomodel the properties and behaviourof the entire universeAt the Total Eclipse of 1919Eddington confirms GR – ageometrical theory, which joins thecosmologists’ toolkit
    13. 13. EDWIN HUBBLE 1889-19541920s, Hubble measures thedistances to nearby galaxies, hisgreatest achievementEdwin Hubble 1889 –1954
    14. 14. The data of Slipher and Hubble combinedThe velocity-distance relation (Hubble Law)SpeedSLIPHERDistance from us HUBBLE
    15. 15. GEORGES LEMAîTRE 1894-19661923-24. Georges Lemaître joinsEddington in Cambridge. Asmathematicians, they worktogether on geometrical models ofthe universe using GR1924 Lemaître the theorist goes tothe other Cambridge to work atHarvard and MIT. He meetsobservers Vesto Slipher and alsoEdwin Hubble, with both of whomhe discusses model universes
    16. 16. The FIREWORKS UNIVERSE 19271927 Lemaître has an explanation for Hubble’s results.Publishes in 1927 a paper (in French) on theexpansion of the universe in which he demonstratesthat the model is an allowed solution to Einstein’sGR equationsEinstein regards this as preposterous but Eddingtonsupports his former student1930 Lemaître speaks in London on the expandinguniverse, and publishes the Primeval Atom concept inNatureLemaître called his model the “Fireworks Universe”.The moniker “Big Bang” came later, in 1948,courtesy of Fred Hoyle.
    17. 17. FRITZ ZWICKY 1898-19741933 Coma cluster, measuresinternal velocities, proposesDark Matter1935 Pioneers the use ofSchmidt cameras for surveywork1942 Caltech. 1948 Firstastronomer to use the 200-inchat Palomar1960s Catalog of Galaxies andClusters of Galaxies
    18. 18. ALLAN SANDAGE 1926-2010Hubble’s successor at PalomarDevoted his career to a “searchfor two numbers”, the Hubbleconstant and the decelerationparameter. These two numberswould specify the type ofuniverse we are in.The work was a quest for“standard candles” to providethe distance scale of theuniverse
    19. 19. BEATRICE TINSLEY 1941-19811966 Awarded PhD Univ Texas atAustin, and received a postdocFellowshipHer 1968 paper in AstrophysicalJournal brings Sandage’s house ofcards crashing down! Stellarevolution implies galactic evolution,therefore all galaxies are not thesame. She destroys the “search fortwo numbers”.Further papers follow; shepublished 11 papers in 1972
    20. 20. ARNO PENZIAS AND ROBERT WILSONArno Penzias and Bob Wilson1978 Nobel Prize Physics1964 This strange radiotelescope accidentallydiscovered that the entire skyemits a weak microwave signalThe microwaves are a formof heat energy at a very lowtemperatureWhat had been discovered washeat energy, in the form ofmicrowaves, released in the BigBang
    21. 21. American Astronomical Society Meeting January 1992
    22. 22. Mapping the microwavebackground1992, Ripples in the background radiation show structurewhen the universe was 380,000 years old
    23. 23. 2003 – 2012 Better maps of cosmic microwavesinterpreted to discover major properties of the universe
    24. 24. 2013 European Space Agency Planck Mission:the most precise all-sky map of the oldest light in the universe
    25. 25. The distant universe imaged bythe Hubble Space Telescope
    26. 26. The Hubble eXtreme Deep Field (2012)5,500 galaxiesup to 13.2 billion light years away
    27. 27. Clusters of galaxies are weighed down by dark matterUnseen dark matter is ten times morecommon than ordinary matter
    28. 28. An enormous ring of dark matter surroundsa great cluster of galaxies
    29. 29. NOBEL PRIZE PHYSICS 2011Discovery of the accelerating universeSaul Perlmutter Brian Schmidt Adam Reiss
    30. 30. A great discovery:the expansion of the universeis accelerating!Distant galaxies - 10 billion light years away -are going more slowly than expectedNearer to home, the rate of expansionhas speeded up in the last 5 billionyears. This cosmic jerk is driven bymysterious Dark Energy!
    31. 31. The universe: what’s in the pie?Just over one quarterof the universe isunseen dark matterLess than one-twentiethof the universe is visiblematterTwo thirds of theuniverse is presentas mysterious darkenergy
    32. 32. The Universe: What we know1. It is expanding, and the rate is speeding up2. It had a hot beginning - the Hot Big Bang3. Its age is 13.82 billion years4. It contains ordinary matter (5%), dark matter (27%),and dark energy (68%)
    33. 33. The Universe: How galaxies formed1. The microwave background radiation showsthat structure existed 380,000 years after the BigBang2. This structure must have been present beforethe inflation era3. Dark Matter provided the gravitational attraction toallow formation of structure on the scale of clusters ofgalaxies4. Without Dark Matter, the Dark Energy wouldhave propelled the expansion too fast. Nogalaxies, stars, or planets would exist!
    34. 34. “Why is there something rather than nothing?”• The universe grew from a singularity, or quantum fluctuation, at the scaleof the Planck length 10-43m. The resulting expansion could not have beeninfinitely uniform• The universe went through cosmic inflation 10-36– 10-33seconds.Fluctuations preserved – baryon acoustic oscillations• The First Three Minutes – origin of light elements. The next 700,000years – era of recombination• Fine tuning of the universe: expand too fast -> no structure, too slow ->collapse under gravity.• The Goldilocks solution: conditions “just right”. But honey and nice wordsdo not work in cosmology …• … Dark matter to the rescue! Amount detected is “just right” to allowstructure to develop via the gravity of dark matter – the visible matteralone is insufficient• Let’s see the dark matter simulation
    35. 35. The Universe: What we do not know1. In cosmology, the current generation alwaysclaims to have the “right” model2. Can we really believe our models of the universewhen it was 10-36seconds old? Is it not hubris toproclaim in these terms?3. We do not know what dark matter is. Our searcheshave been fruitless.4. Dark energy is a complete mystery. Is it a new realmof physics?
    36. 36. Books bySimon Mitton
    37. 37. Hay Festival2013 June 1HEART OF DARKNESSUnraveling the Mysteries of the Invisible UniverseDr Simon MittonSt Edmund’s College,University of CambridgeVice President, Royal Astronomical SocietyGuest Lecturer Astronomy, RMS Queen Mary 2Website www.totalastronomy.comEmail simon@totalastronomy.com

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