Physics in a New Era An Overview (2001) / Chapter Skim
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3. Structure and Evolution of the Universe
3. Structure and Evolution of the Universe
Pages 55-69
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From page 55... ...
For example, detectors based on ultrapure semiconductor chips, carried in satellites guided by radiotelemetry and atomic clocks, detect the light emitted from the hot Big Bang that has been propagating toward us for the last 13 billion years, much cooled by the expansion of the universe. The link between basic physics and the world beyond Earth revealed by astronomy is also one of understanding: · By applying the principles of physics learned in laboratories on Earth we can explain our observations of distant parts of the universe.
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From page 56... ...
Advances in materials and device physics have spawned a new generation of low-noise, high-sensitivity detectors. These new eyes have allowed us to ,, Hi, Jo BIG see the universe as early as 300,000 years after its birth, to detect the presence of black holes and neutron stars, and to watch the birth of stars and galaxies.
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From page 57... ...
STRUCTURE ~N D EV OLUTlO N OF THE U NiVERSE 3/ LlGO (dghtTls a sel of glant laser Snled~ro~eters sensklve to (pplesln the ~br~ ofspace~lme. ~ may detec1 gravilatlonalrad~abon>~aveslnthespace-dme warp produced by coalescing nearby pairs of neulron stars or black holes 1~ ~: 8y 20031he ~icrowave AnTsolropy Probe sateP ~ke {~A ~ (lef6 wlU produce unp ~ edented highresolullon images of the cosm ~ ~ krowave background~thecooUng freba~ofthe 81g 8ang,seenat a me when the universe ~ s only one thousandthi~ present~ze.Together w~h maps ofthe eTusive dark matler in oUr vicinTy, these data wi~ ~ead to a new era in preci~on cosmology.
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From page 58... ...
The Hubble Space Telescope has vastly increased this reach, and the Next-Generation Space Telescope would probe the cosmos to even greater distances, seeing optical and infrared light produced at even earlier epochs. Wide-angle surveys probing the cosmos will generate terabytes of data and provide unique opportunities for understanding the cosmic forces generated by the dark matter that fills the universe.
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From page 59... ...
Gravitational wave detectors may enable us to see creeper into the environment around massive black holes ancl to moments in the universe earlier than those accessible by electromagnetic racliation. Neutrino ancl gravitational wave cletectors, looking outwarcl, are not the only new windows on the universe.
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From page 60... ...
A huge concentration of dark matter seen 10 billion years after the Big Bang—is revealed by the space-time warp it creates around its host cluster of galaxies (see image at bottom)
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From page 61... ...
All these advances in observational capability the product of basic and applied research in the physics of materials, optics, and devices- are enabling us to explore the universe to its furthest reaches, to its earliest moments, and through its most explosive events. NEW LINKS In astrophysics, the basic laws of physics are used to understand the large variety of objects that can be seen in the universe (planets, stars, galaxies, black holes, gravitational waves and lenses, dark matter, pulsars, quasars, x-ray sources, and gamma-ray bursts, to name just a few)
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From page 62... ...
: Our understanding of the synthesis of light elements in the Big Bang, together with recent measurements of the primeval abundance of deuterium, reveals a universe in which ordinary matter (even nonluminous dead stars and dust) composes only 10 to 20 percent of the total mass.
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From page 63... ...
However, observations have only begun to discriminate between different inflationary mechanisms and cl ifferent versions of cold dark matter. The strong link between cosmology and elementary particle physics arises in part because the highest energies characterizing the particle physics frontier, unattainable in any conceivable accelerator on Earth, are actually reached in the Big Bang.
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From page 64... ...
Such events require energies that strain even the capabilities of black hole dynamics, and they could well be a source of measurable gravitational waves and, possibly, neutrino bursts. The possible identification of the unusual supernova SN1 998bw with the equally special gamma-ray burst GRB980425 is a fascinating clue.
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From page 65... ...
Although the laser targets have dimensions of 0.1 cm and explode in 20 ns, this is a good model for supernova mantles with dimensions larger than the Sun and durations of hours. Furthermore, petawatt lasers have reached such high intensities that they can produce relativistic plasmas, making possible the experimental study of relativistic jets of particles believed associated with several exotic astrophysical phenomena.
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From page 66... ...
. Experiments on the Omega laser at the University of Rochester provide small-scale versions of the explosion (100 billion times smaller in radius)
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From page 67... ...
These x rays are generated when hot gases are stripped from the normal companion star ancl fall into the black hole. Supermassive black holes have been detected at the center of many galaxies, including our own, by observing their effects on the motion of the surrounding matter.
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From page 68... ...
Indeed, the smaller the mass, the higher the temperature, so that evaporating black holes eventually explode. In these explosions, which have not yet been detected experimentally, space-time curvatures are reached that are greater than any since the Big Bang.
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From page 69... ...
Can we directly detect neutrinos from the relativistic jets in gamma-ray bursts? Can we detect gravitational waves from core collapse in a supernova or in a merger involving a black hole?
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