Cosmic Modesty
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Fast Radio Bursts May Be Firing Off Every Second 21 September 2017
Fast radio bursts may be firing off every second 21 September 2017 see with our eyes, these flashes come in radio waves." To make their estimate, Fialkov and co-author Avi Loeb assumed that FRB 121102, a fast radio burst located in a galaxy about 3 billion light years away, is representative of all FRBs. Because this FRB has produced repeated bursts since its discovery in 2002, astronomers have been able to study it in much more detail than other FRBs. Using that information, they projected how many FRBs would exist across the entire sky. "In the time it takes you to drink a cup of coffee, hundreds of FRBs may have gone off somewhere This artist's impression shows part of the cosmic web, a in the Universe," said Avi Loeb. "If we can study filamentary structure of galaxies that extends across the even a fraction of those well enough, we should be entire sky. The bright blue, point sources shown here are able to unravel their origin." the signals from Fast Radio Bursts (FRBs) that may accumulate in a radio exposure lasting for a few minutes. The radio signal from an FRB lasts for only a While their exact nature is still unknown, most few thousandths of a second, but they should occur at scientists think FRBs originate in galaxies billions of high rates. Credit: M. Weiss/CfA light years away. One leading idea is that FRBs are the byproducts of young, rapidly spinning neutron stars with extraordinarily strong magnetic fields. When fast radio bursts, or FRBs, were first Fialkov and Loeb point out that FRBs can be used detected in 2001, astronomers had never seen to study the structure and evolution of the Universe anything like them before. -
The Universe, Life and Everything…
Our current understanding of our world is nearly 350 years old. Durston It stems from the ideas of Descartes and Newton and has brought us many great things, including modern science and & increases in wealth, health and everyday living standards. Baggerman Furthermore, it is so engrained in our daily lives that we have forgotten it is a paradigm, not fact. However, there are some problems with it: first, there is no satisfactory explanation for why we have consciousness and experience meaning in our The lives. Second, modern-day physics tells us that observations Universe, depend on characteristics of the observer at the large, cosmic Dialogues on and small, subatomic scales. Third, the ongoing humanitarian and environmental crises show us that our world is vastly The interconnected. Our understanding of reality is expanding to Universe, incorporate these issues. In The Universe, Life and Everything... our Changing Dialogues on our Changing Understanding of Reality, some of the scholars at the forefront of this change discuss the direction it is taking and its urgency. Life Understanding Life and and Sarah Durston is Professor of Developmental Disorders of the Brain at the University Medical Centre Utrecht, and was at the Everything of Reality Netherlands Institute for Advanced Study in 2016/2017. Ton Baggerman is an economic psychologist and psychotherapist in Tilburg. Everything ISBN978-94-629-8740-1 AUP.nl 9789462 987401 Sarah Durston and Ton Baggerman The Universe, Life and Everything… The Universe, Life and Everything… Dialogues on our Changing Understanding of Reality Sarah Durston and Ton Baggerman AUP Contact information for authors Sarah Durston: [email protected] Ton Baggerman: [email protected] Cover design: Suzan Beijer grafisch ontwerp, Amersfoort Lay-out: Crius Group, Hulshout Amsterdam University Press English-language titles are distributed in the US and Canada by the University of Chicago Press. -
Science in Nasa's Vision for Space Exploration
SCIENCE IN NASA’S VISION FOR SPACE EXPLORATION SCIENCE IN NASA’S VISION FOR SPACE EXPLORATION Committee on the Scientific Context for Space Exploration Space Studies Board Division on Engineering and Physical Sciences THE NATIONAL ACADEMIES PRESS Washington, D.C. www.nap.edu THE NATIONAL ACADEMIES PRESS 500 Fifth Street, N.W. Washington, DC 20001 NOTICE: The project that is the subject of this report was approved by the Governing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineering, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance. Support for this project was provided by Contract NASW 01001 between the National Academy of Sciences and the National Aeronautics and Space Administration. Any opinions, findings, conclusions, or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the sponsors. International Standard Book Number 0-309-09593-X (Book) International Standard Book Number 0-309-54880-2 (PDF) Copies of this report are available free of charge from Space Studies Board National Research Council The Keck Center of the National Academies 500 Fifth Street, N.W. Washington, DC 20001 Additional copies of this report are available from the National Academies Press, 500 Fifth Street, N.W., Lockbox 285, Washington, DC 20055; (800) 624-6242 or (202) 334-3313 (in the Washington metropolitan area); Internet, http://www.nap.edu. Copyright 2005 by the National Academy of Sciences. -
Ionization History of Hydrogen
Signatures of the First Generation of Objects KITP 2004 Ionization History of Hydrogen REDSHIFT 6 1000 TIME Billion Million years years Avi Loeb, Harvard (KITP Galaxy-IGM Conference 10/26/04) 1 Signatures of the First Generation of Objects Emergence of the First Star Clusters molecular hydrogen Yoshida et al. 2003 Hydrogen e- p Ground level excitation rate= (atomic collisions)+(radiative coupling to CMB) Couple T s to T k Couples T s to Tí spin 21cm = (1:4GHz) 1 1s 1=2 p e- 0s 1=2 p e- n 1 g1 0:068K Spin Temperature = expf à g (g1=g0) = 3 n 0 g0 Ts Predicted by Van de Hulst in 1944; Observed by Ewen &Purcell in 1951 at Harvard Avi Loeb, Harvard (KITP Galaxy-IGM Conference 10/26/04) 2 Signatures of the First Generation of Objects 21 cm Absorption by Hydrogen Prior to Structure Formation à 1=2 à T = ü Ts Tí T = 28mK 1+ z Ts Tí b 1+ z b 10 Ts Fluctuations in 21cm brightness are sourced by fluctuations in gas density Loeb & Zaldarriaga, Phys. Rev. Lett., 2004; astro-ph/0312134 Observed wavelength=21cm (1+z) 3D tomography (slicing the universe in redshift ) Largest Data Set on the Sky Number of independent patches: 3 16 lmax É ÷ ø 10 106 ÷ while Silk damping limits the primary CMB anisotropies to only ø 107 Noise due to foreground sky brightness: Loeb & Zaldarriaga, Phys. Rev. Lett., 2004; astro-ph/0312134 Avi Loeb, Harvard (KITP Galaxy-IGM Conference 10/26/04) 3 Signatures of the First Generation of Objects Line-of-Sight Anisotropy of 21cm Flux Fluctuations à T = ü Ts Tí b 1+ z 1 + î n HI = nö(1 + î ) Peculiar velocity changes ü / 1 dvr =dr -
Interstellar Interlopers Two Recently Sighted Space Rocks That Came from Beyond the Solar System Have Puzzled Astronomers
A S T R O N O MY InterstellarInterstellar Interlopers Two recently sighted space rocks that came from beyond the solar system have puzzled astronomers 42 Scientific American, October 2020 © 2020 Scientific American 1I/‘OUMUAMUA, the frst interstellar object ever observed in the solar system, passed close to Earth in 2017. InterstellarInterlopers Interlopers Two recently sighted space rocks that came from beyond the solar system have puzzled astronomers By David Jewitt and Amaya Moro-Martín Illustrations by Ron Miller October 2020, ScientificAmerican.com 43 © 2020 Scientific American David Jewitt is an astronomer at the University of California, Los Angeles, where he studies the primitive bodies of the solar system and beyond. Amaya Moro-Martín is an astronomer at the Space Telescope Science Institute in Baltimore. She investigates planetary systems and extrasolar comets. ATE IN THE EVENING OF OCTOBER 24, 2017, AN E-MAIL ARRIVED CONTAINING tantalizing news of the heavens. Astronomer Davide Farnocchia of NASA’s Jet Propulsion Laboratory was writing to one of us (Jewitt) about a new object in the sky with a very strange trajectory. Discovered six days earli- er by University of Hawaii astronomer Robert Weryk, the object, initially dubbed P10Ee5V, was traveling so fast that the sun could not keep it in orbit. Instead of its predicted path being a closed ellipse, its orbit was open, indicating that it would never return. “We still need more data,” Farnocchia wrote, “but the orbit appears to be hyperbolic.” Within a few hours, Jewitt wrote to Jane Luu, a long-time collaborator with Norwegian connections, about observing the new object with the Nordic Optical Telescope in LSpain. -
1 “A Big History of the Universe for Secondary Education” PI
“A Big History of the Universe for Secondary Education” PI: Tara Firenzi Co-Is: Joel Primack, Ph.D, Nancy Abrams, Darrell Steely, Joel Tarbox Collaborator: Doris B. Ash, Ph.D GSR: Zoe Buck Consultant: Solana Pyne Summary Overview Over the last decade, world history and astrophysics have become more and more similar in the way they examine the origins of the universe. Principally, world historians and social science educators have come to realize that the origin of our universe is the beginning of our human story. Though the incorporation of these ideas into secondary curricula is not yet widespread, well respected efforts such as “World History for Us All,” a project of the National Center for History in Schools at UCLA, have strongly advocated for the incorporation of the history of the universe in world history curricula. As put forth by books like David Christian’s Maps of Time: An Introduction to Big History (2005), these ideas will no doubt become a more significant part of both history and science instruction in secondary schools in the near future, and make instruction in both areas more interdisciplinary. In scientific fields, of course, the importance of the origins of the universe has long been understood. Bringing us to a new level of understanding on the subject of these origins, UCSC Professor Joel Primack and Nancy Abrams have recently introduced a number of new ideas about the connections between advanced scientific theories and the historical importance of the origins of the universe as discussed in their book, The View From the Center of the Universe: Discovering Our Extraordinary Place in the Cosmos (2006). -
Report of the Astronomy and Astrophysics Advisory Committee March 15, 2014
Report of the Astronomy and Astrophysics Advisory Committee March 15, 2014 Andreas Albrecht Professor of Physics Voice: (530)-752-5989 Fax: (530)-752-4717 [email protected] March 15, 2014 Dr. Cora Marrett, Acting Director National Science Foundation 4201 Wilson Blvd., Suite 1205 Arlington, VA 22230 Mr. Charles F. Bolden, Jr., Administrator Office of the Administrator NASA Headquarters Washington, DC 20546-0001 Dr. Ernest Moniz, Secretary of Energy U.S. Department of Energy 1000 Independence Ave., SW Washington, DC 20585 The Honorable John D. Rockefeller, IV, Chairman Committee on Commerce, Science and Transportation United States Senate Washington, DC 20510 The Honorable Ron Wyden, Chairman Committee on Energy & Natural Resources United States Senate Washington, DC 20510 The Honorable Lamar Smith, Chairman Committee on Science, Space and Technology United States House of Representatives Washington, DC 20515 Dear Dr. Marrett, Mr. Bolden, Secretary Moniz, Chairman Rockefeller, Chairman Wyden, and Chairman Smith: I am pleased to transmit to you the annual report of the Astronomy and Astrophysics Advisory Committee for 2013–2014. The Astronomy and Astrophysics Advisory Committee was established under the National Science Foundation Authorization Act of 2002 Public Law 107-368 to: (1) assess, and make recommendations regarding, the coordination of astronomy and astrophysics programs of the Foundation and the National Aeronautics and Space Administration, and the Department of Energy; (2) assess, and make recommendations regarding, the -
Geometry of the Universe ______By Avi Loeb on July 8, 2020
Geometry of the Universe _______ By Avi Loeb on July 8, 2020 At ancient times, wise people like Aristotle thought that heavy objects fall faster than lightweight objects under the influence of gravity. About four and a half centuries ago, Galileo Galilei decided to test this assumption experimentally. He dropped objects of different masses from the Leaning Tower of Pisa and found that they all fall the same way under the influence of Earth’s gravity. Three-and-a-quarter centuries later, Albert Einstein was struck by Galileo’s finding and realized that if all objects follow the same trajectory under gravity, then gravity might not be a force but rather a property of spacetime, the fabric which all objects share the same way (establishing the so-called “equivalence principle”). More importantly, Einstein recognized that when spacetime is curved objects do not follow straight lines. He reckoned that the Earth moves around the Sun because the Sun curves spacetime in its vicinity. The Earth’s orbit follows a circle, similarly to a ball on the rubber surface of a trampoline whose center is pulled down by the weight of a person. In November 1915, Einstein formulated his insight through mathematical equations that established the foundation for his General Theory of Relativity. One side of Einstein’s equations includes all masses that source gravity (like the person standing on the trampoline) and the other side quantifies the curvature of spacetime. In the words of John Wheeler: “Spacetime tells matter how to move and matter tells spacetime how to curve”. The first solution of Einstein’s equations was derived by Karl Schwarzschild a few months later, while serving on the German front during World War II. -
B1487(01)Quarks FM.I-Xvi
Connecting Quarks with the Cosmos Eleven Science Questions for the New Century Committee on the Physics of the Universe Board on Physics and Astronomy Division on Engineering and Physical Sciences THE NATIONAL ACADEMIES PRESS Washington, D.C. www.nap.edu THE NATIONAL ACADEMIES PRESS 500 Fifth Street, N.W. Washington, DC 20001 NOTICE: The project that is the subject of this report was approved by the Govern- ing Board of the National Research Council, whose members are drawn from the councils of the National Academy of Sciences, the National Academy of Engineer- ing, and the Institute of Medicine. The members of the committee responsible for the report were chosen for their special competences and with regard for appropriate balance. This project was supported by Grant No. DE-FG02-00ER41141 between the Na- tional Academy of Sciences and the Department of Energy, Grant No. NAG5-9268 between the National Academy of Sciences and the National Aeronautics and Space Administration, and Grant No. PHY-0079915 between the National Academy of Sciences and the National Science Foundation. Any opinions, findings, and conclu- sions or recommendations expressed in this publication are those of the author(s) and do not necessarily reflect the views of the organizations or agencies that pro- vided support for the project. International Standard Book Number 0-309-07406-1 Library of Congress Control Number 2003100888 Additional copies of this report are available from the National Academies Press, 500 Fifth Street, N.W., Lockbox 285, Washington, DC 20055; (800) 624-6242 or (202) 334-3313 (in the Washington metropolitan area); Internet, http://www.nap.edu and Board on Physics and Astronomy, National Research Council, NA 922, 500 Fifth Street, N.W., Washington, DC 20001; Internet, http://www.national-academies.org/bpa. -
Astro2010: the Astronomy and Astrophysics Decadal Survey
Astro2010: The Astronomy and Astrophysics Decadal Survey Notices of Interest 1. 4 m space telescope for terrestrial planet imaging and wide field astrophysics Point of Contact: Roger Angel, University of Arizona Summary Description: The proposed 4 m telescope combines capabilities for imaging terrestrial exoplanets and for general astrophysics without compromising either. Extremely high contrast imaging at very close inner working angle, as needed for terrestrial planet imaging, is accomplished by the powerful phase induced amplitude apodization method (PIAA) developed by Olivier Guyon. This method promises 10-10 contrast at 2.0 l/D angular separation, i.e. 50 mas for a 4 m telescope at 500 nm wavelength. The telescope primary mirror is unobscured with off-axis figure, as needed to achieve such high contrast. Despite the off-axis primary, the telescope nevertheless provides also a very wide field for general astrophysics. A 3 mirror anastigmat design by Jim Burge delivers a 6 by 24 arcminute field whose mean wavefront error of 12 nm rms, i.e.diffraction limited at 360 nm wavelength. Over the best 10 square arcminutes the rms error is 7 nm, for diffraction limited imaging at 200 nm wavelength. Any of the instruments can be fed by part or all of the field, by means of a flat steering mirror at the exit pupil. To allow for this, the field is curved with a radius equal to the distance from the exit pupil. The entire optical system fits in a 4 m diameter cylinder, 8 m long. Many have considered that only by using two spacecraft, a conventional on-axis telescope and a remote occulter, could high contrast and wide field imaging goals be reconciled. -
Searches for Life and Intelligence Beyond Earth
Technologies of Perception: Searches for Life and Intelligence Beyond Earth by Claire Isabel Webb Bachelor of Arts, cum laude Vassar College, 2010 Submitted to the Program in Science, Technology and Society in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in History, Anthropology, and Science, Technology and Society at the Massachusetts Institute of Technology September 2020 © 2020 Claire Isabel Webb. All Rights Reserved. The author hereby grants to MIT permission to reproduce and distribute publicly paper and electronic copies of this thesis document in whole or in part in any medium now known or hereafter created. Signature of Author: _____________________________________________________________ History, Anthropology, and Science, Technology and Society August 24, 2020 Certified by: ___________________________________________________________________ David Kaiser Germeshausen Professor of the History of Science (STS) Professor of Physics Thesis Supervisor Certified by: ___________________________________________________________________ Stefan Helmreich Elting E. Morison Professor of Anthropology Thesis Committee Member Certified by: ___________________________________________________________________ Sally Haslanger Ford Professor of Philosophy and Women’s and Gender Studies Thesis Committee Member Accepted by: ___________________________________________________________________ Graham Jones Associate Professor of Anthropology Director of Graduate Studies, History, Anthropology, and STS Accepted by: ___________________________________________________________________ -
Arxiv:2107.07283V3 [Astro-Ph.IM] 27 Jul 2021
Draft version July 28, 2021 Typeset using LATEX default style in AASTeX63 Strategies and Advice for the Search for Extraterrestrial Intelligence Jason T. Wright 1, 2, 3 1Penn State Extraterrestrial Intelligence Center, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA, 16802, USA 2Department of Astronomy & Astrophysics, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA, 16802, USA 3Center for Exoplanets and Habitable Worlds, 525 Davey Laboratory, The Pennsylvania State University, University Park, PA, 16802, USA ABSTRACT As a guide for astronomers new to the field of technosignature search (i.e. SETI), I present an overview of some of its observational and theoretical approaches. I review some of the various observational search strategies for SETI, focusing not on the variety of technosignatures that have been proposed or which are most likely to be found, but on the underlying philosophies that motivate searches for them. I cover passive versus active searches, ambiguous versus dispositive kinds of technosignatures, com- mensal or archival searches versus dedicated ones, communicative signals versus \artifacts", \ac- tive" versus derelict technologies, searches for beacons versus eavesdropping, and model-based versus anomaly-based searches. I also attempt to roughly map the landscape of technosignatures by kind and the scale over which they appear. I also discuss the importance of setting upper limits in SETI, and offer a heuristic for how to do so in a generic SETI search. I mention and attempt to dispel several misconceptions about the field. I conclude with some personal observations and recommendations for how to practice SETI, including how to choose good theory projects, how to work with experts and skeptics to improve one's search, and how to plan for success.