The Age of the Earth–A Summary

1999 ◽  
Vol 5 ◽  
pp. 17-22
Author(s):  
G. Brent Dalrymple

After two centuries of scientific endeavor, scientists have concluded that the age of the Earth is 4.54 billion years. This value, which is based on the relationships between lead isotopes in meteorites and in the Earth, has an uncertainty of less than 1 percent and is consistent with numerous radiometric age measurements on ancient rocks found on the Earth and Moon as well as on meteorites. In addition, the antiquity of the Earth is consistent with evidence indicating that the Milky Way Galaxy and the universe are of the order of 14-16 billion years (abbreviated Ga) in age.

Religions ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 418 ◽  
Author(s):  
Deana L. Weibel

This paper, based mainly on astronauts’ first-person writings, historical documents, and my own ethnographic interviews with nine astronauts conducted between 2004 and 2020, explores how encountering the earth and other celestial objects in ways never before experienced by human beings has influenced some astronauts’ cosmological understandings. Following the work of Timothy Morton, the earth and other heavenly bodies can be understood as “hyperobjects”, entities that are distributed across time and space in ways that make them difficult for human beings to accurately understand, but whose existence is becoming increasingly detectable to us. Astronauts in outer space are able to perceive celestial objects from vantages literally unavailable on earth, which has often (but not always) had a profound influence on their understandings of humanity, life, and the universe itself. Frank Wright’s term, the “overview effect”, describes a cognitive shift resulting from seeing the Earth from space that increases some astronauts’ sense of connection to humanity, God, or other powerful forces. Following NASA convention (NASA Style Guide, 2012), I will capitalize both Earth and Moon, but will leave all quotations in their original style. The “ultraview effect” is a term I introduce here to describe the parallel experience of viewing the Milky Way galaxy from the Moon’s orbit (a view described reverently by one respondent as a “something I was not ready for”) that can result in strong convictions about the prevalence of life in the universe or even unorthodox beliefs about the origins of humanity. I will compare Morton’s ideas about humanity’s increased awareness of hyperobjects with Joye and Verpooten’s work on awe in response to “bigness”, tying both to astronauts’ lived experiences in order to demonstrate the usefulness of ethnographic data in this context, discuss how human experiences in outer space might influence religious practices and beliefs, and suggest that encounters with hyperobjects hold the potential to be socially beneficial.


Author(s):  
Karel Schrijver

How many planetary systems formed before our’s did, and how many will form after? How old is the average exoplanet in the Galaxy? When did the earliest planets start forming? How different are the ages of terrestrial and giant planets? And, ultimately, what will the fate be of our Solar System, of the Milky Way Galaxy, and of the Universe around us? We cannot know the fate of individual exoplanets with great certainty, but based on population statistics this chapter sketches the past, present, and future of exoworlds and of our Earth in general terms.


Author(s):  
David M. Wittman

Orbits are ubiquitous in the universe: moons orbit planets, planets orbit stars, stars orbit around the center of the Milky Way galaxy, and so on. Any theory of gravity will have to explain the properties of all these orbits. To pave the way for developing the metric theory of gravity (general relativity) this chapter examines the basics of orbits as observed and as explained by the Newtonian model of gravity. We can use our understanding of gravity to infer the masses and other properties of these cosmic systems. Te chapter concludes with four optional sections in this spirit, covering the slingshot maneuver; dark matter; binary star orbits and how they reveal the masses of stars; and extrasolar planets.


2021 ◽  
pp. 47-75
Author(s):  
Raymond T. Pierrehumbert

‘What are planets made of?’ assesses what planets are made of, beginning by looking at the life cycle of stars, and the kinds of stars which populate the Universe. Although the first stars of the Universe could not have formed planetary systems, the process did not take long to get under way. The Milky Way galaxy formed not long after the Big Bang and has been building its stock of heavy elements ever since. Thus, our Solar System incorporates ingredients from a mix of myriad expired stars, most of which have been processed multiple times through short-lived stars.


1998 ◽  
Vol 11 (1) ◽  
pp. 58-61
Author(s):  
T.C. Beers

Measurement of the abundances of the light and heavy elements in stars of the Milky Way galaxy is the cornerstone for the study of numerous aspects of chemical evolution in galaxies and the Universe. We stand poised to enter an era of rapid understanding, as new-generation telescopes with apertures in the 8m-10m class enable astronomers to obtain high-resolution, high-signal-to-noise near-UV, optical, and IR spectra of the stars which have locked up the chemical history of our Galaxy in their outer atmospheres. It is thus appropriate to review present surveys for the low-metallicity stars of our Galaxy, as the stars we uncover today will be studied so intensively in the coming decades.


2008 ◽  
Vol 4 (T27A) ◽  
pp. 280-281
Author(s):  
Joseph Lazio

The Working GroupGalactic Centerwas created following a Business Meeting meeting of Division VIIGalactic Systems, held with the concurrence of Division VIIIGalaxies and the Universe, at the IAU XXVI General Assembly in Prague, 2006. The objective of the meeting was to highlight both recent progress on understanding the Galactic Center as well as to illustrate the way in which the center of the Milky Way Galaxy serves as a laboratory for understanding other galactic nuclei.


2010 ◽  
Vol 6 (T27B) ◽  
pp. 216-217
Author(s):  
Ortwin Gerhard ◽  
Despina Hatzidimitriou ◽  
Patricia A. Whitelock ◽  
Charles J. Lada ◽  
Ata Sarajedini ◽  
...  

Division VII provides a forum for astronomers studying the Milky Way Galaxy and its constituents. Several meetings directly relevant to his subject were held at the General Assembly in Rio: IAU Symp. 262 Stellar Populations, IAU Symp. 265 Chemical Abundances in the Universe, IAU Symp. 266 Star Clusters, Joint Discussion 5 Modeling the Milky Way in the Era of Gaia, and Special Session 5 The Galactic Plane. Division VII therefore did not organize a separate science session at Rio, but business meetings were held for both the Division and for Commissions 33 and 37.


2020 ◽  
Vol 217 ◽  
pp. 11002
Author(s):  
Olga Baryshnikova ◽  
Catherine Sapelnik ◽  
Lyudmila Fedoseeva

The paper investigates a model of the local Universe based on the concepts of nonrelativistic physics. The space-time boundaries of its applicability are estimated. The finiteness of the Universe in space and time arising from the analysis of the field of forces and energy fields of the Universe is affirmed. The necessity of the existence of “dark matter” in the proposed model is shown. On the basis of the presented model (using the modern values of the Hubble parameter and the density of the substance of the Universe), the following are estimated: the age of the Universe; the mass of its substance; period of her life cycle; acceleration of the movement of matter, etc. The dependences of the density of matter (and its minimum value), the radius of the Universe (and its maximum value), and the Hubble parameter on time are obtained. The position of the Milky Way galaxy in the Universe has also been estimated. It is shown that the law of conservation of energy in its classical formulation is not applicable to the Universe as a whole. It is argued that after a while the laws of classical physics will be applicable to the entire Universe as a whole.


2018 ◽  
Vol 184 ◽  
pp. 01001
Author(s):  
Wako Aoki

The r-process nucleosynthesis in the Universe is constrained by observations of chemical abundances of the Solar System and those of old stars that should record the products of the r-process events in the early Universe. This review provides a brief overview of the observational technique to determine chemical abundances of stars. Tar-gets of observations are stars in different populations of the Milky Way Galaxy and sur-rounding dwarf galaxies, providing different kind of constraints on the understanding of the r-process. Recent progress in observational studies to identify the r-process sites are also reviewed.


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