Physical universe

Question

This piglix contains articles or sub-piglix about Physical universe

Answer 1

Cosmic latte

Cosmic latte

Cosmic Latte is a name assigned to the average color of the universe, given by a team of astronomers from Johns Hopkins University. In 2001, Karl Glazebrook and Ivan Baldry determined that the color of the universe was a greenish white, but they soon corrected their analysis in a 2002 paper, in which they reported that their survey of the color of all light in the universe added up to a slightly beigeish white. The survey included more than 200,000 galaxies, and measured the spectral range of the light from a large volume of the universe. The hexadecimal RGB value for Cosmic Latte is #FFF8E7.

The finding of the "color of the universe" was not the focus of the study, which was examining spectral analysis of different galaxies to study star formation. Like Fraunhofer lines, the dark lines displayed in the study's spectral ranges display older and younger stars and allow Glazebrook and Baldry to determine the age of different galaxies and star systems. What the study revealed is that the overwhelming majority of stars formed about 5 billion years ago. Because these stars would have been "brighter" in the past, the color of the universe changes over time shifting from blue to red as more blue stars change to yellow and eventually red giants.

Glazebrook's and Baldry's work was funded by the David and Lucile Packard Foundation.

As light from distant galaxies reaches the Earth, the average "color of the universe" (as seen from Earth) marginally increases towards pure white, due to the light coming from the stars when they were much younger and bluer.

The color was displayed in a Washington Post article. Glazebrook jokingly said that he was looking for suggestions for a name for the new color. Several people who read the article sent in suggestions. These were the results of a vote of the scientists involved based on the new color.

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Answer 2

Cosmogony

Cosmogony (or cosmogeny) is any model concerning the origin of either the cosmos or universe. Developing a complete theoretical model has implications in both the philosophy of science and epistemology.

The word comes from the Koine Greek κοσμογονία (from κόσμος "cosmos, the world") and the root of γί(γ)νομαι / γέγονα ("come into a new state of being"). In astronomy, cosmogony refers to the study of the origin of particular astrophysical objects or systems, and is most commonly used in reference to the origin of the universe, the solar system, or the earth-moon system.

The Big Bang theory is the prevailing cosmological model of the early development of the universe. The most commonly held view is that the universe was once a gravitational singularity, which expanded extremely rapidly from its hot and dense state. However, while this expansion is well-modeled by the Big Bang theory, the origins of the singularity remain as one of the unsolved problems in physics.

Cosmologist and science communicator Sean M. Carroll explains two competing types of explanations for the origins of the singularity which is the main disagreement between the scientists who study cosmogony and centers on the question of whether time existed "before" the emergence of our universe or not. One cosmogonical view sees time as fundamental and even eternal: The universe could have contained the singularity because the universe evolved or changed from a prior state (the prior state was "empty space", or maybe a state that could not be called "space" at all). The other view, held by proponents like Stephen Hawking, says that there was no change through time because "time" itself emerged along with this universe (in other words, there can be no "prior" to the universe). Thus, it remains unclear what combination of "stuff", space, or time emerged with the singularity and this universe.

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Answer 3

Cosmography

Cosmography is the science that maps the general features of the cosmos or universe, describing both heaven and Earth (but without encroaching on geography or astronomy). The 14th-century work 'Aja'ib al-makhluqat wa-ghara'ib al-mawjudat by Arab physician Zakariya al-Qazwini is considered to be an early work of cosmography.

Traditional Hindu, Buddhist and Jain cosmography schematize a universe centered on Mount Meru surrounded by rivers, continents and seas. These cosmographies posit a universe being repeatedly created and destroyed over time cycles of immense lengths.

In 1551, Martín Cortés de Albacar, from Zaragoza, Spain, published Breve compendio de la esfera y del arte de navegar. Translated into English and reprinted several times, the work was of great influence in Britain for many years. He proposed spherical charts and mentioned magnetic deviation and the existence of magnetic poles.

Peter Heylin's 1652 book Cosmographie (enlarged from his Microcosmos of 1621) was one of the earliest attempts to describe the entire world in English, and being the first known description of Australia and among the first of California. The book has 4 sections, examining the geography, politics, and cultures of Europe, Asia, Africa, and America, with an addendum on Terra Incognita, including Australia, and extending to Utopia, Fairyland, and the "Land of Chivalrie".

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Answer 4

Cosmology

Cosmology (from the Greek κόσμος, kosmos "world" and -λογία, -logia "study of") is the study of the origin, evolution, and eventual fate of the universe. Physical cosmology is the scholarly and scientific study of the origin, large-scale structures and dynamics, and ultimate fate of the universe, as well as the scientific laws that govern these realities.

The term cosmology was first used in English in 1656 in Thomas Blount's Glossographia, and in 1731 taken up in Latin by German philosopher Christian Wolff, in Cosmologia Generalis.

Religious or mythological cosmology is a body of beliefs based on mythological, religious, and esoteric literature and traditions of creation and eschatology.

Physical cosmology is studied by scientists, such as astronomers and physicists, as well as philosophers, such as metaphysicians, philosophers of physics, and philosophers of space and time. Because of this shared scope with philosophy, theories in physical cosmology may include both scientific and non-scientific propositions, and may depend upon assumptions that can not be tested. Cosmology differs from astronomy in that the former is concerned with the Universe as a whole while the latter deals with individual celestial objects. Modern physical cosmology is dominated by the Big Bang theory, which attempts to bring together observational astronomy and particle physics; more specifically, a standard parameterization of the Big Bang with dark matter and dark energy, known as the Lambda-CDM model.

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Answer 5

Cosmos

The cosmos (UK /ˈkɒzmɒs/, US /ˈkɒzmoʊs/) is the universe regarded as a complex and orderly system; the opposite of chaos. The philosopher Pythagoras used the term cosmos (Ancient Greek: κόσμος) for the order of the universe, but the term was not part of modern language until the 19th century geographer and polymath, Alexander von Humboldt, resurrected the use of the word from the ancient Greek, assigned it to his multi-volume treatise, Kosmos, which influenced modern and somewhat holistic perception of the universe as one interacting entity.

Cosmology is the study of the cosmos in several of the above meanings, depending on context. All cosmologies have in common an attempt to understand the implicit order within the whole of being. In this way, most religions and philosophical systems have a cosmology.

Cosmology is a branch of metaphysics that deals with the nature of the universe, a theory or doctrine describing the natural order of the universe. The basic definition of Cosmology is the science of the origin and development of the universe. In modern astronomy the Big Bang theory is the dominant postulation.

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Answer 6

Earth%27s location in the Universe

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Answer 7

Gold universe

A Gold universe is a cosmological model of the universe. In these models, the universe starts with a Big Bang and expands for some time, with increasing entropy and a thermodynamic arrow of time pointing in the direction of the expansion. After the universe reaches a low-density state, it recontracts, but entropy now decreases, pointing the thermodynamic arrow of time in the opposite direction, until the universe ends in a low-entropy, high-density Big Crunch. There are two models of the universe which support the possibility of a reversed direction of time. The first begins with a state of low entropy at the Big Bang which continually increases until the Big Crunch. The second, a Gold Universe, posits that entropy will increase only until a moment of contraction, then gradually decrease. This latter model suggests the universe will become more orderly after the moment of contraction. The Gold model has been linked to the possibility of retrocausal change, questions concerning the preservation of information in a time-reversed universe (states of decreasing entropy), and causation in general. The Gold Universe is named after the cosmologist Thomas Gold, who proposed the model in the 1960s.

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Answer 8

Graphical timeline from Big Bang to Heat Death

This is the timeline of the Universe from Big Bang to Heat Death scenario. The different eras of the universe are shown. The heat death will occur in 10¹⁰³ years, if protons decay.

Usually the logarithmic scale is used for such timelines but it compresses the most interesting Stelliferous Era too much as this example shows. Therefore, a double-logarithmic scale s (s*100 in the graphics) is used instead. The minimum of it is unfortunately only 1, not 0 as needed, and the negative outputs for inputs smaller than 10 are useless. Therefore, the time from 0.1 to 10 years is collapsed to a single point 0, but that doesn't matter in this case because nothing special happens in the history of the universe during that time.

The seconds in the timescale have been converted to years by second/31557600{\displaystyle second/31557600} using the Julian year.

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Answer 9

Graphical timeline of the universe

This more than 20-billion-year timeline of our universe shows the best estimates of major events from the universe's beginning to anticipated future events. Zero on the scale is the present day. A large step on the scale is one billion years; a small step, one hundred million years. The past is denoted by a minus sign: e.g., the oldest rock on Earth was formed about four billion years ago and this is marked at -4e+09 years. The "Big Bang" event most likely happened 13.8 billion years ago; see age of the Universe.

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Answer 10

Graphical timeline of the Big Bang

This timeline of the Big Bang shows a sequence of events as currently theorized by scientists, but not yet completely proven. Dark Ages.

It is a logarithmic scale that shows 10â‹…<!-- ⋅ -->log10{\displaystyle 10\cdot \log _{10}} second instead of second. For example, one microsecond is 10â‹…<!-- ⋅ -->log10⁡<!-- ⁡ -->0.000001=10â‹…<!-- ⋅ -->(−<!-- − -->6)=−<!-- − -->60{\displaystyle 10\cdot \log _{10}0.000001=10\cdot (-6)=-60}. To convert -30 read on the scale to second calculate 10−<!-- − -->3010=10−<!-- − -->3=0.001{\displaystyle 10^{-{\frac {30}{10}}}=10^{-3}=0.001} second = one millisecond. On a logarithmic time scale a step lasts ten times longer than the previous step.

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