Universe

Lecture 3 of Leonard Susskind’s Modern Physics concentrating on Cosmology. Recorded January 26, 2009 at Stanford University.

This Stanford Continuing Studies course is the fifth of a six-quarter sequence of classes exploring the essential theoretical foundations of modern physics. The topics covered in this course focus on classical mechanics. Leonard Susskind is the Felix Bloch Professor of Physics at Stanford University.

Stanford University:

http://www.stanford.edu

Stanford Continuing Studies:

http://continuingstudies.stanford.edu/

About Leonard Susskind:

http://www.stanford.edu/dept/physics/people/faculty/susskind_leonard.html

Stanford University Channel on YouTube:
http://www.youtube.com/stanford

Duration : 2:0:27

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The Mystery of Dark Matter (1/4): Stars Are Moving Too Fast.

A mystery exists! Galaxies do not seem to have enough mass for stars to orbit at their observed speeds. Galaxies should be flying apart, but they don’t. Why not? Explore the surreal world of dark matter – one of the universe’s greatest mysteries.

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Shedding Light on Dark Matter

Over the last few decades, physicists have discovered that around ninety percent of every galaxy in the universe is made of an unseen substance called dark matter. Damian Pope, PIs Senior Manager of Scientific Outreach, comments, Its currently one of the hottest topics in physics. The module provides teachers with tools to show how dark matter was discovered, to explain why it remains a mystery, and to share the passion of scientists who are trying to discover what its made of.

This presentation is available to educators on DVD and comes complete with specially-crafted teacher notes.

• http://www.perimeterinstitute.ca

The Mystery of Dark Matter Video Game
• http://perimeterinstitute.ca/dark_matter_game/index.html

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In astronomy and cosmology, dark matter is a form of matter that is undetectable by its emitted electromagnetic radiation, but whose presence can be inferred from gravitational effects on visible matter and background radiation. According to present observations of structures larger than galaxies, as well as Big Bang cosmology, dark matter accounts for the vast majority of the mass in the observable universe.

Dark matter was postulated by Fritz Zwicky in 1934, to account for evidence of “missing mass” in the orbital velocities of galaxies in clusters. Subsequent to then, other observations have indicated the presence of dark matter in the universe, including the rotational speeds of galaxies, gravitational lensing of background objects by galaxy clusters such as the Bullet Cluster, and the temperature distribution of hot gas in galaxies and clusters of galaxies.

Dark matter plays a central role in state-of-the-art modeling of structure formation and galaxy evolution, and has measurable effects on the anisotropies observed in the cosmic microwave background. All these lines of evidence suggest that galaxies, clusters of galaxies, and the universe as a whole contain far more matter than that which interacts with electromagnetic radiation: the remainder is frequently called the “dark matter component,” even though there is a small amount of baryonic dark matter. The largest part of dark matter, which does not interact with electromagnetic radiation, is not only “dark” but also, by definition, utterly transparent.

The vast majority of the dark matter in the universe is believed to be nonbaryonic, which means that it contains no atoms and that it does not interact with ordinary matter via electromagnetic forces. The nonbaryonic dark matter includes neutrinos, and possibly hypothetical entities such as axions, or supersymmetric particles. Unlike baryonic dark matter, nonbaryonic dark matter does not contribute to the formation of the elements in the early universe (“big bang nucleosynthesis”) and so its presence is revealed only via its gravitational attraction. In addition, if the particles of which it is composed are supersymmetric, they can undergo annihilation interactions with themselves resulting in observable by-products such as photons and neutrinos (“indirect detection”).

Nonbaryonic dark matter is classified in terms of the mass of the particle(s) that is assumed to make it up, and/or the typical velocity dispersion of those particles (since more massive particles move more slowly). There are three prominent hypotheses on nonbaryonic dark matter, called Hot Dark Matter (HDM), Warm Dark Matter (WDM), and Cold Dark Matter (CDM); some combination of these is also possible. The most widely discussed models for nonbaryonic dark matter are based on the Cold Dark Matter hypothesis, and the corresponding particle is most commonly assumed to be a neutralino. Hot dark matter might consist of (massive) neutrinos. Cold dark matter would lead to a “bottom-up” formation of structure in the universe while hot dark matter would result in a “top-down” formation scenario.

As important as dark matter is believed to be in the universe, direct evidence of its existence and a concrete understanding of its nature have remained elusive. Though the theory of dark matter remains the most widely accepted theory to explain the anomalies in observed galactic rotation, some alternative theories such as modified Newtonian dynamics and tensor-vector-scalar gravity have been proposed. None of these alternatives, however, has garnered equally widespread support in the scientific community.

• http://en.wikipedia.org/wiki/Dark_matter
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Duration : 0:6:10

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***READ THIS BEFORE ASKING ANYTHING***

This is the ultimate size comparison video that you can find on the internet in HD.
Starts with the tinyest dwarf planets of our solar system, then continues with large planets, dwarf stars, stars giant/supergiant/hypergiant stars, nebulae, globular clusters and galaxies.
There is the famous VY Canis Majoris rated as the biggest star known, but very few know that that the incredible IC 1101 is the largest known object in the entire universe. Only galaxy clusters are bigger than it.
Hope you enjoy this one.

FAQ:
-Sizes are not 100% accurate as there is no way to directly measure them.
-Star sizes may change in the future, and new stars may eventually appear into this biggest stars list
-Song: Celtic Panpipes – Ride on

Duration : 0:4:0

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Science@ESA Vodcast (Episode 2): Planck – Looking Back To The Dawn Of Time (Part 1): Big Bang Cosmology.

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In the Science@ESA series Rebecca Barnes will take you on a journey of discovery into the rapidly evolving field of space astronomy and planetary exploration.

In this second episode Rebecca takes a close look at Planck – a European Space Agency mission built to detect radiation from the microwave portion of the electromagnetic spectrum. This mission will help find answers to some of the most important questions in modern science.

• http://astronomy2009.esa.int
• http://www.youtube.com/esa

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The Big Bang is the cosmological model of the initial conditions and subsequent development of the Universe that is supported by the most comprehensive and accurate explanations from current scientific evidence and observation.

As used by cosmologists, the term Big Bang generally refers to the idea that the Universe has expanded from a primordial hot and dense initial condition at some finite time in the past (currently estimated to have been approximately 13.7 billion years ago), and continues to expand to this day.

• http://en.wikipedia.org/wiki/Big_Bang

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Planck was selected as the third Medium-Sized Mission (M3) of ESA’s Horizon 2000 Scientific Programme, and is today part of its Cosmic Vision Programme. It is designed to image the anisotropies of the Cosmic Background Radiation Field over the whole sky, with unprecedented sensitivity and angular resolution.

Planck will provide a major source of information relevant to several cosmological and astrophysical issues, such as testing theories of the early universe and the origin of cosmic structure.

Planck was launched on 14 May 2009 together with the Herschel satellite. After launch, Planck and Herschel separated and are now proceeding to different orbits around the second Lagrangian point of the Earth-Sun System.

• http://www.esa.int/SPECIALS/Planck/index.html
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Duration : 0:6:4

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Cosmology -is the study of the Universe in its totality, and by extension, humanity’s place in it. Though the word cosmology is recent (first used in 1730 in Christian Wolff’s Cosmologia Generalis), study of the universe has a long history involving science, philosophy, esotericism, and religion. In recent times, physics and astrophysics have played a central role in shaping the understanding of the universe through scientific observation and experiment; or what is known as physical cosmology shaped through both mathematics and observation in the analysis of the whole universe. In other words, in this discipline, which focuses on the universe as it exists on the largest scale and at the earliest moments, it is generally understood to begin with the big bang (possibly combined with cosmic inflation) an expansion of space from which the universe itself is thought to have emerged ~13.7±0.2×109 (13.7 billion) years ago.[1] From its violent beginnings and until its various speculative ends, cosmologists propose that the history of the universe has been governed entirely by physical laws. Theories of an impersonal universe governed by physical laws were first proposed by Roger Bacon, a somewhat persecuted member of the Catholic Church.[2] Later, another member of the Catholic Church, Dmitry Grinevich, supported Bacon’s proposed laws through some experiments that he performed involving different physical laws. Between the domains of religion and science, stands the philosophical perspective of metaphysical cosmology. This ancient field of study seeks to draw intuitive conclusions about the nature of the universe, man, God and/or their relationships based on the extension of some set of presumed facts borrowed from spiritual experience and/or observation.

But metaphysical cosmology has also been observed as the placing of man in the universe in relationship to all other entities. This is demonstrated by the observation made by Marcus Aurelius of a man’s place in that relationship: “He who does not know what the world is does not know where he is, and he who does not know for what purpose the world exists, does not know who he is, nor what the world is.”[3] This is the purpose of the ancient metaphysical cosmology. However, Stoicism rejected Aristotle’s theory of universals as being “in the things themselves,” calling them “figments of the mind.” Stanford Encyclopedia of Philosophy adopting the concept of universals as being “concepts,” and therefore of the mind, and therefore controllable by free will. Thus, we get the analysis of Aurelius’ that the nature of the universe is not from “intuition,” but from a free-will, conceptual understanding of the nature of the universe.[original research?]

Cosmology is often an important aspect of the creation myths of religions that seek to explain the existence and nature of reality. In some cases, views about the creation (cosmogony) and destruction (eschatology) of the universe play a central role in shaping a framework of religious cosmology for understanding humanity’s role in the universe.

A more contemporary distinction between religion and philosophy, esoteric cosmology is distinguished from religion in its less tradition-bound construction and reliance on modern “intellectual understanding” rather than faith, and from philosophy in its emphasis on spirituality as a formative concept.

There are many historical cosmologies:

” the universe itself acts on us as a random, inefficient, and yet in the long run effective, teaching machine. our way of looking at the universe has gradually evolved through a natural selection of ideas.” —Steven Weinberg[4]

Duration : 0:9:30

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Join UCSD Physicist Kim Griest as he takes you on an exploration of two of the major unsolved questions in the physical sciences: What might be the fate of the universe and what is the nature of the dark matter which ultimately decides this fate? Series: “UCSD Millennium Lectures” [2/2000] [Science] [Show ID: 4661]

Duration : 0:57:54

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Velikovsky revisited, again. Dr Immanuel Velikovsky, Hero or Villain?

Plasma Cosmology Astronomy Carl Sagan Cosmology Space Electricity in space Electric Universe Wal Thornhill Dave Talbott Don Scott Petroglyphs rock art dragons and serpents celtic art spirals mythology myth plasma toruses comets venus mars jupiter saturn planets catastrophism catastrophes gradualism geology astrophysics alternative science scientific suppression peer review history of the solar system empiricism

Music By Delirium (First track) and Felix (Second and Third tracks)

Duration : 0:10:6

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http://Cosmology.com Origin & Creation of the Sun, Solar System, Planets, LIfe on Earth. http://BrainMind.com/Astrobiology.html

Duration : 0:20:6

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Lecture 2 of Leonard Susskind’s Modern Physics concentrating on Cosmology. Recorded January 19, 2009 at Stanford University.

This Stanford Continuing Studies course is the fifth of a six-quarter sequence of classes exploring the essential theoretical foundations of modern physics. The topics covered in this course focus on classical mechanics. Leonard Susskind is the Felix Bloch Professor of Physics at Stanford University.

Stanford University:

http://www.stanford.edu

Stanford Continuing Studies:

http://continuingstudies.stanford.edu/

About Leonard Susskind:

http://www.stanford.edu/dept/physics/people/faculty/susskind_leonard.html

Stanford University Channel on YouTube:
http://www.youtube.com/stanford

Duration : 1:57:11

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Complete video at: http://fora.tv/2008/07/23/Leonard_Susskind_-_The_Black_Hole_War

Stanford University physicist Leonard Susskind differentiates the theoretical concept of “dark matter” from its somewhat more controversial cousin, “dark energy.”

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Recognizing a contradiction in Stephen Hawking’s claim that things disappear in black holes, Susskind and Gerard t’Hooft offered a counterargument aimed at disproving this controversial theory.

Susskind discusses the story behind the black hole conflict and how it has led to a better idea of how our universe works – The Commonwealth Club of California

Leonard Susskind is a theoretical physics professor at Stanford University in the field of string theory and quantum field theory. Susskind is widely regarded as one of the fathers of string theory for his early contributions to the String Theory model of particle physics.

Duration : 0:3:14

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