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Best0fScience uploaded a new video
(2 days ago)
Quantum Mechanics (Part 1): A Brief History Of Quantum Mechanics.
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Quantum Mechanics (Part 1): A Brief History Of Quantum Mechanics.
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• http://www.youtub...
• http://www.youtub...
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The history of quantum mechanics began essentially with the 1838 discovery of cathode rays by Michael Faraday, the 1859 statement of the black body radiation problem by Gustav Kirchhoff, the 1877 suggestion by Ludwig Boltzmann that the energy states of a physical system could be discrete, and the 1900 quantum hypothesis by Max Planck that any energy is radiated and absorbed in quantities divisible by discrete energy elements, E, such that each of these energy elements is proportional to the frequency ν with which they each individually radiate energy.
Planck insisted that this was simply an aspect of the processes of absorption and emission of radiation and had nothing to do with the physical reality of the radiation itself.
However, at that time, this appeared not to explain the photoelectric effect (1839), i.e. that shining light on certain materials can function to eject electrons from the material.
In 1905, basing his work on Plancks quantum hypothesis, Albert Einstein postulated that light itself consists of individual quanta. These later came to be called photons (1926). From Einstein's simple postulation was born a flurry of debating, theorizing and testing, and thus, the entire field of quantum physics.
• http://en.wikiped...
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Quantum mechanics (QM) is a set of principles describing the physical reality at the atomic level of matter (molecules and atoms) and the subatomic (electrons, protons, and even smaller particles). These descriptions include the simultaneous wave-like and particle-like behavior of both matter and radiation ("waveparticle duality").
Quantum Mechanics is a mathematical description of reality, like any scientific model. Some of its predictions and implications go against the "common sense" of how humans see a set of bodies (a system) behave. This isn't necessarily a failure of Quantum mechanics - it's more of a reflection of how humans understand space and time on larger scales (e.g., centimetres, seconds) rather than much smaller.
Quantum mechanics says that the most complete description of a system is its wavefunction, which is just a number varying between time and place. One can derive things from the wavefunction, such as the position of a particle, or its momentum. Yet the wavefunction describes probabilities, and some physical quantities which classical physics would assume are both fully defined together simultaneously for a system are not simultaneously given definite values in Quantum mechanics.
It is not that the experimental equipment is not precise enough - the two quantities in question just are not defined at the same time by the Universe. For instance, location and velocity do not exist simultaneously for a body (this is called the Heisenberg uncertainty principle)
Certain systems, however, do exhibit quantum mechanical effects on a larger scale; superfluidity (the frictionless flow of a liquid at temperatures near absolute zero) is one well-known example. Quantum theory also provides accurate descriptions for many previously unexplained phenomena such as black body radiation and the stability of electron orbitals. It has also given insight into the workings of many different biological systems, including smell receptors and protein structures.
Even so, classical physics often can be a good approximation to results otherwise obtained by quantum physics, typically in circumstances with large numbers of particles or large quantum numbers. (However, some open questions remain in the field of quantum chaos.)
• http://en.wikiped...
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Best0fScience uploaded a new video
(4 days ago)
Ariane 30th anniversary: 30 years of Ariane - a success story.
On 24 Dece...
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Ariane 30th anniversary: 30 years of Ariane - a success story.
On 24 December 1979, Ariane made its first flight from French Guyana marking the beginning of 30 years of success and giving Europe a guaranteed independant access to Space.
With Ariane ESA could develop its own programmes in many different domains: Telecommunications, Earth Observation, Satellites, Science and Exploration. With Ariane Europe was the pionneer in the civil launch space market, with the creation of Arianespace, which is now the world leading space transportation company.
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• http://www.youtub...
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Arianespace powers on with 30 years of launches
24 December 1979: The new European launcher lifted off from the South American launch site at Kourou, French Guyana, with thundering engines a day of enormous importance for the entire European space effort. This was the first time that the member states of the European Space Agency (ESA) launched their own rocket into space the foundation stone of the extraordinary success story of the Ariane launcher system.
The German Institute of Aviation and Spaceflight Research and Development (Deutsche Forschungs- und Versuchsanstalt für Luft- und Raumfahrt; DFVLR), the forerunner of todays DLR (Deutsches Zentrum für Luft- und Raumfahrt), played an essential role in the story. It was at the Institutes testing facility near Heilbronn that the Viking rocket engines were tested and qualified.
This historic first launch was a milestone in commercial space flight, but the road to success was beset with innumerable hurdles and stumbling blocks. Understandably enough, there was little need for rocket science in post-war Germany. The first seed for a future rocket programme was sown at the end of the fifties in Baden-Württemberg.
Rocket researcher Eugen Sänger established the Rocket Engine Research Institute (Forschungsinstitut für Physik der Strahlantriebe) in Stuttgart, which later set up a test facility in the Harthäuser Forest near Heilbronn. In autumn 1962, the first tests were conducted using the new engine test stands for what was still a national rocket programme. Test stand P2 was already able to test engines with a thrust of 100 tons.
Learn more: http://www.dlr.de...
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Credits:
• http://www.esa.int/
• ESA/CNES/Arianespace - Chris Hein
• Edited by: Best0fScience/WissensMagazin
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Best0fScience uploaded a new video
(6 days ago)
Hubblecast 12: Hubble sees an Extrasolar Planet's Atmosphere (Murk on a ...
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Hubblecast 12: Hubble sees an Extrasolar Planet's Atmosphere (Murk on a monster planet).
Using the NASA/ESA Hubble Space Telescope, astronomers have found the first clear evidence of high altitude haze or clouds in the atmosphere of an extrasolar planet (exoplanet). This discovery reveals a deeper understanding of the class of giant planets that astronomers call 'hot Jupiters'.
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• http://www.youtub...
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Over the last 15 years astronomers have discovered more than 270 planets around other stars. A burning question is naturally: What are these so called extrasolar planets like?
Most of them are actually giant gaseous worlds several times the size of Jupiter which is our own Solar Systems largest planet. Others are smaller rocky or icy worlds that are still several times larger than our own home planet Earth. We have yet to discover a world that is similar to our own planet.
Using the Advanced Camera for Surveys (or ACS), the Hubble Space Telescope has recently observed a fascinating large gaseous planet around the star HD 189733. Careful analysis of these very high precision observations by a team lead by Frédéric Pont from the Geneva University Observatory showed that this planet, designated HD 189733b, possesses a murky haze layer extending over an altitude range of about 1000 km in the planets upper atmosphere. The atmosphere of this gaseous planet is at around 800 degrees Centigrade.
This is due to its proximity to its parent star and is the reason that astronomers call this type of planet a hot Jupiter. These hazes are probably made of tiny condensed particles less that 1/1000th of a millimetre across, similar to those already known on Venus and Saturns moon, Titan. Their presence means that the sky over HD 189733b would look very much like a red hazy sunset viewed from an industrially polluted city on Earth.
Whats so special about this particular star and its planet? Bob Fosbury: "This is a rather special planetary system because the star itself is quite small, its only about 75% the size of our Sun and yet the planet itself is larger than Jupiter. So when the planet transits in front of the star it obscures quite a large fraction of light from the star which enables a very accurate measurement."
What exactly made these observations so precise? Why was this only possible now? Bob Fosbury: "We have to do this from space because when we try and do this from the ground the atmosphere makes it very difficult to make precise measurements of brightness, so we do it from space. And the special thing about this particular observation is that the scientists spread the light out over many pixels in the detector. So rather than just having a little point of light representing the star on the detector the starlight was spread out into a spectrum using this so called grism mode of the Advanced Camera for Surveys."
"Now, that enables a very precise measurement because you can measure over many many pixels (a large area of detector)but it also, by spreading out the colours, enables you to measure the brightness (or the reduction in brightness) of the starlight over many colours. So having these different measurements in different colours enables you to characterize the nature of the atmosphere."
The reason why this work was possible at all was because from our vantage point the orbit of HD 189733b is seen almost exactly edge on. Now what that means is that every two days or so the planet actually moves across the face of its parent star as seen from here. Now when that happens some small fraction of the light from the star has to pass through the atmosphere of the planet in front of it in order to reach Earth. Because of this process the composition of the atmosphere of the planet is stamped onto the light like a unique fingerprint. Astronomers can then see this fingerprint in the spectrum of the stars light.
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Hubblecast features news and Images from the Hubble Space Telescope (HST).
The space-based observatory is a collaboration between NASA and ESA. The observations are carried out in visible, infrared and ultraviolet light. In many ways Hubble has revolutionised modern astronomy.
The Hubble Space Telescope has made some of the most dramatic discoveries in the history of astronomy. From its vantage point 600 km above the Earth, Hubble can detect light with "eyes" five times sharper than the best ground-based telescopes and looks deep into space where some of the most profound mysteries are still buried in the mists of time.
• http://www.eso.org
• http://www.spacet...
• http://hubblesite...
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Best0fScience uploaded a new video
(1 week ago)
The Standard Model of Particle Physics (Part 8): The Higgs Mechanism.
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The Standard Model of Particle Physics (Part 8): The Higgs Mechanism.
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• http://www.youtub...
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STANDARD MODEL OF PARTICLE PHYSICS:
http://www.youtub...
1) First Second Of The Universe:
http://www.youtub...
2) Force And Matter:
http://www.youtub...
3) Quarks:
http://www.youtub...
4) Gluons:
http://www.youtub...
5) Electrons, Protons And Neutrons:
http://www.youtub...
6) Photons, Gravitons & Weak Bosons:
http://www.youtub...
7) Neutrinos:
http://www.youtub...
8) The Higgs Boson / The Higgs Mechanism:
http://www.youtub...
The Standard Model of particle physics is a theory of three of the four known fundamental interactions and the elementary particles that take part in these interactions. These particles make up all visible matter in the universe.
Every high energy physics experiment carried out since the mid-20th century has eventually yielded findings consistent with the Standard Model.
Still, the Standard Model falls short of being a complete theory of fundamental interactions because it does not include gravitation, dark matter, or dark energy. It is not quite a complete description of leptons either, because it does not describe nonzero neutrino masses, although simple natural extensions do.
• http://en.wikiped...
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The HIGGS BOSON is a massive scalar elementary particle predicted to exist by the Standard Model in particle physics. At present there are no other known fundamental scalar particles in nature.
The Higgs boson is the only Standard Model particle that has not been observed. Experimental detection of the Higgs boson would help explain the origin of mass in the universe.
The Higgs boson would explain the difference between the massless photon, which mediates electromagnetism, and the massive W and Z bosons, which mediate the weak force. If the Higgs boson exists, it is an integral and pervasive component of the material world.
The Large Hadron Collider (LHC) at CERN, which became operational on November 20, 2009, is expected to provide experimental evidence of the existence or non-existence of the Higgs boson. Experiments at Fermilab also continue previous attempts at detection, albeit hindered by the lower energy of the Fermilab Tevatron accelerator.
It has been reported that Fermilab physicists suggest that the odds of Tevatron detecting the Higgs boson are between 50% and 96%, depending on its mass.
The Higgs mechanism, which gives mass to vector bosons, was theorized in 1964 by François Englert and Robert Brout ("boson scalaire"); in October of the same year by Peter Higgs, working from the ideas of Philip Anderson; and independently by Gerald Guralnik, C. R. Hagen, and Tom Kibble,who worked out the results by the spring of 1963.
The three papers written on this discovery by Guralnik, Hagen, Kibble, Higgs, Brout, and Englert were each recognized as milestone papers during Physical Review Letters 50th anniversary celebration. While each of these famous papers took similar approaches, the contributions and differences between the 1964 PRL Symmetry Breaking papers is noteworthy.
These six physicists were also awarded the 2010 J. J. Sakurai Prize for Theoretical Particle Physics for this work. Steven Weinberg and Abdus Salam were the first to apply the Higgs mechanism to the electroweak symmetry breaking. The electroweak theory predicts a neutral particle whose mass is not far from that of the W and Z bosons.
• http://en.wikiped...
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The Cassiopeia Project - making science simple!
The Cassiopeia Project is an effort to make high quality science videos available to everyone. If you can visualize it, then understanding is not far behind.
• http://www.cassio...
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Best0fScience uploaded a new video
(1 week ago)
"Evolution is REAL Science #5: Evidence For Evolution - Transitiona...
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"Evolution is REAL Science #5: Evidence For Evolution - Transitional Forms" by
• http://www.youtub...
• http://www.anevol...
Does the evidence support Evolution?
Find out what evolutionary theory actually predicts about intermediate forms in the fossil record.
Evolution is testable ... human and ape chromosome numbers.
Theories are crucial to science because they provide a coherent framework for making sense out of scientific observations.
An example of such a theory is the Theory of Evolution. Without the theoretical framework of evolution, biologists would be limited to observing living things and noting the similarities and differences between them.
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• http://www.youtub...
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Fossil discoveries, combined with evidence from morphological, genetic, and embryological studies of existing organisms lead us to a powerful explanation of a large set of biological observations. These observations only make sense using the REAL science of evolution.
Read more about this topic:
• http://www.anevol...
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ANYONE WITH AN INTEREST IN ASTRONOMY WILL LOVE GZ2
All the Best
Peace :)
Great videos!