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| What is quantum tunneling? |
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Transcript:
http://www.davidcolarusso.com/blog/?p=33#more
-33
This video is an adaptation of an earlier
piece of mine--Perspective on quantum
mechanical tunneling. That film, however, was
designed for a unique audience, and I felt
its overall length was limiting its appeal
here. So I've repackaged it as one of my
weekly postings. I Hope you enjoy.
People have been asking for the math. So here
it is. The Sun's core temp is ~13.6 MK. For
hydrogen nuclei the Coulomb barrier is
roughly 0.1 MeV. This corresponds to a
temperature in excess of 1 GK! Luckily,
tunneling and the distribution of speeds
among nuclei lower the actual temperature
required. So without tunneling even the Sun's
core isn't hot enough for fusion. To see most
of this worked through, check out this link:
http://burro.cwru.edu/Academics/Astr221/StarP
hys/coulomb.html
for a less mathematical explanation, try:
http://en.wikipedia.org/wiki/Nuclear_fusion#R
equirements
Transcript:
http://www.davidcolarusso.com/edblog/?p=41
The Tabletop Explainer is an intermittent
educational vlog presenting answers to viewer
questions, brief science lessons, and ideas
for teachers and students. It is a feature of
my blog "Tilts at Windmils" which can be
found at http://www.davidcolarusso.com/blog/
Tags : physics quantum mechanics tunneling fusion potential energy star reality uncertainty measurement |
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Affichage : 160447
Durée : 251 s |
| Quantum Computing Day 1: Introduction to Quantum Computing |
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Google Tech Talks
December, 6 2007
ABSTRACT
This tech talk series explores the enormous
opportunities afforded by the emerging field
of quantum computing. The exploitation of
quantum phenomena not only offers tremendous
speed-ups for important algorithms but may
also prove key to achieving genuine synthetic
intelligence. We argue that understanding
higher brain function requires references to
quantum mechanics as well. These talks look
at the topic of quantum computing from
mathematical, engineering and neurobiological
perspectives, and we attempt to present the
material so that the base concepts can be
understood by listeners with no background in
quantum physics.
This first talk of the series introduces the
basic concepts of quantum computing. We start
by looking at the difference in describing a
classical and a quantum mechanical system.
The talk discusses the Turing machine in
quantum mechanical terms and introduces the
notion of a qubit. We study the gate model of
quantum computing and look at the famous
quantum algorithms of Deutsch, Grover and
Shor. Finally we talk about decoherence and
how it destroys superposition states which is
the main obstacle to building large scale
quantum computers. We clarify widely held
misconceptions about decoherence and explain
that environmental interaction tends to
choose a basis in state space in which the
system decoheres while leaving coherences in
other coordinate systems intact.
Speaker: Hartmut Neven
Tags : google techtalks techtalk engedu talk talks googletechtalks education |
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Affichage : 17358
Durée : 3387 s |
| Quantum Of Solace Trailer (Bond 22) |
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This is a fan trailer for the new upcoming
Bond film, Quantum Of Solace. The film will
pick up "literally an hour after" Casino
Royale's conclusion, when a wounded Mr. White
is shot and captured by Bond at Lake Como.
Bond is then involved in a car chase in
Siena, Italy. White reveals to Bond and M
that his organization, Green Planet, has
agents in Her Majesty's Government and the
Central Intelligence Agency. Forensic
evidence of an MI6 traitor leads Bond to
Haiti, where he meets Camille, who then helps
him find Dominic Greene, a ruthless
businessman and a member of the organization.
Greene intends to use his government contacts
to help overthrow the current regime in a
Latin American country, and place the exiled
General Medrano as the head of state. Medrano
will in exchange give the organization a
barren piece of land, which actually will
give them total control of "one of the
world's most important natural resources".
Bond travels to Austria and South America to
unravel Greene's plan, staying one step ahead
of the CIA, terrorists and M whilst trying to
keep his desire for retribution over Vesper
Lynd's death in check. Quantum Of Solace hits
theatres everywhere on November 7th, 2008.
Tags : Quantum Of Solace Trailer James Bond 22 Casino Royale Daniel Craig Marc Forster Spyderfan007 |
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Affichage : 621493
Durée : 111 s |
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