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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/StarPhys/c
oulomb.html
for a less mathematical explanation, try:
http://en.wikipedia.org/wiki/Nuclear_fusion#Requir
ements
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 : 174717
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 : 20147
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 : 726672
Durée : 111 s |
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