Heisenberg's uncertainty principle
http://en.wikipedia.org/wiki/Heisenberg%27s_uncertainty_principle
http://www.youtube.com/watch?v=a8FTr2qMutA
http://www.youtube.com/watch?v=7vc-Uvp3vwg
Heisenberg's uncertainty principle tells us that it is
impossible to simultaneously measure the position and momentum
of a particle with infinite precision. In our everyday lives
we virtually never come up against this limit, hence why it
seems peculiar. In this experiment a laser is shone through a
narrow slit onto a screen. As the slit is made narrower, the
spot on the screen also becomes narrower. But at a certain
point, the spot starts becoming wider. This is because the
photons of light have been so localised at the slit that their
horizontal momentum must become less well defined in order to
satisfy Heisenberg's uncertainty principle.
Quantum vacuum fluctuation (or Quantum Fluctuation for short)
http://en.wikipedia.org/wiki/Quantum_fluctuation
Quoting from the above Wikipedia page:
"In quantum physics, a quantum vacuum fluctuation (or quantum
fluctuation or vacuum fluctuation) is the temporary change in
the amount of energy in a point in space, arising from Werner
Heisenberg's uncertainty principle.
"According to one formulation of the principle, energy and time
can be related by the relation
"That means that conservation of energy can appear to be
violated, but only for small times. This allows the creation of
particle-antiparticle pairs of virtual particles. The effects
of these particles are measurable, for example, in the
effective charge of the electron, different from its "naked"
charge.
"In the modern view, energy is always conserved, but the
eigenstates of the Hamiltonian (energy observable) are not the
same as (i.e., the Hamiltonian doesn't commute with) the
particle number operators.
"Quantum fluctuations may have been very important in the origin
of the structure of the universe: according to the model of
inflation the ones that existed when inflation began were
amplified and formed the seed of all current observed structure."
Empty Space is not Empty (as one would expect from Uncertainty)
http://www.youtube.com/watch?v=y4D6qY2c0Z8
Quoting from A USENET Posting by Steve Carlip (UC Davis):
"CMB fluctuations give evidence for (though not proof of)
inflation.
"So far, I haven't said anything about where the initial
density variations of the pre-recombination plasma came from.
There are many possibilities. We know, at least, that they
must be there -- even if we try to start with a perfectly
smooth, unvarying plasma, the Heisenberg uncertainty principle
tells us that there must be a minimum level of quantum
fluctuations.
"Inflationary" models propose that the very early Universe --
before the time of primordial nucleosynthesis -- underwent a
very rapid expansion. Such an expansion would smooth
out/dilute any earlier inhomogeneities, leaving only the
quantum fluctuations, which would be "stretched" in size by
the rapidly expanding space.
"Such models predict a special pattern of fluctuations. In
particular, although any particular fluctuation is random, the
average number at any particular scale is predictable. This
pattern on initial variations, in turn, should show up in the
details of the CMB variations. So far, observations match the
predictions of inflation very well. Most people in the field
don't consider this conclusive -- one can imagine other ways
of getting a similar pattern of initial perturbations -- but
it is suggestive."
Inflation (cosmology)
http://en.wikipedia.org/wiki/Inflation_(cosmology)
"In physical cosmology, cosmic inflation, cosmological
inflation, or just inflation is the extremely rapid
exponential expansion of the early universe by a factor of at
least 10^78 in volume, driven by a negative-pressure vacuum
energy density.[1] The inflationary epoch comprises the first
part of the electroweak epoch following the grand unification
epoch. It lasted from 10^-36 seconds after the Big Bang to
sometime between 10^-33 and 10^-32 seconds. Following the
inflationary period, the universe continued to expand, but at
a slower rate.
"The term "inflation" is also used to refer to the hypothesis
that inflation occurred, to the theory of inflation, or to
the inflationary epoch. The inflationary hypothesis was
originally proposed in 1980 by American physicist Alan Guth,
who named it "inflation".[2] It was also proposed by
Katsuhiko Sato in 1981.[3]
"As a direct consequence of this expansion, all of the
observable universe originated in a small causally connected
region. Inflation answers the classic conundrum of the Big
Bang cosmology: why does the universe appear flat,
homogeneous, and isotropic in accordance with the
cosmological principle when one would expect, on the basis of
the physics of the Big Bang, a highly curved, heterogeneous
universe? Inflation also explains the origin of the
large-scale structure of the cosmos. Quantum fluctuations in
the microscopic inflationary region, magnified to cosmic
size, become the seeds for the growth of structure in the
universe (see galaxy formation and evolution and structure
formation)."
Cosmic Inflation and the Accelerating Universe - Part 1 - Alan Guth
http://www.youtube.com/watch?v=HwCCMHH378Q
Alan H. Guth describes the theory of inflation and presents
evidence that indicates our universe very likely underwent a
perod of inflation in its early existence. He also discusses
the surprising observation that the expansion of the universe
is accelerating, offers possible explanations for this
acceleration, and describes its impact on particle physics.
Cosmology Lecture -- Leonard Susskind (Stanford)
http://www.youtube.com/watch?v=hADOY0TzLic
Leonard Susskind presents the theory of cosmological inflation
under which the early universe expanded exponentially before
the Big Bang. This theory explains the lack of observed
magnetic monopoles and the uniformity of the cosmic microwave
background radiation.
What if we are wrong?
Inflationary cosmology on trial
http://www.youtube.com/watch?v=IcxptIJS7kQ
Physics Nobel Prize 2011 - Brian Schmidt
http://www.youtube.com/watch?v=YHBvOOX3RJQ
The Nobel Prize for physics in 2011 was awarded to Brian
Schmidt, Adam Riess, and Saul Perlmutter for discovering that
the universe is expanding at an accelerating rate. This
finding was completely unexpected because it was thought that
gravity should slow the expansion of the cosmos. The best
current explanation of why the universe is accelerating is
that there is some energy tied to empty space which pushes
matter apart. This 'Dark Energy' makes up 73% of the universe
but is very difficult to detect. Images courtesy of
NASA/NASAimages.org and Maritza A. Lara-Lopez
No Center
http://www.youtube.com/watch?v=W4c-gX9MT1Q
http://www.astro.ucla.edu/~wright/nocenter.html
http://www.astro.ucla.edu/~wright/infpoint.html
Also see Ned Wright's Cosmology Tutorial
http://www.astro.ucla.edu/~wright/cosmolog.htm
http://www.astro.ucla.edu/~wright/cosmology_faq.html
http://www.astro.ucla.edu/~wright/CosmoCalc.html
WMAP: Foundations of the Big Bang theory
http://map.gsfc.nasa.gov/m_uni.html
WMAP: Tests of Big Bang Cosmology
http://map.gsfc.nasa.gov/m_uni/uni_101bbtest.html
sam.wormley@gmail.com
Heisenberg's uncertainty principle
http://en.wikipedia.org/wiki/Heisenberg%27s_uncertainty_principle
http://www.youtube.com/watch?v=a8FTr2qMutA
http://www.youtube.com/watch?v=7vc-Uvp3vwg
Heisenberg's uncertainty principle tells us that it is
impossible to simultaneously measure the position and momentum
of a particle with infinite precision. In our everyday lives
we virtually never come up against this limit, hence why it
seems peculiar. In this experiment a laser is shone through a
narrow slit onto a screen. As the slit is made narrower, the
spot on the screen also becomes narrower. But at a certain
point, the spot starts becoming wider. This is because the
photons of light have been so localised at the slit that their
horizontal momentum must become less well defined in order to
satisfy Heisenberg's uncertainty principle.
Quantum vacuum fluctuation (or Quantum Fluctuation for short)
http://en.wikipedia.org/wiki/Quantum_fluctuation
Quoting from the above Wikipedia page:
"In quantum physics, a quantum vacuum fluctuation (or quantum
fluctuation or vacuum fluctuation) is the temporary change in
the amount of energy in a point in space, arising from Werner
Heisenberg's uncertainty principle.
"According to one formulation of the principle, energy and time
can be related by the relation
"That means that conservation of energy can appear to be
violated, but only for small times. This allows the creation of
particle-antiparticle pairs of virtual particles. The effects
of these particles are measurable, for example, in the
effective charge of the electron, different from its "naked"
charge.
"In the modern view, energy is always conserved, but the
eigenstates of the Hamiltonian (energy observable) are not the
same as (i.e., the Hamiltonian doesn't commute with) the
particle number operators.
"Quantum fluctuations may have been very important in the origin
of the structure of the universe: according to the model of
inflation the ones that existed when inflation began were
amplified and formed the seed of all current observed structure."
Empty Space is not Empty (as one would expect from Uncertainty)
http://www.youtube.com/watch?v=y4D6qY2c0Z8
Quoting from A USENET Posting by Steve Carlip (UC Davis):
"CMB fluctuations give evidence for (though not proof of)
inflation.
"So far, I haven't said anything about where the initial
density variations of the pre-recombination plasma came from.
There are many possibilities. We know, at least, that they
must be there -- even if we try to start with a perfectly
smooth, unvarying plasma, the Heisenberg uncertainty principle
tells us that there must be a minimum level of quantum
fluctuations.
"Inflationary" models propose that the very early Universe --
before the time of primordial nucleosynthesis -- underwent a
very rapid expansion. Such an expansion would smooth
out/dilute any earlier inhomogeneities, leaving only the
quantum fluctuations, which would be "stretched" in size by
the rapidly expanding space.
"Such models predict a special pattern of fluctuations. In
particular, although any particular fluctuation is random, the
average number at any particular scale is predictable. This
pattern on initial variations, in turn, should show up in the
details of the CMB variations. So far, observations match the
predictions of inflation very well. Most people in the field
don't consider this conclusive -- one can imagine other ways
of getting a similar pattern of initial perturbations -- but
it is suggestive."
Inflation (cosmology)
http://en.wikipedia.org/wiki/Inflation_(cosmology)
"In physical cosmology, cosmic inflation, cosmological
inflation, or just inflation is the extremely rapid
exponential expansion of the early universe by a factor of at
least 10^78 in volume, driven by a negative-pressure vacuum
energy density.[1] The inflationary epoch comprises the first
part of the electroweak epoch following the grand unification
epoch. It lasted from 10^-36 seconds after the Big Bang to
sometime between 10^-33 and 10^-32 seconds. Following the
inflationary period, the universe continued to expand, but at
a slower rate.
"The term "inflation" is also used to refer to the hypothesis
that inflation occurred, to the theory of inflation, or to
the inflationary epoch. The inflationary hypothesis was
originally proposed in 1980 by American physicist Alan Guth,
who named it "inflation".[2] It was also proposed by
Katsuhiko Sato in 1981.[3]
"As a direct consequence of this expansion, all of the
observable universe originated in a small causally connected
region. Inflation answers the classic conundrum of the Big
Bang cosmology: why does the universe appear flat,
homogeneous, and isotropic in accordance with the
cosmological principle when one would expect, on the basis of
the physics of the Big Bang, a highly curved, heterogeneous
universe? Inflation also explains the origin of the
large-scale structure of the cosmos. Quantum fluctuations in
the microscopic inflationary region, magnified to cosmic
size, become the seeds for the growth of structure in the
universe (see galaxy formation and evolution and structure
formation)."
Cosmic Inflation and the Accelerating Universe - Part 1 - Alan Guth
http://www.youtube.com/watch?v=HwCCMHH378Q
Alan H. Guth describes the theory of inflation and presents
evidence that indicates our universe very likely underwent a
perod of inflation in its early existence. He also discusses
the surprising observation that the expansion of the universe
is accelerating, offers possible explanations for this
acceleration, and describes its impact on particle physics.
Cosmology Lecture -- Leonard Susskind (Stanford)
http://www.youtube.com/watch?v=hADOY0TzLic
Leonard Susskind presents the theory of cosmological inflation
under which the early universe expanded exponentially before
the Big Bang. This theory explains the lack of observed
magnetic monopoles and the uniformity of the cosmic microwave
background radiation.
What if we are wrong?
Inflationary cosmology on trial
http://www.youtube.com/watch?v=IcxptIJS7kQ
Physics Nobel Prize 2011 - Brian Schmidt
http://www.youtube.com/watch?v=YHBvOOX3RJQ
The Nobel Prize for physics in 2011 was awarded to Brian
Schmidt, Adam Riess, and Saul Perlmutter for discovering that
the universe is expanding at an accelerating rate. This
finding was completely unexpected because it was thought that
gravity should slow the expansion of the cosmos. The best
current explanation of why the universe is accelerating is
that there is some energy tied to empty space which pushes
matter apart. This 'Dark Energy' makes up 73% of the universe
but is very difficult to detect. Images courtesy of
NASA/NASAimages.org and Maritza A. Lara-Lopez
No Center
http://www.youtube.com/watch?v=W4c-gX9MT1Q
http://www.astro.ucla.edu/~wright/nocenter.html
http://www.astro.ucla.edu/~wright/infpoint.html
Also see Ned Wright's Cosmology Tutorial
http://www.astro.ucla.edu/~wright/cosmolog.htm
http://www.astro.ucla.edu/~wright/cosmology_faq.html
http://www.astro.ucla.edu/~wright/CosmoCalc.html
WMAP: Foundations of the Big Bang theory
http://map.gsfc.nasa.gov/m_uni.html
WMAP: Tests of Big Bang Cosmology
http://map.gsfc.nasa.gov/m_uni/uni_101bbtest.html
sam.wormley@gmail.com