- What is the source of the Sun"s light and heat"
Throughout history people have proposed answers to this question that have
always reflected human experience. The Sun was a shining god, or a "spark"
cast off in the creation. Later it was a pile of burning sticks or coal.
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- By the nineteenth century, astronomers had become accustomed
to thinking that gravity was the dominant force in the heavens. So they
began to conjecture that the energy of the Sun might be due to "gravitational
collapse", a compression of solar gases by gravity. This simple hypothesis,
its proponents claimed, could provide the required energy output for a
few tens of millions of years.
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- By the late 19th century, however, geologists were confident
that Earth was much older than the astronomers" model would allow,
and the conflict between astronomy and geology continued for several decades.
Then, in 1920, the British astronomer Sir Arthur Eddington combined the
principle of gravitational collapse with an exciting new principle in the
physical sciences"nuclear fusion. He proposed that at the core of
the Sun, pressures and temperatures induced a nuclear reaction fusing hydrogen
into helium.
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- In 1939 two astrophysicists, Subrahmanyan Chandrasekhar
and Hans Bethe, working independently, began to quantify the gravitational
collapse and nuclear fusion hypothesis. Bethe described the results of
his calculations in a brief paper entitled "Energy Production in Stars",
published in 1939.
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- The model that followed the work of Eddington, Chandrasekhar,
and Bethe described a "nuclear furnace" responsible for igniting
stars. And for decades now cosmologists, astronomers, and astrophysicists
have accepted the basic concept as fact.
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- In the early formulations of this "standard model"
of star formation, it was said that the gravitational force within a primordial
cloud leads to its progressive compression into a "circumstellar disk",
as the outer material in the cloud "falls" inward, and gravity
gives birth to a star-sized sphere, whose core temperature continues to
rise under increasing pressures. Collisions of atoms within the core eventually
become so energetic that electrons are stripped from their nuclei, leaving
free electrons and hydrogen protons (a plasma as we now understand it).
In stars roughly comparable to our Sun, with envisioned core temperatures
less than 15 million Kelvin, the nuclear reaction begins when hydrogen
protons are joined or stuck together in the "proton-proton fusion"
of hydrogen into helium.
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- Critics, however, pointed out that the temperatures given
by standard gas laws are not sufficient to provoke nuclear fusion. They
cited the "Coulomb barrier", in this case the electric repulsion
between two protons, or like charges. Once protons are fused, they could
be held together by the strong nuclear force, but that force dominates
only at short distances. To achieve fusion, it would be necessary for protons
to cross the barrier of the repulsive electric force, which is sufficient
to keep the protons apart forever. But Eddington"s successors accomplished
the impossible by something called quantum tunneling, enabling an extremely
small percentage of protons to simply "appear" inside the barrier
at any particular time.
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- It is ironic that the early objections to the fusion
model of the Sun focused on the powerful electric force. This was long
before arrival of the space age with its discovery that the charged particles
of plasma permeate interplanetary and interstellar space, and long before
any systematic investigations of plasma and electricity in space.
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- Advocates of the "nuclear furnace" made a series
of fundamental assumptions common to astronomy long before the emergence
of a nuclear model of the Sun. The credibility of these assumptions was
not an issue to them. They assumed that diffuse clouds of gas in space
would collapse gravitationally into star-sized bodies. They assumed that
the Sun"s mass could be calculated simply from the orbital motions
of the planets. They assumed that Newtonian calculations of mass, coupled
with standard gas laws, enabled them to determine the pressure and temperature
of the Sun"s core.
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- The pioneers of the nuclear furnace also followed another
assumption common to astronomy in their time"that the Sun and planets
are electrically neutral. They gave no consideration to the role of electricity
and no consideration to the role of the magnetic fields that electric currents
generate.
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- Are the assumptions made in the first half of the twentieth
century still warranted after decades of space exploration" Those
proposing an electrical perspective, based on more recent data, insist
that the earlier conjectures are not only unwarranted, but discredited
by direct observation and measurement. They emphasize that every feature
of the Sun as we now observe it, defies both the gravitational assumptions
and the standard gas laws relating to pressure, density, temperature and
relative motions of gases. The deepest observable surface of the Sun yields
a temperature of about 6,000 degrees Kelvin. As we peer into the darker
interior of sunspots we see cooler regions, not hotter. But moving outward
to the bottom of the corona, the temperature jumps spectacularly to almost
2 million degrees. Thus, the superheated shell of the Sun"s corona
reverses the expected temperature gradient predicted by models of internal
heating.
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- It seems that the Sun does not even "respect"
gravity. The mass of charged particles expelled by the Sun as the solar
wind continues to accelerate beyond Mercury, Venus, and Earth. Solar prominences
and coronal mass ejections do not obey gravity either. Nor does sunspot
migration. Nor does the movement of the atmosphere, since the upper layers
rotate faster than the lower, reversing the situation predicted by theory,
while the equatorial atmosphere completes its rotation more rapidly than
the atmosphere at higher latitudes, another reversal of predicted motions.If
the Sun"s atmosphere were subject only to gravity and the hot surface,
it should be only a few thousand kilometers thick instead of the hundred
thousand kilometers or more that we measure. Even the shape of the Sun
defies the expectations of theory. The revolving Sun should be an oblate
sphere. But it is a virtually perfect sphere, as if gravity and inertia
have been overruled by something else.
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- For the electrical theorists, the "something else"
should be obvious from the dominant observed features of the Sun (in contrast
to things assumed but never seen). The anomalies facing the standard model
of the Sun are predictable features of a glow discharge, as we shall demonstrate
in coming Pictures of the Day.
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- AUTHOR'S NOTE: The full text of this article, with text
links, can be viewed at: http://www.thunderbolts.info/tpod/2005/arch05/050517fusion.htm
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