“Gateway Vortex” by kyoukizu at DeviantArt
Jan 3, 2017
What prevents stellar dissipation?
Children are taught from an early age that stars are “burning” balls of hydrogen gas. According to standard theories, it is a star like the Sun’s gravitational attraction that keeps planets, along with all other material, in orbit. Fusion fire releases energetic particles from stellar cores that are so dense that it can take a million years before they radiate away.
At some time in the past, billions of years before any particular star was born, they started out as clouds of gas and dust so diffuse that they are a practical vacuum. The question that plagues astronomers about the process is what causes those insubstantial clouds to condense in the first place?
First, a cloud might cool down from whatever high temperature it once possessed, so thermal energy is reduced, allowing gravity to collapse it in on itself. Second, a supernova might create shock waves that force particles to clump together. Gravity then pulls the cloud into a structure dense enough for fusion to take place.
The Nebular Hypothesis was proposed in the eighteenth century by Kant and Laplace, with modifications in the nineteenth and twentieth centuries to accommodate objections. Gravity is a relatively weak force, so for a gas cloud to collapse under its own weight it must be cool and possess no magnetic fields.
Regardless of whether it is shock waves or “radiation pressure”, conventional theories see star formation as kinetic and mechanically induced. In fact, lowering thermal activity is how it is supposed to begin. Since hot gas expands, as the laws of physics insist, then collapsing a cloud of gas and dust should cause it to expand and dissipate, and that is the catch.
Proto-stellar gas and dust must be extremely cold, otherwise, as mentioned, the friction of collapse would cause the cloud to dissipate instead of squeeze down into a star. How the cold is supposed to prevent heating is not explained. If something cold is crushed into a small volume its temperature will rise regardless of its initial state. Many astronomers admit that their theories are lacking, but they are the best they have.
Questions remain. Problems such as, how do massive stars form? Can outward radiation stop their accretion? What causes star clusters to form? Where do the clouds come from? What causes star formation on the galactic scale?
NASA launched the Kepler Mission on March 6, 2009 with some of those questions in mind. Astronomers used Kepler to measure the brightness of various stars, as well as develop a catalog of changes in brightness that are suggestive of changes in conventional ideas about fusion reactions within stars. This technique is known as “astroseismology”: a way for researchers to “see inside” remote stars. The name is derived from “helioseismology”, the study of shock wave propagation through the Sun.
Currently, according to scientists, the only star whose exact age can be known is the Sun, because material from within the Solar System can be brought to Earth and analyzed. Consensus viewpoints believe that that situation makes it possible to use the Sun to calibrate readings from other stars.
Stephen Smith
