Tag Archives: Solar System

The Origin of Our Solar System

Has anyone ever wondered about how the world, and our solar system started? I have countless times, but I am still questioning our current theory of origin, the Nebular Hypothesis. http://en.wikipedia.org/wiki/Nebular_hypothesis

A. solar nebula B. contraction into rotating disk C. Cooling causing condensing into tiny (dust sized) solid particles D. Collisions between these form larger bodies E. These accrete to form planets

First proposed by Emanuel Swedenborg, the Nebular Hypothesis is the most widely accepted theory for the origin of our solar system. It is based upon the assumption that the universe already exists under the Big Bang theory. Under this model, the  molecular hydrogen and “dust particles” had clumped together to form a giant cloud, called a nebula. Due to their own gravity, they collapsed, spiralling down to the centre of the cloud to form a central mass and a rotating flattened disk. High concentration in the center of the cloud lead to temperature and pressure increases, and resulted in nuclear fusion.

Nuclear fusion was the process of which hydrogen molecules fused together, released energy and formed the Sun. The “leftover” dust clumps became the planets, and this is the current theory of how the Solar System came to be. It explains why the planets revolve around the Sun on the ecliptic plane, and the proximity of terrestrial planets and gaseous planets.

However, I question how the hydrogen molecules came together to make a giant ball in the first place. I thought that gaseous molecules have a tendency to go from areas of high concentration to low concentration. Did the gravity of one hydrogen molecule attract another hydrogen molecule, and eventually became a huge giant cloud of hydrogen, and suddenly collapse? The force of gravity of one hydrogen atom to another would not be such a significant force, as Fg = km1m2/ r2, and the constant, k is a very small number of 9.0*10-9.

I am sceptical. What about the second law of thermodynamics, entropy? Molecules want to increase their entropy, and disperse when they can. Would there be any other forces that attracted the hydrogen molecules and dust particles together besides the force of gravity? Perhaps one day, we will be able to understand the mechanisms of our world better.