Hertzsprung-Russell diagram and Stellar Evolution
One of the hotly debated issues in the early 1900’s was the interpretation of the Hertzsprung-Russell diagram. When the energy output of a star (Luminosity) was plotted against the surface temperature (essentially its observed color), it was found that as the temperature increased, so did the energy output. Somewhere between 80 to 90 percent of all stars are plotted in a path across the diagram that has become called the Main Sequence. It was initially thought that the diagram, for the most part, represented the evolutionary process of typical stars. Stars would start off as intensely bright burning, and as they consumed their fuel, they would end up as red dwarf stars. This evolutionary interpretation was abandoned when it was determined that the rate of mass loss was not enough to account for the reduced rate of energy loss. (For an example of the Hertzsprung-Russell diagram Link to http://ast.star.rl.ac.uk/hr.html )
(As another example of Astronomers confusing way to present data, they draw the Hertzsprung-Russell diagram partially “backwards”. The Y-axis is usually associated with the energy output, and as one reads vertically up the y-axis, luminosity increases. This is great. The X-axis on the other hand has decreasing temperature measures as one reads further out horizontally.)
If the expansion of space is truly uniform, as proposed by the uniform expansion theory (www.uniformexpansion.com ) then matter itself expands with the expansion of space. This means that objects in the past were denser. If this were the case then the effect of gravity would be greater in the past. For example, if our Earth, with the present amount of mass were to be reduced to half it’s size; the surface gravity would be increased 4 times. If the effect of gravity were greater in the past, the rate of energy production within stars would dramatically increase. This would reestablish, in part, some of the original arguments for interpreting the Hertzsprung-Russell relationship as illustrating an evolutionary process. (This is going to upset a lot of physicists who think they have the evolutionary process of stars like our sun figured out, actually let me take back that statement, they will just ignore me.)
Energy production from stars.
As a gas is compressed, energy is imparted to the gas, raising the temperature of the gas. Within stars the temperature increase is enough to fuse nuclei together, producing nuclear energy. The impact of the fusing nuclei must be great enough to overcome the forces maintaining the individual structure of the individual nuclei. The average temperature within a star is not enough to cause fusion but since the velocity of the nuclei are statistically distributed, there will be a few with enough momentum to allow fusion.
The velocity distribution of the nuclei in a star is a bell like curve with trailing tips. If we imagine two such curves, representing the probable velocities of two colliding nuclei, and we expand them more and more, starting with only the thin tips touching. Now we can visualize how the rate of energy production dramatically increases as the temperature increases and the bell shape curves expand. The area found within the overlap would indicate the number of nuclei involved in fusion. As the two curves overlap more and more, the intersecting area increases in a non-linear fashion.
It is this nonlinear relationship that primarily describes why the energy production of massive stars is so much greater than less massive stars. A very bright star with a mass equivalent to 60 of our suns represents something close to the maximum mass a star can have. Any more mass and the rate of energy production is so intense the star rips apart or explodes. A red dwarf star with a mass of about .05 solar masses is about the minimum size. (All these ranges of size are subject to variation by a magnitude of two or three). The ratio of masses for a bright star (type O5) and a small red dwarf (M0) is about 1,000 to 2,000 times. The difference in energy production is from about 10^6 of our suns energy output for a “Large Blue star” to about by 5 x 10^-4 of the energy production from our sun for a Red dwarf, a ratio range of 50,000,000 times.
The rate of energy production of a star is also influence by a number of other factors, particularly age and type of nuclear fuel used but this is beyond the point being made about the importance of the mass of a star to its energy output. If the effect of gravity varies as proposed, this in essence would be like increasing the mass of a star. This would mean that stars burned much brighter in the past. This would be in accordance with the original interpretation of the meaning of the Hertzsprung-Russell diagram.
It was illustrated earlier that in an 8 billion year old universe the effect of gravity when the universe was 2 billion years old would be 16 times greater. This would mean that our sun, 6 billion years ago, in an 8 billion year old universe, would behave as if it were 16 times more massive. This is a very bright star. This theory is in marked contrast to the accepted evolutionary model for our sun. Our sun started off not as a typical yellow star, but a bright burning star.
While it is unlikely anyone who was an advocate of the Hertzsprung-Russell / evolution theory is reading this, some of you may know some retired Astronomer who did. They might like to see a theory that bolstered their original ideas.
Snowflake.
Originally Posted by Tobin Dax
