I which people could explain their case a little clearer.
I think this would actually make a testable prediction...such an enormous mass would have measurable gravitational pull on objects on the earth as well, which changes over the course of a day as the sun moves over it, thus changing its location and distance.
The sun moves over the Earth ? This would cause the Earth to be drawn into the sun ?
As it stand the sun does cause a gravitional effect on the Earth.
Gravity bends the fabric of time-space, similar to placing a bowling ball on a mattress.
The sun bends the time space fabric causing a cyclonic drag upon nearby objects that are sitting within the proximity to the sun.
THe erath is spriling around the sun but at the same time is slowly moving closer towards it (very slowly).
The sun is not even close to being exhausted of its hydrogen and helium reactions.
Solace our system in the universe was formed roughly over 5 billion years ago, that includes the formation of our sun, which was much hotter then.
The sun keeps on exploding in and out of hydrogen into helium fussions. This causes photons to radiate from the sun. Slowly the energy lost from the suns material causes heavier elemenst to be formed, such as iron.
As the hydrogen runs out, the sun will begin to die. With stars in general this can happen gradualy as the star gets dimmer and dimmer or spectucaly with the advent of a supernova.
Our star is a medium sized one, and as the iron at the center of the sun increase the out layers expand forming a red giant . As it expands the very outer layers release gasses which are known as planetry nebulas they come apart. Because the sun is unable to fuse any more hydrogen with helium it collapses and shrinks down in size becoming what is known as a white dwarf.
It is predicted that the earth still has another 5 billion yrs left of its hydrogen suply. Once this runs out it "good by soloar system, planet earth and the life that is on it at the time".
This evidence is not infered by measuring joules or mass, but by observatiosn of other stars and how they behaviour.