And of course, the size of the Sun has not been been a topic with widely varying answers at least since shortly after it was accepted that the Earth went around it.
What's next in your fantasy universe, a flat Earth?
Surely you are not trying to imply that fusion and the resultant energy release which proceedes from it is somehow afunction of matter spotaneously generating itself without expense! Making Helium from of Hydrogen expends and releases frictional and photon energy, it does not create matter. Is this what forms the basis of your "open system" position? If so, you may wish to refresh your memory with regard to the Laws of Conservation of Matter and Energy, and mass-balance.
The heat which warms our planet and proceedes from the sun should be evidence enough to the junior physicist that energy is expended from a finite energy producing source. The sun does not recapture energy lost to entropy.
Whether one generates heat from burning methane or from a fusion reaction, both systems deplete their inherent mass as energy is released to entropy. As was pointed out to you in the orignal post, the rate of solar burn is able to be measured. The Sun is depleting is resources at a measure-able rate.
By definition the Sun is losing its mass and with it, its size at a measureable rate, and if the rate observed today is the same as the rate that has been, the Earth would be uninhabitable at a fixed point in the past due to the size of solar mass as yet unconsumed. Fusion does not change classical principles of mass-balance. You, like balrog666 might want to write to Starfleet Academy and ask for a refund.
Where "flat Earth" history is concerned, those who promoted it (e.g., Lactantius c. 245-325 A.D. and Cosmas Indicopleustes in the 6th century) were identified as heretics by early Church fathers, and their writings were shelved and decried. Your knowledge of the intellectual history of the church ignores Judeo-Christian scripturual references to the round Earth (Isaiah 40:22), and evidently stretches only so far back as to 18th-19th century myths promoted by novelists like Washington Irving.
It is you whose pretense to knowledge alludes to "history" as imagined in a novelist's "fantasy," not I.
I think your use of the plural (in "references") is incorrect. Isaiah 40:22 is the only passage I know of where the earth is described as a circle (not a "sphere"). Everywhere else, there are references to the earth's four corners, the ends of the earth, the pillars supporting the earth, and several statements that the earth is unmoveable. The New Testament states (twice) that from a high mountain one can see all the nations of the earth at one time.
As for the circle reference in Isaiah (which I believe is a unique anomaly in scripture), it was not impossible for ancients to observe that the earth's shadow during a lunar eclipse was in the shape of a circle. Thus it was quite possible for ancients to think of the earth as disk-shaped. Only a sea-faring people (like the Greeks) could also observe vanishing ship masts on the horizon and conclude that the earth was a sphere.
Congatulation for proving that all astronomers are in on Darwin's "old Earth" scam, and that only by ignoring e=mc2 can the Sun really be billions of years old.
In fact, I said, "What's next in your fantasy universe, a flat Earth?" I did not imply that the early Christians were so ignorant, merely that you are.
Dear Aggie,
No. I'm sure you can calculate the rate of mass loss to first order. Why don't you do so, and tell the class what that number is. Please show all of your work. To make it easy, you can assume that the Sun is all hydrogen, and that the byproducts cannot burn (both wrong). Assume that all reactions are from the P-P chain. Good luck.
Cheers,
Thinkplease.