this theory is saying that. the molten rock/core constantly produces rocks that expands the earth?
This is why it was rejected in the 1960's and about the only (albeit big) objection to it becoming accepted today. However, looking at the positive evidence for an expanding earth, it certainly warrants further investigation.
1. Isn't the expansion of planets and moons geophysically impossible and wouldn't it violate
conservation of mass?
Since planets and moons did not pop into existence at their current size, everyone agrees they must have expanded at some point in their history. Currently, the process of planetary formation is one of the most important, outstanding mysteries in all of science. In July of 2005, Science Magazine listed the 125 most significant questions facing scientists today in an article sub-titled "What we don't know." One of the questions was, "How do planetsform?"
Current theories of planetary formation are known to be inadequate, and expanding Earth theory is, at bottom, a planetary formation theory. The seminal questions are: what are all the ways in which planets and moons have accumulated their mass, and when did they stop? There are only two plausible ways that planets can increase in mass: 1) Macroscopic objects can collide with or add to their surfaces, augmenting their size layer by layer or 2) ultra-mundane (e.g., sub-quantum) material can pass through the external layers and collect at the cores of planets and moons, causing them to expand from the inside out. This last method, which is consistent with ether-sink views of gravity, may be one aspect of planetary formation not adequately considered.
In fact, it is now widely accepted that the Jovian moon, Ganymede, has experienced significant, internally-generated, post-formation expansion. As Prockter (2001) writes: "The bright terrain formed as Ganymede underwent some extreme resurfacing event, probably as a result of the moon's increase in size". Collins et al. (1999) agree that the formation of the grooved terrain on Ganymede was likely the result of post-formation "global expansion"
References:
Collins, G.C., Pappalardo, R.T. & Head, J.W. (1999) Surface stresses resulting from internal
differentiation: Application to Ganymede tectonics. 30th Annual Lunar and Planetary
Science Conference, Houston, 1695. Available at
http://www.lpi.usra.edu/meetings/LPSC99/pdf/1695.pdfKerr, R.A. (2001) Jupiter's two-faced moon, Ganymede, falling into line. Science, 291, 22-23.
Prockter, L.M. (2001) Icing Ganymede. Nature, 410, 25-27.
Ravilious, K. (2002) Wind Up. New Scientist, 176, 30-33.