jackson33

i should research some figures, but the earth is really a heavy place. i do feel you figures are a little high and what reaches the ground is maybe a ton a year. now, quite a few meteors are made up of ice and rock combinations. these burn up quickly and add some to the atmosphere, hydrogen, oxygen and carbon by products from the burn. the addition to the overall weight of earths mass, over a billion years may be one percent, of what was then. your gravity notion was one i put up for a possible cause of dinosaurs extinction 65 million years back. this was based more on a felt, missing component to gravity, than mass to create gravity. to me a spices that thrived well over a 100 million years, continental shifts, what should have been a good deal of volcano activity, asteroid and comet hits, plus total dominance over life, would die off so suddenly or could have been from all it had previously survived. i do not, but some have suggested the moon was formed from earths matter some time back. you are probably correct in that more mass was collected in the first billion or two years, but even there the totals would be limited, to allow a cooling of the planet. Jupiter has over 300 times our mass, we know gets hit often and is still in the gaseous state.

midnight; personally i think the Universe has always been, about the same size and leave the possibilities for multiply universe open. the known universe (what is seen through telescopes and/or Hubble) is about 29 billion light years across. we see 14+ in each direction. few suggest that there is more beyond our mechanical sight. the Hubble update scheduled for next year, i think and a new system is planned for 2013 should provide additional evidence. my own guess would be this universe is nearer to 1/2 trillion light years than to 50. there are many thoughts on BBT. the originals from the 1927 to the 60's or so, do not resemble most of todays. expansion was an outgrowth and although both BBT and universal expansion are what is called "accepted theory", many do not agree. no "bang" is now considered and a mis-nomer. yes, some galaxy have been seen colliding, but maybe "all the time" is a little off. actually the Milky Way, our galaxy is in the process of absorbing a small dwarf galaxy now and another dwarf is on its way. spiral Andromeda, is well out there and we really don't know how close it may come to ours. remember its thought there are 2 billion and counting galaxy in our known universe.