Bryan Kelly

From an earlier post I get to here: http://www.phinds.com/balloonanalogy/ From there are these links: And here is an excellent discussion: Misconceptions About the Big Bang good site A couple of other good ones: a brief history of cosmology --- two pages on your computer screen MS Edge reports cannot reach this page a history of cosmology theories from the Greeks to now --- a considerably more extensive discussion page not found Sean Carroll's Cosmology Primer --- an extensive discussion This page doesn’t seem to exist errors in some popular attacks on the big bang --- may dispel any misconceptions you might have, looks OK Does anyone know of anyone who might be in a position to make some updates?

“… one of the tenets of GR is invariance of geometric choice.” I don’t understand that invariance concept. I presume that BH means Black Hole. There are several things that lead me to the conclusion that mass draws in spacetime. The first is the quote about mass curves spacetime and spacetime tells mass how to move. While cute quotes and sayings may not be technically true, there seems to be much to this one. Another is the concept of the universe expanding. Some 13 billion years in the past the universe was much smaller. It expanded so fast that light could not keep up with the expansion. How did the universe become much smaller? Some effect, some thing, made it smaller. If this is so, then space must be something more substantial that just empty void. It can be shrunk down and can be expanded. What can cause it to be shrunk down? To at least some degree, that is mass. The more mass per unit of volume, the more space is made smaller, it is shrunk by mass. When something is in the presence of mass, even time slows down. I take this as another indicator that spacetime can be made smaller and can be made larger. The current expansion of the universe appears to support this concept. And thank you for the two links. Regarding the first, I see the opportunities to change parameters, but don't know what i am changing or how to interpret the results. Regarding the second, wow, there is a lot there and I will be looking there for quite a while. Days, weeks, or more. Thank you.

The guidelines for this Speculations Forum mention the concept Wild Ass Guesswork (WAG). I rather favor a term I learned in the military, SWAG, sophisticated wild ass guess. Well, maybe not real sophisticated, but to at least some degree. An ultimate goal of mine is this question: What would it mean if there is an upper limit to the size of a black hole? For now, I stop on the major concept and begin with a minor one that is important to the larger. I have read widely about spacetime but not deeply. I am not good with mathematics. I am aware of and comfortable with the concept: “matter tells spacetime how to curve, and curved spacetime tells matter how to move.” But not much deeper. Is there an equation that calculates how mass curves spacetime? Specifically, the question is how much a black hole, or any large mass, will draw in space time. I suspect it does, but am not positive this is a valid concept. To be explicit, presume we stand off from a solar system in space and that we can see the lines of space and that we are not affected by changes. Presume we can see the lines where planets A, B, and C orbit the sun S. Just for a starting point, presume one solar mass. We replace sun S with one that is ten or a hundred times as massive. How would those circles for the orbits of the planets move? From our distant and unaffected location, my speculation is that we would see the line for each planet would move in closer to the sun and the closer ones would be affected more than those further away. Do you think those orbit lines would move? If so, how much would they move? I suspect there are equations for this, but, not being mathematically endowed, I cannot recognize them and/or extract just the parts needed. (Let’s ignore the sudden change on the planets themselves for several reasons.) But how would we measure it? From our location, let’s say directly above the orbital plane of the planets, use Pythagorean’s theorem. Set the adjacent as the line to the sun, the hypotenuse as the line to each of the planets, and the opposite is the distance between the sun and the planet. And since this is a thought experiment, presume our visual lines of sight to the planets and the sun are not changed by the changes in mass and that we can see the changes instantly. Is this a valid thought experiment? Your thoughts please