Thread: outside space?

Originally Posted by David E. Eaton Sr.

Perhaps I am taking 'statements' too literal; however, in my defense I must say that is how I was taught. When a statement is made then one must either prove or disprove it. It appears to me as if 'you' are taking a 'local phenomenon' which adheres to the laws of physics as currently defined and saying that those same laws do not apply on the grander scheme of things. I was using the (our) planetary system as an example of a 'local' event. It appears as if what is being said is that the planetary systems within our galaxy do not have a gravitational effect on each other. Likewise, our galaxy does not have a similar effect on our neighbor galaxy(ies). I was taught that the laws of physics apply uniformly no matter where in the Universe one applies them. (That is to say no matter if they are applied 'here' or the next galaxy over.) Perhaps, for me, it is time for another cup of coffee....

You appear to be insisting on confusing yourself. Nothing in my previous post stated or implied that the laws of physics are not universal. But there is a reason why we fall to Earth when we slip on ice and not to Mars or WASP-4 b. The gravitational field of Earth is stronger where we live. However, the same law of gravity applies to Mars or to WASP-4 b.

We live on Earth in the Sol system. However, Sol is just one star in a spiral arm of the Milky Way Galaxy out of 100 billion stars in our galaxy. There are billions of other galaxies in the Universe. That the galaxies are moving away from each other is attributed to the Big Bang. That the separation rate is increasing is attributed to Dark Energy. However, Dark Energy does not negate gravity. The gravitational attraction between nearby objects is great and decreases as they separate. Dark Energy, on the other hand, appears to be greatest for objects separated from each other by great distance. This implies that Dark Energy has little effect on nearby objects.

However, Dark Energy is currently a hypothesis developed to explain an observed fact. We do not yet know its functional form.

Understand this: No force in nature is constant over anything larger than a relatively tiny volume. When we talk about galaxies, even Local Groups, which are composed of several neighboring galaxies, are considered to be "local." The Universe is much larger.

Originally Posted by Wayne Bruinekool

If you only wish to chew the fat over being and nothingness, I would not want to rain on your parade, but if you are genuinely interested in objective reality as it relates to the nature of our universe, you need not trouble yourself about what is outside. There is no outside. We are of the universe, but technically we are not in it. If this feels a little awkward at first, take heart, there are very few physicists alive today who can fully grasp the significance of this phenomenon.

With all due respect to Mr. Bruinekool: To take our pooled ignorance and emphatically establish it as knowledge runs counter to the spirit of knowldege. Given that the most knowledgeable person on this planet can, at this point in time, only know less than 1% of the information contained in our Universe (I am being infinitely generous) to vehemntly declare "There is no outside" smacks of the line of reasoning that not long ago declared that the Milky Way was the entire Universe. Let's speculate, as it is the path to child-like wonder and exploration and expectancy. Knowledge can only puff up.

Originally Posted by MisterMe

You appear to be insisting on confusing yourself. ... That the separation rate is increasing is attributed to Dark Energy. However, Dark Energy does not negate gravity. The gravitational attraction between nearby objects is great and decreases as they separate. Dark Energy, on the other hand, appears to be greatest for objects separated from each other by great distance. This implies that Dark Energy has little effect on nearby objects.

However, Dark Energy is currently a hypothesis developed to explain an observed fact. We do not yet know its functional form. ...

Ack...time to go back to school....thanks, MisterMe, for opportunity of learning...

think of the balloon analogy. each penny can represent a galactic cluster and each atom of the penny can be individual galaxies. as the balloon inflates the space between the pennies grows but the space between each pennies atoms does not.

Like many of the questions we ask of physics, this topic too puzzles us. I think, not because there is not an answer, but rather because in our ignorance we do not clearly perceive the answer. So very often we must speculate, hypothesize or theorize with the limited resources of our own perception and seeming logic. Over the course of mankind's history we have come up with a lot of wrong answers. And many of the answers which seem right at the time later become modified and may sometimes be disproven altogether. But still we continue to seek ultimate or absolute Truth.

One might say this defines the difference between faith and fact. Do we actually have fact or are our facts really only relative to that which we perceive and believe. Who can even truly answer that?

Anyway, here is a thought which my mind kicks out to ponder, though I admit it seems to have some sense of intrinsic fallacy which I can't quite put my finger on. Consider that if the universe as an entity does indeed have an outer boundary and there is nothing outside of it for anything to move into then the seeming expansion of the universe would have to be contained within that outer boundary. And rather than expanding outward, space would seemingly have to be dividing inward if the actual volume of the universe were in fact set. But this would seem to imply that all matter and energy in the universe would have to be 'shrinking' or 'compacting' uniformly as space divides. Objects would then seem to be moving away from one another from a relative point of view, but from some point 'outside' of the universal boundary everything would seem to be shrinking. For some reason fractal patterns come to mind. When we observe one of these fractal pattern animations are we seeing larger to smaller or smaller to larger? I guess that too is a relative question.

Well, that's just the immediate thought which comes to mind and as I said, it seems counter-intuitive, but I offer it anyway.

Originally Posted by MisterMe

Understand this: No force in nature is constant over anything larger than a relatively tiny volume. When we talk about galaxies, even Local Groups, which are composed of several neighboring galaxies, are considered to be "local." The Universe is much larger.

I agree, but you might want to whisper this on BAUT and PhysicsForums. The first will label you a conspiracy theorist, and the second will label you a heretic!

My take is that one or more universal constants are not constant over time, thus, the further back we see, we observe their effects at their previous, historical values. Why they vary over time may be the result of gravimetric potential density, the localized expansion of space, or some other phenomena.