Strictly speaking, it’s still just barely possible that the Universe is slightly smaller than the observable portion: The statistics aren’t good enough to rule out a grazing overlap. But it’s at least big enough that we’re sure we can’t see any galaxies repeated.
The gist of the observations is that if the Universe were smaller than the observable portion, there would be repeating patterns which would show up in the Cosmic Microwave Background, but exhaustive searches have failed to find any such patterns.
Nobody’s talking about things being “random;” you’re the one who brought it up. The alternatives aren’t merely higher being vs. random. . . . The alternatives are higher being vs. random vs. cause and effect. Cause and effect does not require a supreme being, nor is it random.
And your belief in a “one sentence answer” . . . what is that belief based on, other than your random subjective hunch?
Yes, but in the OP, your opinion of the age of the universe wasn’t based on an alternate theory (at least you didn’t mention one). It seemed to be just a stubborn emotional refusal to believe what most scientists believe. Why do you have trouble agreeing that the universe is relatively young, that it has existed only 14 billion years so far, with a whole lot more bazillion years in the future.
I’m not saying everyone has to accept the current estimate, but if you don’t, what is your alternative theory?
This was not how it was explained to me at the “Stars and Galaxies” course I took at the Harvard-Smithsonian observatory one semester a little over a decade ago.
While the galaxies farther out are moving away faster, we have nowhere near gotten to the point that the furthest galaxies we can see are moving at a large majority fraction of the speed of light.
What we see instead is that about every year, we can see about 1 light year further out, which doesn’t amount to hill of beans at the Universal scale. The limit we can see is currently a radius of about 14.5 billion light years. The light reaching us from that far out is 14.5 billion years old. The reason we get no light from further out is that the universe isn’t old enough for it to have reached us yet. Hence the 14.5 billion year estimate for the Universe’s age. as the Universe conitnues to age toward 15 billion years, what Earthlings there may be will be able to see what the stuff 15 billion light years away looks like, but the universe will have expanded in the meantime, so we’ll never know what it looked like at the 14.5-billion year old mark.
Eventually, we will stop seeing anything new appear over the “horizon” due to increased expansion, but we’re not there yet.
If anyone insists, I’ll dig out my notes to remind myself of the name of my professor, who was an astronomer at the observatory, but I’d like to see some cites on the other side first.
I’ll give my standard rebuttal to this line of thought:
What advanced knowledge of both randomness and intelligence do you lay claim to that you feel comfortable declaring what can or can not be accomplished by one or the other? Can you provide a link to some of this material?
This is called the Cosmic Event Horizon, and like the event horizon around a black hole, it occurs when light becomes “accelerated”, or more properly, redshifted to the point that it can no longer be seen past that boundary. Note that the CEH is somewhere around 45Bly away (and that applies not only to us but from any point in the Universe, assuming that the Hubble Constant is invariant), but when the light that we now see as the edge of the Universe was emitted, it was around 40Mly away, which is a consequence of space itself expanding. If that doesn’t bend your brain, I don’t think an acid trip will do you any harm.
As for this business about a center, the universe (which exists in 3 spatial dimenions plus one time dimension) does have one, but it’s not a point in space, it’s an initial point in time. As an analogy that we can cope with in our own understanding, which is limited to three spatial dimensions at any instant in time, think of two ants on the outer surface of a balloon. The balloon definitely has a center, but it’s not some place you can get to; it only existed at t=0, before inflation started. As inflation continues (with time being the radial distance between the center and the surface) the two ants are seperated from each other at an ever increasing rate proportional to their distance from each other. If the balloon expands fast enough (or the ants are slow enough) there are even places on the balloon they can never get to because the skin expands faster than they can move; eventually, the areas they can reach (corresponding to the “light cone” mentioned by David Simmons becomes a very small portion of the surface of the balloon. Hence, no physical center, even though you have an effective boundary or edge.
Because there’s no way to go expand a finite system–one in which you can count all of the objects or measure the distances–to an infinite system. The universe either started out of infinite size, and bigger or smaller have no rational meaning (though they still have application in areas of mathematics), or it was of finite size and has continued to expand by a finite amount, resulting in a larger but still measureable volume. Now, you can create discontinuities that are immeasurable and have infinitesmals, like dividing an integer by zero, but that’s just a mathematical inconvenience (and very likely doesn’t even technically exist within the universe), not a sudden growth from finite to infinite.
I’m not going to participate in an “ass rape”, but I’ll suggest that you are applying a misperception based upon a false application of the concept of “random”. In fact, there is very little about the physical world–perhaps nothing–that can be properly described as random, though there is much which is unpredictable. Physical phenomena, even fundamentally statistical phenomena like quantum mechanics, follow explicit laws, and all processes progress in an order from energy concentrations to the equilibrium of energy dispersal; this is sometimes crudely stated as going from order to disorder, which is true in a certain fashion, but this is a very simplistic and likely to be misinterpreted statement of the Second Law of Thermodynamics; there’s plenty of ways in which to create greater complexity via energy flow from the high to low reservoirs (which is a more generally accurate statement). Now, why these fundamental laws exist and how they work beyond the veil of the stochastic curtain of QM and statistical mechanics is unknown and perhaps unknowable; invoking a god of some sort is, well, no less supported than any other interpretation. But it does involved an added complication of some kind of intellect that exists outside the universe. We can’t say it’s wrong, but it isn’t really necessary nor does it do anything to complete our understand the world any more than sacrificing virgins to the Rain God makes the sky water our crops.
ha! Just remembered another source for what I was saying earlier, and this book should be on your required reading list if you have a strong interested in the topics raised in this thread.
The Universe At Midnight(2001), by Ken Crosswell (Harvard PhD. in Astronomy). He discusses the matter of the “observable universe” beginning on pages 70:
When cosmologists talk of the expanding universe, they don’t speak of volumes. It’s difficult to measure what the volume of the universe is, especially if it’s infinite, so instead they use density. Density is just mass over volume, and if we assume the mass of the universe is constant, then we avoid the funny business of infinite volumes and just say that the density is decreasing as the universe expands. When you think about it this way, it’s easier to imagine a universe that’s infinitely big that can “expand”.
I don’t wanna hijack things here, but properly explained, it’s not too hard to understand proper classes.
We have some things we call “sets”. With every set, we associate a bunch of other sets (called its extension) which we say are elements of it. The details of this setup don’t matter; no matter what, Russell’s paradox tells us that not every bunch of sets can be the extension of some set.
All well and good. But bunches of sets are still something, all the same. So what are they? Well, we introduce the technical term “class” as just a fancier way of saying “bunch of sets”. Some classes will be extensions of sets and some won’t. Those classes which aren’t extensions of sets are called “proper classes”. That’s all there is to it.
Russell’s paradox tells us there can be no set whose extension is all and only the sets which aren’t elements of themselves. Great, there’s no set like that. But that property, of not-self-containing, it does still define some bunch of sets. Which is to say, there is a proper class containing all and only the sets which don’t contain themselves. And there’s nothing inconsistent about this.
(Incidentally, in most modern set theories, all sets are non-self-containing. Therefore, in most modern set theories, the proper class corresponding to Russell’s paradox would be the proper class containing every set)
I guess the scientists were right and my puny mind cannot conceive of something that is 14 billion years old existing infinitely. If it did not exist 15 billion years ago, then, it didn’t exist.
Unless they mean that nothing existed 15 billion years ago. Time started when the universe started and there is no before since time is only a measure of how things relate to each other.
This all has to do with the “Big Bang Theories of the Universe Theory of the Universe”.
The question is, will the number of theories about the life of the universe keep expanding forever? Or, will the number of theories level off and start going down again, eventually becoming a singularity, a single remaining theory about the life of the universe.
I might be misunderstanding you but you seem to be asking how can something be both bounded and infinite.
It that is so there are examples. The sequence of numbers greater than zero and less than 1 has both lower and upper bounds and an infinite number of members.
And yes, time is, for one thing, a measure of the life of the universe and began with the BB. Whether or not there was “nothing” or “something” before the BB is something that we don’t and can’t know as I understand things.
It seems to me, and I am not sure why, that the Universe is the Big Bang, as opposed to begins with the Big Bang. The latter implies that space time has some limit that is not part of the universe, but bounds it. The former simply includes those bounds, if any, as elements of the Universe.
I’m not sure I understand exactly what your saying here, but if you’re saying what I think you are then my answer is that no one has said that the universe has existed for an infinitely long time. It may be infinitive in extent but it’s only about 15 billion years old.
The BB occurred at t equals zero, so todays universe cannot be the BB. However, the BB did occur everywhere in the universe. Or at the BB it was the entire universe. Or the universe is todays extent of the BB.
Wait a minute—I thought that this was not true, yet. I thought we could only see as far as the surface of last scattering, because earlier than that, the universe was not transparent.
You don’t understand what I’m saying? You don’t understand what I’m saying???
Then we have something in common.
An infinite amount of matter does not equal an infinite amount of time, which is what I took away from Mr. Simmon’s post.
Which reminds me of another point made on the show-- that matter, energy-- everything-- cannot be split an infinite number of times. There will come a time/space where everything will rend itself into nothingness. Which suggests to me that the universe is not infinite whether bounded or not.