The end of the Universe

[loftar]

I don't think that there is a "vacuum" outside of the universe.
There is no space or time outside the universe, though it is constantly expanding.

Certainly current cosmology would agree with that. The (very) prevalent opinion is that the universe is of fairly homogeneous density, both inside and outside the part of it that we can observe, the reason being that, prior to Inflation, the universe was small and hot enough to have no choice but to be homogeneously filled with primordial energy (whatever form that took, which is still very much under examination), and that inflation spread that uniformly with the expansion of space itself. The very small fluctuations that did exist (due to quantum uncertainty) are what is reflected in the microwave background radiation.

As for the big crunch, I don't that that has been in fashion for a very long time now. Current "haute" theories imply Dark Energy (the nature of which is, however, completely, entirely unknown) causes space to not only expand, but accelerate indefinitely in expansion, which will continue until space expands so fast that not even elementary particles will be able to stick together, which phenomenon is colloquially referred to as the Big Rip. All that being said, I myself don't really take such theories too seriously since there's so much that we can't currently even come close to explaining, including but not limited to the aforementioned dark energy, but also dark matter (which is really just a very handwaving explanation for the otherwise unexplained phenomenon of the strange galactic rotation curve) and various large cosmological structural phenomena like the great attractor. There seems to be too many too large unknowns to be able to ascribe any particularly great predictive powers to current cosmological theories.

[Jalpha]

That's a large spoonful to digest. I'm going to share something said by Dr Karl just recently which, although I am having difficulty finding an online reference, should be legitimate given the source.

What he said was that the LHC was trying to identify where mass comes from because none of the individual constituents of an atom thusfar discovered have any mass (paraphrased).

Increasingly the viewpoint held by people like dafels is taking over. I'm not interested in trancending to the spiritual level of a yogi in life though. I believe we manifest within a physical realm because we have some greater purpose within this place and rather than distracting from it we should instead seek our greater destiny as a species. My opinion.

Maybe jumping ahead to the end of the Universe is too distant to properly conceive. I'll try to bring the topic back toward the ways in which we may begin to escape our solar system.

Do you suppose that, with large enough magnets, we could squeeze a Dyson Sphere out of the sun? It needn't be constructed of anything more than particles, kind of like a dust cloud made of absorbtive and conductive particles. Certainly in the initial phases at least.

[Alitis]

Do you suppose that, with large enough magnets, we could squeeze a Dyson Sphere out of the sun? It needn't be constructed of anything more than particles, kind of like a dust cloud made of absorbtive and conductive particles. Certainly in the initial phases at least.

sure

[Jalpha]

Okay so it would stand to reason then that the solar wind could be focussed on a single direction and we could use it to move through space like a rocket ship. Right?

We don't need FTL or antimatter rockets. Now with antimatter if it is exactly opposite to matter while a whole atom and thus bearing mass then the only time all matter and antimatter can combine and explode would be at the end (or beginning) of the Universe. In that soup. When everything reaches that point it explodes again I suppose in an endless cycle.

Is infinity real though?

Edit: To elucidate if totally opposite they would have opposite mass when whole atoms and in this state simply cannot combine.

[loftar]

What he said was that the LHC was trying to identify where mass comes from because none of the individual constituents of an atom thusfar discovered have any mass (paraphrased).

That's just the whole Higgs boson thing that you hear about literally everywhere.

I'm not familiar enough with quantum field theory to understand the details of it, but I know that the Higgs field is the standard mathematical explanation of how momentum (and therefore mass) works at all within the framework of QFT, the "problem" just being that the Higgs boson (the excitations of the Higgs field) hasn't been experimentally confirmed to actually exist, and a failure to demonstrate its existence would put the mathematical theory on shaky grounds. The problem has been that the Higgs boson is really heavy and thus quite hard to "synthesize", which is one of the main reasons the LHC was built. I know they announced a while ago that they did finally discover traces of the Higgs boson, but I'm not sure to what degree the findings have been verified.

Increasingly the viewpoint held by people like dafels is taking over.

I wouldn't at all say that it's "taking over", but I do know that it's a "Youtube phenomenon", and in fact Jorb pointed me to a couple of vidyas on the subject just a few months back. Some of them were really stupid (like literally comparing Minecraft phenomena to reality and concluding that since they kinda look similar, reality must be a video game). Others weren't plain stupid, but seemed to me to just present an alternative model of reality that is congruent with, but "formulistically different" from, the standard model, and I didn't quite get the point. It sounded like saying that something new was discovered by stating that "x² - y² = 5" can also be expressed as "x + y = 5 / (x - y)". In other words, it's just a mathematical permutation of the same thing, and while that can sometimes be useful and practical, it also doesn't really change our current understanding of anything. In particular, it does not support their claims that "since, therefore, the universe is a simulation, there must be an owner of that simulation outside the universe".

I'd be happy to be proven wrong on that part and hear about what is actually different about these "simulation theories", but so far I haven't been able to find anything.

Is infinity real though?

No, infinity is just a mathematical construct. "Indefinite", however, is real.

We don't need FTL or antimatter rockets. Now with antimatter if it is exactly opposite to matter while a whole atom and thus bearing mass then the only time all matter and antimatter can combine and explode would be at the end (or beginning) of the Universe. In that soup. When everything reaches that point it explodes again I suppose in an endless cycle.

[Jalpha]

Looks like Jalpha has been digging into his bush stash again

I have a bad habit of condensing paragraphs into sentences. Basically if matter and antimatter are totally opposite they should have opposite mass. This should behave like the north and south poles of a magnet in the sense that an atom with a positive value for its mass, and an atom with a negative value for its mass should repel each other and hence could never touch and release energy. The only time matter and antimatter could touch would be after atoms evaporate into their constituent parts and the higgs boson (which I understand to be a field which attributes mass to atoms) breaks down. This should occur at near the same moment as all these tiny pices of atoms are distributed evenly accross space.

In a way as though the Universe goes through an endless cycle of turning itself inside out perhaps.

[MagicManICT]

I want to get into this discussion, but I'm not in the mind to.

I don't have a link handy, and I wish I could remember the name of the theory, but an alternative theory was posted a good while back to "expansion" and "collapse" that the universe is an odd torus type shape that folds back in on itself. Math can't disprove it, but it doesn't meet that whole "nice a simple" solution. I think certain of current theories need substantiating (like dark matter) before this one gets moved up as "more possible (than other theories)" or disproven.

[loftar]

Basically if matter and antimatter are totally opposite they should have opposite mass.

That's not actually the case, however. Mass cannot be negative, and particles have the exact same (positive) mass as their respective antiparticles. Moreover, even if that were not the case, the electromagnetic force is much, much stronger than gravity, and so even if these particle pairs repelled each other gravity-wise, their attraction (from having opposite charge) would massively overwhelm that repulsion.

Perhaps more importantly, however, there's more matter in the universe than antimatter, so there wouldn't be antimatter to cancel out all matter anyway. The reason why that is so is, however, yet another one of those completely unsolved mysteries.

[dafels]

Looks like Jalpha has been digging into his bush stash again

[sMartins]

We give the meaning to things, all of us, not scientists .... reality has no meaning at all.

"In quantum physics, however, each observation implies an intervention in the observed. Because of the quantum physical laws of nature, a change of state of the observed is inevitably coupled to the observation process. So it's not a situation independent from the experiment that is observed, but we ourselves call forth the facts (or compel them to go in a certain direction to a disambiguation), that then become an observation".
Pascual Jordan

In short, we are part of the nature, we are inside, our ideas and the meaning we give to things has to take a precise position to be real. That's why we won't ever be able to understand the "whole" thing .... with very high probability, in my opinion.

Also the good old Feynman: "I think I can safely say that nobody understands quantum mechanics". I add to that ...... it just works.

Also F=m*a doesn't mean anything, it just works. It's not "true" that the force is equal to mass*acceleration, it's just us in a very specific context.

I'm saying all of this, cause nowdays we make the huge mistake of thinking that science is the "true", it's not, it's just one, between multiple, of our skills.
We cannot beleive in science, it's an absurd.