I’m a voracious reader of popular physics and consider myself fairly well-informed for a layperson.
But I can’t help recalling one of my professors who stated that magnets work because it is their “preferred state.” He had just gone into great detail about atomic dipoles and electron spin, but then just shook his head and said, “Your refrigerator magnets stay on the door because it is their preferred state.”
When I consider the universe, I usually end up just thinking, “It’s the preferred state.”
Whenever I read about quantum mechanics, I find myself thinking that Coyote or the Monkey King must be running the universe. One of the tricksters, not the grumpy old curmudgeon of the Old Testament.
There’s quite a profound point here. Stephen Hawking proposed a cosmological model involving what he called “imaginary time” but which he insisted might be very real, and indeed the actual reality that we cannot perceive. The name comes from the use of (also unfortunately named) imaginary numbers in the model. Simply put, the model can be thought of as a four-dimensional sphere in which the universe is finite but unbounded, and the paradox of the Big Bang singularity disappears. Questions like “where did the Big Bang come from? What was there ‘before’?” vanish – the Big Bang is just a coordinate on the four-dimensional manifold: finite, unbounded, and eternal.
Empty space, like the vacuum of outer space, is actually a very busy place, filled with vibrating quantum fields representing all the fundamental particles, and in which particle-antiparticle pairs are always spontaneously popping into existence and annihilating each other.
“Before” doesn’t really work when talking about the origins of time and space themselves. I believe it was either in the forward or the introduction of Hawking’s “A Brief History of Time” he attempted to put it in extremely layman’s terms, and it went something like “going backwards from the current expansion of the universe towards the Big Bang and the infinitesimally small universe is similar to traveling from the equator to the North Pole. Once we reach the destination, there’s nothing north of the North Pole. Similarly, there’s nothing “before” the existence of time.”
EVERY bit of cosmology is “hard to wrap one’s head around”!
Well, the universe IS expanding.
Some boffins ask "Into what…?"
Not me! As of this thread, I’m going to stop worrying about the Very Large, the Very Small, the Distant Past, and the Distant Future.
And instead worry about something human-scale: “When is the local boathouse going to start selling corn dogs for the season?”
My cosmological question is: why is the best fish & chips in the whole world only sold out of a converted school bus in a small lakeside village hundreds of miles away from me?
Here’s a post from last night that coincidentally touches on exactly these points. Written by somebody with a pretty good, albeit non-professional, grasp of this topic:
IMHO the reason this is difficult to comprehend is because time seems to have a directional arrow that space doesn’t. I could go to the North Pole, leave, and go back again. When I’m there, I won’t notice anything special when compared to any other spatial coordinates. With time, since it seems to have a direction, the time = zero (or time = 1 Planck time, or whatever the smallest unit of time is) coordinate seems to be a privileged location in a way the North Pole isn’t. The only way around that seems to be to agree with Einstein’s saying that “time is an illusion”.*
*. I was surprised to find out that it was Einstein who said that. It sounds like the sort of thing that would have been said by some ancient philosopher like Socrates, Buddha, etc., or maybe written for some modern fictional sci-fi guru type like Yoda.
His original read, "The Universe is not only queerer than we imagine—it is queerer than we can imagine.” But as time passed, queerer became a word that was no longer acceptable so it got changed.
That, queerly, is key to this discussion. We no longer find the physics of the ancients acceptable, or the medicine of the ancients, or the geography of the ancients, or, most certainly, the cosmology of the ancients. Modern science has tossed them all out for conclusions far more sophisticated, detailed, and counterintuitive.
So why do we still insist upon accepting the philosophy of the ancients when it comes to words like “something” and “nothing”? Or “everything,” or “inside” and “outside,” or “time,” or “before,” or “universe?” That whole vocabulary people are applying to modern physics should be tossed out as well.
My best understanding of quantum mechanics is that it states that there can never be nothing. No vacuum, no void. “Always” has little meaning as well if time is tied to space and matter. We’re playing semantic games with our definitions, just like we do with “god” or “creator,” except those words have no hard math behind them.
QM theorists could be wrong about its implications, of course, nothing is settled. But trying to make sense as laypeople by applying thoroughly obsolete philosophic notions makes our task harder.
I have to push back a bit here (just a little). Yes, Stephen Hawking, in collaboration with James Hartle, proposed a cosmological model known as the “Hartle-Hawking state” that involves the concept of “imaginary time” or “Euclidean time”. This model suggests that quantum effects near the Big Bang alter the nature of space and time, effectively turning the time dimension into a fourth spatial dimension.
Note that it’s proposed - not yet fact. Regardless, there is Hawking’s “time” and what we colloquially know as (chronological) time. I’m not sure how this fits into Hartle-Hawking state, but I know I was born in the distant past. A past that everyone agrees was 70 years ago. There was a time, a long time ago that dinosaurs lived on earth. A time that we all agree chronologically happened ‘before’ now. There was a time this known universe existed and the earth did not yet.
Every essay and lecture I’ve read or heard, without exception, refers to the Big Bang as happening 13.8 billion years ago. I don’t think it’s too much to ask - in a thread entitled “pondering” located the ‘Miscellaneous and Personal Stuff I Must Share’ forum - that it’s possible to muse on the chronological order of things coming into existence in what we all agree on as time in that (colloquial) sense.
It’s because we don’t have anything better to replace them with. Take any sport that has been played for a long time as an analogy. We’ve developed better training methods, have a better knowledge of nutrition, how often an athlete needs to rest, which strategies work well in a particular situation, etc. The way things are done now compared to how they used to be done 100 years ago WRT all those things have changed accordingly. But all those athletic activities still need to be carried out by humans with human arms, human legs, human cardiovascular systems, etc. Those things haven’t, and can’t change. We have to make do with the hand we’re dealt in terms of what the human brain can imagine.
ETA: For now. Maybe AI will some day advance to the point where it can do a better job of imagining these things than we can do as puny humans.
So the thing to do is continue having futile arguments based on false premises?
I reject that, just as I reject your sports analogy. Bodies aren’t brains. We’ve made progress on concepts from slavery to monarchy. Education introduced dozens of new concepts into average discourse based on other sciences. Physics may take time because even physicists have not settled on some meanings. That doesn’t mean that time will never come.