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What Is Space?
111–120 of 155 posts
Re: What Is Space?
#112"Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space." - Douglas Adams
The way the first paragraph was written instantly reminded me of Douglas Adams and his works. Glad to see another one. :)
Re: What Is Space?
#113Earlier quoted context omitted.
You may enjoy contemplating a sort of "epiphany" that I had during that usual pondering of imponderables: That the default or base state of existence may not be nothing, not "not even nothing", but rather Everything. ... Instead of viewing the origin of all reality/creation as things being added to a canvas of blackness/emptiness/voidness, rather consider that "Existence" may be a subtractive process: akin to holes b…
I've had the same thought about the starting from nothing rather than everything, but in an entirely different context. Axiomatic Set Theory is taught starting with the empty set as an axiom and along with a small number of additional axioms, and from that you can build the integers and rationals and real numbers as well as an impressive hierarchy of different infinities. And one thing that's proved is there is no la…
I remember a mention somewhere of this kind of approach to inverse foundations for set theory, but lost track of the reference. IIRC, the approach didnt have problem with empty set, but would allow the existence as a default until some obstruction. So, 'large sets' (nowadays called proper classes) would exist.
Re: What Is Space?
#114Do we know enough yet to have some good guesses about (1) the purpose of the universe, https://news.ycombinator.com/item?id=14570170 (2) the end of the universe, (A) big expansion and cool down to nothing, (B) no more expansion and cool down to nothing, (C) contraction back to another big bang, (D) something else very different?
The best idea I've heard about a purpose for the universe is the theory that it evolved to create black holes which contain 'child' universes inside. That would mean the purpose of the universe is the same as the purpose of life in general.
https://phys.org/news/2013-05-universe-evolve-black-holes.ht...
Re: What Is Space?
#115"baby don't hurt me, don't hurt me, no more"
Re: What Is Space?
#116Earlier quoted context omitted.
The biggest issue I see with the goo metaphor, is that it seems to suggest some sort of stationary ether that we move through as we move through space. That is to say, the mathaphor suggests that it makes sense to differentiate between stationary objects and moving objects in an objective sense. However, the core insight of relativity is that there is no such distinction.
I'm reading the whole book right now and the chapter after the one from the article is about time and goes more into spacetime according to relativity. So far it seems to me that they sometimes provide an oversimplified analogy which they revise in a later chapter.
I'm really loving the book (half way through it!).
Part of me knows that a lot of this is being simplified down for me, but I also trust the authors to not steer the reader too far off course.
I may not have all the math and physics understanding, but I get that dark matter is real. I didn't before. That's the kind of thing the book is about, imho.
Re: What Is Space?
#117If you are really serious about this question then you would also consider what mathematicians have to say about "space". Unfortunately, this is pretty much the whole of mathematics, but I think special attention should be given to the duality between geometry and algebra . This stuff goes back to Descarte. For example, you can consider the points equidistant from a specific point, which gives a circle. Or you can co…
Controversial, I know—but I wonder how deep that connection actually is...
'the points equidistant from a specific point' and 'X^2+Y^2=1' are both descriptions that we know how to parse and and evaluate into the same thing.
Don't get me wrong, I do think it's a super interesting property of the systems of description we formulate that it's possible to talk about the same things with different abstractions (which happens a lot in math: https://en.wikipedia.org/wiki/Duality_(mathematics)), even with very high degrees of precision—but I have a hard time seeing how this could be a property of space rather than of human conceptual structure/language.
Re: What Is Space?
#118Earlier quoted context omitted.
From my understanding (just a Quantum Physics I class, I could be wrong here) the Planck units quantize space or time to the extent that they define the smallest thing we can practically measure due to Heisenberg's Uncertainty Principle, but they do not preclude that things can actually be smaller than that. That is, something like length or time can be continuous, but our measurements can only ever be discrete multi…
> For example, a really small object can have a length smaller than the Planck length, but we wouldn't truly know how long it was because the Planck length acts as a fundamental limit on the precision/granularity of our measuring instruments. Would that be, to all intents and purposes, undetectable by us then? If so then that might be a possible explanation of "dark matter", assuming all these things were individuall…
> Would that be, to all intents and purposes, undetectable by us then?
In so far as our means for measuring particles doesn't change; namely, smashing things together at extremely high energies.
If you suppose that there are methods for measuring sub-Planck length areas then one must assume that they involve either: energies lower than those believed to be needed (which doesn't necessarily come to a solution, but pushes the problem to even higher energies and shorter lengths) OR that there is a default force that keeps space-time stable unless high energies are approached.
Note that both notions are mere speculation, the first on logic and the second on intuition about phase changes in states of matter.
Re: What Is Space?
#119How fast are you really going? One of the things I've thought about is relatively. Consider a toddler strapped to his car seat in a luxurious BMW cocoon while his father speeds down the autobahn at 200km/h. He calmy drinks from his sippy cup. You're in a passenger jet above him going 700km/hr. You're going 500km/hr faster than him. But how fast are you really going? Consider that the Earth is spinning around the sun…
It's consistently relative, because the unit of speed we use is relative to our subjective experience. Hell, if you were American you would've given these values in miles/hr, so localised is the subjectivity of distance. Hours too are a relative measure of time (consider an alien who could live for thousands of years and how they would measure time, or a being that could travel near the speed of light).
Re: What Is Space?
#120If you are really serious about this question then you would also consider what mathematicians have to say about "space". Unfortunately, this is pretty much the whole of mathematics, but I think special attention should be given to the duality between geometry and algebra . This stuff goes back to Descarte. For example, you can consider the points equidistant from a specific point, which gives a circle. Or you can co…
The humblest of nicknames!