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Quantum Gravity’s Time Problem

quantamagazine.org

31–40 of 86 posts

Re: Quantum Gravity’s Time Problem

#31
post #21

Earlier quoted context omitted.

"I would argue that solipsism and a universe simulation are actually very close." I agree with you that from the point of view of testability both are very similar, but, in my view, from the point of view of logic reasoning are almost the opposite. Solipsism is just bad reasoning or, at most, a semantic trick: I define my mind as everything there is out there, so, obviously, everything is in my mind. But we have scie…

I define my mind as everything there is out there, so, obviously, everything is in my mind. But we have science, precisely, to try to understand what it is out there, and "out there" means outside of our minds. But that is the very point of solipsism - because you are experiencing the outside world only through your senses in your mind, you are unable to decide whether the outside world even exists. The two options a…

Well, obviously, we only have access to our senses.

As I have not control through introspection to my sensorial experience, surely, there is something "out there" generating it. That something is what we (or, as we are talking about solipsism, I) are trying to understand.

What is the point of saying that, what is doing it, i's "my mind"? What have we learned doing that except to mud the issue at hand?

Re: Quantum Gravity’s Time Problem

#32
post #16

I have a question as a non physics/math person: We assume that light speed is a constant, but we also know that speed is measured as distance/time. We know that in the presence of high gravity (or proximity to very high mass), or very high speed, we experience time dilation, and that perspective and location matters WRT actual time. So, how do we assume that light speed is constant? Does the distance moved change rel…

I'm also not a physicist, but as far as I understood special relativity and also according to this [1] Quora answer, the speed of light is same in every frame of reference, so the universe compensates variations in speed by dilating time. This is also consistent with Maxwell's equations [2].

[1] https://www.quora.com/Why-does-time-dilation-occur-And-why-d... [2] https://van.physics.illinois.edu/qa/listing.php?id=2605

Re: Quantum Gravity’s Time Problem

#34
post #22
post #19

Earlier quoted context omitted.

It's constant within a given frame of reference .

No, the speed of light is the same in ALL inertial frames of reference. This is the crucial postulate from which all special relativity comes as a consequence.

SR is the model of fixed continuous space-time (and the "inertial frames of reference" are defined only in such model). Thus the SR is applicable to the reality only as much as the real space-time can be approximated by such a model. That approximation is pretty good usually, except at the very large scales (the non-fixed, expanding, nature of the real space-time starts to show more than negligible deviation from the SR model) and at the very low scales where the non-continuous nature of the real space-time starts to play a role.

>“anti-de Sitter” (AdS) space. In these warped worlds, spatial increments get shorter and shorter as you move out from the center.

and that sounds like the metric is p-adic there. While our typical Cartesian coordinates express the metric naturally produced by the real numbers, at large scale the world may have different metric. Our 46B ly radius visible Universe's Schwarzschild radius is about 10B ly, so if we go about 160B ly beyond the visible Universe border - we "can" do it as otherwise the Earth would be the "center of Creation" - we will have the 200B ly radius Universe which is inside its own Schwarzschild radius equal to those 200B ly - so our visible 46B ly radius Universe is basically inside that large black hole and at that scale the space seems to be AdS.

Re: Quantum Gravity’s Time Problem

#36
post #21

Earlier quoted context omitted.

I define my mind as everything there is out there, so, obviously, everything is in my mind. But we have science, precisely, to try to understand what it is out there, and "out there" means outside of our minds. But that is the very point of solipsism - because you are experiencing the outside world only through your senses in your mind, you are unable to decide whether the outside world even exists. The two options a…

Well, obviously, we only have access to our senses. As I have not control through introspection to my sensorial experience, surely, there is something "out there" generating it. That something is what we (or, as we are talking about solipsism, I) are trying to understand. What is the point of saying that, what is doing it, i's "my mind"? What have we learned doing that except to mud the issue at hand?

I am actually a bit confused, maybe it is just because English is not my first language and I am misunderstanding some nuances of what you are trying to say. So let my try it from another point of view.

I personally don't dream much or at least usually do not remember much or any of it, but in principle walking along a beach and dreaming about walking along a beach should feel pretty much the same until you realize you only dreamed the latter. So more or less identical experiences to you can have two very different origins, one is rooted in some external reality, the other one is just some kind of hallucination.

You can easily inspect the world of the real beach and at least in principle, maybe by lucid dreaming or something like that, you could also inspect the world of the dreamed up beach. If you never realized you were dreaming, both scenarios might be indistinguishable for you and form the reality you are living in, but nonetheless with very different underlying realities. Does that make sense? There is the reality you are experiencing (beach) and there is the reality that is causing your experience, which may (dreamed up beach) or may not (real beach) be the same thing.

Re: Quantum Gravity’s Time Problem

#37
post #28
post #16

I have a question as a non physics/math person: We assume that light speed is a constant, but we also know that speed is measured as distance/time. We know that in the presence of high gravity (or proximity to very high mass), or very high speed, we experience time dilation, and that perspective and location matters WRT actual time. So, how do we assume that light speed is constant? Does the distance moved change rel…

> We assume that light speed is a constant, but we also know that speed is measured as distance/time. Correct. However, the crucial part that is missing from your thought process is that: 1) light can only travel in a "straight" line, and 2) "straight" lines are defined by the spacetime metric. As a lower-dimensional analogy, think of what a "straight" line means on the surface of a sphere[1]. The shortest path betwe…

Gravity can stretch spacetime to make the distance light has to travel longer than in an unaltered "flat" universe. But can it also shrink, causing a photon to arrive at a destination in a shorter time? And I don't mean a wormhole, which requires tearing in a topological sense.

Re: Quantum Gravity’s Time Problem

#38
I just ran into an interesting theory for Gravity: Subquantum Kinetics

It's featured in Dr. Paul LaViolette's book The Secrets of Anti-gravity Propulsion, and there's a really interesting section that challenges the Standard Model in Quantum Mechanics called the Model G in Subquantum Kinetics.

The idea is that matter is born out of what's called the Ether, the origin to all energy. The positive and negative electrical energy sums a positive or negative charge with a "spin" -- which also yields positive or negative gravity.

This is a video that simulates matter being created out of the Ether:

https://www.youtube.com/watch?v=jPLNfgxD2ic

Supposedly, it's been rejected by other researchers because it goes against Einstein's theory of Relativity and the Big Bang, -- however, there's been rumors the Model G is being used by underground, black-project sites like Lockheed-Martin and Boeing (e.g. Northrop Grumman's B-2 Spirit stealth bomber.)

Here's a lecture by Dr. Paul LaViolette featuring content from his book:

https://www.youtube.com/watch?v=ifEgGMFK-VU - (warning: audio isn't great)

Re: Quantum Gravity’s Time Problem

#39
post #38

I just ran into an interesting theory for Gravity: Subquantum Kinetics It's featured in Dr. Paul LaViolette's book The Secrets of Anti-gravity Propulsion, and there's a really interesting section that challenges the Standard Model in Quantum Mechanics called the Model G in Subquantum Kinetics. The idea is that matter is born out of what's called the Ether, the origin to all energy. The positive and negative electrica…

I don't care as much for the Big Bang, but for it to go against relativity seems a bit hard to swallow.

Re: Quantum Gravity’s Time Problem

#40
post #38

I just ran into an interesting theory for Gravity: Subquantum Kinetics It's featured in Dr. Paul LaViolette's book The Secrets of Anti-gravity Propulsion, and there's a really interesting section that challenges the Standard Model in Quantum Mechanics called the Model G in Subquantum Kinetics. The idea is that matter is born out of what's called the Ether, the origin to all energy. The positive and negative electrica…

I don't care as much for the Big Bang, but for it to go against relativity seems a bit hard to swallow.

Yeah, no kidding... because that would also challenge the "Laws" of Thermodynamics, too: Free Energy from the Ether.

*I have to put that in quotes because it's not actually a law, right? You shouldn't go to jail for breaking it.

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