Talk:Preliminary reference Earth model

Newtonian methodology

• I accidentally deleted a conversation in editing this article. My apologies.

It should be a great clue to the error in thinking here that we can measure a higher acceleration at the poles where there is less physical matter underfoot than at the top of an equatorial mountain where there's considerably more mass underfoot.

This speaks volumes to the lack of understanding involving gravity wells that pervades modern academia and leads to regurgitated disinformation as found in this article.

The gravity depends only on the mass inside the sphere of radius r

It's a Newtonian notion of mass attracting mass that has you arriving at an acceleration of zero at the core. That's incorrect.

We know that matter curves spacetime. A gravity well like the Earth is a four-dimensional hole that three-dimensional material falls into and then gets stratified by density. The fourth dimension - time - is what is getting stretched.

An object in motion tangent to the Earth will have its path curved by the warpage of spacetime. However, an object sitting motionless on the surface has a spacetime line that runs from space straight through the top of the object, out of the bottom, making a direct line to the core. The object's straightest line of travel through spacetime is now a straight line radial to the core, which happens to be blocked here at the surface, 3963 miles from the center. Your spacetime line sitting at your desk reading this is pinched in from outer space to our core and back out again. You can't travel there because denser matter is between you and it, so your body is stuck, constantly feeling the deceleration of your fall like an elevator continually coming to a stop at a floor.

When you theorize on a subject where time is the agent of change specifically, you cannot use a formula that does not consider the main variable. This is precisely the case with 'gravity.' Newton didn't know about time dilation, but Einstein did. You cannot develop a theory of what acceleration looks like at the center of any gravity well without first asking the simple question, "What time is it there relative to the surface?"

from phys.org "A trio of researchers in Denmark has calculated the relative ages of the surface of the Earth versus its core and has found that the core is 2.5 years younger than the crust. [it's likely considerably younger than even this] During one of his famous lectures at Caltech in the 1960's, Richard Feynman remarked that due to time dilation, the Earth's core is actually younger than its crust. General relativity suggests that really big objects, like planets and stars, actually warp the fabric of spacetime, which results in a gravitational pull capable of slowing down time. Thus, an object closer to Earth's center would feel a stronger pull—a clock set near the core would run slower than one placed at the surface, which means that the material that makes up the core is actually younger than the material that makes up the crust. In this new effort, the research trio ran the math to discover the actual number involved. They found that over the course of our planet's 4.5-billion-year history, the pull of gravity causes the core to be approximately 2.5 years younger than the crust—ignoring geological processes, of course." -phys.org

Time cannot be slower at the core and simultaneously be at zero acceleration. That's not how relativity works.

As a thought experiment, consider the Earth, as it is with its stratified layers - a dense core with progressively less dense layers on top until you get to the crust and out into the atmosphere. Now take the moon and shrink it down to the size of a softball. Retain the mass of the moon, but now it’s close to a neutron star in density. Hold this ultra-dense object directly over the surface of the Earth and let it fall. The deepest portion of Earth’s core and the center of the softball-sized moon will quickly displace the less dense materials between them and merge, with the little moon traveling the most distance and the core moving slightly for the merging. There will be some oscillation, but the dropped "softball moon" will quickly occupy the center of the center, driving the gravity well ever deeper with its added mass. And due to its ultra-density, it will reside at the point of greatest acceleration - the center.

So, for essentially the same volume, Earth’s surface acceleration is now over 10 m/s² due to being in a deeper gravity well because the mass of the Earth has increased an entire moon’s worth without gaining any significant volume. An acceleration tapering to zero at the core is a physics recipe for a hollow earth rather than the densest matter in the gravity well.

-Thanks, Joe — Preceding unsigned comment added by 2605:59C8:41D:2010:707E:6379:1269:FB26 (talk) 16:22, 25 August 2024 (UTC)

to further this perspective, if you had a shaft that ran through to the center of the earth and then shown a light down that shaft, it would blue shift all the way to the core. The model as depicted would have it red shifting below the surface and that is not correct

Additionally, if you pointed the light just right, you'd see it reflected back at you. This is because the light's straightest line through space is a radial pinched into and then back out of a gravity well

Regards

Joe 2605:59C8:41D:2010:9898:C682:F5C5:EBAE (talk) 15:30, 29 August 2024 (UTC)