Uploaded April 2026 | Updated September 2026, 2 weeks ago
In this second discussion with Chantal, we continue from the basic idea that space may have real physical properties, and ask what follows from that for general relativity.
The main question is very simple: if space behaves like an elastic medium, could gravity be understood as refraction? We go step by step through the logic. First, we talk about why transverse gravitational waves and electromagnetic waves suggest that the medium must support shear, and therefore must in some sense be elastic.
From there, I use several simple visualizations - including marching people walking from grass into mud - to show how a wave bends whenever its speed changes across a gradient. That gives a very intuitive picture of refraction, and from that, a simple way to think about gravitational bending of light.
We then connect this to clocks, time dilation, and the metric tensor. The core idea is that if the wave speed changes locally because density or elasticity changes, then light clocks slow down as well. In this view, the metric tensor is not something mysterious - it is simply a way to describe local stretching, compression, and distortion of the medium.
We also talk about gravitational redshift, optical black-hole analogies, the photon sphere, and why refractive models of gravity are not new. Newton already suggested something very similar, and later work by people like Kleinert and Robert Close explored related ideas in more detail.
We also discuss he river model of gravity, Halton Arp and redshift, analog black holes, and possible medium models. Throughout the discussion, the focus stays on one basic question: if space has physical qualities, can general relativity emerge naturally from an elastic-medium picture?
Simulations:
Properties of space:
Michelson-Morley 1887: https://jsfiddle.net/Chenopdodium/yba...
Speed of waves in solids: https://jsfiddle.net/Chenopdodium/2ed...
Elastic continuum variant s: https://jsfiddle.net/Chenopdodium/9wo...
https://jsfiddle.net/Chenopdodium/6h8...
https://jsfiddle.net/Chenopdodium/tzd...
https://jsfiddle.net/Chenopdodium/q7r...
https://jsfiddle.net/Chenopdodium/61z...
1D elasticity: https://jsfiddle.net/Chenopdodium/pbz...
Elastic waves variant 1: https://jsfiddle.net/Chenopdodium/reh...
Elastic waves variant 2: https://jsfiddle.net/Chenopdodium/7ty...
GR waves variant 1: https://jsfiddle.net/Chenopdodium/tga...
GR waves variant 2: https://jsfiddle.net/Chenopdodium/n45...
General relativity / refraction / metric / time:
LIGO / Virgo / KAGRA: https://jsfiddle.net/Chenopdodium/30g...
Waves in an elastic continuum variant 1: https://jsfiddle.net/Chenopdodium/4pe...
Waves in an elastic continuum variant 2: https://jsfiddle.net/Chenopdodium/w6o...
Snell's law / refraction: https://jsfiddle.net/Chenopdodium/3mL...
Optical lenses with gradients: https://jsfiddle.net/Chenopdodium/bw6...
Optical black holes: https://jsfiddle.net/Chenopdodium/j1b...
The metric tensor: https://jsfiddle.net/Chenopdodium/soz...
What about time?: https://jsfiddle.net/Chenopdodium/nxp...
Time in the metric tensor variant 1: https://jsfiddle.net/Chenopdodium/n87...
Time in the metric tensor variant 2: https://jsfiddle.net/Chenopdodium/fke...
Frequency and wavelength: https://jsfiddle.net/Chenopdodium/9jc...
Matter / gravity / alternatives:
What about matter? / inertia vs gravity: https://jsfiddle.net/Chenopdodium/69m...
How matter bends space variant 2: https://jsfiddle.net/Chenopdodium/L0a...
How matter bends space variant 3: https://jsfiddle.net/Chenopdodium/cg0...
Twisted rubber band analogy: https://jsfiddle.net/Chenopdodium/fpo...
From slower waves to gravity variant 1: https://jsfiddle.net/Chenopdodium/9rt...
From slower waves to gravity variant 2: https://jsfiddle.net/Chenopdodium/vgb...
GR alternative visualization: https://jsfiddle.net/Chenopdodium/15t...
References:
Einstein (Leiden 1920) - ether / space with physical qualities: https://mathshistory.st-andrews.ac.uk...
Baird (2000) - Newton's Aether Model: arxiv.org/pdf/physics/0011003
Refraction video: • Refractive Properties of Gradient Index Op...
Dialect (Chris) - metric tensor / geometry video: • Demystifying The Metric Tensor in General ...
Close, Robert A. - A Classical Wave Model of Quasi-Static General Relativity: vixra.org/abs/2407.0047
Sagnac effect figure / reference: https://www.researchgate.net/figure/a...
In this second discussion with Chantal, we continue from the basic idea that space may have real physical properties, and ask what follows from that for general relativity.
The main question is very simple: if space behaves like an elastic medium, could gravity be understood as refraction? We go step by step through the logic. First, we talk about why transverse gravitational waves and electromagnetic waves suggest that the medium must support shear, and therefore must in some sense be elastic.
From there, I use several simple visualizations - including marching people walking from grass into mud - to show how a wave bends whenever its speed changes across a gradient. That gives a very intuitive picture of refraction, and from that, a simple way to think about gravitational bending of light.
We then connect this to clocks, time dilation, and the metric tensor. The core idea is that if the wave speed changes locally because density or elasticity changes, then light clocks slow down as well. In this view, the metric tensor is not something mysterious - it is simply a way to describe local stretching, compression, and distortion of the medium.
We also talk about gravitational redshift, optical black-hole analogies, the photon sphere, and why refractive models of gravity are not new. Newton already suggested something very similar, and later work by people like Kleinert and Robert Close explored related ideas in more detail.
We also discuss he river model of gravity, Halton Arp and redshift, analog black holes, and possible medium models. Throughout the discussion, the focus stays on one basic question: if space has physical qualities, can general relativity emerge naturally from an elastic-medium picture?
Simulations:
Properties of space:
Michelson-Morley 1887: https://jsfiddle.net/Chenopdodium/yba...
Speed of waves in solids: https://jsfiddle.net/Chenopdodium/2ed...
Elastic continuum variant s: https://jsfiddle.net/Chenopdodium/9wo...
https://jsfiddle.net/Chenopdodium/6h8...
https://jsfiddle.net/Chenopdodium/tzd...
https://jsfiddle.net/Chenopdodium/q7r...
https://jsfiddle.net/Chenopdodium/61z...
1D elasticity: https://jsfiddle.net/Chenopdodium/pbz...
Elastic waves variant 1: https://jsfiddle.net/Chenopdodium/reh...
Elastic waves variant 2: https://jsfiddle.net/Chenopdodium/7ty...
GR waves variant 1: https://jsfiddle.net/Chenopdodium/tga...
GR waves variant 2: https://jsfiddle.net/Chenopdodium/n45...
General relativity / refraction / metric / time:
LIGO / Virgo / KAGRA: https://jsfiddle.net/Chenopdodium/30g...
Waves in an elastic continuum variant 1: https://jsfiddle.net/Chenopdodium/4pe...
Waves in an elastic continuum variant 2: https://jsfiddle.net/Chenopdodium/w6o...
Snell's law / refraction: https://jsfiddle.net/Chenopdodium/3mL...
Optical lenses with gradients: https://jsfiddle.net/Chenopdodium/bw6...
Optical black holes: https://jsfiddle.net/Chenopdodium/j1b...
The metric tensor: https://jsfiddle.net/Chenopdodium/soz...
What about time?: https://jsfiddle.net/Chenopdodium/nxp...
Time in the metric tensor variant 1: https://jsfiddle.net/Chenopdodium/n87...
Time in the metric tensor variant 2: https://jsfiddle.net/Chenopdodium/fke...
Frequency and wavelength: https://jsfiddle.net/Chenopdodium/9jc...
Matter / gravity / alternatives:
What about matter? / inertia vs gravity: https://jsfiddle.net/Chenopdodium/69m...
How matter bends space variant 2: https://jsfiddle.net/Chenopdodium/L0a...
How matter bends space variant 3: https://jsfiddle.net/Chenopdodium/cg0...
Twisted rubber band analogy: https://jsfiddle.net/Chenopdodium/fpo...
From slower waves to gravity variant 1: https://jsfiddle.net/Chenopdodium/9rt...
From slower waves to gravity variant 2: https://jsfiddle.net/Chenopdodium/vgb...
GR alternative visualization: https://jsfiddle.net/Chenopdodium/15t...
References:
Einstein (Leiden 1920) - ether / space with physical qualities: https://mathshistory.st-andrews.ac.uk...
Baird (2000) - Newton's Aether Model: arxiv.org/pdf/physics/0011003
Refraction video: • Refractive Properties of Gradient Index Op...
Dialect (Chris) - metric tensor / geometry video: • Demystifying The Metric Tensor in General ...
Close, Robert A. - A Classical Wave Model of Quasi-Static General Relativity: vixra.org/abs/2407.0047
Sagnac effect figure / reference: https://www.researchgate.net/figure/a...
