Sorry to bother you with this again. I have posted about this 2 times in the last 6 months already, because it is a fascinating topic and i want to talk about it. The issue is, whether there is renewable energy in the universe (truly renewable). Solar energy is called “renewable” but ultimately the sun will burn out. What then?
I have last time gotten the answers that “it’s a stupid question because we have more urgent problems, such as corrupt politics etc.”. Frankly, i disagree. This question is of existential importance, because it gives us an outlook into the far future. These perspectives are more valuable than playing 15 minutes of a computer game, which you could do instead of reading this article.
I uploaded a neat PDF here: https://files.catbox.moe/p8tg6i.pdf
Additionally i will copy-paste the article text here.
Spider Web Cosmology
From: https://feddit.org/u/gandalf_der_12te
Date: 2026-07-26
Subject: Renewable energy in a cosmological context
Abstract
In this paper i present a simple and clear approach to extract useful energy out of the cosmic expansion using mithril material wires, i.e. wires with very high Young’s modulus and ultimate tensile strength. This energy is renewable, such that it represents a continuous and probably eternal power source.
Introduction and Motivation
The industrial revolution has allowed for a significant growth of humanity. While global population numbers were around 300 million around 1000 CE, it scaled to almost 8 billion by 2000 CE. That is an almost 30-fold increase. This was made possible largely by two inventions: the combustion-engine driven tractor and the natural-gas-based ammonia synthesis. Both consume massive amounts of energy, which mostly came from fossil fuels, which are not renewable. This naturally raises the question of whether humanity will ever run out of energy, which would induce a reversal of this massive growth, i.e. a significant population shrinkage. Related to this is the problem of climate change, i.e. whether there exists a long-lasting energy source that does not poison our own living conditions that we rely on.
Ever since solar energy started around 2020 to become economically competitive, many people have felt deep relief from the anxiety around climate change and the threat that humanity would eventually run out of fuel. However, the sun is predicted to burn out in approximately 10 billion years, and then humanity will have to find a new source of energy. While other stars do exist, those too will eventually run out of energy, with the slowest- burning stars (red dwarf stars) predicted to last for approximately 1000 billion years. Slower-burning stars do not practically exist as they would not be massive enough to ignite nuclear fusion in the first place.
What other sources of energy are there in cosmology? Especially, do sources exist that do not run out after a while, i.e. that are truly renewable?
Scope and Context
This paper uses the insights from general relativity, especially cosmic expansion, and simple mechanics to present a mechanism for renewable power in cosmology. While quantum aspects, such as vacuum energy, are highly interesting and might slightly change the reality, they’re left out of this analysis and regarded as an extra feature of nature that will have to be stacked on top of this one.
Mechanism
The term „spider web cosmology“ is justified if one visualizes the core concepts of this proposal:
An array of wires made from a very thin (lightweight) material called „Mithril“ are laid out throughout the universe, which have extremely high elasticity (Young’s modulus), which means they exert force when stretched without significantly changing length.
Living organisms reside at the intersection points. As the intersection points are pulled away from each other over time, the wires between them will be stretched. The force that each wire exerts can then be calculated from Hooke’s law: F=σ⋅A=E⋅ε⋅A , with F being force, σ being stress, E being Young’s modulus, ε being axial strain, A being cross-section area.
The mithril wires are chains of small link elements. As the living organisms at the intersection point let the wires contract from time to time, while generating power from that contraction, new link elements are produced and attached to the wire.
The mithril wires have to be produced from new matter that gets produced from a matter-anti-matter pair, that gets produced from the energy harvested from the chain relaxation. In other words, the chain has to release more energy when it relaxes than the rest mass of the mithril chain links.
This is why this mithril material has to be extremely lightweight while still having high Young’s modulus and high ultimate tensile strength. Practically speaking, I’m not entirely sure whether such a material could exist. Using simplifications and a linear model of elasticity, common steel does not have good enough properties for this application.
I will proof this in the following calculation. For this, we have to look at the rest mass of a steel chain link and the energy that can be released when the chain is relaxed by the length of one link element. Let x be the length of one link element.
The work W1 released by the chain is W 1=F⋅x=E⋅ε⋅A⋅x , while the rest mass (rest energy W2) of one chain link is W 2= ρ⋅A⋅x with density ρ, therefore for W1 to be larger than W2 one gets the relation E⋅ε > ρ. Comparing this to the actual values for steel:
- E is around 200 GPa (2·10¹¹ J/m³)
- ρ is around 8 000 kg/m³, equivalent to a rest energy of around 8·10²⁰ J/m³
Therefore, ε would have to be larger than 4·10⁹, i.e. the steel wire would have to stretch to 4 billion times its usual length. However, commercially available steel used in construction typically breaks apart for ε > 3·10⁻³ (Source: Wikipedia). These steel wires would have to have a factor 10¹² higher ultimate tensile strength!!
The judgement is still out on whether a good enough mithril material could hypothetically exist.
cosmic expansion (if you represent it as a pseudo-force) increases linearly with distance, meanwhile gravity gets weaker quadratically with distance. that means, at a certain point, cosmic expansion is going to be stronger than gravity. here’s a visualization for you:
(forgive that i didn’t pretty up the diagram much. i just don’t care enough to label everything properly. you get the idea)
but you’re talking about a material, which are governed by electromagnetic forces. These are simply way too strong. You simply can’t build a structure that is so flimsy that it could be affected by cosmic expansion but not also be torn down by the smallest local distortions.
Also there is a huge gaping question of how to build and maintain such a structure, because it would needs to light-year long. Even if this magical material existed we wouldn’t be able to do anything without signifiant advances in space travel … and we’re talking things like “warp drive” here. So just more Science Fiction.
Well you’re treating this as a logistical engineering question. We’re not at that point, this is a manner of energy generation that only becomes necessary after a trillion years, after all the stars have burned out, after all the available hydrogen in the galaxy has been burned up in fusion reactions. How to build and maintain this system is definitely a problem for someone else, many years from now.
Also, you say this wouldn’t be possible without spacecraft advances like warp drive… But over this incredible time frame, you really don’t need any magical advance in spacecraft. Over the course of a trillion years, at the rate it’s going now, the Voyager spacecraft will have traveled over 50 million light years (that distance is about 500 times the diameter of the Milky Way). So, we can travel the distances needed to do this over the truly, epically, astonishingly immense timeframe available.
But more to the point, this is a theoretical question, a question about the nature of the universe. This isn’t really a logistical question. We’re not asking “how” one could do it, we’re asking “if” one could do it. Or, what aspect of physics, if any, precludes this from ever being viable?
I wasn’t mostly, it’s just one more implausible aspect I added to this “story”. It already fails at the fundamental physics level.
Care to elaborate? (As again, that’s the actual point of the thread)
See my previous comments.
The core proposition here is that some material could be stretched by cosmic expansion. But cosmic expansion is so weak it can already be countered by gravity. But gravity is orders of magnitudes weaker than the electromagnetic force governing materials.
Take interstellar gas clouds for example. They are barely denser than the vacuum of empty space, yet still bound by gravity and thus immune to cosmic expansion. OP would need a material that is somehow weaker bound than a gas cloud, which could hardly be called a material any more. That’s just random atoms in space.