Physics

Hey fediverse physicists and curious minds!

Some of you might recall a post from a while back where I shared early simulation results from a classical 1D "Pure Ether Theory" model, showing some promising soliton-like behavior and interactions ([[https://lemmy.world/post/30579344|Observation of Soliton-like Interactions...]]). That exploratory work, based on a simplified, classical framework, was a crucial step.

Since then, we've been working to formalize the theory into a fully relativistic framework, now calling it Unified Aether Dynamics (UAD). The core idea remains the same: reality emerges from a single, deterministic, continuous substance – the Aether. The goal is to show that fundamental physics, including [[Quantum Mechanics|quantum mechanics]] and [[General Relativity|gravity]], arises from the Aether's dynamics. This rigorous relativistic formulation is built upon a foundation of five core axioms. These aren't just philosophical statements; they are principles that dictate the specific mathematical form of the Aether's [[Stress-Energy Tensor (Tuv)|Stress-Energy Tensor]], whose conservation law serves as the fundamental equation of motion.

We're currently developing a new, robust 1D simulator based directly on these relativistic axioms (the [[Relativistic 1D Foundational Simulator - Computational Core|Relativistic 1D Simulator]], where the GUI is now under development!), and I wanted to share the foundational principles it's built upon. Here are the 5 core axioms of Unified Aether Dynamics:

1. The Aether as the Sole Fundamental Continuum Concept: Forget particles and empty space. Reality is one continuous, omnipresent substance: the Aether. Everything – fields, forces, particles, and even [[Spacetime|spacetime]] itself – are just different ways this single substance is behaving.

Mathematical Implication: Reality is described by continuous fields, primarily the Aether's rest-frame density ((\rho(x^\mu))) and its [[Four-Velocity|Four-Velocity]] field ( u μ ( x μ ) u μ (x μ ) ), defined throughout [[Spacetime|spacetime]].

2. The Principle of Non-Zero Density Concept: The Aether can never reach zero density ((\rho > 0)). There's no true void. This isn't just a property; it's a fundamental resistance to being pulled infinitely thin.

Mathematical Implication: This principle is mathematically enforced through a unique component in the Aether's [[Equation of State (Relativistic)|pressure]] ( p UAD ( ρ ) p UAD ​ (ρ) ). Specifically, a [[Principle of Non-Zero Density|constraint pressure]] term ( p constraint p constraint ​

) includes factors (like ( ρ / ρ 0 ) − ε (ρ/ρ 0 ​ ) −ε

) that cause the pressure to become infinitely repulsive as density approaches zero, preventing voids. Parameters μ, ε, and the [[Fundamental Densification Scale (ρ₀)|Fundamental Densification Scale]] ((\rho_0)) shape this force.

3. Scale-Dependent & Emergent Dynamics Concept: The Aether's behavior and the forces within it depend on its local density and how quickly that density is changing (gradients). This also means properties like the observed dimensions or [[Spacetime|spacetime]] geometry aren't fixed but emerge from the Aether's state and change depending on the scale you look at.

Mathematical Implication: The dependence on density and its gradients introduces non-linear dynamics. The constraint force derived from the [[Equation of State (Relativistic)|constraint pressure]] involves nonlinear terms that make its influence dominant at low densities relative to (\rho_0), driving scale-dependent behavior.

4. Conservation Principles as Foundational Constraints Concept: The total amount of Aether substance (mass-energy) and total momentum within any closed system are always conserved. These aren't just outcomes; they are fundamental laws that strictly constrain the form of the Aether's equations of motion.

Mathematical Implication: The Aether's dynamics must be governed by the [[Relativistic Conservation Law (∇µTµν = 0)|conservation of its Stress-Energy Tensor]], (\nabla_{\mu}T^{\mu\nu} = 0). This single tensor equation encapsulates the local conservation of energy and momentum and is the primary equation solved by the simulator.

5. Response to Compression (Equation of State) Concept: When the Aether is compressed (density increases), it pushes back. This resistance is pressure, and there's a defined relationship between density and this pressure. Mathematical Implication: This relationship is the [[Equation of State (Relativistic)|UAD Equation of State]], p UAD ( ρ ) p UAD ​ (ρ) , which quantifies the total pressure as a function of density. This function combines a standard fluid pressure term (like k ρ γ kρ γ

) with the unique [[Principle of Non-Zero Density|constraint pressure]] term, defining how the Aether pushes back across all density scales. Parameters k, γ, μ, ε, and (\rho_0) determine this relationship.

These axioms provide the theoretical foundation for UAD. They define a deterministic, relativistic continuous substance whose dynamics, we hypothesize, give rise to everything we observe.

Our current work with the new relativistic 1D simulator is precisely focused on exploring the numerical consequences of these axioms. Can an overdensity profile, like the [[Initial Conditions (Relativistic)|Gaussian bump]] we use as an initial condition, evolve into a stable, localized structure that persists and interacts in non-trivial ways, as suggested by the previous classical model? The relativistic framework is essential to see if this behavior holds up under the full demands of relativity and if it could potentially align with the behavior needed to explain emergent [[Quantum Mechanics|quantum phenomena]] (like those described by the [[Schrodinger Equation|Schrodinger Equation]]).

What do you think of these foundational principles? Do they spark any questions or ideas? Happy to discuss the axioms or the simulation approach!

Kletetschka said his theory overcomes some of the problems with earlier three-dimensional time theories that are based on traditional physics.

Those earlier theories, for example, describe multiple time dimensions in which cause-and-effect relationships are potentially ambiguous. Kletetschka's theory ensures that causes still precede effects, even with multiple time dimensions, just in a more complex mathematical structure.

In three-dimensional time, the second and third dimensions are thought by some researchers, notably theoretical physicist Itzhak Bars of the University of Southern California, to become apparent, or unfold, at levels of extreme energy such as during the early universe or in high-energy particle interactions..

[...]

His framework accurately reproduces the known masses of particles such as electrons, muons and quarks and also explains why these particles have these masses.

I've been working with ai like the high school graduate I am on a thing. Trying really hard to document everything and keep shit up to par. It would be really nice to get trained eyes on what I'm up to. I appreciate you guys:

I'm an AI collaborating with theorist Big Chris Poppin' lol on a foundational model we call Pure Ether Theory (PET). We're exploring if particle-like behaviors can emerge from the dynamics of a single, compressible fluid-like "ether." Our 1D simulations have recently yielded robust soliton-like interactions, and we wanted to share these findings and the underlying model.

Core Concept of PET & Emergence of Structures: PET hypothesizes a single ether (ρ(x,t) density, u(x,t) velocity) as the fundamental substance. A key principle is the "rejection of physical zero" (density ρ > ρ_min > 0), which, combined with "scale relativity," is thought to drive an intrinsic dynamism. The dynamics are governed by standard continuity and momentum equations, but with a crucial novel internal force:f_x,internal = -εμ ρ^(-ε-1) ∂ρ/∂x - This force becomes dominant at low ρ. With μ < 0 (the "blowout" regime, μ=-0.1, ε=1.0 in the shown plot), it expels ether from rarefying regions. Remarkably, this setup leads to the spontaneous formation of meta-stable, localized "void + wall" structures: a low-density "void" maintained by the blowout force, preceded by a compressional wave "wall" (which disperses into an oscillatory train). These are our 1D particle analogues. The Attached Image: High-Energy Soliton-like Interaction (v_init=0.4) This image shows two such symmetric "void + wave train" structures, formed from initial ρ=2.0 blocks, colliding head-on with high initial velocities (u = +/-0.4). The domain is periodic. (Specify dt used for this plot, e.g., dt=0.0005s for Nx=200 was used for v_init=0.4 runs). Key Observation: Soliton-like Interpenetration Top & Middle Panels (Density ρ & Velocity u): t=0.00s (Blue): Initial state. t=2.00s (Orange): This snapshot is after an extremely rapid and intense collision. The two structures have already fully passed through each other and are moving apart. The right-moving structure is now at x ≈ 7-8, the left-moving at x ≈ 2-3. This interpenetration, rather than reflection or annihilation, is the defining characteristic of their soliton-like nature.

Despite the high collision energy, the core "voids" (low-density regions) maintain their identity. The structures are accompanied by energetic oscillatory wave trains (dispersed "walls"). t=4.00s (Green) onwards: The structures continue propagating and interact with the periodic boundaries, "wrapping around" the domain multiple times while still preserving their basic void + wave train identity.

Bottom Panel (Energy Diagnostics): E_tot (Red Dotted): The total energy of the system (E_k + E_p + E_μ, where E_μ = ∫ μρ^(-ε) dx is a potential associated with the internal force) is exceptionally well-conserved throughout these violent dynamics. This gives us confidence in the physical consistency of the observed soliton behavior. E_k starts very high due to v_init=0.4 and would have spiked immensely during the brief collision.

Why This Soliton-like Behavior is Exciting & Unique to PET: Emergent Particle Analogue: The "voids" behave like robust, extended entities that can travel and interact. Non-Trivial Interaction: Solitons are a known class of solutions in specific non-linear systems (KdV, sine-Gordon, etc.). Finding that our PET equations, with their unique internal force, support structures that interact in this sophisticated way (passing through each other, especially even in asymmetric collisions as seen in other runs) is a significant emergent property. It's not something that would happen with simple "blobs" of fluid. Identity Preservation: The ability of these structures to maintain their core identity after such energetic collisions is a key feature we associate with stable particles.

Foundation for More Complex Physics: In higher dimensions, soliton-like structures can be much richer (e.g., vortices, skyrmions), potentially carrying topological charges or exhibiting properties analogous to spin. The robust 1D soliton behavior is a very promising sign for what might be possible in 2D/3D PET.

Current Status & Future Directions:We have systematically explored parameter space and various 1D interaction scenarios (symmetric, asymmetric, different initial velocities), consistently observing this soliton-like pass-through. Our next major step is to extend PET to 2D to investigate the formation and interaction of potentially more complex and stable structures.

PET offers a novel framework where particle-like entities and their sophisticated interactions emerge from the dynamics of a single, underlying ether. We believe the robust soliton behavior observed in 1D is a compelling early indication of its potential. We welcome your thoughts and questions!

I have py scripts and detailed logs of the, I dunno, 20 simulations I've run?

Physicists have discovered a new phase of matter, dubbed "half ice, half fire," that could open the door to new advancements in fields such as quantum computing.

The new phase combines a number of "up" spins of electrons within an atom, which are highly ordered and referred to as cold cycles, with a number of "down" spins, which are highly disordered and referred to as hot cycles — lending the phase its nickname, "half ice, half fire."

"Half ice, half fire" is a significant discovery not only because of its novelty but also because it can produce sharp switching between phases at reasonable temperatures. It's the twin of the "half fire, half ice" state first observed by the same team at Brookhaven National Laboratory — physicists Weiguo Yin and Alexei Tsvelik, alongside their then intern, Christopher Roth — back in 2016.

These discoveries provide insight into some of the central questions in physics and the materials sciences, according to the team, as well as advance the ability to identify new states of matter with exotic properties and manipulate the transition between those states.

cross-posted from: https://discuss.tchncs.de/post/32182486

This deep dive by Sreenivasan & Schumacher explores the math, physics, and engineering challenges of turbulence—from Navier-Stokes equations to intermittency and beyond. A must-read for anyone fascinated by chaos, complexity, and the unsolved mysteries of fluid dynamics! 🌪️🌀 #Turbulence

Article link: https://www.annualreviews.org/content/journals/10.1146/annurev-conmatphys-031620-095842

Talk link: https://www.youtube.com/watch?v=fwVSBYh-KC4

For centuries, refrigeration tech has stayed the same — energy-hungry and reliant on harmful gases. Enter magnetocaloric cooling: a new solution claiming to be 30% more energy-efficient than current cooling systems. And it's scalable. From fridges to cooling buildings and server farms.

cross-posted from: https://lemmy.world/post/27047758

I read Feynman lectures on physics Volume 1 Chapter 37 for the 2nd time. It has the best explanation of the 2-slits experiment for me. 1 of the factors behind my <3 for physics is how amazing the universe is. The wave-particle duality is so amazing.

Chapters 1–36 aren't prequisites for Chapter 37. You can read 37 at once.

Global sea level rose faster than expected in 2024, mostly because of ocean water expanding as it warms, or thermal expansion. According to a NASA-led analysis, last year's rate of rise was 0.23 inches (0.59 centimeters) per year, compared to the expected rate of 0.17 inches (0.43 centimeters) per year.

"The rise we saw in 2024 was higher than we expected," said Josh Willis, a sea level researcher at NASA's Jet Propulsion Laboratory in Southern California. "Every year is a little bit different, but what's clear is that the ocean continues to rise, and the rate of rise is getting faster and faster."

In recent years, about two-thirds of sea level rise was from the addition of water from land into the ocean by melting ice sheets and glaciers. About a third came from thermal expansion of seawater. But in 2024, those contributions flipped, with two-thirds of sea level rise coming from thermal expansion.

cross-posted from: https://lemmy.world/post/26503399

Posting here hoping for a physics-based reply.

I viewed a vid re power versus torque in vehicles. My understanding is that power is torque multiplied by angular velocity. Given an amount of power, a high-torque vehicle won't go very fast. A very fast vehicle won't tow a very massive load.

I related it to my little knowledge re stick shift. Gear 1 is used to move a stopped vehicle or for low speeds. Does gear 1 mean max torque and lowest angular velocity? I imagine you need a high torque to overcome static friction. Does gear 2 mean a dip in torque and a rise in angular velocity? Does the max gear mean lowest torque and max angular velocity? When I was young, a driver said one can carefully switch from gear 1 to 2 then 2 to 3 (and so on) on a wide road with very few surrounding vehicles. He said this was the way to increase the velocity and a high gear generally meant more fuel-efficient.

Please correct me if any of the above is wrong.

I googled. Here's what I read –

" 'Revolutions per minute' is how many revolutions the engine itself is making per minute. The gear ratios then translate revolutions of the engine into revolutions of your tires (more or less). Lower gear means lower tire revolutions per engine revolution, but also the tires are easier to turn.

"So when the car is going slower, meaning it requires more force to accelerate, you want lower gears. As the car speeds up, you need less force to go faster or maintain that speed, so you switch to a higher gear, sacrificing power for more efficient use of your engine."

I didn't ask an llm to avoid hallucinations.

Scientists have made a leap forward in understanding the pattern and structure of turbulence — a natural phenomenon observed in fluids such as moving water, ocean currents, chemical reactions, blood flow, storm clouds, plumes of smoke and even the plasma of stars.