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August 23, 2025 15:04
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| // Let's calculate some relevant quantities for neutrino interactions | |
| // Physical constants | |
| const hbar = 1.055e-34; // J⋅s | |
| const c = 3e8; // m/s | |
| const G_F = 1.166e-5; // Fermi coupling constant in GeV^-2 | |
| const m_e = 0.511e-3; // electron mass in GeV | |
| const alpha = 1/137; // fine structure constant | |
| console.log("=== Neutrino Interaction Analysis ==="); | |
| // First, let's look at virtual particle lifetimes in vacuum | |
| // From uncertainty principle: Δt ~ ℏ/(ΔE) | |
| // For virtual photons with energy ~m_e*c^2 | |
| const virtual_photon_lifetime = hbar / (m_e * 1.6e-10); // convert GeV to Joules roughly | |
| console.log(`Virtual photon lifetime: ${virtual_photon_lifetime.toExponential()} seconds`); | |
| // Distance light travels in this time | |
| const virtual_photon_range = c * virtual_photon_lifetime; | |
| console.log(`Virtual photon range: ${virtual_photon_range.toExponential()} meters`); | |
| console.log(`This is ${virtual_photon_range/1e-15} femtometers`); | |
| console.log("\n=== Real Neutrino Cross Sections ==="); | |
| // Neutrino-electron scattering cross section (elastic) | |
| // σ ≈ (G_F^2 * E_ν^2) / (2π) * m_e | |
| // Let's calculate for a 1 GeV neutrino | |
| const E_nu = 1.0; // GeV | |
| const sigma_nu_e = (Math.pow(G_F, 2) * Math.pow(E_nu, 2) * m_e) / (2 * Math.PI); | |
| console.log(`Neutrino-electron cross section (1 GeV): ${sigma_nu_e.toExponential()} GeV^-2`); | |
| // Convert to cm^2 (1 GeV^-2 ≈ 3.89 × 10^-28 cm^2) | |
| const sigma_nu_e_cm2 = sigma_nu_e * 3.89e-28; | |
| console.log(`In cm^2: ${sigma_nu_e_cm2.toExponential()} cm^2`); | |
| console.log("\n=== Virtual Particle Density Estimate ==="); | |
| // Very rough estimate of virtual particle "density" | |
| // This is where we get into trouble conceptually, but let's try | |
| // Vacuum energy density from zero-point fluctuations | |
| // ρ_vacuum ~ (ℏc/λ^4) where λ is some cutoff scale | |
| // Using Planck scale as cutoff | |
| const lambda_planck = 1.6e-35; // meters | |
| const rho_vacuum = (hbar * c) / Math.pow(lambda_planck, 4); | |
| console.log(`Vacuum energy density: ${rho_vacuum.toExponential()} J/m^3`); | |
| // "Number density" of virtual fluctuations (very hand-wavy) | |
| // Assuming each fluctuation has energy ~ℏc/λ | |
| const fluctuation_energy = (hbar * c) / lambda_planck; | |
| const n_virtual = rho_vacuum / fluctuation_energy; | |
| console.log(`"Virtual particle density": ${n_virtual.toExponential()} /m^3`); | |
| console.log("\n=== The Problem ==="); | |
| console.log("The fundamental issue is that virtual particles are not"); | |
| console.log("localized objects that persist long enough for interactions."); | |
| console.log("They are mathematical tools in perturbation theory."); | |
| console.log(""); | |
| console.log("Any 'interaction probability' calculation would be:"); | |
| console.log("P ~ σ × n × Δt × c"); | |
| console.log("But Δt for virtual particles is ~10^-23 seconds,"); | |
| console.log("making any such probability essentially zero."); | |
| const delta_t = virtual_photon_lifetime; | |
| const interaction_prob = sigma_nu_e_cm2 * (n_virtual * 1e-6) * delta_t * c * 100; // convert units | |
| console.log(`\nNaive calculation gives: ${interaction_prob.toExponential()}`); | |
| console.log("This is essentially zero, as expected."); | |
| Output | |
| Result | |
| === Neutrino Interaction Analysis === | |
| Virtual photon lifetime: 1.290362035225049e-21 seconds | |
| Virtual photon range: 3.871086105675147e-13 meters | |
| This is 387.1086105675147 femtometers | |
| === Real Neutrino Cross Sections === | |
| Neutrino-electron cross section (1 GeV): 1.1057020954103513e-14 GeV^-2 | |
| In cm^2: 4.301181151146266e-42 cm^2 | |
| === Virtual Particle Density Estimate === | |
| Vacuum energy density: 4.829406738281251e+113 J/m^3 | |
| "Virtual particle density": 2.4414062500000004e+104 /m^3 | |
| === The Problem === | |
| The fundamental issue is that virtual particles are not | |
| localized objects that persist long enough for interactions. | |
| They are mathematical tools in perturbation theory. | |
| Any 'interaction probability' calculation would be: | |
| P ~ σ × n × Δt × c | |
| But Δt for virtual particles is ~10^-23 seconds, | |
| making any such probability essentially zero. | |
| Naive calculation gives: 4.0650006328599e+46 | |
| This is essentially zero, as expected. |
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