Hubble's Law Recession Velocity Calculator
ANA›Life Services Authority›National Calculator Authority›Hubble's Law Recession Velocity Calculator
.calc-container { max-width: 640px; margin: 2rem 0; padding: 1.5rem; background: #fff; border: 1px solid #ddd; border-radius: 8px; box-shadow: 0 1px 3px rgba(0,0,0,0.06); font-family: system-ui, -apple-system, sans-serif; } .calc-container h3 { font-family: Georgia, serif; font-size: 1.15rem; color: #1a1a1a; margin-bottom: 1rem; padding-bottom: 0.5rem; border-bottom: 2px solid var(--ac, #3d5a80); } .calc-row { display: flex; align-items: center; gap: 0.75rem; margin-bottom: 0.75rem; flex-wrap: wrap; } .calc-row label { min-width: 160px; font-size: 0.9rem; color: #333; font-weight: 500; } .calc-row input[type="number"], .calc-row select { flex: 1; min-width: 120px; max-width: 200px; padding: 0.5rem 0.6rem; border: 1px solid #ccc; border-radius: 4px; font-size: 0.9rem; font-family: system-ui, sans-serif; color: #1a1a1a; background: #fafaf8; } .calc-row input:focus, .calc-row select:focus { outline: none; border-color: var(--ac, #3d5a80); box-shadow: 0 0 0 2px rgba(26,74,138,0.12); } .calc-row .unit { font-size: 0.82rem; color: #888; min-width: 30px; } .calc-btn { display: inline-block; margin-top: 0.5rem; padding: 0.55rem 1.5rem; background: var(--ac, #3d5a80); color: #fff; border: none; border-radius: 4px; font-size: 0.9rem; font-weight: 600; cursor: pointer; font-family: system-ui, sans-serif; } .calc-btn:hover { opacity: 0.9; } .calc-result { margin-top: 1.25rem; padding: 1rem 1.25rem; background: #f0f6fc; border-left: 3px solid var(--ac, #3d5a80); border-radius: 0 6px 6px 0; display: none; } .calc-result.visible { display: block; } .calc-result-label { font-size: 0.78rem; text-transform: uppercase; letter-spacing: 0.06em; color: #666; margin-bottom: 0.25rem; } .calc-result-value { font-size: 1.6rem; font-weight: 700; color: var(--ac, #3d5a80); } .calc-result-detail { font-size: 0.85rem; color: #555; margin-top: 0.5rem; line-height: 1.5; } .calc-note { margin-top: 1rem; font-size: 0.8rem; color: #888; font-style: italic; } .calc-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.75rem; margin-top: 0.75rem; } .calc-grid-item { padding: 0.6rem 0.8rem; background: #f8f9fa; border-radius: 4px; border: 1px solid #eee; } .calc-grid-item .label { font-size: 0.75rem; color: #888; text-transform: uppercase; letter-spacing: 0.04em; } .calc-grid-item .value { font-size: 1.1rem; font-weight: 600; color: #1a1a1a; } @media (max-width: 720px) { .calc-row { flex-direction: column; align-items: flex-start; gap: 0.3rem; } .calc-row label { min-width: auto; } .calc-row input[type="number"], .calc-row select { max-width: 100%; width: 100%; } .calc-grid { grid-template-columns: 1fr; } } .calc-chart { margin: 1rem 0; text-align: center; } .calc-chart svg { max-width: 100%; height: auto; } .calc-chart-legend { display: flex; flex-wrap: wrap; justify-content: center; gap: 0.6rem 1.2rem; margin-top: 0.6rem; font-size: 0.8rem; color: #555; } .calc-chart-legend span { display: inline-flex; align-items: center; gap: 0.3rem; } .calc-chart-legend i { display: inline-block; width: 10px; height: 10px; border-radius: 2px; font-style: normal; } .calc-related { max-width: 640px; margin: 2rem 0 1rem; padding: 1.25rem 1.5rem; background: #f8f9fa; border: 1px solid #e8e8e8; border-radius: 8px; } .calc-related h3 { font-family: Georgia, serif; font-size: 1rem; color: #1a1a1a; margin: 0 0 0.75rem; padding-bottom: 0.4rem; border-bottom: 2px solid var(--ac, #3d5a80); } .calc-related-list { list-style: none; padding: 0; margin: 0 0 0.75rem; display: grid; grid-template-columns: 1fr 1fr; gap: 0.4rem 1.5rem; } .calc-related-list li a { font-size: 0.88rem; color: var(--ac, #3d5a80); text-decoration: none; } .calc-related-list li a:hover { text-decoration: underline; } .calc-browse-all { margin: 0.5rem 0 0; font-size: 0.9rem; font-weight: 600; } .calc-browse-all a { color: var(--ac, #3d5a80); text-decoration: none; } .calc-browse-all a:hover { text-decoration: underline; } @media (max-width: 720px) { .calc-related-list { grid-template-columns: 1fr; } }
Hubble's Law Recession Velocity Calculator
Calculate the recession velocity of a distant galaxy based on its distance from Earth using Hubble's Law.
Distance to Galaxy (Mpc)
Hubble Constant H₀ (km/s/Mpc)
Calculate Results will appear here.
function hubCalc() { const resultDiv = document.getElementById('hub-result'); const distanceVal = document.getElementById('hub-distance').value.trim(); const constantVal = document.getElementById('hub-constant').value.trim();
// Input validation if (distanceVal === '' || constantVal === '') { resultDiv.innerHTML = 'Please fill in all fields.'; return; }
const d = parseFloat(distanceVal); const H0 = parseFloat(constantVal);
if (isNaN(d) || isNaN(H0)) { resultDiv.innerHTML = 'Please enter valid numeric values.'; return; } if (d Distance must be a non-negative value.'; return; } if (H0 Hubble Constant must be a positive value.'; return; }
// Hubble's Law: v = H0 * d const v = H0 * d; // km/s
// Speed of light in km/s const c = 299792.458; const vFractionOfC = v / c;
// Convert distance to light-years (1 Mpc = 3,261,563.78 light-years) const dLy = d * 3261563.78;
// Convert velocity to m/s const vMs = v * 1000;
let warningMsg = ''; if (vFractionOfC > 1) { warningMsg = '⚠️ Note: The calculated recession velocity exceeds the speed of light. This is permitted in cosmology due to the expansion of space itself (not motion through space), but classical Hubble's Law is no longer accurate at these scales. A relativistic treatment is required.
'; }
resultDiv.innerHTML = '### Results ' + '' + 'Recession Velocity' + v.toLocaleString('en-US', {maximumFractionDigits: 4}) + ' km/s' + 'Recession Velocity (m/s)' + vMs.toLocaleString('en-US', {maximumFractionDigits: 2}) + ' m/s' + 'Fraction of Speed of Light (v/c)' + vFractionOfC.toFixed(6) + '' + 'Distance' + d.toLocaleString('en-US', {maximumFractionDigits: 4}) + ' Mpc ≈ ' + dLy.toLocaleString('en-US', {maximumFractionDigits: 0}) + ' light-years' + 'Hubble Constant Used' + H0 + ' km/s/Mpc' + '' + warningMsg; }
#### Formula
v = H₀ × d
- v = Recession velocity of the galaxy (km/s)
- H₀ = Hubble Constant (km/s/Mpc) — the rate of expansion of the universe
- d = Proper distance to the galaxy (Megaparsecs, Mpc)
1 Megaparsec (Mpc) = 3.085678 × 10²² m ≈ 3,261,563.78 light-years
Speed of light c = 299,792.458 km/s
#### Assumptions & References
- The default Hubble Constant of 70 km/s/Mpc is a commonly used approximation. Current measurements range from ~67 km/s/Mpc (Planck CMB data) to ~73 km/s/Mpc (distance ladder measurements), reflecting the ongoing "Hubble tension."
- Reference: Hubble, E. (1929). "A relation between distance and radial velocity among extra-galactic nebulae." PNAS, 15(3), 168–173.
- Reference: Planck Collaboration (2020). Astronomy & Astrophysics, 641, A6. H₀ = 67.4 ± 0.5 km/s/Mpc.
More Calculators
- Roof Slope and Coating Thickness Calculator
- Roof Drainage and Gutter Size Calculator
- IMU Accelerometer + Gyroscope Complementary Filter Calculator
- Kalman Filter Noise Covariance Calculator
- GPS + INS Position Fusion Accuracy Estimator
- Acceptable Quality Level (AQL) Sample Size Calculator
- Salary Range Calculator
- Pay Equity Analysis Calculator
- Compa-Ratio & Range Penetration Calculator
- Benefits Package Value Calculator
- Retirement Plan Calculator
Read Next
Study Time Planner Authority Network America › Life Services Authority › National Calculator Authority .calc-container { max-width: 640px;...