Instant · Precise · Universal
32 units available
6 categories total
To convert Planck lengths to meters: multiply by 1.616255 × 10⁻³⁵.
ℓP = √(ℏG/c³) ≈ 1.616255 × 10⁻³⁵ m.
For example, 1 Planck Length (ℓP) = 1.708388e-51 Light Year (ly).
| Planck Length (ℓP) | Light Year (ly) |
|---|---|
| 0.1 | 1.708388e-52 |
| 0.5 | 8.541942e-52 |
| 1 | 1.708388e-51 |
| 2 | 3.416777e-51 |
| 5 | 8.541942e-51 |
| 10 | 1.708388e-50 |
| 25 | 4.270971e-50 |
| 50 | 8.541942e-50 |
| 100 | 1.708388e-49 |
| 500 | 8.541942e-49 |
| 1000 | 1.708388e-48 |
The Planck length is the fundamental natural unit of length, approximately 1.616 × 10⁻³⁵ meters, below which the conventional concepts of space may cease to exist.
ℓP = √(ℏG/c³) ≈ 1.616255 × 10⁻³⁵ m.
To convert Planck lengths to meters: multiply by 1.616255 × 10⁻³⁵.
No practical applications — purely theoretical. It represents the scale at which quantum gravity effects become significant.
The Planck length is about 10⁻²⁰ times the diameter of a proton. It's as far below a proton as a proton is below a grain of sand.
Thinking the Planck length is the 'smallest possible length' — it's the scale where our current physics models break down, not a proven minimum.
The Planck length arises from combining the three constants that govern quantum mechanics (ℏ), gravity (G), and relativity (c).
The light-year is the distance that light travels in one Julian year (365.25 days) in a vacuum, approximately 9.461 × 10¹⁵ meters.
1 ly = 9.4607 × 10¹⁵ m = 63,241 AU = 0.3066 pc ≈ 9.461 trillion km.
To convert ly to km: multiply by 9.461 × 10¹². To convert ly to parsecs: multiply by 0.3066.
Expressing distances to stars: Proxima Centauri ≈ 4.24 ly, Sirius ≈ 8.6 ly, Vega ≈ 25 ly.
When you see a star 100 light-years away, you're seeing it as it was 100 years ago — you're literally looking into the past.
Thinking a light-year is a unit of time — it's a unit of distance! It's how far light travels in one year.
Light speed = ~300,000 km/s. In one year, light covers ~9.46 trillion km. That distance is one light-year.



© 2026 UntangleTools. All Rights Reserved.