Instant · Precise · Universal
32 units available
6 categories total
To convert Pm to light-years: divide by 9.461. To convert Pm to parsecs: divide by 30.857.
1 Pm = 10¹⁵ m ≈ 0.1057 light-years ≈ 0.0324 parsecs.
For example, 1 Petameter (Pm) = 1.889726e+25 Bohr Radius (a₀).
| Petameter (Pm) | Bohr Radius (a₀) |
|---|---|
| 0.1 | 1.889726e+24 |
| 0.5 | 9.448631e+24 |
| 1 | 1.889726e+25 |
| 2 | 3.779452e+25 |
| 5 | 9.448631e+25 |
| 10 | 1.889726e+26 |
| 25 | 4.724315e+26 |
| 50 | 9.448631e+26 |
| 100 | 1.889726e+27 |
| 500 | 9.448631e+27 |
| 1000 | 1.889726e+28 |
The petameter is a unit of length equal to 10¹⁵ meters, or about 0.1 light-years.
1 Pm = 10¹⁵ m ≈ 0.1057 light-years ≈ 0.0324 parsecs.
To convert Pm to light-years: divide by 9.461. To convert Pm to parsecs: divide by 30.857.
No practical everyday applications. Would describe distances to nearby stars in metric.
1 light-year ≈ 9.46 Pm. The Oort Cloud extends to roughly 15,000 Pm from the Sun.
Case sensitivity is critical: Pm (petameter) vs. pm (picometer) differ by a factor of 10²⁷!
Remember: 1 light-year ≈ 9.46 Pm, so a few Pm is a fraction of the distance to the nearest star.
The Bohr radius is the most probable distance between the nucleus and the electron in a ground-state hydrogen atom, approximately 5.292 × 10⁻¹¹ meters.
a₀ = ℏ/(mec α) = 4πε₀ℏ²/(mee²) ≈ 5.29177 × 10⁻¹¹ m, where α is the fine-structure constant.
To convert Bohr radii to meters: multiply by 5.29177210903 × 10⁻¹¹.
Sets the characteristic scale for atomic sizes. Most atoms have radii of 1–3 Bohr radii.
The Bohr radius gives atoms their characteristic size of ~1 Å (10⁻¹⁰ m), explaining why matter has the volume it does.
Confusing Bohr radius with atomic radius — the Bohr radius is specific to hydrogen; other atoms have different sizes.
The Bohr radius tells you 'how big atoms are' — about 0.5 angstroms. It's the atomic analog of a ruler for atomic-scale physics.



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