중력과 궤도
별, 행성, 위성을 발사하고 뉴턴의 만유인력으로 실제 궤도가 그려지는 것을 관찰하세요.
이것은 애니메이션이 아니라 진짜 뉴턴 중력입니다. 프리셋을 고르거나 캔버스를 드래그해 천체를 발사한 뒤, 질량·거리·궤도 속도·케플러 주기를 실제 단위로 읽을 수 있습니다.
프리셋
선택한 천체
천체를 탭하면 질량·거리·속도·공전 주기가 표시됩니다.
에너지 오차: 0.000%
상수 및 출처
G = 4π² AU³·M☉⁻¹·yr⁻²
1 AU = 1.496×10¹¹ m
1 M☉ = 1.989×10³⁰ kg
1 AU/yr = 4.741 km/s
T² = a³/M (Kepler)
The units and constants behind these orbits
This simulation does not work in metres and kilograms — it works in astronomical units, solar masses and years, because that is what keeps the numbers human-sized. Here is what each one is worth in SI.
What you are changing
The constant in the law
- G = 6.67430 × 10⁻¹¹ m³ kg⁻¹ s⁻² Newtonian constant of gravitation · the least precisely known of the fundamental constants
What this simulation's units are worth in SI
| Unit | In SI | Where it comes from |
|---|---|---|
| 1 AU | 149,597,870.7 km | Defined exactly since 2012 (IAU) — originally the mean Earth–Sun distance |
| 1 M☉ | 1.98892 × 10^30 kg | Mass of the Sun; the Solar System's natural mass yardstick |
| 1 M⊕ | 5.9720 × 10^24 kg | Mass of the Earth, for comparison — the Sun is about 333,000 times heavier |
| 1 yr | 365.25 days | The Julian year used in astronomy, not the calendar year |
Values come from the same constants the simulation integrates with (lib/physics/gravityOrbits.ts), so what you see here is what it actually computes.
The constant we know worst
Every value in this simulation rests on G = 6.67430 × 10⁻¹¹ m³ kg⁻¹ s⁻². Its standard uncertainty is ±1.5 × 10⁻¹⁵, about 22 parts per million — thousands of times worse than the speed of light or the Planck constant, which are exact by definition. Gravity is the force we can least precisely measure.
Compare it with the other constants and their uncertainties →