diff --git a/Cargo.toml b/Cargo.toml
index 69ab763..15aa436 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -11,5 +11,6 @@ clap = { version = "4.5.39", features = ["derive"] }
 env_logger = "0.11.8"
 glam = { version = "0.30.4", features = ["serde"] }
 log = "0.4.27"
+once_cell = "1.21.3"
 serde = { version = "1.0.219", features = ["derive"] }
 serde_json = "1.0.140"
diff --git a/src/types.rs b/src/types.rs
index 86df870..957b529 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -1,6 +1,80 @@
 use glam::DVec3;
+use once_cell::sync::Lazy;
 
 pub type Position = DVec3;
 pub type Velocity = DVec3;
 pub type Acceleration = DVec3;
 pub type Mass = f64;
+pub type Time = f64;
+
+
+// Constants
+const EARTH_RADIUS: f64 = 6.378e6; //meters
+const EARTH_MASS: f64 = 5.972e24; //kg
+const EARTH_ORBITAL_VELOCITY: f64 = 2.9780e4; //m/s
+const AU: f64 = 1.49597870700e11; //meters
+
+const MOON_MASS: Mass = 7.34767309e22; // kg
+const MOON_ORBITAL_VELOCITY: f64 = 1.022e3; //m/s relative to earth
+
+const SUN_MASS: f64 = 1.989e30; //kg
+const SUN_RADIUS: f64 = 6.957e8; //meters
+
+const G: f64 = 6.67430e-11;
+const r_0: f64 = EARTH_RADIUS;
+const m_0: f64 = EARTH_MASS;
+
+static t_0: Lazy<f64> = Lazy::new(|| {
+    (r_0.powf(3.0) / (G * m_0)).sqrt()
+});
+
+
+#[inline]
+pub fn norm_pos(pos: Position) -> Position {
+    pos / r_0
+}
+
+#[inline]
+pub fn real_pos(pos: Position) -> Position {
+    pos * r_0
+}
+
+#[inline]
+pub fn norm_mass(mass: Mass) -> Mass {
+    mass / m_0
+}
+
+#[inline]
+pub fn real_mass(mass: Mass) -> Mass {
+    mass * m_0
+}
+
+#[inline]
+pub fn norm_time(time: Time) -> Time {
+    time / *t_0
+}
+
+#[inline]
+pub fn real_time(time: Time) -> Time {
+    time * *t_0
+}
+
+#[inline]
+pub fn norm_vel(vel: Velocity) -> Velocity {
+    vel / (r_0 / *t_0)
+}
+
+#[inline]
+pub fn real_vel(vel: Velocity) -> Velocity {
+    vel * (r_0 / *t_0)
+}
+
+#[inline]
+pub fn norm_acc(acc: Acceleration) -> Acceleration {
+    acc / (r_0 / (*t_0 * *t_0))
+}
+
+#[inline]
+pub fn real_acc(acc: Acceleration) -> Acceleration {
+    acc * (r_0 / (*t_0 * *t_0))
+}