Milky Way Volume Estimate

Project: Milky Way Volume Estimate

Estimate the volume of the [[Milky Way]] Galaxy. Assume that the Milky Way Galaxy can be modeled by a disk with radius of 52,850 light-years and thickness of 1,000 light-years. Also assume a central bulge modeled as a sphere of radius 10,000 light-years. The disk should have a 10,000 light-year hole in it so we don't double count the volume included in the sphere.

See [[Cylinder#Right_circular_hollow_cylinder_(cylindrical_shell)|Cylinder Volume]] and [[Sphere#Enclosed_volume|Sphere Volume]]

Output

$ rustc MilkyWayVolume.rs error[E0425]: cannot find value `PI` in this scope --> MilkyWayVolume.rs:14:23 | 14 | let diskVolume:f64 = PI * pow(DISK_RADIUS - BULGE_RADIUS,2.f64) * DISK_THICKNESS; | ^^ not found in this scope | help: consider importing one of these items | 7 + use consts::PI; | 7 + use std::f32::consts::PI; | error[E0425]: cannot find value `PI` in this scope --> MilkyWayVolume.rs:15:43 | 15 | let sphereVolume:f64 = 4.0f64 / 3.0f64 * PI * pow(BULGE_RADIUS,3.0f64); | ^^ not found in this scope | help: consider importing one of these items | 7 + use consts::PI; | 7 + use std::f32::consts::PI; | warning: unused import: `std::f64::consts` --> MilkyWayVolume.rs:7:5 | 7 | use std::f64::consts; | ^^^^^^^^^^^^^^^^ | = note: `#[warn(unused_imports)]` on by default error[E0308]: mismatched types --> MilkyWayVolume.rs:9:27 | 9 | static BULGE_RADIUS:f64 = 10000; | ^^^^^ | | | expected `f64`, found integer | help: use a float literal: `10000.0` error[E0308]: mismatched types --> MilkyWayVolume.rs:10:26 | 10 | static DISK_RADIUS:f64 = 52850; | ^^^^^ | | | expected `f64`, found integer | help: use a float literal: `52850.0` error[E0308]: mismatched types --> MilkyWayVolume.rs:11:29 | 11 | static DISK_THICKNESS:f64 = 1000; | ^^^^ | | | expected `f64`, found integer | help: use a float literal: `1000.0` error[E0610]: `{integer}` is a primitive type and therefore doesn't have fields --> MilkyWayVolume.rs:14:61 | 14 | let diskVolume:f64 = PI * pow(DISK_RADIUS - BULGE_RADIUS,2.f64) * DISK_THICKNESS; | ^^^ | help: if intended to be a floating point literal, consider adding a `0` after the period | 14 | let diskVolume:f64 = PI * pow(DISK_RADIUS - BULGE_RADIUS,2.0f64) * DISK_THICKNESS; | + error[E0425]: cannot find function `pow` in this scope --> MilkyWayVolume.rs:14:28 | 14 | let diskVolume:f64 = PI * pow(DISK_RADIUS - BULGE_RADIUS,2.f64) * DISK_THICKNESS; | ^^^ not found in this scope error[E0425]: cannot find function `pow` in this scope --> MilkyWayVolume.rs:15:48 | 15 | let sphereVolume:f64 = 4.0f64 / 3.0f64 * PI * pow(BULGE_RADIUS,3.0f64); | ^^^ not found in this scope error: aborting due to 8 previous errors; 1 warning emitted Some errors have detailed explanations: E0308, E0425, E0610. For more information about an error, try `rustc --explain E0308`.

Solution