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{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Chapter 16: Cosmology"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 16.1: Hubbles_law.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"// Scilab code Ex16.1: Pg 15 (2005)\n",
"clc; clear;\n",
"c = 3e+05; // Velocity of light, km/s\n",
"v = c/4; // Recessional velocity, km/s\n",
"H_0 = 20e-06; // Hubble's constant, km/s/lightyear\n",
"// From Hubble's law, v = H_o*R_max, solving for R_max\n",
"R_max = v/H_0; // Maximum distance at which Hubble's law applies without relativistic correction, lightyears\n",
"printf('\nThe maximum distance at which Hubbles law applies without relativistic correction = %1.0e ly', R_max);\n",
"printf('\n');\n",
"\n",
"// Result\n",
"// The maximum distance at which Hubbles law applies without relativistic correction = 4e+09 ly"
]
}
,
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## Example 16.2: Critical_density_of_universe.sce"
]
},
{
"cell_type": "code",
"execution_count": null,
"metadata": {
"collapsed": true
},
"outputs": [],
"source": [
"// Scilab code Ex16.2: Pg 22 (2005)\n",
"clc; clear;\n",
"H = 23e-03/(9.46e15); // Hubble's constant, km/s/ly\n",
"G = 6.67e-11; // Gravitational constant, N-m^2/kg^2\n",
"// Since H^2 = (8*%pi*G*p_c)/3, solving for p_c\n",
"p_c = (3*H^2)/(8*%pi*G); // Critical mass density of universe, kg/m^3\n",
"printf('\nCritical mass density of universe = %4.2e kg per metre cube', p_c);\n",
"\n",
"\n",
"// Result\n",
"// Critical mass density of universe = %1.06e-27 kg/m^3"
]
}
],
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{
"text": "MetaKernel Magics",
"url": "https://github.com/calysto/metakernel/blob/master/metakernel/magics/README.md"
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"mimetype": "text/x-octave",
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|
