<?php   /* Dusty Plasma Collapse © Charles Chandler http://qdl.scs-inc.us/?top=15107 */   /* To find the time to implosion for a dusty plasma, I have to accelerate all of that mass. But some of it comes from the outer reaches, and some of it travels much less distance. I guess I could just calculate the time it takes for the outer 1/10 to collapse.   It would be more accurate if I used the actual mass of the dusty plasma (i.e., the same as that of the Sun). Knowing the volume of the dusty plasma, I can find the mass per 10 cubic meters, and assign all of that mass to a point source, assuming that it's all packed into a Debye cell at the center. Then I can calculate the gravity between that point source, and all of the others, in an HCP closest packed arrangement of 57 of them. Knowing the gravitational body force, I can scale the gravity and the electric force that I got in previous calcs, which didn't use realistic amount of matter, but which did yield the correct proportions of the forces, given the degree of ionization. */   function SciNotToFloat($str) { $str = str_replace('&minus;', '-', $str); $str = str_replace('&thinsp;&times;&thinsp;10<sup>', 'e', $str); $str = StripOneTailer($str, '</sup>'); return $str; }   define('neutralsPerIon', pow(10, 14)); // degree of ionization $nucMass = 150 * neutralsPerIon * p; $totalDistance = RadiusOfSphere(5.9460543541638e48); $stepDistance = $totalDistance / 100; $debyeCellMass = 3.345243554e-19; // kg/m^3 $outputRows = Row(' <th>meters</th> <th>N<sub>E</sub></th> <th>N<sub>G</sub></th> <th>N/kg</th> <th>sec</th> <th>m/s</th> '); $v = 0; $forcesPerSpacingPg = GetPageByID(13885); $tmp = array_reverse(TableToArray($forcesPerSpacingPg->contents)); foreach($tmp as $row) { if (is_numeric($row[0])) { $d = $row[0]; // center-to-center spacing (in meters, from 0 to 10) $e = SciNotToFloat($row[1]); // electric force $g = SciNotToFloat($row[2]); // gravity $a = ($e + $g) / $nucMass; // acceleration = force divided by the mass $t = sqrt(($stepDistance / $t) / (.5 * $a)); $v = $v + ($a * $t); if ($d >= 1) $outputRows .= Row( Cell(1, $d, 'center'). Cell(1, nbsp(1).ScientificNotation($e, 2).nbsp(1)). Cell(1, nbsp(1).ScientificNotation($g, 2).nbsp(1)). Cell(1, nbsp(1).ScientificNotation($a, 2).nbsp(1)). Cell(1, nbsp(1).ScientificNotation($t, 2).nbsp(1)). Cell(1, nbsp(1).ScientificNotation($v, 2).nbsp(1)) ); } } if (1) echo Table($outputRows, 'standard');   // http://www.dummies.com/how-to/content/how-to-calculate-time-and-distance-from-accelerati.html // d = .5 * a * t^2 // t = sqrt(d / (.5 * a)) // a = f / m   ?>