Code crashes codea

Questions
1 
-- Physics

CONST_G = 1 -- <<< 6.6738 * 10 ^ (-11) >>> m^3 / (kg s^2) "Gravitational constant"

function setup()
    displayMode(OVERLAY)
    particles = {}
    _gId = 1 -- Global Id
    
    for i = 1, 50 do
        local p = Particle()
        
        p.pos.x, p.pos.y = math.random(0, WIDTH), math.random(0, HEIGHT)
        
        table.insert(particles, p)
    end
end

function draw()
    background(0)
    for a, b in ipairs(particles) do
        b:draw()
        b:update()
    end
end

-- Particle class

Particle = class()

function Particle:init()
    self.id = _gId
    _gId = _gId + 1
    
    -- Attributes
    self.mass = 1
    self.color = color(255)
    self.size = 5
    
    -- Position
    self.pos = vec2(0, 0) -- pixels
    self.speed = vec2(0, 0) -- pixels / frame
    self.acc = vec2(0, 0) -- pixels / frame ^ 2
end

function Particle:draw()
    resetStyle()
    fill(self.color)
    ellipse(self.pos.x, self.pos.y, self.size)
end

function Particle:update()
    v = vec2(0, 0)
    
    -- Calculate acceleration
    for a, b in ipairs(particles) do
        if not (self.id == b.id) then
            --[[ Speed:
            r = math.sqrt((self.pos.x - b.pos.x)^2 + (self.pos.y - b.pos.y)^2)
            F = self.mass * b.mass / r^2
            a = F / self.mass]]
            
            -- Average speed
            local a = CONST_G * b.mass / ((self.pos.x - b.pos.x)^2 + (self.pos.y - b.pos.y)^2)
            -- ?y / ?x
            local m = (self.pos.y - b.pos.y)/(self.pos.x - b.pos.x)
            -- y = mx + t - a line between both points
            local t = m * self.pos.x - self.pos.y
            
            v = v + vec2(.0001, m * self.pos.x + t)
        end
    end
    
    -- Update parameters
    self.pos = self.pos + self.speed
    self.speed = self.speed + self.acc
    self.acc = v
    if self.id == 5 then
        print(self.pos, self.speed, self.acc)
    end
end
2

@TokOut Comment out the last print statement and it won’t crash. Your values are way out of wack for self.pos, self.speed, self.acc . Here’s some values before it crashes. You need to recheck your calculations.

(623.852200, -28921982519067048803797183765449539584.000000)
(0.137200, -1574872098314025940019901817338323795968.000000)
(0.004900, -27882067698290623052232668640255068340224.000000)