Sorry, double post.

He put c^2 as a common denominator on the right hand side, then brought the 10^18 x v^2, with sign change to the left hand side =, factoring out V^2 from both terms now on the left hand side. What remains on the right hand side is (c^2)x10^18.

Exceptional!

Explaining without using the Lorentz contraction: The number of Earth years needed to get to Zakstar is 10^9/ v where v is the speed of the rocket. Divide by the time dilation factor to get to rocket years (equal to multiplying by the square root of (1 - v^2). We take units where c is 1 (light years per year). So 10^9 * sqrt( 1 - v^2) = 1 or 10^18 * (1 - v^2) = 1. Solving this gives the required answer. This speed is just about 1 billionth of a meter less than the speed of light.

B2 technology is decided by aEther concepts, often called debunked by modern science. Prof. Brown & Bifost (2Bs) allow for aEther physics. Distant spaceflight as seen by Einstein allows Einstein to debunk aEther, but the tech exists, so Einsteinian concepts need updating or we need to find jobs with the military to pursue truth in science. Historically, Einsteinianism is good for where it takes us. But i have friends on other planets.