In short, NO. Do we need to invoke an intelligent designer to explain why the natural forces are the way they are? NO. Science is still researching how the laws of physics are determined, but everything that we know today tells us its not the universe that is fine-tuned for life, but life, through evolution, that has fine-tuned itself for the universe.
Why do I spend time debunking these absurd creationist arguments? My goal is to produce a series of videos that attacks the problem of ignorance from two angles: 1) Tell people what science actually says, how science works, what we know and are still figuring out; 2) Tell people why each of the creationist arguments are wrong, thereby not ignoring their claims and seeming to hide from them. Also, its so easy, its fun.
Heres how the calculation was done. Total volume = volume of the Milkyway galaxy (radius = Milkyway to Andromeda galaxy / 2) so the volume = 6.88e66 cubic meters. The volume of the habitable space on earth (-2000m to +8000m) = 5e18 cubic meters. Assume 1e11 habitable worlds per volume like the Milkyway. Total habitable volume (5e29 cubic meters) per unit volume (6.88e66 cubic meters) gives 7.3e-38 universe is habitable.