You mean life as we know it here on Earth, right?
Contrary to comedy movies like Evolution, it is simply not feasible for any sort of dynamic matter to be based off of anything except carbon. You will never find a hydrogen-based life-form, or even a nitrogen-based life-form (a la the movie, Evolution).
The laws of physics were created here on this planet and in this solar system. There is no way of knowing what is and isn't possible outside here yet.
The laws of physics are
universal, and were not "created" on Earth; they were observed. The laws of physics are the same here as they are on the edge of the universe.
If light can be pulled by gravity, it has mass. Look at black holes for example.. The gravity is so powerful that it can pull light into it. If you want to go back to physics.. If something can be pulled, it can also push.
Not quite. "Mass" is a variable, dynamic quantity, which changes with respect to it's velocity. The mass in Newton's equation [F = ma] is different then the mass in another of his equations, [Fg = (Gm1m2)/r^2]. The mass in the gravitational equation (the second one) refers to an object's "rest mass". But since photons can only go the speed of light at all times, it's "rest mass" basically only refers to gravity and gravitational fields (and momentum, to an extent, but that's where things get too confusing to explain in normal text without the benefit of mathematical symbols). The mass in the equation [F = ma], however, refers to it's "travelling mass", or what I like to call 'effective mass'. This is found by dividing an object's rest mass by the square root of one minus it's velocity squared divided by the speed of light squared. So, [m = m'/sqrt(1-(v^2/c^2))]. So since the definition of mass attributed to being able to "push and pull" by contact is zero for a proton, you can't have a ship being propelled by light.
This arguement really is pointless though, because what the human mind can't comprehend it doesn't want to believe.
It's not pointless. I believe that the humans, as a race, will never discover the existence of any other intelligent life-form, and I have the knowledge and willingness to debate my point. Besides, it's about time we did something else around here than flame Celtic, so bring it on.
