There probably is life on other planets, but I highly doubt their evolution would produce anything like humans, either in form or what we call civilization. Add the remote likelihood that a technologically advanced life form would exist close enough in either time or proximity to come into contact with us, and the question become moot. 

On a cosmic time scale, stars, and their systems of planets, wink in and out of existence so quickly, and we are barely a blip on Earth's relatively short life. Winning the lottery looks like a slam dunk compared to bumping into anything cruising around out there in a ship. All this in direct contradiction to Dr. Kaku. 

You know, I used to know an astronomer who described himself as a sun worshipper. I'm sort of eying quantum gravity at the moment...