Not true.
What part is "not true"?
What you are saying is just silly.
If you're referring to the population example. Yes. That was intended to be "silly". Just like this eminent scientists theory.
Your claim is much akin to the flat-earthers or those claiming the earth is the center of the solar system.
What claim? The tides? Have you ever been to the Oceans?
Have you even looked into this comet information? Every time a comet blows through the solar system, it upsets the flow of most of the bodies.
Really? I've seen several close comet encounters with no known affect on planet earth or any other. They are miniscule in size compared to the masses of our solar bodies.
This one coming in now - Elenin-
appears to be more than twice the size of Jupiter. If you think that will have (and hasn't already) no impact on earth, let's talk again in August. I expect that this event will kill many millions of people THIS YEAR.