You should not take his ideas seriously; only God knows when the world will come to an end, and He has not revealed that date to any person - past or present. As the Bible says, "Since no man knows the future, who can tell him what is to come?" (Ecclesiastes 8:7).
We do know, however, that someday this world as we know it will come to an end - when Jesus Christ comes again to establish His Kingdom of righteousness and peace. Think of it: Someday all the evils and injustices we see around us will be overcome, and Christ will rule as Lord over all! No wonder the Bible calls this "the blessed hope - the glorious appearing of our great God and Savior, Jesus Christ" (Titus 2:13).
Is Christ's coming near? We do not know - although we already see many events taking place that He said must happen before His coming. For example, He said that the Gospel must be preached to the whole world before He would come again (see Matthew 24:14). Never has this been more possible than it is today through the Internet and other means of communication.
But the most important question I can ask is this: Are you ready for that day? Some people go through life without ever thinking about their death, or about the fact that this world will come to an end. Don't be one of them, but be prepared by opening your heart and life to Jesus Christ today.