If you're NOT a Christian, and you're scientifically learned, then you believe something like what Mark Chaos up there said. Or you could theorize that the world will end once the big crunch starts, or somewhere within that time period.
Actually, 5,4 billion years from now. When the Sun is using its own core as fuel in its last moments, grows tremendously and "swallows' Mercury, Venus and Earth
Some people have said that on 2012 the magnetic field protecting the earth will momentarily disappear due to the magnetic poles shifting positions, as it has been said to have happened in the past. During this time period, there will be nothing protecting us from solar winds, and all satellites will most certainly burn up, this could go in corralation with the Solar Storm Mark Chaos posted about.
The field doesn't dissappear when the poles shift, it only weakens (raising the chance of getting skin cancer with 90%)
Most people know of the ancient calendar, and it ending in 2012, but what some don't know, is that for every sun that has "died" in the past, a new one has taken it's place, or so they have theorized, thus the fifth sun thing.
Actually, I have no clue what you're talking about in this part. It is true that the sun possibly was formed because of the destruction of another star, but it's more likely that a big cloud of gasses collapsed and the sun was formed from the reactions. Even if it was formed out of another star, it'd be only the 2nd one, not the 5th.
Forgive me if you meant something else than this.
According to science, matter cannot be created or diminished from existence; according to science, all our interactions with the world as we know it are electrical pulses interpreted by our brain. "I think, therefore I am" and so on, and so forth
Matter can be created out of energy. It is true that energy can't be created or destroyed