Consider the differences in two particular fields of study: Evolutionary Biology, and Astronomy. Evolutionary Biologists ask us to believe that mankind evolved in an unbroken progression from primordial goo over the past 4.1 billion years (plus or minus 15 minutes). Ok, fine. Astronomists ask us to believe that the chances of all life on earth being wiped out by a giant, city-sized (10 kilometers or greater) meteorite are about every 100 million or so years (plus or minus the time it will take you to read this blog). How do these two ideas sync up?
Answer: they don't. In the 4.1 billion years that evolution is supposed to have taken place from goo into macro-creatures such as man, the earth is supposed to have been destroyed, um...lemme see...41 times. So we've just gotten lucky, right? Well, how lucky have we been?
If you want to approach it mathematically, then the odds are 1 in 2^40, or one in two to the fortieth power. To break it down for you, if we go 100 million years without being struck by a very big rock, then we've defied the odds by 1 out of 2. If we go another 100 million years and still haven't been impacted, then we've again beaten the odds 1 out of 2, but now twice. Therefore, we've beaten the odds at a 1 in 4, still not that impressive. For every 100 million years we go without being struck by Synthia McKinn...er... a large meteor (or NEO for Near Earth Object), we have defied the odds by twice the previous 100 million years. So, the 1st 100 million years: 1 in 2 (or 2^1). The 2nd 100 million years: 1 in 4 (or 2^2). The 3rd 100 million years: 1 in 8 (or 2^3), etc... By the time we go 4.1 billion years, the odds are 2^40!!! That's 1 in 1,099,511,627,776! If these were 2.25 inch wide playing cards, then they would span from here to Mars (in it’s closest approach to earth in August 2003), 35 million miles! So pick a card.
In the mind of Evolutionary Biologists, the likelihood of life springing from dead materials by means of unlikely events is benefited by more time. But the Astrologists (using far more empirical methods) show that the more time you throw at the problem (past 100 million years), the more problematic evolution becomes. Each time a massive meteor hits, it pushes the reset button of life, and evolution is forced to restart!
The numbers against the Evolutionary Biologists are so massive that they make the belief in evolution highly mathematically improbable and, well...simply unscientific! They must either accept Divine protection of earth during those 4.1 billion years, or they must accept that the earth is a good deal younger than their illustrious theories assert.
P.S. - Check out this map of NEO's in and around the orbit of earth. These are detected using a radio telescope.