(image credit Astronomy Picture of the Day).
Geoffrey Pearce sent me this argument he uses with creationists, and I thought others might find it useful, too:
I am regularly approached by young Earth creationists (yes, even in the bedlam of sin that is Montreal...) both on the street and at home. If I have the time I try to engage them on the age of Earth, since Earth is something whose existence them and I agree upon. They will tell me that Earth is somewhere between 6,000 - 10,000 years old, and, when prompted, that the rest of the universe is the same age as well. I have taken the approach of responding to this assertion by pulling out a print of the far side of the Moon [see above].
I cannot tell you how handy this is! Once they've had a good look I usually point out that almost all of the craters were formed by asteroids smashing into the planet, and that the Moon has over 250 craters with a diameter of 100 km or more. After explaining that Earth is just as likely to be struck by large asteroids as the Moon (is more likely to be struck, in-fact, due to its greater gravitational well), I then ask them to consider what their time-scale entails: that Earth should be struck every couple of decades by an asteroid capable of completely ejecting an area about the size of New Hampshire (not to pick on New Hampshire). Since such an event has never been observed and there are no well-preserved impact structures anywhere close to this size range, I then suggest to them that the only sensible conclusion is that Earth is much older than they had thought.
I have nothing to add. Except I'd better fold up a copy of that photo and keep it in my wallet.
Wouldn't the atmosphere of the Earth eliminate many craters though? There is no weather or water on the moon either for erosion to occur to eliminate these craters. And erosion can occur fairly quickly, see the huge canyon on Mars.
ReplyDeleteTake a planet like Mercury too that is similar, it's got a lot of craters too. Mars has a very think atmosphere and is closer to the asteroid belt (4 times as many asteroids cross Martian orbit than that of Earth), and it's loaded with craters. Mars also doesn't have plate technonics like Earth to further mask craters.I wonder if maybe Earth is just designed to be an amazing "fixes itself" structure, though I would like to know about possibilities of observing meteor impacts on the moon, especially the rather large ones. Then again, NASA has said 100s of meteors hit the moon every year, and on March 17, 2013 one so bright struck the moon it could be seen by the naked eye.
Thanks for the comment. I'm not an earth scientist or geologist, but do understand that there is near-absolute consensus on the vast age of the earth--much longer than a few thousand years. Your point about the earth masking crater impacts might hold true for small impacts, but in the piece I quote above, what about the "...250 craters with a diameter of 100 km?" Anything near that size would devastate the earth, much less 250 of them.
DeletePlease be aware that I am not dissing faith per se--I recognize that religious belief is of great comfort to many people. It's just that if God did create things, I cannot imagine that he would want people to check their minds at the door and totally disregard science. The creation account in Genesis is a beautiful story...but is symbolic, not a literal science text.