Beth
Philosopher
- Joined
- Dec 6, 2004
- Messages
- 5,598
I don't think that's the time scale I saw hypothesized.If the Earth was covered with deep (kilometers) water until a few hundred million years ago then none of the marine fossils that form in shallow water would exist. They do and so the Earth has not totally covered with deep water until a few hundred million years ago.
I agree. This is a serious problem with the theory. On the other hand, there are various theories on how the earth, as well as other planets, developed. Clearly, the earth was once much smaller than it is now. I believe there are some competing theories about how it to be the size it is today.Another problem:
Shrinking the Earth increases its density and gravity. So a 50% size about 250 million years ago means that gravity is 4 times greater. But there is no sign of this in the fossil record or in astronomy (e.g. the same mechanism should apply to all of the planets and the stars).
I don't think that is a requirement of this theory.Another problem:
An expanding Earth means that all of the continents move at the same rate (the rate of expansion). But that is not the case - India has just about raced across the Indian Sea to crash into Asia and form the Himalayas.
I don't think this theory discounts the existance of all the supercontinents. My recollection (I read about it more than a year ago) was that it had a different explanation for how and why the supercontinent dissembled.Another problem:
Have a look at list of supercontinents. Rodinia, Pangaea and Gondwana have plenty of evidence for their existence (some of the others are hypothetical).
I don't know. At any rate, if the earth is actually expanding, we should soon have sufficiently accurate data over a long enough period of time to determine it conclusively with our instruments. At the time I was reading about it, the expected difference over the period of time data was available was smaller than the margin of error.
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