Nope - "Adam's" day was only, what, 6000 years ago? Barely any difference in days or years in that time. Tree growth rings, written accounts of years and days going back around 5000 years indicate no change. Physics and astronomy would suggest it is impossible for the earth to orbit the sun 9 or 10 times faster than it does now too. Ever.

I think I covered this pretty well while answering your other question on Adam reaching 930 years in age. I would just like to add that the change in atmosphere from pre-flood to post-flood would have been profound. The earth went from temperate globally to having a change of seasons and weather. It went from being waterd by a mist to having unpredictable weather changes. It is also clear that night and day refers to 12 hour spans of equal day and night.

Yes, the Earth was rotating faster in Adam's day. Tidal interactions between Earth and Moon have been slowing Earth's rotation ever since the Moon formed. This is causing days to become longer. However, the rate at which this is occurring is not fast enough to cause a significant change in the length of the day within the amount of time that we humans have been around. Additionally, the rate of rotation would only change the length of the day and, therefore, the number of days in a year. It would not affect the length of a year. It would still take just as many hours, minutes and seconds for Earth to complete one orbit (one revolution). So, a changing rate of rotation cannot explain why people lived to such extreme ages prior to the Flood.

There was an interesting show about Siberians. In the 1960's and 70's it was believed they lived to be very old - someone reaching 90 wasn't a big deal. Getting to over 100 was thought to be pretty normal. Doctors, anthropologists, dietitians... all manner of people studied them. Then came a pair of anthros who looked for more about their culture and answered the big question, 2 answers really. - 1) They told histories in the 1st person. So when they said, "I remember when Czar Nicholas was born" it could have meant that their grandfather (or great grandfather) told the tale and this guy was repeating it in the traditional way. 2) They couldn't count to much over 40. - Moral of the story? There are often much more mundane answers to such question. Perhaps they counted years differently - more like we count months or seasons. Maybe the first guy to write it down had trouble with numbers. Maybe the people lied. Who knows. But there are all kinds of simple possibilities that don't involve 500 year lifespans of the earth changing the speed of it's orbit around the sun. - Look at the simple answers first. Not only are they often the closes to true but even if not - they are the easiest to eliminate.

As the bible teaches, the world was flat in Adam's day, and the Sun and Moon rose and fell. The Earth was not round, and didn't rotate. Nobody knows when the modern cosmology started ;-)

Not at all likely. If you check the genealogy, age of the father when a son is born etc. (I did once) you find that Adam was contemporary with about 11 generations of his descendants. No conceivable variation in length of day or year can explain that. Only the idea that he actually lived that long does so. Note also that ages stayed in that range up to the flood, and dropped to more modern norms in only a couple of generations. This suggests that the flood made profound changes in conditions affecting longevity.

The Earth did spin faster in the past and it has been slowing down gradually ever since. Billions of years ago, the Earth rotated every 18-20 hours instead of the current 24 hours.In Biblical times there would have been no significant difference from today. However, the Biblical writers were not aware that the Earth is a sphere or that it is rotating. Of coarse, Young Earth Creationists do not believe that the Earth is billions of years old. http://www.astronomycafe.net/qadir/q395.html

Whether it was or not, the length of a year is dependent on the earth's orbit around the sun, not the rotation around its axis. +5

Well, that’s one of the “mysteries” that are really not easily understood in modern times. One thing is for sure is that in the Bible there is a reference (scripture) to the fact when God reduced the lifespan drastically. Genesis 6:3 (KJV) And the LORD said, “My Spirit shall not strive with man forever, for he is indeed flesh; yet his days shall be one hundred and twenty years.” Genesis 6:2-4 (in Context) Genesis 6 (Whole Chapter)