Was an Earth Year shorter in Adam's time?
According the Biblical record, Adam lived 930 years and he died, Abraham died at the age of 175.
In Chinese myths, or semi-history, the first of the Three Sovereigns Fuxi lived for 197 years altogether, while Peng Zu supposedly lived 800 years.
Longest-lived vertebrate on earth is tortoise or a kind of fish called Koi. Tortoises are known to have lived more than 150 years. A longest-lived Koi named Hanako whose death on July 17, 1977 ended a 226 year life span.
A maximum life expectancy of human being is about 120 years according with current data.
There are skepticism towards the long life span, scientific evidence in biochemistry of aging and theological explanation that God intervened to shorten man's life from 900 to 120. But none of these hypothesis can actually solve the problem of this dramatic change in human life spans.
There could be another hypothesis added to current ones, that is, the YEAR in Adam's time might be shorter due to the evolution of the universe.
I'm not an astronomer, and will not start with the Big Bang theory. Because its quite obvious that all astronomers believes the universe is expanding, the Moon is actually moving away from Earth at a rate of 3.8 cm each year. When it was formed it was about 22,530 km away. It is now more than 450,000 km.
I just want to point out what DAY and YEAR is, and how a DAY and a YEAR means on different planets and satellites.
A day is defined to be from sunrise to sunset for a particular body. A year is defined to be one complete revolution around the sun.
The further distance of the planet from the sun, the longer time it takes to complete the revolution around the sun. The revolution orbit of Earth has obviously been changed during history.
One Mercury day is 58.65 Earth days, and one Mercury year 87.9 Earth days. So Mercury rotates around its axis every two orbits around the Sun. A year is less than two Mercurial days, so you'd have a birthday every other day. Then a 930 Years old Mercurrian actually lived only 1860 Meciurial days, and 223 Earth Years.
It's quite a different story for Venusian, because on Venus 1 day equals 243 Earth days, and 1 year 225 Earth days. If a 930 years old Venusian actually, according to the current Earth year, he is 576 years old.
The mars is similar to Earth, and scientists have long speculated about the possibility of life on Mars. 1 Day on Mars is 24.62 hours, quite similar, but 1 year equals 687 days! A 930 year old Marsian actually is 1750 Earth years old!
Jupiter day is 9.84 Earth hours, and 1 year equals 11.86. Likewise a 930 years old Jupterian's current Earth age is 10974. Likewise a Saturn year is 29.5 Earth years.
Suppose the life span of human race has never changed, the longest-lived person according to current data is 120, then we suppose Adam was 120 Current Earth Years old, the YEAR in his time must be shorter. The Earth revolved on its orbit either in a higher velocity or the perimeter of the orbit must be shorter.
Earth quake can change Earth's axis, a NASA scientist says that a massive 8.8 earthquake that struck Chile may have changed the entire Earth's rotation and shortened the length of days on our planet. How about a meteor impact which cause the dinosaurs to extinct?
Then how long was an Earth Year in Adam's time suppose the length of Earth Day and the longest possible Life Span of Human Being (120 year on average) has never been changed?
Biblical Earth Year = 120 x 365 / 930 = 47 (days)
Abraham's age was 175, Chinese Sovereign Fuxi was 197, we take it average, 180, then the Biblical Earth Year at that time has changed at his time to 243 days.
The Earth Year has been changed at least TWICE in the history.