Posted on 08/29/2002 10:42:37 AM PDT by Junior
Scientists have found evidence that Earth made its final step to planet status about 30 million years earlier than previous research had suggested.
Working independently, two groups of scientists analyzed meteorites that contain telltale clues about planetary formation and compared them to rocks from Earth.
Both teams reached the same conclusion: Earth's metallic core formed about 30 million years after the solar system's birth.
The findings contrast with 1995 research that suggested Earth's core formed about 60 million years after the sun condensed at the center of a swirling disc of gas and dust. The new date pinpoints the approximate time that Earth had nearly reached its current mass.
David Stevenson, a professor of planetary sciences at Cal Tech in Pasadena, Calif., said the new analyses fit well with current theoretical ideas about the pace of Earth's formation.
Stevenson, who wasn't involved with the research, said the new calculations give an approximate date for when Earth's metallic core finished separating from its silicate-based mantle. That event is considered the last major event of Earth's formation.
The research, which appears in Thursday's issue of the journal Nature, was done by a German team and Harvard University researchers who collaborated with French scientists.
Stevenson said the fact that the two groups of scientists reached the same results increases the weight of the findings.
The new date for Earth's core was reached through a series of complex calculations of the ratios of the radioactive elements hafnium and tungsten found in primitive chondrite meteorites left over from the solar system's formation.
These meteorites provide a baseline for determining the age of planetary cores because they come from planetary bodies that never formed a core, said Thorsten Kleine of the University of Munster in Germany, who led the German team.
Those results were then compared with rocks from the Earth, Mars and meteorites believed to have originated on the large asteroid Vesta, yielding evidence that each was older than previous estimates.
"Generally speaking this means that all of the planets, not just the Earth, formed much faster than we had assumed," Kleine said.
The refined figures yielded a precise date — 4.530 billion years ago — that marks Earth's unofficial status as a planet, he said.
The findings also push back the origin of Earth's moon because most scientists believe the moon formed from material ejected when a Mars-sized planet collided with the proto-Earth, Kleine said.
Geologist Alex N. Halliday, whose 1995 research produced the figure that Earth formed about 60 million years after the solar system's birth, said his team apparently made an error in one if its measurements.
"We do not have a clear explanation for the apparent error in our ... data at this time," Halliday, of the Swiss Federal Institute of Technology in Zurich, said via e-mail message.
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On the Net:
Nature: http://www.nature.com</a
A meteorite that never...uhhh, hmmm....joined together with another meteor to form a single body? Not unprecedented, you know...
Just a Wolfram Principle of Computational Equivalence bump. Nothing to see here, move along.
What chapter and verse does this "7000 year" age occur in?
The Bible doesn't specifically say 7000 years in a set verse, but you can determine the age based upon the geneologies and family trees listed. In many cases a life span was given, so we can tell from Adam to Christ, about 4000-4500 years passed. Add another 2002 years and we are setting in the range of 6000-7000 years.
Good Question. Considering that Adam was made on day 6, there were no human witnesses of the previous 5 days. My studies show that unless you were associating the word Day (as used in the Bible) to a period of time (such as using the term "In the Day of Moses" which would refer to a period of days during the life of Moses), then the period of a day was essentially one passing of the sun. If daytime was longer at that time, we could be looking at a long period of time, but if all things have remained "essentially" unchanged, then we are looking at about a day as we know it.
It's problematic to discuss day and night in terms of the sun, as the sun wasn't created until day 4 (the day after grasses and trees were created).
410 times it appears with a number and always means a 24-hour day.
Whenever the phrase "evening and morning" is used outside of Genesis 1 without the word day (38 times) it always means an ordinary day - no exception. Whenever the words "evening" and "morning" are used individually with the word day (in fact 23 times each) outside of Genesis 1, the word day always means an ordinary day.
Whenever the word "night" is used with the word day (52 times outside of Genesis 1) the word day always means an ordinary day. In other words, whenever the word day is used with a number, or with the words evening or morning, or with the word night, or whenever the phrase "evening and morning" is used, outside of Genesis 1 the Hebrew word for day always means an ordinary day, or the phrase evening morning means an ordinary day.
The first time the word day is used in Genesis 1, it is qualified with the words night, evening, morning, and number. And for each of the other times the word day is used for the six days of Creation, it is used with a number and the words evening or morning. In other words, the contextual usage of the word day in Genesis 1 makes it obvious that it must be interpreted as an ordinary day.
Nope. Only their methods would have to be repeatable. Additionally, other researchers could test the dates of the rocks using different methods to cross-check the results arrived at by these researchers.
Actually, I first thought it was funny that the "journalist" added another two significant figures to the age of the Earth with that 30 million year figure. Now it's just sad.
When in doubt, start with "RadioAstronomer".....
meteorites believed to have originated on the large asteroid Vesta Those who have a problem with Martian meteorites are going to be skeptically blue with disbelief over Vestal meteorites.
I don't see why, we know they had virgins.
I believe that the Bible is from God, and I'm also sure that the Bible was never intended to be a science book; so we should not try to interpret it that way. Also, when Scripture was written, remember that God was communicating the words to very primitive man who could not comprehend anything close to what man can today. God had to communicate in simple language because that was all man understood.
Nothing to see? It means that what is dogmatically stated as evolutionary fact today is not a fact tomorrow. It means that dating methods and the presuppositions behind those dating methods are seriously flawed and subject to change as the evolutionary story-tellers see fit. It means that the event of life arising from non-life is no less than a miracle which is minimized by adding lots and lots of time.
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