Instant Earth, Just Add Dust Particles

EvilSuggestions writes "Apparently, the estimate for how long it took for the Earth to form just got chopped in half. Now just a paltry 30 million years (which, IIRC, is less than one day on Carl Sagan's 1 year = the life of the universe calendar). So, adjust your terraforming plans appropriately. The good folks over at Science News have been following the gory details behind this conclusion."

Comments

Re:accuracy?

[roachmotel3]

Further research on my part:

From the article:
Kleine suggests that in previous studies, researchers came up with formation times that were twice as long because they had less accurate determinations of the amount of tungsten-182 in meteorites.

It has nothing to do with the accuracy of the radioactive dating, but rather the sampling techniques used in the original estimates.

Re:accuracy?

[a302b]

I suppose I wasn't clear in my earlier post.

I'm quite confident radioactive dating is very accurate in lab contitions. The amount of trace elements can be accurately determined, and based on the half-life, an age can be fairly accurately estimated.
However, how accurate are field conditions? Minerals move and change over such a large period of time, so how does one know when one has a representative ratio of (say) tungsten-182 and hafnium-182? A you pointed out, it was the sampling techniques that were flawed in the original estimate. How does one show that the techniques used in this sample (and others) are accurate?

Re:accuracy?

[gi-tux]

I have often wondered along this same line. How do we know that the ratio of (say) tungsten-182 and hafnium-182 is a constant? Or how do we know that the change in the speed of light didn't change the half-life of hafnium-182?

I agree that in lab conditions the process works very well, but we are talking about very controlled testing. And even very controlled testing isn't perfect, as bugs are accidentally released with software, and consumer products aren't all hugh successes.

Also, in the "real world" environment, how are they sure that there hasn't been a loss of one of the elements? A loss of tungsten-182 would make the time measurement be less as the ratio would be higher in favor of hafnium-182. And how do they know that the astroids that they used were not from a planet, moon, or something that didn't form a core? I seriously doubt that they can prove where that astroid came from.

It seems to me that they are extending the scientific process over things that aren't controllable. The scientific process is susceptible to error when a lack of control is allowed to enter the experiment.