coral clocks

Well that was an unpleasant series of negative posts. But, well, obviously I felt they were things that needed to be said.

So let's turn to a less controversial topic. Actually.. it's still going to be controversial among the creationists, the truth is I found out about this on one of the links I gave in the last post.

But ignoring the anti bible literalist angle that this information could be used for, it's still darned fascinating.

The concept goes like this. We all know that you can count the age of a tree by counting its rings, one for every year, right? Well it turns out that, at least to some degree, you can do the same thing with coral, because as it grows it expands and leaves similar layer patterns. But it doesn't just leave a single layer per year, it leaves a detectable layer every day, as well as patterns that indicate the passing of a year. This in itself blows my mind because much has been made about how coral is an extremely slow growing organism. To think that despite that it leaves behind detectable layers for every day is incredible.
But it gets better. This isn't about measuring how many days old the coral in our oceans is. The method has been used on fossilized coral.
Some of you reading this may just see where I'm going with this. But rather than attempt to ease gradually into the concept I'll just spring it. The older the coral samples get, the more days per year they indicate.
I'm not a scientist, I merely have an extreme fascination with science. I only encountered this coral concept recently. I've attempted to do some research into the concept, but specific information is difficult to find. I've found a research paper that appears to give different numbers for days per year for the same fossils, I'm not sure what's going on there, it seems to be a reflection of different methods or differing formulas or an indication of a margin of error.
But the number of days per year of the older samples gets at least as large as 400.

What this is about, of course, is the fact that the Moon is constantly slowing down the rotation of the Earth through tidal friction. Don't ask me to explain how, I only barely have a handle on the concept myself. The same or at least a similar effect is behind the fact that the same side of the moon faces the Earth at all times (give or take a few percent because of libration, but that's beyond the scope of what I'm talking about).
Ultimately what will happen is that the Earth will rotate slow enough that the same side always faces the moon. The moon will, essentially, appear to stay in the same place in the sky at all times. There'll be some variations to that because its orbit isn't perfectly circular, but basically that's what will happen. I don't know how long it will take off hand, but it will take a VERY long time. Believe me you shouldn't be starting to think ahead to prime real estate if you want to be able to see the moon hanging outside your kitchen window every day of the year. In about 400 million years we've gone from 400 days per year to 365. So we have a bit of time yet before we reach full tidal lock.


But back to the coral. I'm practically giddy with the revelation that it's possible to go so far back in time and count how many days were in the year. If I understood what I read it sounded like they were using the coral research to track tidal cycles from the era of the coral being studied as well.
Perhaps this seems odd that I'd be that impressed by counting layers in coral, but it's the idea that we're able to get this much information about a time so far in the past.
It appears that coral clocks aren't the only way to do this. One of the nearly unintelligible (to the average reader) scientific papers I found on the subject seemed to refer to using bivalves (in other words, things like clams) to do similar research. Or using silt accumulation. Clearly there's much more to this type of research than I'd ever heard about.

But the fact remains that we can look back in time using evidence of when a year was 4oo days long, and conversely each day was shorter. It's not about exactly what the numbers say, it's that we can actually get them in the first place.

I don't think my fascination with this concept is that weird.  I'm interested in the past because it's something that I can never personally witness.  I wish I could go back in time to see what the ancient Roman empire was really like, I'd even settle for a one way visual portal that would let me see (and preferably hear) without interfering in any way.
But the fact that it's permanently out of reach means it will never lose its appeal, it's a mysterious world that I can only get glimpses of.  This is even more true for the pre historic era, including the time before humans were even around at all.

Take for example the Devonian era, roughly about 400 million years ago.  Life in the seas was well established, but life on land was still in its infancy.  Land plants were well established and becoming more complex, and fish evolved legs to take their first steps onto land (although arthropods, which is to say insects, appear to have been first onto land).  I want to know what it would be like to be there to see it.  Not to see the changes happening, but just to see a moment in time, just a tiny slice of what the world looked like then.  The alien vista of the primitive plants with the comparative lack of animal life variety.  A world completely unsuited to humans, that very fact alone makes me want to be able to be standing there, intruding into a place I don't belong.  The fact that I can never see it makes it all the more intriguing.

But now I find out that just by looking at coral they can count how many days were in a year, and analyze the tidal patterns of the age.  In a way it makes the ancient past seem slightly less out of reach.  It suggests that there's a great deal of information out there that I've never even heard of.  And in the end I always get a kick out of that.  I have a definite "know-it-all" complex, I try to accumulate as much general knowledge as I can.  But I'm continuously reminded that there's a great deal more information out there, including stuff that I don't even know exists.  And it's so much fun when something pops up out of the blue and surprises me.

I should specify that it appears that the data is actually being used to fine tune the age of the coral.  It may be that scientists are actually using the information to figure out how old the coral is, because they already know (or at least have a reasonable understanding of) how fast the Earth's rotation is slowing down.  So they can use the rotation information to get another estimate of when the coral lived, to compare with the dates obtained by radiological dating or by using the geologic layer.
The inexplicable complexity of the paper I read on the issue may have been because of the need to compensate for differing tidal levels caused by ice ages and such.  I say that because it would seem that having more or less liquid water in the ocean would change the way the tides slow down the rotation.  Before I realized that I was baffled at how what would seem to be a simple relationship should call for a mathmatical formula that I couldn't even read.