Dinolava Theory Back in Eruption

Meteor impact or volcanic eruption?  Science Now reports that the volcano theory of dinosaur extinction has rejuvenated, challenging the long popularity of the Chicxulub impact hypothesis.
    Notwithstanding all the dramatic animations on science documentaries of a cataclysmic meteor wiping out the dinosaurs, the article by Carolyn Gramling states that “Scientists have long wrangled over the cause of the extinctions….”  A new French study of magnetic alignments of lavas in the Deccan Traps of India, some of the biggest lava fields in the world, suggests that the cataclysmic eruptions occurred over a much shorter time period than previously believed – 30,000 years instead of millions – short enough, they claim, to affect worldwide climate.  Some of the older eruptions may have happened even more rapidly because there is no evidence of weathering between successive layers.
    A Dutch proponent of the impact scenario is not convinced, however.  He said we don’t know enough about behavior and variability of the Earth’s magnetic field to make strong arguments based on magnetic alignments in rocks.  Gramling says, “He also questions whether any known geophysical mechanism could have spewed out so much lava in such a short time.”

Readers, take note: the Science Channel and all the documentaries present their scenarios as fact, and try to make them seem so certain that all scientists agree.  The dating of events, especially, is rarely if ever questioned.  Here, one side is claiming that the old dates of the Deccan Traps are wrong; the other side is questioning whether we can tell anything from magnetic alignments (even though they are commonly used to convince the viewing public of the precision of dating methods).  Since, in the above article, neither theory overlaps the other (see 10/01/2003 entry), each must independently make its case.  Do you begin to get the idea that neither side knows what on earth they are talking about?  Good.  Your eyes are open.
    We need to realize how little we can know about prehistory by empirical methods (cf. 11/05/2003)  We need to acknowledge to what extent the data are subject to being molded to human interpretations and presuppositions.  Data exist in the present, not the past (visualize this).  Scientists build models to incorporate the present observations, but short of a time machine or eyewitnesses (02/17/2003 commentary), the past is forever out of reach, and getting more so all the time.  This is not to overlook that some models are more plausible than others (cf. 04/22/2004).  But while seemingly plausible now, today’s leading model can be (and often is) overturned with the next finding.  The Chicxulub story attained such a consensus in recent years as to be nearly enshrined as The Official Story of the Death of the Dinosaurs, but now look; it’s got major problems (04/10/2003, 09/25/2003, 11/25/2003).  Reporters, TV producers and writers of children’s books have not, for the most part, caught up with this development (see 05/13/2004 example), but it is another case of a popular model becoming a has-been.  Such turnarounds litter the history of science.  Writing with an air of certainty about prehistory, therefore, mars otherwise good books like The Privileged Planet (e.g., pp. 22ff) that speak of events in the unobservable past, including magnetic field signatures, as if recorded on steadily-moving tape to be just read off by the unbiased eyes of scientists.  The Dutch critic here reminds us that we know too little about planetary magnetic fields to speak so confidently.  That goes for other dating methods as well.  Discerning minds do well not to attribute infallibility to mortals.

As we have pointed out before (10/06/2004 commentary), it is much safer to play conservative and not extrapolate observed measurements recklessly into the past.  It is easier to set upper limits on time than lower limits.  For example, estimating the lifetime of a comet into the past by a few more orbits than have been observed is reasonable, but claiming it came into existence a million years ago extends the observations far beyond human experience.  The former stretches observed behavior a little way back; the latter extrapolates a few data points into unknown territory by many orders of magnitude.  Who knows what perturbations might have changed the orbit before we observed it?  It’s more justifiable to project how long the comet might last given its present rate of mass loss (an upper limit), than to claim it has had to exist for at least umpty million years (a lower limit).  In the current case, the lack of weathering between layers would seem to place an upper limit to the amount of time that must have transpired during the sequence of eruptions.  An upper limit is, of course, a limit; the actual age could have been much lower.  For more examples, see 05/01/2004 story about tufa formations, and the 05/10/2004 article about caves.

The admission about whether any known geophysical mechanism could have spewed out so much lava in such a short time is revealing.  Whatever happened to uniformitarianism?  (Notice: it’s gone; catastrophism rules—see 11/04/2003 and 05/22/2003.)  But don’t let these guys puzzle about that problem only here at home.  Have them tell us why big eruptions should be happening right now on Io (05/04/2004), Triton (06/05/2003), Titan (06/09/2005) and Enceladus (07/29/2005) after billions of years, each of them smaller than the Earth (and therefore possessing less gravitational heat), or why comets should still be erupting after so many trips around the sun (03/27/2003).  It’s not that the moyboys^* can’t concoct a good story, but to do so, they must keep inserting ad hoc assumptions to keep processes going that would otherwise fizzle out in far less time.  In today’s case, we see two sides (both naturalistic and evolutionary) undermining the credibility of each other’s tale.  The proper lesson is that neither idea can be trusted, and neither side knows what happened, because they weren’t there.
^*A new word meaning scientists and reporters who toss around the terms millions of years, billions of years with reckless abandon.
    The upshot is that, despite all the appearance of scientific rigor, the measurements and jargon, neither story explains the extinction of the dinosaurs, or why some organisms carried on through the catastrophe as if nothing happened (11/08/2004).  A corollary is that any sufficiently advanced model resting on uncertain premises is indistinguishable from a novel.  After all, a good novel usually takes place in the real world and deals with observable, tangible things.  Some novels even describe historical personages and places in exquisite detail (cf. the detailed measurements of magnetic field orientations in present-day rocks).  It does not follow that the events described ever happened, or even if they did, that they happened when the believer claims they happened, or in the way they happened, or that nothing else happened that might bear on what happened.  Another corollary is that a newer model is not necessarily better.  A fancier mansion built on the same shifting sand has the same underlying vulnerability (see 05/13/2004).  It is a specious response, therefore, to retort, “Well, then, what is your model?”  Some choose not to build on the sand, but on the rock.