Evolution is now so much a part of science that people are
actually trying to work what science says into the bible stories because
they cannot deny the truth of it - insidious and obnoxious lies such
as that propagated by the
Boone County museum
in Kentucky - would have us believe that dinosaurs were on the ark and
that they were friendly vegetarians! Even Steven Spielberg stuck to the
scientific orthodoxy in Jurassic Park -that the structure of such lizards
and their teeth rendered them flesh eaters - and that the rock dating methods
showed them to be millions not thousands of years old.
There is no end to how far people will go to excuse their own ignorance and
pretend that their beliefs are still sustainable in the light of evidence
that denies them.No one can deny evolution takes place - so the idea of taking
evolution as a fact and then saying it is the work of God to create evolution
is a farce -either you accept how science discerns things or you don't -
if you do - then you cannot afterward try and shoehorn what it says into
some previously conceived idea of the world and expect it to fit.
There ARE fossil records -there IS carbon dating - and however inaccurate
believers like to think these processes are at telling the truth - they do
say that the animals who were alive - were NOT 6,000 years old - and
ate flesh - and did not live alongside man. There is no evidence whatever
of a dinosaur in an ark - and there is no mention of such in the bible
either.
Anyone who says "T-Rex once was a vegetarian" is wholly ignorant of biology
- though an advocate of vegetarianism myself - I do know that the construction
of the organism indicates it's diet - and T-rex was flesh eater.
Radiocarbon dating
A radiometric method for measuring the decay of the radioactive isotope carbon-
14 in organic material up to 80 000 years old, developed in 1948-9 by Willard
Libby. Living animals and plants take in carbon, which contains some radioactive
carbon-14. When the organism dies, it stops taking in carbon, and as the
carbon- 14 decays, its proportion to the total amount of carbon decreases
in away which is directly related to the time elapsed since death.
Using samples principally from wood and charcoal, the technique revolutionized
archaeological dating across the world. Recent refinements allow reliable
determinations of date from no more than a few fibres of cloth or a grain
of wheat. Radiocarbon dating was the technique by which in 1988 the Turin
Shroud was shown to date from the 14th-c.
Argon dating
(August 1997)
When Mount vesuvius erupted in 79 AD, there may have been no media coverage
in our modern sense, but it was widely studied and reported, and we even
know that the Roman writer on scientific matters, Pliny the Elder, died when
he got too close to the volcano, which also destroyed Pompeii. So if we know
the date so accurately, why would anybody bother to try to determine the
age of the volcanic debris that flowed forth in that eruption?
The answer is found in a single word: calibration. Accurate radiometric dating
of young rocks is essential for scientists in many fields and where samples
from the Holocene, the last ten thousand years are involved, the primary
method has been radiocarbon dating. The problem with relying on just
one method is that it may be open to some kind of systematic error, such
as the slow seepage of newer carbon into old deposits, topping up the
carbon- 14 levels
and giving us spuriously young ages for material which is more than 40 000
years old. Nobody can say for sure if this is a problem or not, at least
until an independent way of assessing ages can be used alongside the carbon
method.
So if we can use the argon-40/argon-39 method to date material in the historical
period, this will give us a second version of the dates we have established.
Paul Renne, a geochronologist at the university of California, Berkeley,
and his colleagues have reported to Science that this is exactly what they
can do.
Argon dating tells us how long it is since an eruption, when lava solidified
and trapped radioactive elements in its crystal lattice, setting the radio
clock to zero. All you have to do is measure the ratio of potassium-40, a
radioactive isotope with a half-life of 1.25 billion years, compared with
the concentration of its daughter product, argon-40.
The method has been around for many years. but recent malor refinements have
made it
possible to detect tiny amounts of argon, making it possible to calculate
the age of younger rocks. Because the decay rate is so slow, quite a few
years have to pass before the argon levels are high enough to allow accurate
measurement, so that until now, the youngest rocks dated this way were more
than 5000 years old, and the accuracy was no better than 10%.
By heating samples of volcanic ash with a very precisely controlled laser
in careful steps, Renne and his team were able to date the 1918-year-old
rock to 1925 years, plus or minus 94 years, a remarkably accurate result.
(Note that dates like this always come with a confidence level: there is
only a 5% chance that the rock is outside the range 1831 years to 2019
years.)
This may open the way to even more exciting possibilities, such as dating
strata a long way from volcanoes by dating volcanic ash that blows into a
deposit. More importantly, the occasional fall of volcanic ash onto an ice
core may serve to place a set of time stamps on levels in the core where
the ash has fallen.
New volcanoes were also in the news this month. The record for hottest volcano
and hottest magma looks to belong to Io, one of supiter's satellites. At
the start of the month, Alfred McEwan told the American Astronomical Society's
flivision of Planetary Sciences about the most recent Galileo results. It
seems that the volcanoes on Io have a temperature of around 1800 K, some
200 degrees hotter than on Earth, and this translates to a magma temperature
of about 2000K, suggesting that the magma is a molten silicate rock which
is rich in magnesium.
©WebsterWorld Pty Ltd/contributors 2002. |
