It's untrue, sorry, in spite of statements like these:
The world was created on 22nd October, 4004
BC at 6 o’clock in the evening.
—James Ussher, Archbishop of Armagh (1581–1656), Chronologia Sacra.
The poor world is almost six thousand years
old …
— William Shakespeare (1564–1616), As You
Like It, IV, i, 95.
James Ussher was an Irish Church of England clergyman who became archbishop of Armagh before moving to London in 1640. A learned
gentleman with leanings towards John Calvin, he believed in the literal truth
of the Bible, and deduced from a careful reading that the world was created on
October 23, 4004 BC at noon. He is now a feature of scientific mythology, often
spelt Usher (as he often was in his own life), and with a number of variant
dates and/or times other than the time and date he actually specified (9 am is
popular, so is October 26: for example, Daniel Boorstin, in The Discoverers, p. 451, has October 26
at 9 am).
Relying on the Maker’s Manual (the Bible), Ussher added
together the ages of the Biblical patriarchs, and got a planetary age of around
6000 years (today) in post-Eden timing. The actual Day One that Ussher selected was the autumn equinox in
the northern hemisphere, with a thirty-day correction thrown in to allow for
known faults in the calendar which had been used before the corrected Julian
calendar. For about two centuries, we have been aware (or the thinkers among us
have) that humans have been around for more than the 6000 years that Bishop
Ussher suggested.
There were too many contradictions, at least if you were
a scientist who assumed that the world got to be the way it is by the operation
of processes that we can still see today. This date implied only a short time
since the start of the earth, far too little time for evolution and geology,
meaning that fossils, species and the landscape had to be explained in some
other way.
A dispute over flint tools in The Times in November 1859, a month before Darwin published his Origin of Species, and the argument
turned on age. The tools lay far deeper than tombs which contained coins 2000
years old. The Biblical 6000 years was too short for the depths at which the
flints occurred, unless you assume a change in conditions. A massive flood like
Noah’s might explain the deep burial, but geologists knew that chalk beds are
formed slowly by tiny organisms, not by floods. “The discovery of these relics
of a race which seems to have been of far greater antiquity than any that has
been hitherto supposed to have inhabited our planet, involves many interesting
and difficult questions,” wrote T. W. Flower.
Boucher de Perthes was an amateur at a time when
geologists were becoming professional. It took the mainstream scientists a
while to trust him, but he just kept on, digging interesting human-made tools
from deep chalk deposits in France. In the end, the scientists came around to
his ideas (or his results, anyhow), thanks mainly to Charles Lyell, who visited
Boucher de Perthes’ excavations in 1859 and came away convinced that the tools
were not only real, but offered strong evidence that humans were older than
supposed.
The geologists ended up pushing the age of the Earth out
from the 6000 years that was popular in the 1600s to 4.6 billion years, making
the planet 750,000 times as old as people had once assumed. It was like
expanding the distance between New York and London from 7.5 metres (a distance
Jesse Owens could jump as a school boy) to 5500 kilometres.
A popular solution to the 6000 years problem was to
assume a number of separate creations of life, with humans only appearing in
the most recent round of creation. That would account for older fossils and
other embarrassing contradictions, but it was at best a poor work-around. When
human remains were found with those of extinct animals previously assigned to
earlier cycles, the whole scheme would fall apart.
Hugh Miller, a geologist and stern Scottish churchman,
died in 1856. In 1857, his widow referred in a new edition of his The Old Red Sandstone to “infidels”
among the geologists, so clearly the lines were being drawn on the Biblical age
of the Earth. A few geologists joined Mrs Miller in her fundamentalist approach
to the age of the Earth, but the professional geologists and most trained
scientists already accepted that life had been on Earth far longer than the
6000 years that could be read into a literal reading of the Old Testament.
Reading the rocks requires a far cleverer type of literacy.
Fossils are curious things, and fossil experts are adept at detecting slight
variations that reveal hidden secrets. Most fossils carry subtle clues in their
shape, their form, where they lie, or what lies around them, but perceiving
this only comes after looking at large numbers of fossils with a clever eye.
That sort of insight does not necessarily help explain
how a fossil came to be where it was, but it is a start. After that, you are
left with a choice between logical reasoning and inference, or supposition and
wild fantasy. Many people, finding a conclusion they don’t like, will denounce
another scientist’s logical reasoning as crazy fantasy, or hail a colleague’s
wild surmise as pure gold. Those who do this can sometimes be anti-scientists
of the worst sort, some of them may also be qualified as scientists.
The mainstream geologists were annoyed by the catastrophists,
moist of them amateurs who wanted all geology to have been produced in several
major disasters like Noah’s flood. The normal geologist’s view is
uniformitarian, meaning that conditions have been the same, uniform, over the
eons, with geology caused by processes we can see today, with weathering,
erosion, volcanoes and other ordinary events shaping the Earth.
Some of the modern opposition to asteroid theories that
account for the “end of the dinosaurs” stemmed from this same visceral reaction
to any suggestion that catastrophes shaped the Earth. Rational geologists now
tend to assume a sort of geological punctuated equilibrium, where normal
conditions apply most of the time, with the occasional surprise. All the same,
geological mavericks who stress tsunamis, asteroids and other catastrophes tend
to be looked down on, even today.
The debate was not straightforward, because physicists also
questioned the geological view on the planet’s age from their own scientific
perspectives. The planet was warm below ground, they said, so it must be
cooling, which meant it used to be hotter, because there was no apparent source
of continuing warmth.
If you went back far enough, they said, the planet would
have been too hot for life, and that set a limit to the time life had existed.
The answer to this paradox later turned out to be that internal radioactivity
has kept the planet warm for billions of years, but in 1859, radioactivity was
unknown, and it is the decay of radioactive nuclei that keeps the planet’s
interior hot.
Note that science never offers proof, just evidence, although
as we have seen, Thomas Jefferson did
manage to prove from scientific data that Noah’s flood could not have happened. All the same, when so
many different classes of evidence point in the same direction, perhaps we
should forgive those scientists claim to have “proof that evolution happened”.
Now back to the age evidence.
Edmond Halley suggested a method of determining the age
of the Earth’s oceans: measuring the salinity of the sea, and finding the rate
at which salt was added to the sea each year. The Irish physicist John Joly
calculated in the late 19th century that the sodium content of the oceans was
1.5 x 1016 tonnes. Sodium is now believed to be added at the rate of
6 x 107 tonnes per year, giving an estimated age for the oceans of
about 250 million years.
The method will always give low estimates because it
does not allow for any losses of salt back to the land, either as salt spray,
or as halite deposits. Still, in an age when James Ussher was still setting the
world’s age at 6000 years, scientists like Halley, were looking at a far
greater time-scale:
But the rivers in their long passage over
the earth do imbibe some of the saline particles thereof, though in so small a
quantity as not to be perceived, unless in these their depositories [lakes and
rivers] over a long tract of time … Now if this be the true reason for the
saltness of these lakes, ‘tis not improbable but that the ocean itself is
become salt from the same cause, and we are thereby furnished with an argument
for estimating the duration of all things, from an observation of the increment
of saltness in their waters.
Against that, Georges Louis Leclerc, Comte de Buffon
(1707–1788) carried out cooling experiments with large hot iron balls. From his
data, he deduced the planet was at white heat, 75,000 years ago, and had
carried life only for 40,000 years.
Jean-Baptiste Joseph, Baron de Fourier (1768–1830)
argued that the earth’s central heat, revealed in higher temperatures in mines
and by volcanic activity could best be explained by assuming the whole earth
was once hot, and that the temperature of the earth was now falling.
In 1862 Lord Kelvin estimated the age of the Earth,
based on its cooling time to be 98 million years, but by 1897 he had lowered
this to between 20 and 40 million years, unless some other source of heat could
be found. In May 1892, Scientific
American reported an opinion from Sir Robert Ball that the Sun had existed
for 18 million years, and would burn out in another 5 million, still limiting
the planet to a very short age.
The debate boiled down to a struggle between the
biologists and the geologists on the one hand, who all demanded ever-longer
ages for life on earth as they saw it, and the physicists on the other, who
could see no way of fuelling the long, slow, steady-state earth that we now
accept.
The question of age arose slowly, starting with an estimate, based on the ages of the patriarchs in the Bible, of some 6000 years, though many assumed that there had been a lifeless Earth before the Garden of Eden affair, but the stopping point was that nobody could explain why the Earth had not frozen. Long before Charles Lyell and Ernest Rutherford showed that Ussher’s date was impossible, people had realised that this was so.
In fairness, Ussher
cannot be accused of holding back science with his calculation, though this
accusation is commonly levelled at him. So until the 19th century,
the age of the planet was taken largely from the Biblical record, but then they
discovered radioactivity...
