5 - The Age of Our World Made Easy


Uploaded by PolarisHorizon on 15.02.2009

Transcript:
In the 17th century
a theologian called James Ussher
worked out the age of the Universe
based on the chronology of the Bible
It was created, he concluded,
in a week in October, 4004 BC
Even today, millions of people still
believe that this 17th century calculation
is about right
and that the overwhelming evidence
of geology, cosmology, paleontology
chemistry, astrophysics, geophysics
stratigraphy and biology
... is wrong.
So let's take a look at what that evidence is
starting with a principle that even creationists
don't dispute
The golden rule is that newer sedimentary
deposits are always laid on top of older ones
so except when rocks have been folded
this orange bed would be older than the green one
and the green one is
older than the blue one
geologists can then follow
a single bed to make similar deductions
in a different locality
the dark grey bed may be at the surface
or even at a higher point than
the others, but it is older than all of them
and the light grey bed is older still
What we end up with is what is called
the geological column
To get the absolute dates
of these rocks, scientists use a
variety of different methods
I'll start with one of the easiest
and most recent
We all know trees have rings
because in summer they grow faster than in winter
but seasonal growing conditions
vary according to the weather
so the bands will vary
in size; each time period
in each geographical location
has its own distinctive pattern
of tree rings, like a fingerprint
So if we take wood of known age
we can match the oldest part of it
with the youngest part of another
piece of wood
and so on back through time
back 10,000 years in fact
and already way beyond
the biblical chronology
Okay I'll spend a bit of time
on this one, because creationists preachers
spend a lot of time talking about it
but don't seem to understand it
Our upper atmosphere is constantly
being bombarded by neutrons
from the Sun
When one of them hits a nitrogen atom
in the air, it knocks off a proton
changing the atom from nitrogen into carbon
but this is an heavy and unstable form of carbon
called Carbon 14
or C14
the normal form of carbon is C12
In the atmosphere, C14 combines with oxygen
to make carbon dioxyde
which is then absorbed by plants
and into the bodies of animals that eat the plants
The ratio of these two isotopes
in animals and plants
is roughly the same as the ratio in the atmosphere around them
but when the animal or plant dies
C14 decays over time
and reverts back to nitrogen
so compared to C12
which doesn't change
the amount of C14
falls at a constant, measurable rate
By measuring this ratio
inside the dead animal or plant
scientists can find out when it died
Before I look at other dating techniques
I'll bat a few old myths
about carbon 14 out of the ballpark
No, it's not.
That's like saying cars don't work
because sometimes drivers get lost
carbon dating works fine
but if the wrong stuff gets analyzed
then you'll end up getting the wrong date
so if there is bacteria or mold
or any kind of contamination
on the sample, the date will be wrong
if the results aren't calibrated
properly, the results will be wrong
and in some environments, carbon dating
is impractical, so the results will be wrong
but when everything is done properly
the results are right
but that's no different to
any sophisticated analysis technique
from X-ray imaging, to spectroscopy
contaminated samples don't invalidate
the principles of DNA analysis
or chromatography or spectroscopy
we know they work
and we know carbon dating works
Firstly, carbon dating can be checked
against artifacts of known age
such as ships timber
secondly, it can be checked by sending the same
artifact to different labs
for analysis
thirdly, let's take a sample of organic material
from each of these layers
if carbon dating was random nonsense
you'd expect the chronological order
of these samples to be all over the place
but that doesn't happen
the results show each of these samples
in its correct chronological order
the ones from the upper beds are younger
and the ones from the lower beds are older
is it magic? Or is it because carbon dating works?
And that's why it's used
To quote Kent Hovind:
"samples don't come with labels attached
telling the lab their age"
Testing is always blind
if it's not blind, it's not science
and if creationists don't trust
the carbon dating method
they're perfectly welcomed to
conduct their own blind test
to prove it wrong
But carbon dating is not used on diamonds and coal
and for very good reason
as I explained, C14 is formed
when neutrons collide with nitrogen atoms
the C14 used in carbon dating
originated in the atmosphere
but you can also get it deep underground
in places where decaying uranium
is giving off neutrons
coal and diamonds are made of carbon
so you'd expect to find higher levels of C14
in coal and diamonds close to
rocks that contain uranium
and much lower levels away from those rocks
and that's exactly what we do find
carbon dating is only used
and only useful
for dating organic material
in the topmost sedimentary layers
Now that we got carbon dating out of the way
let's quickly run through a few more
absolute dating methods
Biologists know that human DNA
mutates at a fairly regular rate
and they can trace these mutations back
like following the branches of a tree
back to the trunk
it's not a greatly accurate method
but it does give a rough idea
of when humans migrated
and a very definite idea of where
it doesn't lead back to mount Ararat
4,000 years ago
but to Africa, around 50,000 years ago
just as other dating methods
suggested it should
Every 250,000 years,
or so, the Earth's magnetic field
flip over, and the South pole becomes the North pole
magnetized minerals within rocks
show the polarity of the Earth
when the rocks were laid down
so throughout the geological column
rocks show a regular magnetic
banding depending on the polarity of the Earth
and that can be dated.
Potassium-argon dating works on the same principles
as carbon dating
but instead of carbon decaying to nitrogen
we have potassium decaying to argon
and instead of a half-life of 5,500 years
we have a half-life of 1.3 billion years
that means the method can be used
for dating rocks and fossils
hundreds of millions of years old
The technique has largely been replaced
by the far more accurate argon-argon method
and there are other decaying processes
that can be measured each with different
half-lives, such as uranium-thorium
and rubidium-strontium
Radiometric dating takes us back to the
oldest rocks we found on Earth
3.8 billion years old
If you want to go back even further
you have to look into space
My video "The History Of The Universe Made Easy"
explains how we can calculate
the age of stars and galaxies
so I won't repeat that here
just take a look at the video
what's important is that the results
fit perfectly with the chronology
we find on Earth
the Sun, for example,
doesn't turn out to be younger than the Earth
or older than the Universe
its age, based on the amount of
hydrogen fused into helium
is exactly what you'd expect
and as with dating methods
devised for rocks on Earth
the method for measuring the age
of stars and galaxies
is devised first, and tested afterwards.
There is no way of knowing in advance
what age these tests will show
but every time the age confirms
the known chronology of our world
As technology expand,
new dating techniques are constantly being developed
If the world really was around 6,000 years old
you'd expect them to show it
or at least disprove the established chronology
but they don't.
Every new technique confirms
what we know.
There's thermoluminescence
that can measure the number of trapped electrons
on the surface of volcanic rocks
the speed that continents are drifting
can be measured today
so their position millions of years ago
can be calculated
it matches perfectly with
the geological chronology
we've already worked out
climatic banding in sedimentary rocks
can be measured, caused by a wobble in the Earth
motion every 12,000 years
I could go on but there is no time here
to list every dating method
let alone spell out the details of how they work
but if creationist preachers are so
convinced that every single dating
method is wrong
and that the single story they tell
is either the result of a huge coincidence
or a giant conspiracy
it's very easy for them to prove it
Hey guys! Do your own tests!
After all, a few creationists
have university degrees
in biology and geology
Okay then, devise a dating technique
of your own choosing
explain publicly how it works
have it tested against samples
whose age we all agree on
so we know it works
then go out and take samples of
sedimentary rocks throughout the geological column
and have them tested by the method you
have devised
Not surprisingly, not one of the creation science organizations
has bothered to do this
Why not?
If the Bible is right
then all the samples would date to around
4,000 years ago
and provide strong evidence
that the biblical flood was real
but if the bible is wrong
then the dates will be much older
and more importantly
the chronological order of the samples
will be in perfect accord
with their comparative ages
in the geological column
For some reasons, so-called creation
scientists, despite their professed faith
that the Bible is right
don't think that's a risk worth taking.