Chronometric Revolution

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Chronometric Revolution : Discussion of the relatively recent changes in our ability as a species to shine light on our deep past

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If we want to understand where we come from
the stories that have led us to our present condition
if we want to understand our history
one of the prerequisites is to have a good sense of
chronometry. Chronometry is a fancy word
but its really just the science of the passage of time
chrono relating to time
metry, time measurement
and we take many things forgranted these days
we assume we know what happen the last fifty years
the last hundred years
and now we're starting to assume what happened
to ten thousand years ago
or what happened to our planet a hundred million years ago
or a billion years ago
but these are all very very new phenomena
this ability to kind of shine a light on the past
and even the traditional notions of history
the traditional stories of what lead to what
the political nations that formed the migrations of people
and when they happened
that tradition notion of history is fairly new
when you think about just the scope of how long
humans have been on this planet
and that first traditional notion of history
you can kind of view as the first chronometric revolution
and that first chronometric revolution that gives us
this kind of tradition notion of history really just
come out of humanities ability to write
so writing gives us our first chronometric revolution
because this was the first time
even through we think that humans or human like creatures
have been around for hundreds or hundreds of years
at this point
they weren't able to keep their stories in a very exact way
they might have had an oral tradition
that might have gone from one generation to another
but those oral traditions things would get lost
and the most important information that would get lost
is how long ago did these stories stories start up
and we weren't able as a species to understand
when things happened and how long ago things happened
until writing became mainstream
and until writing became permanent
and our best sense of when this happened
the first time is by the sumarians with cuneiform
and this happened right around the third millenia b.c.
so around five thousand years before the present time
and this is what some of the writing looked like
this is actually a letter from a king
and you can see its just highly symbolic carvings
this is what we more traditionally associate with cuneiform
and it was symbolic based as opposed to now
most of our language most of our language
is based on phonetics which has fewer symbols
so you can have more meanings
but this was a huge technological revolution for humanity
because now with the advent of cuneiform you had writing
that someone could look at a thousand years later
two thousand years later
and if they can decipher the cuneiform
they can get a written testimony of what was
happening at that time
and they didn't have to rely on an oral story
or guess when that oral story started
but writing since it only happened five thousand
years ago
so this is five thousand years before the present
or you could say three thousand B.C.
that was a start but this only gave us stories about
five thousand years old
but even then it was a very spotty historical record
we didn't get really deep, depending on where you are
in the world until really the last few thousand years
but it was a start
this was the first chronometric revolution
but what you may, or may not, realize is that frankly
we are I believe at the start of another chonometric
revolution that has really just begun to accelerate
in the last fifty, sixty, seventy years
and this second chonometric revolution
2nd chonometric revolution
I should write revolution up here too
this was a revolution, it allowed us to keep time in a
permanent way to understand things
to not have to talk to the people to whom something
happened we can see their written testimony of it
but the second revolution really comes out of our
understanding of modern science
so in the late eighteen hundreds you have radio activity
discovered by Marie Curie
so this is nineteen hundred here
so this is relatively recent here
remember we're talking about a species that has been
around for several hundreds of thousands of years
and proto-humans have been around for millions of years
and now only five thousand years ago
at least as far as we know was the first writing
and then only a little over a hundred years ago
was the discovery of radio-activity, so radio-activity
and then the ability to use radio activity
so radio activity is interesting
its the idea that elements can change
from one variation to another variation over a long
periods of time through radio activity
they become kind of this natural clock
no one had to go there and set up a time piece for it
that luckily there are these things that decay at a very
predictable rate
so we discover radio activity a little over a hundred
years ago and then over the course of the twentieth century
we got better and better, more sophisticated
at understanding radio activity to be able
to use it to measure the times of things
and if you fast forward to second half of the twentieth
century, so now we're at 1950, this is where
the second chronomentric revolution really took hold
where we started to understand carbon-14 dating
we started to understand other techniques that we
talk as we can start to date older and older things
and I want to be clear, radio activity, the understanding of
radio activity was just the beginning of the second
chronometric revolution, the second chronometric revolution
which frankly we're still a part of isn't just radio activity
its also understanding the expansion of the universe
the constancy, the speed limit of light, that allows us
to figure out that, wow, that background radiation that
we're getting that must have be traveling for
13.7 billion years ago, so now we can look at evidence
from our environment and our environment isnt just
earth it's self its radion bombarding us from space
that allows us to make -- that gives us clues as to not just
the age of us, the age of species, the age of the planet
but the age of the universe it's self, so it isn't just about
radio activity, radio activity is a big part of the chronometric
revolution, this is what allowed us for the first time
if we have layers on the earth
people have known for a long time that if we assume
these layers haven't been jostled
that something at a lower layer down here is probably
going to be older than an upper layer
because year after year you have deposits
if it hasn't been messed up in some way
but no one knew, they said ok
well this is relative dating this is older, this is younger
but we had no way of knowing is this a hundred years old
is this a billion years old
but now with radio activity we can start to say hey
we can date some of the rocks here that are a 150 million
years old and some of the rocks here are 100 million
years old
so maybe this fossil of a fish we're finding
or this primitive fish like creature over here would be
between 100 - 150 million years old
and the only way we're able to do this is with being able
to date things using radio activity
but radio acitivity is just the start as I mentioned
we're getting better and better understanding of cosmology
we're getting better measurements of the universe it's self
we're understanding physics and a deeper level
now we can start to look at the genome
and think about how the genome diverges