Speaker 1: Welcome to tech Stuff, a production from my Heart Radio.
Speaker 1: Hey there, and welcome to tex Stuff. I'm your host,
Speaker 1: Jonathan Strickland. I'm an executive producer with I Heart Radio,
Speaker 1: and I love all things tech and typically I would
Speaker 1: have a news episode for you on today, which is Thursday,
Speaker 1: April twenty one, but this week got away from the
Speaker 1: big time. On the bright side, we have a really
Speaker 1: cool thing coming up early next month that um tech
Speaker 1: Stuff is taking part in that I think you guys
Speaker 1: are really gonna dig. But that doesn't help me today,
Speaker 1: does it. So instead of a news episode, we're going
Speaker 1: to have a little bit of a classic episode here.
Speaker 1: I thought, because I'm feeling so very old as I
Speaker 1: try to to make sure I have these episodes ready
Speaker 1: for you guys, it would be good to kind of
Speaker 1: take stock. And by that I mean we're going to
Speaker 1: listen to a classic episode called is carbon Dating on
Speaker 1: the Way Out? This episode originally published on August two
Speaker 1: thousand and fifteen. I hope you enjoy. This comes from
Speaker 1: nikkil Cardale, and I do apologize that I'm sure I
Speaker 1: mispronounced your name. The request was, could you do an
Speaker 1: episode explaining this carbon dating is pretty useful, So this
Speaker 1: effect seems relevant and uh Cardale actually uh commented on
Speaker 1: and and included another tweet from real scientists that included
Speaker 1: an article titled will our fossil use ruin our ability
Speaker 1: to use carbon dating as a scientific tool? This is
Speaker 1: really fascinating the idea of using carbon dating, uh, and
Speaker 1: how that that method might be in jeopardy because the
Speaker 1: use of fossil fuels. So I thought I would go
Speaker 1: into that explain what carbon dating is and why it
Speaker 1: might not be an accurate means of telling how old
Speaker 1: something is after too long. So going into the article,
Speaker 1: it's about how the enormous amount of carbon emissions we
Speaker 1: generate could make carbon dating and unreliable means to determine
Speaker 1: the age of certain types of materials. But to understand
Speaker 1: how that's possible, we need to know how carbon dating
Speaker 1: works first, So we're gonna do a carbon dating one
Speaker 1: oh one. Now, the first thing that we have to
Speaker 1: talk about is carbon fourteen. So the fourteen in carbon
Speaker 1: fourteen tells us it's an isotope of carbon. This particular
Speaker 1: isotope must have eight neutrons because carbon has six protons.
Speaker 1: You can change the number of neutrons in an atom.
Speaker 1: That's the different types of isotopes atoms may have. But
Speaker 1: you can't change the number of protons and atom has
Speaker 1: without changing that element. So carbon had six protons, and
Speaker 1: if you change that number of protons, you change the
Speaker 1: element itself. It acts reacts differently in chemical operations, and
Speaker 1: uh is no longer carbon. So carbon twelve is the
Speaker 1: most common form of carbon that we find. It has
Speaker 1: six protons and six neutrons. Then you have carbon thirteen,
Speaker 1: which is six protons and seven neutrons, and both of
Speaker 1: those are stable forms of carbon. That means they don't decay.
Speaker 1: So if you have carbon twelve or carbon thirteen, you
Speaker 1: put it in a box and you leave for I
Speaker 1: don't know, two billion years, and you come back, you're
Speaker 1: still gonna have carbon twelve or carbon thirteen because they
Speaker 1: remain stable. They do not decay. But carbon fourteen is different.
Speaker 1: It is a radio isotope. Radioisotopes are also known as
Speaker 1: radio nucleides, and these are isotopes of a particular atom
Speaker 1: that have an unstable nucleus. These isotopes undergo what we
Speaker 1: call nuclear decay, and in that process they release some
Speaker 1: excess energy in the form of stuff like gamma rays
Speaker 1: and or subatomic particles. Carbon fourteen undergoes what is called
Speaker 1: beta decay. So when it decays, one of the neutrons
Speaker 1: in the nucleus spontaneously changes into a proton, an electron,
Speaker 1: and an anti neutrino. The nucleus gives the boot to
Speaker 1: the electron and the anti neutrino, but the proton stays behind,
Speaker 1: which means the atom no longer is a carbon atom.
Speaker 1: Since again we mentioned that atoms depend upon the number
Speaker 1: of protons and the nucleus, so the carbon fourteen decays
Speaker 1: into nitrogen fourteen, and nitrogen fourteen has seven protons and
Speaker 1: seven neutrons. Also, by the way, one of the few
Speaker 1: stable elements that has both an odd number of protons
Speaker 1: and an odd number of neutrons uh, and nitrogen fourteen
Speaker 1: is stable. It makes up the vast majority of the
Speaker 1: nitrogen found naturally under Earth, More than of the nitrogen
Speaker 1: found on Earth is nitrogen fourteen. So radioactive decay occurs
Speaker 1: naturally within these isotopes, and it's a spontaneous occurrence. That's
Speaker 1: really important to remember. Carbon fourteen has a radioactive half
Speaker 1: life of about five thousand, seven hundred years. There's some
Speaker 1: confusion about what that means. I find in day to
Speaker 1: day conversations with people who haven't had science in a while.
Speaker 1: You guys who have recently had this in science class,
Speaker 1: you're rolling your eyes right now. But for adults who
Speaker 1: have not taken a science class in a long time,
Speaker 1: this might require some some refreshing. So, half life of
Speaker 1: five thousand, seven hundred years, what does that mean? It
Speaker 1: means if you have a given amount of carbon fourteen,
Speaker 1: after five thousand, seven hundred years or so, you'll have
Speaker 1: only half of that carbon fourteen remaining, the other half
Speaker 1: having undergone decay, radioactive decay and turning into nitrogen. Now,
Speaker 1: this doesn't mean that all the carbon four team will
Speaker 1: be gone after another five thousand, seven hundred years, nor
Speaker 1: doesn't mean that carbon fourteen has a full life of
Speaker 1: eleven thousand, four hundred years or anything like that. In fact,
Speaker 1: what it really means is that after another five thousand,
Speaker 1: seven hundred years, half of the remaining sample will have decayed,
Speaker 1: leaving you with about a quarter of what you started with.
Speaker 1: And another five thousand, seven hundred years if that means
Speaker 1: you be left with about an eighth of that sample,
Speaker 1: and so on. Carbon fourteen exists naturally on Earth in
Speaker 1: trace amounts. Before the nineteen forties, the carbon fourteen on
Speaker 1: Earth was created through a natural process. Once in a while,
Speaker 1: cosmic rays, these very high energy particles in outer space,
Speaker 1: would collide with an atom in our atmosphere or upper atmosphere,
Speaker 1: and this collision would end up emitting a high energy
Speaker 1: neutron that then could collide with nitrogen atoms that are
Speaker 1: also way up there in our atmosphere. Now, cosmic rays
Speaker 1: are high energy sub atomic particles. They originate outside of
Speaker 1: our solar system, usually are admitted by supernova of massive stars,
Speaker 1: and these sub atomic particles are primarily atomic nuclei and
Speaker 1: high energy protons. So this collision of the high energy
Speaker 1: neutron with the nitrogen forces a proton to leave the
Speaker 1: nucleus and the in fourteen changes to C fourteen. So,
Speaker 1: in other words, nitrogen fourteen turns to carbon fourteen. So
Speaker 1: instead of having seven protons and seven neutrons, the new
Speaker 1: atom has six protons and eight neutrons. The proton that
Speaker 1: was broken off from the nucleus zooms off with an electron,
Speaker 1: so you get one proton and one electron. That means
Speaker 1: you have an atom of hydrogen. So again what's happening
Speaker 1: is a high energy neutron collides with nitrogen fourteen, forces
Speaker 1: out a proton. The proton and an electron high tail
Speaker 1: it and honeymoon off as hydrogen and the incoming neutron
Speaker 1: joins the party, and now you've got carbon fourteen. So
Speaker 1: pre nineteen forties, carbon fourteen is rare because of two reasons.
Speaker 1: It undergoes radioactive decay, so over time it disappears, and
Speaker 1: it's produced by an event that's not super frequent, though
Speaker 1: it's also not uncommon, so it does happen regularly enough
Speaker 1: that carbon fourteen is replenished, but it's a very small
Speaker 1: overall percentage of the carbon here on Earth. We've got
Speaker 1: some more to say about carbon dating in just a second,
Speaker 1: but first let's take a quick break for our sponsor. Now,
Speaker 1: living things here on Earth absorb carbon through various means,
Speaker 1: and some of that carbon is carbon fourteen. So it
Speaker 1: maybe that you know, you eat a plant in that
Speaker 1: plant has some of the carbon fourteen in it. Now
Speaker 1: you have some of the carbon fourteen and you and
Speaker 1: if we know the ratio of carbon fourteen to the
Speaker 1: stable form of carbon twelve, we can look at materials
Speaker 1: and analyze them to see how the ratio of carbon
Speaker 1: fourteen to carbon twelve in the material stacks up to
Speaker 1: the standard ratio. With living things, this becomes a matter
Speaker 1: of looking at how much carbon fourteen is not there?
Speaker 1: All right, That's it's a little confusing. Let me explain. So,
Speaker 1: when a living thing is still alive, it accumulates carbon
Speaker 1: at about the same rate it loses carbon, so carbon
Speaker 1: cosmic rays produced this carbon fourteen frequently enough that the
Speaker 1: ratio between carbon fourteen and carbon twelve remains steady, So
Speaker 1: the percentage of carbon fourteen to carbon twelve is fairly standardized.
Speaker 1: But when a living thing stops being alive and turns
Speaker 1: into a not living anymore thing, it stops accumulating carbon,
Speaker 1: so it has the carbon that it has inside of
Speaker 1: it stays. That's it. You're not losing anymore. You're not
Speaker 1: gaining any more except for carbon fourteen because carbon fourteen
Speaker 1: undergoes radioactive decay, so over time, some of that carbon
Speaker 1: fourteen starts to convert to nitrogen. So that means if
Speaker 1: you can look at the remains of a living thing
Speaker 1: and detect the ratio of carbon fourteen to carbon twelve.
Speaker 1: You can get an idea of how long ago it
Speaker 1: was that it stopped taking in carbon, as in, how
Speaker 1: long ago was it that this lip, once living thing died.
Speaker 1: It gets a little more complicated than all that, but
Speaker 1: here's the basic rule. If we want to be really precise,
Speaker 1: here's the equation we use to determine the age of
Speaker 1: a sample of material. You have an equation where you
Speaker 1: take the natural logarithm of n F divided by n
Speaker 1: o uh that in turn is divided by negative point
Speaker 1: six nine three, and then you multiply it by t
Speaker 1: uh one half, so one half t the natural logarithm
Speaker 1: is a specific logarithm applied to this equation and other
Speaker 1: things as well. N F divided and oh actually refers
Speaker 1: to the percentage of carbon fourteen and the sample compared
Speaker 1: to the amount found in living stuff today at times
Speaker 1: one half is the half life of carbon, so that's
Speaker 1: five thousand, seven hundred years. So it was a lot
Speaker 1: easier to understand this if we take a specific example.
Speaker 1: So let's say you've got a sample of some sort
Speaker 1: of material and you have determined that there is five
Speaker 1: percent of the amount of carbon fourteen in that material
Speaker 1: compared to what you would find in something that is alive.
Speaker 1: Right now, so you take a sample of a living thing,
Speaker 1: and then you take the sample of the thing you're testing.
Speaker 1: You see that the thing you're testing only has five
Speaker 1: percent of the carbon fourteen you would find in living things.
Speaker 1: That means you would fill out the equation with the
Speaker 1: natural logarithm of point zero five divided by negative point
Speaker 1: six nine three, and you multiply that that result to
Speaker 1: with five thousand, seven hundred years. The natural lug ay
Speaker 1: them at point zero five, by the way, in case
Speaker 1: you don't want to whip out your calculator, is negative
Speaker 1: two point nine nine five seven three to two seven
Speaker 1: three five five. If you divide that by negative point
Speaker 1: six nine three, you get four point three to two
Speaker 1: eight four five. Don't dial that number. If you take
Speaker 1: that number, the four point three, etcetera, and you multiply
Speaker 1: that by five thousand, seven hundred years, you end up
Speaker 1: with twenty four thousand, six hundred forty point two years.
Speaker 1: I mean, the stuff you're looking at died somewhere around
Speaker 1: that time frame, give or take thirty two hundred years,
Speaker 1: So somewhere on twenty four thousand, six hundred forty years
Speaker 1: ago is when that thing no longer breathed or lived,
Speaker 1: or however you wanted to find it. By the way,
Speaker 1: this approach does have a limitation. Anything older than sixty
Speaker 1: thousand years is pretty much out of bounds. Carbon fourteen
Speaker 1: just isn't a reliable means of dating that sort of material,
Speaker 1: and we have to rely on other methods so and
Speaker 1: fourteen because of the decay once against two very small amounts,
Speaker 1: it's very difficult to narrow it down to a specific time,
Speaker 1: and if it's long enough, there won't be any carbon
Speaker 1: fourteen at all all the carbon fourteen will have decayed
Speaker 1: by then. You can't use carbon dating if there's no
Speaker 1: carbon fourteen left. So to actually test the carbon fourteen concentration,
Speaker 1: you first have to take the sample, uh whatever object
Speaker 1: it might be. You have to remove part of it,
Speaker 1: and typically you would apply some chemicals to the material,
Speaker 1: usually a very strong acid wash and a strong base wash.
Speaker 1: That's to remove all the contaminating materials that could end
Speaker 1: up giving you false readings on carbon fourteen. Then you
Speaker 1: would burn the sample within a glass container to capture
Speaker 1: the carbon dioxide that is emitted when you burn the material.
Speaker 1: And then you would analyze the carbon dioxide to find
Speaker 1: out the concentration of carbon fourteen. So you can see
Speaker 1: that this approach has a big drawback. It ends up
Speaker 1: damaging whatever it is you are attempting to date in
Speaker 1: the first place. And that's why some particularly high valued
Speaker 1: items go without being tested, because the perception is that
Speaker 1: even a small sample of that original piece would be
Speaker 1: too much damage to to uh make on this item.
Speaker 1: So certain items are considered very precious and there's a
Speaker 1: big resistance to using carbon dating because by definition, you're
Speaker 1: going to be damaging the material. Now, there's several lines
Speaker 1: of research they're exploring possible non destructive means of using
Speaker 1: radiocarbon dating. There's one that uses plasma oxidation and the
Speaker 1: use of non destructive washes to clean samples of those
Speaker 1: contaminating humic acids, which would lead to errors if they
Speaker 1: remain behind. But those are still largely in the testing
Speaker 1: phase and aren't the common means of using carbon dating. Also,
Speaker 1: keep in mind that we use this method to estimate
Speaker 1: the date of things made from organic materials, like the
Speaker 1: Dead Sea scrolls, but this estimation is based upon when
Speaker 1: the materials were harvested So, in other words, whenever the
Speaker 1: living thing that the materials came from stopped being alive,
Speaker 1: it doesn't tell us the date of when the artifact
Speaker 1: was actually produced. So it's possible that you could come
Speaker 1: across an artifact like a scroll, and you use carbon
Speaker 1: dating on it and find out that the scroll material
Speaker 1: is two thousand years old, meaning two thousand years ago
Speaker 1: whatever the scroll was made out of stopped living, But
Speaker 1: it doesn't tell you about the contents written in the scroll.
Speaker 1: It's possible that the contents were added to the scroll
Speaker 1: much after the living thing stopped being alive. Still, it's
Speaker 1: a pretty good bet that the two are within the
Speaker 1: same neighborhood of time, rather than someone held onto blank
Speaker 1: scrolls for a few centuries before finally jotting something down.
Speaker 1: All right, it's all this is cool, But how did
Speaker 1: we even figure out radio Carbon dating would be a
Speaker 1: possible way of figuring out how old something is. Well,
Speaker 1: some early discoveries were made in the nineteen thirties at
Speaker 1: the Lawrence Radiation Laboratory in Berkeley, and you probably remember
Speaker 1: that if you've been listening to tech stuff. It factored
Speaker 1: heavily into the discussion I had with Ben Boland about
Speaker 1: the Manhattan Project. So Franz Curry, an American physicist, observed
Speaker 1: something really interesting when he irradiated a cloud of air
Speaker 1: in a cloud chamber. He used neutrons to UH to
Speaker 1: irradiate that cloud, and he saw proton recoil tracks that
Speaker 1: indicated something was losing protons. So he concluded that the
Speaker 1: neutrons that he was using were colliding with nitrogen fourteen
Speaker 1: and producing what was believed to be a form of
Speaker 1: carbon as a result, with hydrogen being the other product
Speaker 1: of this collision. His work was further explored by physicists
Speaker 1: like Tom W. Bonner, W. M. Brubaker, W. J. Burcham,
Speaker 1: and Maurice gold Hauber. Now collectively, this laid the foundation
Speaker 1: for the simple equation of a high energy neutron plus
Speaker 1: nitrogen fourteen produces one hydrogen atom and one carbon fourteen atom.
Speaker 1: Then you had Narrico Fermi. We talked about him in
Speaker 1: the Manhattan Project, and his work showed that the cross
Speaker 1: section of a nitrogen fourteen atom was much larger than
Speaker 1: other materials, and that suggested that neutron and nitrogen collisions
Speaker 1: might happen fairly regularly in nature as long as there
Speaker 1: were a supply of high energy neutrons. All right, we
Speaker 1: got a little bit more about carbon dating, and then
Speaker 1: what's It's back to reality for me? I guess so
Speaker 1: Sage Korff, who was a physicist who was born in
Speaker 1: Finland and whose family immigrated to the United States in
Speaker 1: the early twentieth century, he discovered the phenomenon that cosmic
Speaker 1: rays interact with atoms and produce high energy neutrons in
Speaker 1: the upper atmosphere. So Pharem's prediction and course observation, we're
Speaker 1: starting to kind of coalesce here. The observations convinced scientists
Speaker 1: that the neutrons themselves were not cosmic rays, because the
Speaker 1: neutrons had a lifespan of just eighteen minutes, and therefore
Speaker 1: a neutron wouldn't be able to survive the long trip
Speaker 1: through space. They must have been something else first, so
Speaker 1: they said the neutrons had to be a byproduct of
Speaker 1: another interaction. A cosmic ray must be interacting with something
Speaker 1: in the atmosphere. That interaction caused this high energy neutron
Speaker 1: to be emitted, and Quarter hypothesized that these neutrons could
Speaker 1: then interact with nitrogen fourteen to produce carbon fourteen in
Speaker 1: the upper atmosphere. Now, it was Willard F. Libby who
Speaker 1: came up with the idea that since carbon fourteen is
Speaker 1: generated at a steady rate due to cosmic ray interactions
Speaker 1: in our atmosphere, you should be able to use it
Speaker 1: to measure how long something has been dead. Libby would
Speaker 1: measure the value of carbon fourteen's half life at five thousand,
Speaker 1: five hundred sixty eight years, give or take thirty years,
Speaker 1: which became known as the Libby half life. And Libby
Speaker 1: himself would be awarded the Nobel Prize in nineteen sixty
Speaker 1: for his work in radiocarbon dating. All right, so that's
Speaker 1: the history of radiocarbon dating and generally how radiocarbon dating works.
Speaker 1: So why is it in trouble or what could possibly
Speaker 1: be causing confusion with radiocarbon dating. Well, there are two
Speaker 1: big things we need to talk about, and one was
Speaker 1: one that I've alluded to a couple of times. I
Speaker 1: mentioned that, you know, pre nineteen forties, you had a
Speaker 1: certain level of carbon fourteen that was pretty standard, but
Speaker 1: the nuclear age really messed things up for us. They
Speaker 1: made carbon fourteen dating a bit tricky. Starting in the
Speaker 1: nineteen forties, we began testing nuclear bombs. Now, these bombs
Speaker 1: released a lot of energy upon exploding, partly in the
Speaker 1: form of high energy neutrons. You could probably see where
Speaker 1: this is going. Some of those high energy neutrons ended
Speaker 1: up interacting with night jan fourteen atoms, which meant that
Speaker 1: it produced carbon fourteen atoms as a result. So the
Speaker 1: concentration of carbon fourteen increased in the wake of nuclear
Speaker 1: bomb testing. So anything that died after the nineteen forties
Speaker 1: actually has a higher concentration of carbon fourteen than the
Speaker 1: stuff that died before the nineteen forties did even at
Speaker 1: the time of death. According to Professor Nalini nod Karnie
Speaker 1: of the Evergreen State College, the nineteen fifties saw a
Speaker 1: one hundred percent spike in carbon fourteen coming into the atmosphere.
Speaker 1: In nineteen sixty three, the United States and Russia agreed
Speaker 1: to stop above ground nuclear testing, and the levels of
Speaker 1: carbon fourteen in the atmosphere gradually dropped down to their
Speaker 1: normal levels. But that means there's a blip in the
Speaker 1: carbon fourteen radar between the nineteen forties and nineteen sixty three.
Speaker 1: So if you put yourself in the shoes of a
Speaker 1: future archaeologist. Radio carbon dating becomes unreliable because the levels
Speaker 1: of carbon fourteen could be decept tip. If the thing
Speaker 1: you're measuring died during the era of nuclear testing, it
Speaker 1: might appear to be younger than you thought because there's
Speaker 1: a higher concentration of carbon fourteen in its sample than
Speaker 1: you otherwise would have expected. So it may seem that
Speaker 1: something died in twenty fifteen as opposed to nineteen sixty three.
Speaker 1: That's just an example. Now to the article that prompted
Speaker 1: this episode in the first place, that's a different case.
Speaker 1: Researchers published a study in the Proceedings of the National
Speaker 1: Academy of Sciences about how the use of fossil fuels
Speaker 1: is further making radiocarbon dating less reliable, and this time
Speaker 1: it's not an excess of carbon fourteen. It's actually the
Speaker 1: opposite problem. Fossil fuels have no carbon fourteen in them
Speaker 1: because they are fossil fuels. This is billions of years old,
Speaker 1: so they're far too old for any carbon fourteen to remain.
Speaker 1: Remember that carbon fourteen is decaying over time and turning
Speaker 1: into nitrogen, so eventually all of those carbon fourteen atoms decay.
Speaker 1: So burning a fossil fuel create releases carbon dioxide, and
Speaker 1: the carbon in that CEO two has no carbon fourteen
Speaker 1: and it's all carbon twolve carbon thirteen. So the more
Speaker 1: fossil fuels we burn, the more we dilute the concentration
Speaker 1: of carbon fourteen that's in the atmosphere. So stuff from
Speaker 1: the nuclear age tends to look younger than it really
Speaker 1: is because of the higher concentration of carbon fourteen. Stuff
Speaker 1: from the later ages of fossil fuel use will look
Speaker 1: older than they really are because carbon fourteen has been diluted. So,
Speaker 1: according to the study, fresh organic material in twenty fifty
Speaker 1: would contain the same amount of carbon fourteen relative to
Speaker 1: carbon twelve as something dating from ten fifty. So you
Speaker 1: have a thousand years of doubt in any radio carbon
Speaker 1: dated samples. You would look at the two samples if
Speaker 1: you if all you had were miniscule samples of two
Speaker 1: things and one of them was a T shirt that
Speaker 1: was made in and another was a piece of cloth
Speaker 1: that dated from ten fifty, and you did radiocarbon dating,
Speaker 1: you'd get the same result. This is not good if
Speaker 1: you are trying to figure out how old something is
Speaker 1: Heather Graven, who authored the study on fossil fuel emissions
Speaker 1: and the effect on radiocarbon dating, says that if we
Speaker 1: were to reduce carbon dioxide emissions drastically in the very
Speaker 1: near future, the effect on future radiocarbon dating would be
Speaker 1: equivalent to inserting a one year error on top of
Speaker 1: any estimation. If we don't drastically reduce emissions, that error
Speaker 1: range will continue to grow over time. One thing that
Speaker 1: the concentration of carbon fourteen tells us is how much
Speaker 1: carbon dioxide in the atmosphere comes from the burning of
Speaker 1: fossil fuels. So as we see the concentration decrease, we
Speaker 1: know that's because proportionally more carbon twelve is being released
Speaker 1: into the atmosphere, diluting the already tiny concentration of carbon fourteen.
Speaker 1: So that's useful for scientists who are studying climate change
Speaker 1: and pollution. That's not exactly a happy story, is it.
Speaker 1: So what are our options if carbon dating becomes unreliable, Well,
Speaker 1: that depends on what you're trying to analyze. If you're
Speaker 1: looking at inorganic stuff like rocks, you don't need to
Speaker 1: use carbon fourteen in the first place. That would be
Speaker 1: pretty much useless. You would use something else like potassium
Speaker 1: argon dating, which is useful to estimate the age of
Speaker 1: rocks that are a hundred thousand years old or younger.
Speaker 1: And if that's not a big enough range, you can
Speaker 1: actually use uranium lead dating, and that will let you
Speaker 1: estimate rocks between one point four and five million years old.
Speaker 1: There's a lot of different options if you're trying to
Speaker 1: date stuff. When it comes to organic materials, however, it's
Speaker 1: a lot more tricky. Radio carbon was a great tool,
Speaker 1: but if it becomes unreliable, we're gonna have to use
Speaker 1: other methods like contextual clues and other items that are
Speaker 1: helping us connect things to dates. So this is a
Speaker 1: big problem. I guess you could argue that's a big
Speaker 1: problem for future generations and perhaps the records we leave
Speaker 1: behind now are so uh so complete, they're so voluminous,
Speaker 1: I guess is the best word. That future generations will
Speaker 1: likely have more than enough material to determine when something
Speaker 1: originated from our time versus earlier times. But the point
Speaker 1: being that the way we're interacting with our world is changing.
Speaker 1: This fundamental ratio of carbon fourteen to carbon twelve, and
Speaker 1: that means that a really brilliant means of determining how
Speaker 1: old something is is not really going to be an
Speaker 1: accurate measure for very much longer. So it's kind of
Speaker 1: a bummer. Obviously for things that are much much much older.
Speaker 1: UH will at least in the short term, not be
Speaker 1: that big of a deal, especially if we can relate
Speaker 1: it to other items that we we already know the
Speaker 1: age of those items. It won't be as destructive as
Speaker 1: saying we can never use radio carbon dating again. We
Speaker 1: just have to keep that changing ratio of carbon fourteen
Speaker 1: to carbon twelve in mind so that we make sure
Speaker 1: we're making accurate measurements. I hope you enjoyed that classic
Speaker 1: episode of tech Stuff. Again, my apologies. I've got a
Speaker 1: lot of things I wish I could have talked about,
Speaker 1: like the fact that there's now a patent for a
Speaker 1: retractable lightsaber blade thing. I really want to talk more
Speaker 1: about that, so maybe next week. But in the meantime,
Speaker 1: if you have any suggestions for topics I should tackle
Speaker 1: on tech Stuff, let me know. Send me a message
Speaker 1: on Twitter. The handle is text stuff h s W.
Speaker 1: I'll talk to you again really soon. Yeah. Text stuff
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