Radiometric Dating: Carbon-14 and Uranium-238

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  • Опубліковано 16 жов 2024
  • When you read about the ages of certain ancient artifacts, or even the age of the earth itself, how do we know such numbers? How can we know that a fossil is precisely 250 million years old? The key technique here is radiometric dating. This is where we use our understanding of radioactive decay to measure the age of an object. How does this work, you ask? Watch and find out!
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КОМЕНТАРІ • 321

  • @sirish6444
    @sirish6444 3 роки тому +15

    Thank you so much!!! No one explains like you!!!! I understood all the concepts clearly!!! Thanks for making my life easier

  • @iankingston480
    @iankingston480 3 роки тому +28

    Thank you Professor Dave. I just started learning about radiometric dating.
    I took 1 course in geology. It was boring but now that I am older I have a greater appreciation for geology.
    I am also using this dating method to prove the earth is older than 6000 years
    old.
    I know there also other scientific methods to prove earth is older than 6000 years old.
    You made radiometric dating easier to understand.

    • @Just_Moh_it
      @Just_Moh_it 2 роки тому +4

      Any follow-ups on your objective?

    • @CrimsonChin1013
      @CrimsonChin1013 11 місяців тому

      @iankingston480 I think you’ll find that C14 dating is wrong and cannot be accepted do to wide speculation

    • @barco111
      @barco111 11 місяців тому

      ​@@CrimsonChin1013creationist nonsense

    • @CrimsonChin1013
      @CrimsonChin1013 11 місяців тому

      @@barco111 Literal fact. Explain how C14 is found in diamonds hot shot

    • @barco111
      @barco111 11 місяців тому

      @@CrimsonChin1013 you can't carbon date diamonds...

  • @aniawo5119
    @aniawo5119 5 років тому +99

    Dating with Professor Dave? - with pleasure❣😉

  • @Mac_TO20
    @Mac_TO20 3 роки тому +9

    Your explanations are so simplified and informative!

  • @aradarbel4579
    @aradarbel4579 5 років тому +3

    your channel deserves way more than that

  • @hansweichselbaum2534
    @hansweichselbaum2534 5 років тому +12

    Great video and great channel! Thank you for sharing your expert knowledge and your knack for teaching science. Just at the right level and the optimal length for the general public.

  • @davidjohansson7646
    @davidjohansson7646 2 роки тому +2

    I left you a comment recent on thermal isotopic mass spectrometry. I found this video enlightening on the question so thank you!

  • @Markle2k
    @Markle2k 5 років тому +15

    This is getting into the weeds (pun intended) a bit, but it's not quite the same C14/C12 ratio as the atmosphere. Photosynthesis prefers lighter isotopes of carbon over heavier ones due to diffusion separation and chemical preferences of enzymes. And different photo carbon-fixation processes also differ. CAM plants show slightly more of an effect than C4 plants, and C4 significantly less than C3. The mechanism that creates carbonate shells does not have a preference, however. This distinction gets important for other uses beyond carbon dating, not the focus of this particular video, but it matters for dating if an animal eats trees, grasses, or marine life.

    • @herfio
      @herfio 3 роки тому

      You r smart

  • @burnmyuncle141
    @burnmyuncle141 5 років тому +5

    Pls put link to the previous vid makes it so much more convinient

  • @matthamilton72
    @matthamilton72 23 дні тому

    A suggestion. It would be helpful to provide a link to the radioactivity video in the description field so one can easily go back and learn about it prior to this video.

  • @KevinChantal
    @KevinChantal 3 роки тому +7

    So I hope I understood it correctly
    If we know the ratio is 99% C12 and 1% C14 than they measure the amount of C12 for example 594 atoms. Through the ratio they now know that there were 6 C14 atoms at the beginning. So if the sample has 3 C14 atoms then we can say one half life is over and the sample is 5730 years old. Did I do something wrong or is my understanding of this process correct?

  • @aaronh.8230
    @aaronh.8230 5 років тому +61

    Lol - someone downvoted the vid. It’s like screaming “I want to remain ignorant and not understand reality”. Excellent vid - clear and concise.

    • @JimmyTang721
      @JimmyTang721 4 роки тому +3

      @@georgebond7777 "C-14 will be at equilibrium if the production of C-14 is constant (or changes very slowly compared to the decay rate) and if you wait long enough -- a few half-lives will get you pretty close. The amount approaches equilibrium because the amount that decays is proportional to the amount that is present; the equilibrium value is just the amount of C-14 for which the amount that decays equals the amount that is being produced (which we've assumed to be constant).
      In the real world, the rate of production is not constant -- but it also doesn't vary wildly. Since it doesn't vary very much, uncorrected age estimates from C-14 will at least give you a ball-park figure for the age, and you can get a more accurate value by estimating the production rate in the past by comparison with events of known age (mostly overlapping sets of tree rings). The exception to "doesn't vary wildly" is during the era of above-ground nuclear testing, which would give future archeologists fits if they try to date artifacts from the current era."

    • @JimmyTang721
      @JimmyTang721 4 роки тому +2

      @@georgebond7777 That has merit as well, but that's also why Carbon 13 is used as a reference to check, since it is stable. It serves as a signal to tell if something is askew with the information received from carbon 14 dating.

    • @JimmyTang721
      @JimmyTang721 4 роки тому +2

      @@georgebond7777 "Yes, C-14 is forming today faster than it's decaying. However, the amount of C-14 has not been rising steadily; instead, it has fluctuated up and down over the past ten thousand years. How do we know this? From radiocarbon dates taken from bristlecone pines.
      There are two ways of dating wood from bristlecone pines: one can count rings or one can radiocarbon-date the wood. Since the tree ring counts have reliably dated some specimens of wood all the way back to 6200 BC, one can check out the C-14 dates against the tree-ring-count dates. Admittedly, this old wood comes from trees that have been dead for hundreds of years, but you don't have to have an 8,200-year-old bristlecone pine tree alive today to validly determine that sort of date. It is easy to correlate the inner rings of a younger living tree with the outer rings of an older dead tree. The correlation is possible because, in the Southwest region of the United States, the widths of tree rings vary from year to year with the rainfall, and trees all over the Southwest have the same pattern of variations.
      When experts compare the tree-ring dates with the C-14 dates, they find that radiocarbon ages before 1000 BC are really too young-not too old as Cook maintains. For example, pieces of wood that date at about 6200 BC by tree-ring counts date at only 5400 BC by regular C-14 dating and 3900 BC by Cook's creationist revision of C-14 dating (as we see in the article, "Dating, Relative and Absolute," in the Encyclopaedia Britannica). So, despite creationist claims, C-14 before three thousand years ago was decaying faster than it was being formed and C-14 dating errs on the side of making objects from before 1000 BC look too young, not too old." - ncse.ngo/answers-creationist-attacks-carbon-14-dating

    • @JimmyTang721
      @JimmyTang721 4 роки тому +3

      @@georgebond7777 That devolved quickly. That's a reflective mirror, it appears that you are projecting your thoughts on to me. You could say the same of yourself in that you only read things that supports your own perspective.

    • @JC-yb3zb
      @JC-yb3zb 4 роки тому

      @@georgebond7777 The number of references that support the theory dwarf those that contradict it.
      Do I win now?

  • @BiboyBiboy-i7i
    @BiboyBiboy-i7i 5 місяців тому +1

    Asking permission to use your video/Content for my students. Thank you professor

  • @parasuramang1860
    @parasuramang1860 5 років тому +6

    Keep making more videos.....
    Provide resource links like books, webs, apps please...

  • @argossiiner1746
    @argossiiner1746 7 місяців тому

    You saved my physics assignment, thank you so much!!!❤️

  • @quicksilver3687
    @quicksilver3687 3 роки тому +6

    Nice vid, it reminded me of why my Dad left. Keep it up!!!

  • @cv60ac3
    @cv60ac3 Рік тому

    Thank you for the video. I am having difficulty with the years, though, as I read a paper that stated it to be 5,370 years plus or minus 200 years. Journal of Research of the National Bureau of Standards, Vol. 46, No. 4, April 1951, Research Paper 2203. I am not disputing the years you use, but I don't know when it changed. Thank you and keep doing these wonderful teaching videos.

  • @danieltedrow3169
    @danieltedrow3169 2 роки тому +5

    In the one example at the end, you got a date from the uranium, and then from the lead. But if uranium turns into lead, wouldn't that scew the data. I'm a little confused about it.

    • @wds8369
      @wds8369 2 місяці тому

      I thought the same, doesn’t uranium decay into lead? How are they separate studies then? Aren’t they watching the half life of uranium before it decays into lead? That’s one study not two

  • @pixelprincess9
    @pixelprincess9 3 роки тому +8

    How do we know that the carbon 14 ratio in the atmosphere (and thereby trees) were the same 50,000 years ago as it is today?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +14

      Because solar activity doesn't change appreciably over short spans of time, and we have geological data to tell us the composition of the atmosphere up to millions of years ago.

    • @HarrisTheHypnotist
      @HarrisTheHypnotist 3 роки тому +1

      @@ProfessorDaveExplains which kind of data?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +7

      Mainly ice cores.

    • @HarrisTheHypnotist
      @HarrisTheHypnotist 3 роки тому +2

      @@ProfessorDaveExplains
      How would ice cores influence the composition of the atmosphere for example, 15,000 years ago?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +7

      They don't influence it. They record it.

  • @antonteodor6305
    @antonteodor6305 Рік тому +3

    Hello, and thank you for your clear explanation.
    There is yet something that I don't quite understand about dating.
    Let's say, simplifiying, that in an object we have element isotope A, that decays into element isotope B with a known hálf-life. Then, by looking at the proportions of A and B in the object, we can tell its age.
    But how do we know that there wasn't some B in the object at the beginning, that stayed the same to the present, and adds to the total amount of B, making the object look older?

    • @gurt_right1148
      @gurt_right1148 Рік тому +1

      I only understand the basics of this, but I know Uranium-Lead dating is usually applied to zircon. Zircon is particularly important for this method since it allows uranium-238 in during the crystallization process while letting in virtually no lead-206. Since uranium-238 decays into lead-206, the only lead present in the zircon would have to be the result of radioactive decay. Uranium-238 has a half-life of about 4.5 billion years, so it's very useful in measuring the age of the earth. I can't speak to other radiometric dating methods though, I'm just a layman.

    • @antonteodor6305
      @antonteodor6305 Рік тому +1

      @@gurt_right1148 I read similar things, indeed. Basically we use chemical and physical properties of the substances to prove that impurities could not be there.

    • @CrimsonChin1013
      @CrimsonChin1013 11 місяців тому

      Exactly, and we have no way of knowing how much Carbon12/14 was in the atmosphere or being produced at the time. It is all speculation

  • @user-he4ef9br7z
    @user-he4ef9br7z 4 роки тому +7

    i need some help here , i understand carbon dating but am a bit confused with uranium dating .
    How do we know the original ratio of uranium and lead in a rock ?
    What do we mean by "age of a rock" , for example in carbon dating we are measuring the how long ago did the organism die , in case of uranium dating in rocks , what event are we tracing back to ?
    While dating the age of the earth , how does the age of a meteorite correspond with the age of the Earth , they are meteors and existed in space before they came here , and the uranium could have decayed while it was in space before the earth was formed ?
    also related to carbon dating ,
    How do we know that the ratio of C12:C14 is stable over time?
    How do we carbon date artifacts that are not made from living things eg: clay pots?
    Any scientific answers appreciated , do not give me creationist or conspiracy theory bs.

    • @user-he4ef9br7z
      @user-he4ef9br7z 4 роки тому +3

      ok i know the answers to the first 2 questions now .

    • @loggedin5359
      @loggedin5359 4 роки тому +1

      @Professor Dave Explains

    • @preethins2973
      @preethins2973 3 роки тому +1

      In uranium lead dating , we take zircon crystals . While crystallising zircon incorporates uranium but rejects lead due he structure of its crystal lattice. Thus initial lead : uranium ration is 0:x . Thus with the number of lead and uranium the age can be found easily

    • @jgone4856
      @jgone4856 3 роки тому +1

      I'd like to know these too. I saw a video where a "scientist" said uranium could sometimes be washed away?

  • @HT-rq5pi
    @HT-rq5pi Рік тому +1

    When explaining carbon-14 dating, Dave said that the C-14 only starts decaying after the organism dies because at this point there is no longer a continuous exchange with the environment. What is the equivalent step for dating rocks? At what point is there no longer a continuous exchange of Uranium between the rock and the environment? Why does this exchange stop when the rock is formed, but able to take place when it is in its molten form?

    • @gurt_right1148
      @gurt_right1148 Рік тому +1

      I don't know all of the specifics, but you may want to look into "closure temperature". It seems that molten rocks are capable of diffusing radioactive isotopes into their environment, but the process is halted once the rock cools to a particular temperature (the closure temperature varies by material). So when taking measurements of a system, the "start date" is the point at which the system reached its closure temperature. This would be analogous to an organism dying since there is no longer a continuous exchange with the surrounding environment.

    • @wds8369
      @wds8369 2 місяці тому

      @@gurt_right1148So how do we know when the rock got to its closure temperature?

    • @gurt_right1148
      @gurt_right1148 2 місяці тому

      @@wds8369 Radiometric dating compares the ratio of a particular radioactive isotope to its decay product. If you look up radioactive decay chains, you can see how a given isotope decays into another until it reaches a stable state (where it can no longer emit alpha or beta particles). Although the time it takes for a single atom to decay is probabilistic, when taking the measurements for an entire closed system, the resulting average rate of decay can be reliably measured. The time it takes for half the atoms of a given quantity of a subtance to decay is known as its half-life, and this (in conjunction with the ratio of the original isotope to its decay products) is what is used when dating a rock sample. Radiometric dating of minerals begins at the point the closure temperature was reached, since it is the point at which the system became closed and nuclear isotopes and their decay products could not diffuse into the surrounding environment. In other words, the only thing affecting the ratio of the radioactive isotopes to their decay products within the system is the process of radioactive decay (which is constant and consistent for a given substance).

  • @mkin5868
    @mkin5868 4 роки тому +2

    Very good explanation.

  • @nainaramola426
    @nainaramola426 6 місяців тому

    He is such a great teacher❤

  • @TheDannielboy
    @TheDannielboy 2 роки тому +1

    Thanks for the video and the chanel!
    I have a question.
    So if I understand correctly, we are trying to date the age of the earth, by looking at heavy elements, and since we know the half-life, we can trace back how long ago the elements ''started'' to decay. If that is the mechanism, than why do we say that the earth is approximatly 4.6 B yo? Wouldn't it be more accurate to say that the elements that came together to form the earth are 4.6B yo? Maybe there's something that I'm missing.. But since the heavy elements are normally a product of a neutron star collision or some other grand event, would it be better to say that the elements we can date here at the surface of the earth are about 4.6 B yo and the earth is at least younger then that?
    I understand that if it than took 50 millions years for the solar system to take shape following the event it's basically the same time scale wise, but what if it took much longer like 1 B years, how would we know?
    Thanks

  • @100rubmighty
    @100rubmighty Рік тому

    Q: In the atmosphere we have N2. Would this for C2 molecule? But then this molecule will have 2 extra electrons, no? So C2-? How does it form CO2? Where do the electrons go? Does the proton and electron form a H?

  • @enclaus
    @enclaus Рік тому

    Thank you smart Nick Miller

  • @malaikabaig4929
    @malaikabaig4929 4 роки тому +2

    Thank you!!! Loved to examples and proof for how accurate the dating process is.

  • @drlouiscardinal752
    @drlouiscardinal752 2 місяці тому

    Well explained….a lot of explanations of radioactive decay dating do NOT refer to the starting point ratio. Without the starting point ratio no dating is possible.

  • @MrAdryan1603
    @MrAdryan1603 3 роки тому

    A little late I guess, but Subscribed. This channel is so rad. Cheers!

  • @bigbanggaming2023
    @bigbanggaming2023 Місяць тому

    When did the uranium start to decay, right after supernova which created it, u are determining the age of the uranium from the day it was created, how is that age of the earth???

  • @prakashvenglat2596
    @prakashvenglat2596 Рік тому

    Thank you. You are a master teacher!

  • @AHSears
    @AHSears 5 років тому +2

    Which is used more often for dating rocks, though, Potassium or Uranium? Or, does it depend on the scenario?
    Love your vids, by the way.

    • @gwynethjones3503
      @gwynethjones3503 4 роки тому +2

      Depends on the scenario. :)

    • @malinm1615
      @malinm1615 2 роки тому

      Under the right conditions, you can also use Luminescence Dating. It relies on different concepts though

  • @PavelBuravtsov
    @PavelBuravtsov 3 місяці тому

    Thank you, Professor Dave. However, can anybody help, please? I understand that we compare C-14 and C-12 ratio from an old plant to C-12 to C-14 ratio in a new plant. So, we can compare the ratios and figure out how many half-lives already passed in the old plant. However, when we talk about rocks, how do we know which rock is a "new" one?
    Thank you in advance to whoever you are!)

  • @kacperzegado9155
    @kacperzegado9155 2 роки тому

    I have a question. You said that trees while alive have the same ratio of C-14 and C-12. I heard that the ratio of C-12 to C-13 in trees is higher than that in the atmosphere, since trees intake CO2 with C-12 atoms selectively over C-13. This is why f.e. the ratio of C-12 to C-13 in the fossil fuels is different from C in the atmosphere.
    Are you sure the same isn't true about C-14? That is: do trees "prefer" C-12 over C-14, which would change the ratio C-12/C-14 in them comparing it to the atmospheric ratio, or not?

  • @crocopie
    @crocopie 5 років тому +5

    Love the hair!

  • @nineofnine
    @nineofnine 8 місяців тому

    Every theist should have to watch this...they intentionally ignore scientific proofs like this excellent explanation.
    Thank you so much

    • @jmt8029
      @jmt8029 6 місяців тому +1

      As a theist I have no problem watching this. It doesn’t say anything about creation or the existence of God.

  • @shaguftanasreen5019
    @shaguftanasreen5019 10 місяців тому

    Job well done sir 👍👍

  • @CaseyFinSF
    @CaseyFinSF 5 років тому +6

    Hey Dave, that was a good video for 2 reasons.
    1) it was informative and easy to understand
    2) Your new hair cut makes you look presentable and professional, and not like the geeky dweeb with long hair and bad skin in your base line intro.
    (this is a blatant hint to change your goody info)

    • @danielauto3767
      @danielauto3767 5 років тому +4

      I like the intro. Geek dweebs are often good professionals.

    • @CaseyFinSF
      @CaseyFinSF 5 років тому +1

      @@danielauto3767 I agree with you on that. But I think he has matured enough to have a new intro with his new polished look out front to bring in even more than he gets now.
      I respect him either way. And was only meaning to give him some constructive criticism, that's all.
      You Rock Dave...!👉👍🏻👍🏻👈😉😎

  • @hdthor
    @hdthor 2 роки тому +1

    This makes sense for plants and herbivores as well as carnivores that eat herbivores. But for creatures that are very far up on the trophic levels, or for creatures that are scavengers for ancient necrotic meals, won’t it create a large lag between CO2 absorption in plants to a high trophic level carnivore?
    Terrestrial trophic levels aren’t very deep, but marine trophic levels can be very deep. Additionally, marine trophic levels also include extremophiles near volcanic vents, or are consuming ancient necrotic tissue sunken to the ocean floor. And their lag will permeate into the entire food cycle of higher trophic levels. How large is the lag for atmospheric carbon permeating marine life, including the fish that may be in the diet of human settlements?
    Most fish are many trophic levels away from the algae that absorbs atmospheric CO2. And extremophile may be absorbing dissolved CO2 in the ocean. What is the concentration of C14 in deep ocean life, considering many of the dissolved gasses may have been synthesized from underwater volcanic activity?

    • @kenshinsan12
      @kenshinsan12 2 роки тому

      Very complex and interesting question! Sadly no one answered.

  • @Nails077
    @Nails077 5 років тому +2

    What is the next step if you get two measurements that are vastly different?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  5 років тому +7

      Oh I dunno, try a third?

    • @Nails077
      @Nails077 5 років тому +3

      @@ProfessorDaveExplains so simple and makes sense. I like it. The third measurement should match one of the previous two and the date with no match should be the false one. I'm sure it would be a whole other video but I'm curious about how some of the false results occur. I imagine the isotope you measure having gotten replenished at some point somehow? Curious about how that might happen and if you can tell that it has happened in a way other than by the date being off.
      Sorry if my questions are silly. This is a topic I don't know that much about but recently discovered that I find fascinating.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  5 років тому +9

      Who knows, sample contamination, experimental error, plenty of ways to screw things up in science.

  • @herfio
    @herfio 3 роки тому

    i love his new videos

  • @ticktock2000x
    @ticktock2000x 4 роки тому

    I actually just sent an email to the Good Professor regarding something similar to this topic. I hope he gets around to reading it as I'm curious about the consistency of what we believe to be constants about the universe. I love that this is an easily accessible video on youtube, regardless. :)

  • @sms70968
    @sms70968 2 роки тому

    Well explained

  • @stiddleficks4044
    @stiddleficks4044 5 років тому +3

    found out one of my co-workers thinks that dinosaurs never existed and the fossils that we have are fake. i really want to share this video with him, but i don't think he's even open to the possibility of being wrong.

  • @Uramledtube
    @Uramledtube 11 місяців тому

    Thanks!

  • @chopppacalamari
    @chopppacalamari 4 роки тому +3

    Thanks Dave. Why is there carbon 14 in coal and diamonds. Doesn’t this mean they are only thousands of years and not millions?

    • @loggedin5359
      @loggedin5359 4 роки тому

      @Professor Dave Explains

    • @jesushad12gayfriendwhoallb50
      @jesushad12gayfriendwhoallb50 3 роки тому

      C14 can form in coal from the radiation given off by radioactive decay.

    • @antiksur8883
      @antiksur8883 2 роки тому

      There isn't or is negligible. This lie that creationists have spread is bullshit. These incorrect readings only happen due to contamination, either before excavation or in the measuring instrument.

  • @ruhfuhquh
    @ruhfuhquh 2 роки тому +2

    it's valentines day, and the only dating that's going on in my life right now is this

  • @AbrarManzoor
    @AbrarManzoor 3 роки тому

    What is the falsification test of radioactive dating? How can one falsify the ages provided by radiometric dating because i have heard that radiometric dating cannot date the items that we see forming during ones lifetime or more than that how can then we know it is accurate in case of the deep past?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +4

      Why would you need to date something that you observed in formation? That doesn't make any sense. And we verify accuracy by cross-referencing dating results with different nuclides.

  • @shriyanshpandey112
    @shriyanshpandey112 3 роки тому

    I understood the living organism part that we can determine when that organism died.
    But what do we mean when we say a rock is 4bya, when did the rock had a constant supply of the radioactive isotope and when the supply stopped.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +3

      It doesn't have a constant supply, that's why we can age it.

    • @shriyanshpandey112
      @shriyanshpandey112 3 роки тому +1

      @@ProfessorDaveExplains A living organism has constant supply of C¹⁴ so the ratios between C¹⁴ to C¹² remains same. After it dies the ratios starts changing cause C¹² remains and C¹⁴ starts to decay so we can calculate how long the organism has been dead.
      But for rocks they never had a constant supply of their radioactive isotope and they dont die, so I don't understand what are we measuring when analyzing how much of the radioactive isotope has decayed.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +5

      It's about what's locked into the rock when it forms from magma.

    • @shriyanshpandey112
      @shriyanshpandey112 3 роки тому +1

      @@ProfessorDaveExplains
      I didn't considered that.
      Thank you

  • @crystalliu9056
    @crystalliu9056 7 місяців тому

    On the wooden jar example, how do people know the ratio of the original carbon 14 amount?

  • @mar-ww3if
    @mar-ww3if Рік тому

    Can the rate of decay ever be changed or is it always constant no matter what?

    • @bass-dc9175
      @bass-dc9175 Рік тому +1

      The rate of decay is constant. Half of the fundamental laws of physics (Strong and weak force) would need to change for decayrates to vary.

  • @droidzilla22
    @droidzilla22 2 роки тому +1

    I have to wonder about the variable involving change in levels of atmospheric carbon 14 through different eras as climate changes? Is there a possibility of that causing different results?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  2 роки тому +1

      But we can use ice cores to know the atmospheric composition way in the past.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  2 роки тому +2

      Because they produce an annual pattern due to seasonal changes. They are like tree rings.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  2 роки тому

      @@Hellohellohello803 Yes. It's seasonal. Again, like tree rings.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  2 роки тому +1

      @@Hellohellohello803 I really hope you're joking.

  • @michaelgreco3648
    @michaelgreco3648 4 роки тому +5

    How can anyone know that the half life of uranium is accurate? How can we know that the constant has never changed in 4.5 billion years? Serious questions, I've been trying to find out that and how we know that the amount of c14 in the atmosphere is constant if they are cause by cosmic rays which I would assume are dependant on an origin and not just constantly permeating all space..?
    PS. Great videos, this was the 5th one I watched and was by far the best.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  4 роки тому +12

      Well, seemingly a fair question, but a much better question would be, why would the rate of decay for any particular nucleon change over time? Why would the laws of physics change over time? In fact we can simply look out into the universe and see billions of years back in time to verify that they don't!

    • @hizand.5346
      @hizand.5346 4 роки тому +2

      i mean dude, if a radioactive material loses 0.1% percent of its mass when u wait for 1 year then it makes sense that their half life will be astronomically long time

    • @darkness8488
      @darkness8488 Рік тому

      @@ProfessorDaveExplains how? how do we look back in time? is there a youtube video i can watch about this

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  Рік тому

      @@darkness8488 My astronomy playlist.

  • @thegreatcasts4142
    @thegreatcasts4142 2 роки тому

    Amazing!

  • @saracarnes3198
    @saracarnes3198 4 роки тому +2

    This will not be a helpful comment but the shadow on your neck makes it look like you're decapitated and your head is just floating while you speak. Also, thank you for making this video so easy to understand.

  • @u235u235u235
    @u235u235u235 4 дні тому

    how does carbon 14 gain a proton to become nitrogen?

  • @DavidBadilloMusic
    @DavidBadilloMusic 3 роки тому

    Profesor Dave, how did scientists come up with the 5730 year rate in the first place?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +3

      By measuring the rate of decay.

    • @DavidBadilloMusic
      @DavidBadilloMusic 3 роки тому

      @@ProfessorDaveExplains Thank you, professor Dave! I was more looking for how exactly that rate of decay is calculated as they obviously cannot wait for 5730 years, but I'm guessing that they probably have some isolated 'chunk' of carbon 14 and after a number of atoms have decayed they use timing and amount percentages what has decayed and what hasn't to come up with the number of years? I guess my next question is how do they know this rate is consistent? Isn't the rate of decay random at a single atom level?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +4

      We don't look at individual atoms, we look at samples, and they always decay at the same rate. Furthermore, there is no physical mechanism by which nuclides could decay at anything other than a constant rate.

    • @DavidBadilloMusic
      @DavidBadilloMusic 3 роки тому

      @@ProfessorDaveExplains Thank you, Professor!

  • @amarilloshim
    @amarilloshim 3 роки тому

    Are we not assuming that carbon levels over the last several thousand years or more has remained constant in order to compare 12-14 carbon samples?

    • @amarilloshim
      @amarilloshim 3 роки тому

      @@karhukivi Thank you for sound reply. But what if carbon levels were not constant...say from massive volcanic activity or inactivity or pressure fluctuations or many other possibilities...would that not mean that carbon dating is only a best guess scenario? Can we assume otherwise?
      Specifically estimated date or age of earth, dinosaurs or other ancient beings and events. Thank you

    • @amarilloshim
      @amarilloshim 3 роки тому

      @@karhukivi Thank you again. Much appreciated

    • @FinBoyXD
      @FinBoyXD 3 роки тому

      @@karhukivi Nicely explained!

  • @REHANKHAN-en5zn
    @REHANKHAN-en5zn 4 роки тому +4

    Isn't dating illegal iin Arab?

  • @anthonygirdler606
    @anthonygirdler606 3 місяці тому

    Ok.
    I understood the starting point of organic materials that absorb carbon, but you lost me with the starting point of rocks.
    When do rocks absorb their uranium?
    Are all rocks 4.6 billion?

  • @whiterazer1
    @whiterazer1 Рік тому

    How can c14 be used to date objects over 2 half lives old? Wouldn’t there be 0 c14 left, meaning it could be any age over 2 X 5730 = 11460 year old? How does it work up to 10 half lives?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  Рік тому

      Please actually watch this video.

    • @nebuchadnezzar6894
      @nebuchadnezzar6894 Рік тому +1

      Because half life is the amount time it takes for half of a sample to decay. So after one half life 1/2 is left, after two half lives 1/4, after 3 it's 1/8 and so on.

  • @jimmychurch9588
    @jimmychurch9588 3 роки тому +1

    So, I might be dumb. Someone help me out. If carbon 14 has a half life of 5730 years how is it that it’s accurate up to 50000 years? It seems to me that it would only be accurate up to 11260? How does it work up to 50k? I’m sure there’s an answer but I can’t find it...

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +4

      We say that around 10 half lives can elapse before the concentration is too small for accurate measurement. That applies to any nuclide.

    • @jimmychurch9588
      @jimmychurch9588 3 роки тому

      Thanks for the reply, I appreciate it.

    • @jgone4856
      @jgone4856 3 роки тому +5

      @@jimmychurch9588 I think I made the same mistake you did. It's not that the 5730 halves every half-life, it's that the amount of 14-C present halves every 5730 years. Cool.

    • @jimmychurch9588
      @jimmychurch9588 3 роки тому +1

      Oooh, that makes more sense. Thanks man, I see now.

  • @mikev4621
    @mikev4621 Рік тому

    But how are the half-lives of the radionuclides determined? For the U238 one, you would have to wait 100s of thousands of years for a sample to decay measurably?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  Рік тому

      Nah. There are so many nuclides in any macroscopic sample that it's very easy to measure disintegrations per unit time for any type of nuclide.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  Рік тому +1

      @@mikev4621 it's good question, i doubt that long but i don't really know

    • @mikev4621
      @mikev4621 Рік тому

      @@ProfessorDaveExplains So, for U238 would you need to let the test go for a week, or a month, or a year....?

    • @mikev4621
      @mikev4621 Рік тому

      @@ProfessorDaveExplains

    • @mikev4621
      @mikev4621 Рік тому

      @@ProfessorDaveExplains It would either require a fairly large sample, or a fairly long time, according to a rough calculation

  • @nomadicmetalhed891
    @nomadicmetalhed891 2 роки тому

    Would this process be at all affected by different conditions or environments?

    • @youtuberesearch7017
      @youtuberesearch7017 Рік тому

      In open envirmoment uranium 235 or c14 will completly decay in less than half year.

    • @nebuchadnezzar6894
      @nebuchadnezzar6894 Рік тому

      @@youtuberesearch7017 No it won't. The rate of the decay is the same regardless of environmental conditions

    • @youtuberesearch7017
      @youtuberesearch7017 Рік тому

      @@nebuchadnezzar6894 it is much much faster.

  • @18despues
    @18despues Рік тому

    Once you have to assume the ratio of c14 to C12 in animals for that time period? What if one of them was more abundant then it is today?

    • @alvertising9555
      @alvertising9555 Рік тому

      Yeah he only assumed that organic material only contained a certain amount of C14-C12 (parent isotope), but in fact organic material must have amino acids or nitrogen N14 (daughter isotope), even the atmosphere itself contains 70% nitrogen N14 (daughter isotope). In short, if our bodies were calculated using carbon dating now, they would be 2000-3000 years old even though we are still alive. what a science :)

    • @nebuchadnezzar6894
      @nebuchadnezzar6894 Рік тому

      @@alvertising9555 No cos you only measure the ratio of C14 to C12. You don't care about the amount of N14, since only C14 decays into N14, C12 is stable and doesn't decay.

  • @mukhammadsalimov3254
    @mukhammadsalimov3254 3 роки тому

    Hi Dave. How to make sure the carbon isotopes have had the same ratio over the past fifty thousand years?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +6

      Scientists can examine ice cores and check isotope ratios at various depths.

    • @mukhammadsalimov3254
      @mukhammadsalimov3254 3 роки тому

      @@ProfessorDaveExplains Thanks.

    • @scientist110
      @scientist110 3 роки тому

      @@ProfessorDaveExplains what iff all of it is different

    • @Trythis837
      @Trythis837 2 роки тому +1

      @@ProfessorDaveExplains if determining the age of the half life is dependent on having an object of a known age to “calibrate” it to how can any of this be accurate?
      Did scientists just say oh that rock is 70 million years old then go measure the level of decay and calibrate the tests to that?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  2 роки тому

      @@Trythis837 It is not dependent on that. I have no idea what you're talking about. We measure rate of disintegrations and calculate half life from that.

  • @thesunman
    @thesunman 9 місяців тому +1

    You're assuming that the ratio/amount of carbon-14 and carbon-12 in the Earth's atmosphere has always been the same.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  9 місяців тому +2

      It is. I explain all the mechanisms in this video. Actually watch it.

    • @jeffreyerwin3665
      @jeffreyerwin3665 8 місяців тому

      Variations are known and corrections are always applied.

  • @manthansagar2532
    @manthansagar2532 Рік тому

    How can know how much C-14 was present in the organism when it died?

  • @latino.raptor
    @latino.raptor 2 роки тому

    Great! thanks :)

  • @robertfindley921
    @robertfindley921 10 місяців тому +1

    It's always fun to hear young Earth Creationists reject these methods as false or lies, and twist and turn to find ways to explain how the evidence yields about 6000 years.

  • @EndureTemptation
    @EndureTemptation 3 роки тому

    How does the cow analogy explain how Earth age is measured?

  • @thivhaedgar9700
    @thivhaedgar9700 Рік тому

    Does C14 exist naturally in the atmosphere?

  • @footballnewscr
    @footballnewscr 8 місяців тому

    but how we know age of other planets that we have not visited

  • @arcadyy_
    @arcadyy_ 3 роки тому

    After carbon-14 decays and turns into nitrogen-14, is it still radioactive??

  • @keerthanaap4824
    @keerthanaap4824 3 роки тому +2

    Let's do some dating - lol😂😂

  • @jeffreyerwin3665
    @jeffreyerwin3665 8 місяців тому

    If the subject has been exposed to neutron radiation, and if the subject contains even trace amounts of nitrogen, then its radiocarbon date will be skewed by an unknown amount.

  • @kabilsreeram1184
    @kabilsreeram1184 2 роки тому

    What about plutonium 238??

  • @Aaurelion
    @Aaurelion Рік тому +2

    One error in carbon dating is that they say you cannot use it as a valid measurement for anything about 60,000 years old or older, yet it has been found impossible to find any living creature even the ones that are supposedly 200 million years old without carbon 14 in them xD lol. There are at least a dozen errors in carbon 14 dating that renders the method to be based off of assumptions or just straight out lying about the facts in order to be sure the theory or narrative that one desires to be true is protected rather than holding true to the actual discoveries being made.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  Рік тому +7

      Wow it’s like you didn’t even watch this. We don’t use it to date anything after ten half lives have elapsed because it’s too imprecise to be reliable. That doesn’t mean there’s none of that nuclide left in the sample. No, there are no “assumptions” or “lying”. You’re just desperately trying to discredit science that demolished your pathetic fragile worldview. Sorry, sweetie.

  • @s7en64
    @s7en64 3 роки тому

    so.. it's reliable but also not? we can't deviate the problems occuring when we just flip the time backwards right? there are all kinds of assumptions being made too, right? what about sunlight? photosynthesis? i saw some news saying that a metal bar from 1982 was estimated as 144,000 years old. i mean if there's a big gap such as 144,000 years, i don't exactly call that reliable.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +5

      It's reliable, "flip the time backwards" doesn't mean anything, no there are no assumptions, sunlight doesn't have anything to do with it, and you heard wrong about a metal bar.

    • @s7en64
      @s7en64 3 роки тому

      @@ProfessorDaveExplains i see, thanks for replying. earned a subscriber there. but what about the process when a rock formed? it could have influence on daughter to parent ratios of Uranium and Lead. it could cause the daughter product to be enriched relative to the parent. making the rock look way more older. for ex, take a rock that was cooled off from an erupting volcano. if you use radiometric dating on it, it concludes that the rock is million of years old, even though it was just erupted and cooled down. not to mention it could solidify and melt again, again and again.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +2

      Dating which nuclide? I'm not sure you understood the bit about that process.

    • @s7en64
      @s7en64 3 роки тому

      @@ProfessorDaveExplains can you elaborate? i’d love to understand.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +2

      Look up the process by which rock formation traps argon.

  • @henrim9348
    @henrim9348 3 роки тому +3

    So you are saying that the earth is older than 6, 000 years? who would have thought !!!

  • @abirmakesdumbvideos
    @abirmakesdumbvideos 2 роки тому +1

    ALLAH HU AKBER!

  • @moazamraza2434
    @moazamraza2434 3 роки тому +1

    I am listening you after 2 years . Where are your beautiful long hair sir😐 ...? Respect from Pakistan 🇵🇰

  • @korbendallas5318
    @korbendallas5318 2 роки тому

    I don't see how measurement of different elements are corroboration of each other. It's the same method.

    • @korbendallas5318
      @korbendallas5318 2 роки тому

      @Null Pointer So it's the same method.

    • @korbendallas5318
      @korbendallas5318 2 роки тому

      @Null Pointer What are the different processes?

    • @korbendallas5318
      @korbendallas5318 2 роки тому

      @Null Pointer You're just throwing words at me. What are the different underlying processes?

    • @korbendallas5318
      @korbendallas5318 2 роки тому

      @Null Pointer So there *is* a difference in the fundamental idea after all, and they are *not* just differing in implementation.
      Now only one piece seems to be missing: Please name a pair of alpha-/beta-decays that support each other's results.

    • @korbendallas5318
      @korbendallas5318 2 роки тому

      @Null Pointer No doubt about that, but I asked for a pair of alpha-beta-decays that support each other's results.

  • @davidsandell7833
    @davidsandell7833 5 років тому +2

    How do we know half lives have always been the same?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  5 років тому +9

      because that's how physics works

    • @filiphavojic8045
      @filiphavojic8045 5 років тому +3

      Statistics. We know that nuclear decay is a probabilistic process and can be explained by Poisson's distribution. If you're interested in topic you should read a book or two about it.

    • @danielauto3767
      @danielauto3767 5 років тому +8

      The fundamental properties of substances don't change willy nilly over time. We know that because these properties ultimately are a consequence of the fact that all matter is made out of fundamental particles and its properties are due to the way these particles interact with each other. In order for these fundamental properties to change you would have to have changing fundamental physical constants such as speed of light, planks constant, electron charge, etc... These changes would necessarily come with side effects which are not observed. The idea that lifetimes may have changed is completely untenable.

    • @davidsandell7833
      @davidsandell7833 5 років тому +2

      Nothing here proves half lives have remained constant over time.

    • @filiphavojic8045
      @filiphavojic8045 5 років тому +2

      @@davidsandell7833 Like I said read a book or two.

  • @mrjoehimself
    @mrjoehimself Рік тому

    All of this assumes the levels of said molecules in our atmosphere are the same today as they were billions of years ago.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  Рік тому

      Nope. Carbon dating is used over tens of thousands of years, not billions. For other isotope pairs it has nothing to do with the atmosphere, but rather rocks, so it's a totally different concept.

    • @mrjoehimself
      @mrjoehimself Рік тому

      @@ProfessorDaveExplains Ok, so with respect to carbon dating methods only, we assume that the levels of carbon in the atmosphere were the same ~50,000 years ago as they are today. How do we know the initial levels of argon or potassium or uranium from which the level we find them at decayed from?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  Рік тому

      @@mrjoehimself Argon is always zero. It's an inert gas that doesn't form rocks. I explained that in the video.

  • @markvegar33
    @markvegar33 4 роки тому +2

    This is based on an assumption about a constant rate of decay. Better to have something that you know the exact date of and make a comparison as the radiometric dating of rocks has been shown to be incorrect and wildly inaccurate due to volcanic activity.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  4 роки тому +6

      There is absolutely no basis for the presumption that the rate of decay would change. And we do compare dating techniques to objects of known age by comparing with tree ring dating or known historical events. We also compare with other radioactive nuclides and get the same result. You clearly have some kind of personal agenda, and it's irrelevant. Radiometric dating works.

    • @ajsanchez2434
      @ajsanchez2434 4 роки тому +2

      You are very correct Mark. Many times in Radiometric dating scientists run to use C-14 dating as their example of how it works. Although C-14 dating is to a degree verifiable especially with organic artifacts and tree rings, the inorganic radiometric dating is more of a shot in the dark being that no sedimentary layers or fossils directly contain the metamorphic rocks necessary to date AND little is known about the atmospheric conditions at the time. In my opinion, other than C-14 dating, most all radiometric dating is a complete guess.

    • @chopppacalamari
      @chopppacalamari 4 роки тому

      Professor Dave Explains radiometric dating works only if you don’t know the age of thing tested. 80 year old volcanics eruptions test at 2 million yrs old. Old trees have way more rings than the known age. The people doing the tests won’t tell you that but you go cut a tree that your family planted and documented and it’s not true.

    • @chopppacalamari
      @chopppacalamari 4 роки тому

      Professor Dave Explains ice layers above airplanes from the war showed the planes should have been tens of thousands of years old.

  • @dylanphillips3575
    @dylanphillips3575 3 роки тому

    Wait how are uranium and lead disparate?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  3 роки тому +3

      Well they are different elements.

    • @glowstick8639
      @glowstick8639 2 роки тому

      @@ProfessorDaveExplains Doesn't uranium decay into lead though?

    • @Dmitr0Cirrsa
      @Dmitr0Cirrsa Рік тому +1

      @@glowstick8639 Yeah. Refer to the video about radioactivity.

  • @aaronmarkham4424
    @aaronmarkham4424 Рік тому

    Sorry but how can you prove how long C14 lives

  • @mohammedanwarsha4273
    @mohammedanwarsha4273 5 років тому +2

    Malayalies undo...?

  • @kabilsreeram1184
    @kabilsreeram1184 2 роки тому

    And lead 237

  • @kamalaharriswalz2025
    @kamalaharriswalz2025 4 роки тому +1

    How do you know that the artifact contained half as much carbon as a living tree and not that it started out with half as much carbon as a living tree?

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  4 роки тому +6

      it's not carbon in general, it's the ratio of 14-C to 12-C. that's fixed.

  • @jeonmai97
    @jeonmai97 11 місяців тому

    I'm just here cuz I scaned a QR code in my Geology book +_+

  • @userbosco
    @userbosco 10 місяців тому

    You watch this and wonder how Creationists can ignore science so willingly. Sheesh.

  • @justindarnellfpv
    @justindarnellfpv 2 роки тому

    Interesting stuff… have they ever used c-14 dating to date the known age of a rock, accurately? Answer… no. In other words, if they knew the age of the rock and used carbon 14 dating, the age came out way off… such as mount saint Helen’s

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  2 роки тому +8

      Um, we don't use carbon to date rocks. We use other nuclides. Please at least try to pretend you watched this and care about learning.

    • @bass-dc9175
      @bass-dc9175 Рік тому +1

      Carbon dating rocks? To quote Potholer: "Oi. We can't carbon date that! There is no ****Ing carbon in it!"

    • @bass-dc9175
      @bass-dc9175 Рік тому +1

      Oh and about that:
      "if they knew the age of the rock and used carbon 14 dating, the age came out way off… such as mount saint Helen’s"
      They did not date the pure erruption. It was contaminated with the rock that makes up the top of the vulcano and zircon crystals that formed way way WAY earlier.
      Who would make such grevious errors? Any geologist half their salt would not have taken raw, contaminated samples. It allmost looks deliberate as if it was a creationistic institution that messed up the measurements in order to cast doubt on radiometric dating ... let me check ... It was the "institute" for creation "research". That explains it.

    • @nebuchadnezzar6894
      @nebuchadnezzar6894 Рік тому +2

      C14 was never meant to be used to date rocks.

    • @justindarnellfpv
      @justindarnellfpv Рік тому

      @@nebuchadnezzar6894 fossils are rocks… just google it one time

  • @afreenshaik1814
    @afreenshaik1814 5 років тому +2

    😁

  • @Guitor972
    @Guitor972 10 місяців тому

    how could it have a half life of 4.5 billion years if the Theory of evolution says the world is 4.5 billion years old

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  10 місяців тому

      Well those two things are completely and totally unrelated, and also uranium existed before the earth did.

    • @Guitor972
      @Guitor972 10 місяців тому

      @@ProfessorDaveExplains oh I understand , but how do we know that these isotopes always had the same concentration in the atmosphere? The atmosphere is always changing in its ratio of chemicals.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  10 місяців тому

      Uranium dating is not based on the atmosphere, that's carbon dating, and we are looking at solar output which we know is consistent over the short time span that carbon dating can be used.

    • @ProfessorDaveExplains
      @ProfessorDaveExplains  10 місяців тому

      You don't "date" lava flows, sweetie. You date rocks. This is why you need to learn basic science. So that when idiot apologists lie to you, you can immediately tell and not fall for it.

  • @samuelwetterau9226
    @samuelwetterau9226 Рік тому

    I already watched a video were this was explained. I found that video on the channel Inspiring Philosophy which is run by Michael Jones.

  • @sajanaryal6932
    @sajanaryal6932 10 днів тому

    There are some insecure creationists in the comment section.

  • @abidkhandakar1679
    @abidkhandakar1679 4 роки тому +2

    He looks like Jesus..!

    • @herfio
      @herfio 3 роки тому

      Nooooooo