Radioactive Dating

Have you ever wondered how paleontologists and geologists determine the age of fossils or geologic events which occurred in the past? Explore the processes of radioactive decay and radioactive dating.

[@alexnita6871]

Thank you! This video explained what a whole book chapter couldn't.

[@basharatahmad9314]

Exactly

[@basharatahmad9314]

Where r u from?

[@eleanorfreebern8945]

This was so helpful! Me and my sister are homeschoolers and this explained everything and was actually sort of fun! We would pause the video at times before you did the problems to see if we could do them. Thank you very much for being so clear and helpful!

[@HolyKoolaid]

This was really good, but there were a few mistakes. 1. A sample doesn't have to go through an entire half life in order to be dated with that particular method. You're right that you can't date something that's 1000 years old using uranium lead, because there hasn't been enough radioactive decay. But you don't have to wait an entire half life. Otherwise we wouldn't be able to carbon date materials that are less than 5000 years old. The rate of radioactive decay is constant and measurable once you reach detectable levels. 2. You can't use carbon dating on fossils. Fossils are by definition petrified and are no longer organic. In other words there's no carbon in them to measure. You can however, use carbon dating on 11,000 year old bones.

[@williamchamberlain2263]

(2) isn't strictly true; some fossils do have organic material left in them. But there are all sorts of carbon contamination issues with fossils, on top of the age leading to very little original carbon being left, so radiocarbon dating still isn't useful.

[@janverboven]

@@williamchamberlain2263 you should have put in the word 'always', like 'always useful'. Thanks sir.

[@Shichwa]

That was very informative and easy to understand. I’m a literature graduate and yet I understood your lesson completely. Greetings from Iraq 🌹

[@SpaceCadet4Jesus]

Excellent and logically explained basics of Radioactive dating. If the rest of your videos are equally lucid, you get another supporter.

[@Tropax1]

What an excellent teacher, I could listen to you all day sir. Thanks.

[@MOPLE.]

Thank you very much..........This lecture contains the most lucid explanation of radioactive dating.....

[@JJ-pg9ri]

Simply the BEST !!! Exactly what is needed for high school Earth-Space Science class. Thanks a lot !!!

[@asheer5854]

This is such an amazing video, helped me understand it so easily. I love the pacing of the video. Thanks for the amazing video!

[@justshoby3374]

Simple and thorough explanation. Great!

[@orfeasorfeas9346]

Very explainatory and helpful! Thanks!

[@Wupass1000]

very well explained, thank you. Love the examples

[@pitbed]

Great explanation Seth and very understandable video. Thank you a lot.

[@mohawkc91]

Great video. Insightful.

[@vincentgomez319]

I wish you were my chemistry teacher at school 15 yrs ago. Awesome video. thanks!!

[@RafaelPacheco2000]

You're really an excellent teacher!!! Thanks!

[@yahawahdahyath7669]

I go to ucla and I’m taking my an anthro class where this was so confusing in the textbook but you broke it down perfectly!!

[@coripaez8386]

Thank you for this awesome video I spend 3 days trying to understand it and your video did it all. I still view it like 3 times but I finally understood it. And other videos you have are well explained. I hope we continue to see more.

[@arunbadetia2459]

Thanks sir... It really helps to understand this radioactive topic..

[@pagoboy8034]

Thank you for the mid-presentation test questions! Really helped. Keep it up brother.

[@abhishekhpalaparambil6188]

Very informative. Thank you

[@akshatdixit2871]

Neat and clean presentation with beautiful Voice. Thank U😘❤️

[@Flowraince]

Fantastic video! Thank you! :)

[@meenudesilva6499]

A really important lesson taught simply and easily-understandable. Thank you it was very helpful. 👍

[@acamapichtli.raul.suppachok]

best explanation about this on youtube

[@nybowtiejeep]

Great job Seth! This video is perfect for my 8th grade ES students during distance learning!

[@veronicap.2264]

you're great at explaining this

[@springbok4015]

Well explained. Thank you.

[@honestpledges8435]

Wonderful video

[@mmakingdom1290]

Great video!

[@PABITRABADHUK]

Hii Seth, excellent video! Can you tell about what are the techniques available for absolute dating of fossils older than 70k years? Thanks!

[@BearKire]

Your voice reminds me about Steve Jobs. Thanks for a great video!

[@fuhrer6819]

Great👌very valuable information❤😍

[@hashimmukhtar8039]

Splendid video. Well presented.

[@latino.raptor]

really great way to explain the concepts, many thanks :)

[@langsircoklat]

Good explanation.. easy to understand 👍👍👍👍👍

[@tarekabdullah6119]

Thank you. Great video. One question though. How do you know the original amount of the radioactive elements in the objects?

[@Oliver-xv1qf]

I just stumbled on this video after searching the age of earth and now I'm happy I learnt soemthing new, thank God we have the internet 😂😂

[@pkjoshik8076]

Very deep and very clear

[@OliveBishop]

This was super helpful!

[@mrsas5926]

very nicely explained!

[@amarjeetgill9824]

Very well explained

[@Cookieman524]

Thanks for the video ☺

[@afnanabood5488]

Thank you soo much this was so helpful for me to understand this concept

[@monicaa6345]

Great video Thank you

[@manh385]

Great work

Brilliant! Thnx! 👍🏼

[@SNROPQUEYR]

Very interesting subject - Thanking you for your input -

[@hamidghulami1321]

I loved the way he Simply explained

[@mehboobali5091]

very nicely explained. thanks. it was very useful for me.

[@lordsMobile...]

thanks, was so helpful

[@muskanbansal6509]

Sir, I have a doubt. How do we know at first plce, what was the original amount of element present in the fossil ? Like how do we know that element has decayed to half of its original value? How do we know this original value ?

[@konradk1066]

I’ve been binging a ton of videos on ancient Earth stuff (animals, geology, etc), and before I found this awesome video, I saw one that said there are other stable elements such as Carbon-12, and my understanding so far is that the ratio of Carbon-12 to Carbon-14 can be used to determine how much has decayed. I’m still not 100% about this, so I’m gonna keep researching. I just love how this video explained how we can date stuff past C-14’s max reliable readability.

[@alanniketic7690]

Yes... All they do is assuming that it was always so. Carbon 14 dating is not reliable more than 5000 years.

[@joratto2833]

The atmosphere’s carbon isotope ratio actually did vary by a little over time and we have to adjust for that. We can get an idea of the ratio by looking at ancient preserved gas bubbles in arctic ice, but of course there’s not all that much of that, so carbon dating is not that reliable in the long term and we have to use other radioactive elements

[@HolyKoolaid]

@@alanniketic7690 Not true. It's reliable to about 50,000 years but not due to atmospheric carbon levels, but rather due to the fact that after about 50,000 years all the carbon 14 in the sample will have decayed into nitrogen. The real answer to OP's question is that carbon levels are fairly stable over time, but can fluctuate slightly and we know what can cause it. Not enough to throw off carbon dating by thousands of years, but enough to have a few decades margin of error (or even a few hundred years if you go way back). However, scientists actually have a really good idea exactly how much carbon was in the atmosphere (even tens of thousands of years ago) because we can measure carbon levels in ice cores found at the poles. We can also measure carbon levels in other sources like tree rings. Those are just a few of the many examples of ways scientists cross check and calibrate their measurements. So yes, carbon dating is very accurate back to about 50,000 years, but it usually has a margin for error of several decades depending on how far back you go.

[@alanniketic7690]

@@HolyKoolaid nothing is old 50000 years, thats in your mind and wishes. We certainly cannot date a rock. The best geologist admit it, you don't.

[@jaryd7544]

Thank you Seth that was a very good video, however you did make a small mistake in your fraction calculations to work out a 1/4 of the carbon remaining

[@venshi7643]

Oh my God please replace my earth systems teacher. You're making this way easier to understand

[@patrickhowden1601]

I think you failed to mention; How was it determind that the igneous rock contained half of it's original potassium-14 carbon 14. Would it be true to say that without knowing how tall a candle was to start with, it would be impossible to determined by how much is left, how long it has been burning or when it was half of it's original size.

[@damianschmitt9752]

good question, i.e. how do you determine the 100% that you start with? great video though Thanks!

[@yotamweingarten4052]

So helpful!

[@blindandwatching]

Some isotopes with unequal numbers of protons and neutrons are stable. Argon-36, Argon 38, and Argon 40 are all stable. Oxygen-16, 17, and 18 are all stable.

[@mbart]

I am sorry to disagree with you on the general statement at 2:48 that isotopes with unequal protons and neutrons are unstable. To prove this is wrong, skip forward to 4:09, where you mention Lead-206. This isotope has 82 protons and 124 neutrons, which is unequal. Nevertheless, you (correctly) state that is is stable. So the general rule you define n the first place, doesn't hold.

[@briansammond7801]

I was about to make the same comment; I decided to stop right there, since I knew that this was flagrantly false, and it made me wonder what other bad information might be in the video.

[@stephenfletcher5391]

Great video. But how do you tell how long a bone found has been decaying? And how do we know that Potassium has a half-life is 1,3 billion years?

[@ohyeahyeah4312]

Stephen Fletcher calculus

[@kennyw871]

A bone stops accumulating Carbon-14 from the environment at death.

[@JesusSavesSouls]

@@kennyw871 And how do we know when it died, if we need the time of its death to calculate the amount of Carbon-14?

[@christopherperez7039]

this helped me so much

[@mnizam84]

Thanks

[@Poseidon6363]

We have multiple absolute dating methods. Radiocarbon dating, dendrochronology (tree/wood dating), thermoluminescence dating, archaeomagnetic dating (looking at the orientation of rocks during pole shifts), amino acid dating, obsidian hydration dating Do you know that for the time frames in which these methods are valid, they all give consistent results with each other.

[@kennyw871]

This is the part that die-hard young earth creationist have the most trouble with. But, everything else science gives us is perfectly okay. Go figure!

[@fortniteclips8984]

Saved me for my quiz tmr thx

[@loweltomale5204]

Thank you🤗

[@MyGamerTV]

Awesome!

[@sylvesterpalermo937]

This part of the calculation is simple and straightforward. My question is..............How was the "half-life" determined for each element? An element with a billion year half-life will only decay a minute amount in an entire life of a human. An equation that is A X B = C requires that you know both A and B

[@MOHDANWARify]

Perfect thanks

[@thinkwithgaurav6819]

nice explanation sir

[@huttonflakne7300]

good this i was here on youtube to see this before my test

[@GamehubSL]

Thank you

[@SFRJshone]

Awesome.I always wonder how... Ty

[@slimanmohammed2754]

thx for this video sir

[@Leeminhoocats]

You're da best👍🏼

[@Nabeelahmed-vj1rc]

Thank yew sir u have cleared my all concept about this. Its really helped me .. I am ur new subscribers.

[@deepgreenbear]

Watching this video makes me think you are the perfect person to ask this question. And let me just say, it may be a really dumb question that I just completely overlooked the answer to but I can’t seem to find one. So, star explodes creating all the elements that eventually come together as a planet. All of the radioactive isotopes are presumably made during this stellar explosion. So, planet forms from this space dust with all of the isotopes within the dust and makes the compositions of the planet. So, my question, why is there any difference between the amounts of isotopes anywhere on a planet? Shouldn’t the age of all rock be the same age as the space dust it was made from? Again, maybe it’s a supper dumb question but my understanding is that there is not really any new isotope formation so when we radiometrically date rocks there was kind of a fixed concentration at the starting point which is why the dating is reliable. I feel like I’m missing something, can you help?

[@djshahtes2257]

thanks, man that's a very intellectual, could you tell me all radio active element? how many are they?

[@kennyw871]

All known are in the Periodic Table.

[@margaretmcaurthur439]

Hi there. Nice video. I have a couple questions. If carbon 14 is created in the upper atmosphere by cosmic rays penetrating through the magnetic field, and knowing that the magnetic field is deteriorating at a rate of 5% per century, wouldn't that tell us there was a far less concentration of C14 hundreds of years ago leaving the current understanding of carbon dating inaccurate? Oh, well I guess that's only one question. haha thanks

[@AB-mh6nj]

Hi I thought that isotope was for only unstable atom. ..?

[@plaguey2022]

I was sent here from homework but great video

[@inderjeetsharma2662]

Thanku

[@Meine.Postma]

If I understand it correctly the assumption is that the amount of C-14 (and the other measured elements) are in the same ratios in the atmosphere now as when the measured organism when it died? Because you are measuring in percentages of the current ratio.

[@UnKnown-ku7ro]

When was the conversion of U238 to lead repeated consistently (The empirical method) in scientifically conducted experimentation

[@gregoswald7723]

A few questions: 1. If a 200 million year old sedimentary rock was composed of sand from a 1 billion year old rock, which age would this method determine? 2. How do you know what the original mix of Carbon 14 and Nitrogen 14 was, in an animal or plant when it died? 3. IF it already had some Nitrogen 14 in it's tissues then how do you know the percent that was a radioactive decay product?

[@davidwhitehead3089]

Hello Seth, I have a dumb question. If I understood correctly, and I obviously did not, if we cannot measure things before the first half life has occurred, then why can we carbon date things that are younger than 5700 years? My understanding of the video is that we should be able to carbon date anything between 5700 years and 70,000 years old. Sorry for my ignorance on this.

[@amirzlakers]

In the case of things younger than 5700 yrs they would probably not use carbon dating, maybe a different isotope or a testing type that does not use half life measurements

[@DestinyLabMusic]

I have a question I am trying to figure out. How old is molten lava?

[@JoeTheJew]

About 4 billion years

[@DestinyLabMusic]

Hmmm...looks like I have gotten multiple different answers to this question....how are you arriving at that 4 billion year old date?

[@freemind..]

@@DestinyLabMusic - It depends on when it was melted.. It could have melted just a few days before you saw it. Once melted, it can't be dated to find out how old the rock that it came from was.

[@swapnildongare3384]

You explain very wel. But how we know the exact amount of C14 present in the parent molecule.

[@ohyeahyeah4312]

Ratio to the daughter atom

[@40blocks]

At what point, in C-14 decay, does C-14 BECOME N-14? After 2.1 half-lives? What quantity of protons or neutrons are emitted in decay (beta decay?) of C-14 after each half-life? In short, please provide a BEFORE-AFTER picture of the isotope and its atomic constituents.

[@Mohammadssalehi]

Great Video! However, you are making a huge assumption that the parent contained 100% of the radioactive element. This method is not accurate at all because you never can find a fossil with 100% of the radioactive element.

[@Mohammadssalehi]

kzbin.info/www/bejne/n3ino6Rup86egMU

[@jhaylward]

Mohammadsadegh Salehi exactly my thought ;)

[@braggsean1026]

@frankos rooni how do we know uranium will turn into iron in several million years, or its half life at all? Is that proven in a lab or just an algebraic equation? Honest question from a dumb agnostic

[@nopenopenope7129]

Interesting. But how do they know how much of the isotope the object had to start with. As in your question 5 (11:28) "What is the approximate age of an igneous rock that contains only 1/4th of its original potassium-40". How do they know how much potassium-40 that rock originally had?

[@johnkissler2623]

Only thing that makes sense is taking the amount of daughter material and adding it to the remaining amount of parent material. This would tell you how much parent material the specimen started out with.

[@ZuluOnly]

yea its literally just a ratio thing; daughter material + radioactive = 1

[@shaaa6420]

but the daughter material is not potassium-40 though, so adding it to the remaining parent material would not give the original amount of K-40.

[@Nitsujcm2600]

And what happens if the parent material is water soluble, but the daughter material is not? Exposure to water at any point would remove some of the parent material and throw off the ratio, making it look significantly older. This has been show with rocks formed very recently being dated as millions of years old.

[@kennyw871]

@@Nitsujcm2600 Really, shown by whom?

[@seanmcrae6890]

If a parent element never fully decays to zero, why is carbon 14 inadequate for measuring materials older than 70,000 years? Your teaching method is commendable

[@paulgarrett4474]

One only a small amount is left an accurate measurement isn't possible because the neutrons are shed too slowly.

[@titushelmi6997]

I'm a lawyer and now fully understand the lesson,. Don't ask why

[@blue...]

Some of the yt videos about carbon dating says scientists compare left of C14 to C12 (cause the ratio of those two is aproximately the same in the living organismas and in the atmosphere). And some of the videos (like yours) says scientists compare C14 to N14. So do they use both methods? How can they tell for sure that ratio of C12 and C14 was the same 50 000 years ago and today? And what scientific method did they use to find out that the time of decay is always the same? Also if we can find N14 in living organisms (I pressume it stays when organism dies), how can we know which ones are from C14 decay and which one's are not? sorry for all the questions, but I'm new to the subject and curious..

[@Abo_Abdullah87]

Why did you stop making videos? 💔

[@katrinadelosreyes4324]

This is amazing 🤩! It’s so easy to understand now how to know the age of stuffs. I’m not a scientist or archaeologists, but I became very curious after watching ancient history such in Egypt mummies, etc. Thank you so much for this video! Well done 👍 ☺️

[@darkness8488]

this is so great, i do have a question however, how do we know that carbon dating is reliable, how do we know that half-life doesn’t change, no one was there thousands of years ago to measure it, how do we know that it doesn’t get affected by the earth magnet and the amount of UV light we get from the sun? if it does change then our science is corrupt!! m really curious to know :0

[@starman9458]

I have a bunch of arrowheads found from a field I wonder what the half-life will be in them

[@Dudecarmap]

I am not in college but I wanted to know the ins and outs of radiometric dating. Thank you very much for this. :)

[@noneyabidness9644]

Except radiometry failed by several orders of magnitude, when a blind dating of rocks with known ages are done. So, it gets known ages *wayyyy* wrong, but it is correct with unknown ages?

[@paulgarrett4474]

This only happens when the tests are carried out by dishonest or incompetent creationists.

[@rickandrygel913]

Eventually wouldn't you have 10 atoms left? Then five, then... Two or three? Can't have half an atom. Then one or two? Then zero or one? Then one forever?

[@Morewecanthink]

Thats very nice explained. But the conclusion that this measures age is due to presuppositions without any valid foundation, the assumptions of amount of elements in the beginning, that there weren't a more rapid loss or an addition of elements in the past. The dating of rocks or layers with known ages produces as well thousands and millions of 'years'. So far to the reliability of the timescale in which evolutionary scientists trust. They conclude what they presuppose.

[@tgstudio85]

So far science is working fine, and i didn't see any religious miracles only claims of them, very strange:/

[@ohyeahyeah4312]

Morewecanthink um no those assumptions are well based in testing.