How Old is that Rock?

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GNS Science

11 жыл бұрын

Uranium-Lead Dating using Zircon Crystals.

Пікірлер: 86

@stevepompe273 3 жыл бұрын

Best explanation of the process I've watched. Loved being taken from the field to the lab.

@MAMP 6 жыл бұрын

Thank you! This is the only video I've found that really shows the gritty "how it works in a lab". All the other videos were really dumbed down just explaining half life but not showing how the measurements were actually taken.

@GNSscience 6 жыл бұрын

Glad you like it!

@ashishupadhyay5643 Жыл бұрын

@@GNSscience I also liked it 🥺🇮🇳

@priscillagluszak5546 Жыл бұрын

This is such a great video, now I might not understand some of these things but they word it great so I can understand easily. I’m only a 12 year old learning about geology. Such a great video

@eleseeagle9664 10 жыл бұрын

This is extremely helpful! Thanks so much!

@Osama84ca 9 жыл бұрын

great video, nobody could answer this simple question before!

@BerryTheBnnuy 9 жыл бұрын

This was answered by Clair Patterson many decades ago. It's just public schools tend to not teach about it...

@sallymay3643 2 жыл бұрын

That was very interesting. Iv loved & collected rocks since I was a kid Iv had some rocks 35 yrs now. My favorite rock is the pudding stone & the Petoskey.

@drmuller77 6 жыл бұрын

Nice explanation!

@codenamerishi 5 жыл бұрын

Great video! Thanks

@sumertheory 10 жыл бұрын

err so how old was that rock.

@kaptinkrunch197 3 жыл бұрын

It’s 4.375 billion years old and it was formed 165 million years after the earth formed

@ummtzbubba6208 3 жыл бұрын

@@kaptinkrunch197 u are wayyyy to smart alr chill 🥲

@ashishupadhyay5643 Жыл бұрын

Awesome 😎👍💯

@overhang88 11 жыл бұрын

Awesome video

@jahanhajiyeva 3 жыл бұрын

good explanation

@theblue92 10 жыл бұрын

Would one be correct in assuming that the formation of zircon crystals in a laboratory setting results in lead-free crystals? Presumably due to the composition of the molecular crystal latice rejecting the lead in some manner? As the formation of such heavy elements apparently only come from supernovae one might wonder if any dating method would ever effectively measure the time between atomic formation (last supernova) and the formation of the Earth/Solar System.

@mynameisvv 5 жыл бұрын

Wonderful video.. at least it explains me 10 percent that how the find the age of rock.. Hardly anything available on youtube.

@DestinyLabMusic 9 ай бұрын

I have a question I am trying to figure out. How old is liquid lava and can it be dated?

@noobsaibot5285 5 ай бұрын

Fossils found traversing multiple cross-bedded stratum mean they were deposited in different geological periods - Today's Geologists

@andrewblack4157 5 жыл бұрын

What I'm curious to know is how we know how fast uranium isotopes turn into lead isotopes.

@GeovaniLopesDias 4 жыл бұрын

You may know it by analyzing smaller masses decays. 4.5 billion years pass until half of the mass decay, but less time will pass to less mass come to decay. You can do it by analyzing "big" quantities of U-238 and exponential calculation.

@Daniel-gf5id 3 жыл бұрын

@@GeovaniLopesDias this answer still seems confusing to me, can you explain it in simpler words I can understand in? (I’m not so knowledgeable in science)

@GeovaniLopesDias 3 жыл бұрын

@@Daniel-gf5id The first thing we must to know is that radioactive decay is a quantum process, is to say, it is a random phenomena at atomic level, as the atomic movement is as well. Despite it, at macroscopic level, with a big mass (billions of billions of atoms), it is a predictable phenomena, so is thermic ones. Distinct isotopes has a special half-life, as they have different nuclei; this means a specific isotope will decay half of their mass in some specific time (we historically choose to measure half, but one may choose another fraction). As the time of a certain isotope has to decay is predictable, one can calculate, even after a small decay, how much time will demand to half of the mass decay. I'm deliberately ommiting the math, but you may easily find it online, even at KZfaq. Hope that helps.

@jojohnson6392 3 жыл бұрын

@@Daniel-gf5id What I want to know is who decided that the half life was 4.5 billion years? It seems to me to be impossible to get accurate ages using this crazy method. Way to many variables at play. This is exactly how scientific theory wrongly gets turned into fact. To much money involved to let the truth get in the way.

@m-zap1332 8 жыл бұрын

How do we know whether the Lead present in the rocks are a result of the Uranium decay or if it's already a part of the rock due to Lead naturally occurring in nature?

@krickrack 8 жыл бұрын

+Matheas I think when zircon crystals are made (process called crystallization) some elements can be incorporated (elements that substitute for Zirconium). Uranium is one of these elements and Lead is not. So when zircon crystals are made, there is no Lead in them. So the Lead we find in zircon crystals are the result of the Uranium decay.

@charmainemcgregor7221 7 жыл бұрын

Matheas Zircon strongly rejects Pb during it's crystallisation. Therefore within it's crystal structure the Pb is produced as a result of radioactive decay.

@ohyeahyeah4312 5 жыл бұрын

krickrack thanks I was wondering that

@kleenex3000 3 жыл бұрын

The Zircon crystals are, as explained, avoiding Lead. On the other hand your question is a big elefant in the theological discussion. IF any primordial Lead, THEN it is being accounted for, by the additional measurement of the mass of Pb-204. which is entirely non-radiogenic, it allows for a correction of the primordial fraction of the radiogenic isotopes. The idea (presupposition) is, that the primordial ratios between the masses of the isotopes were / are constant. This has been scientifically verified. If you are interested in the topic GOOGLE *primordial lead*

@jesseregiec6816 9 ай бұрын

I would love to know how old the rock was in the video...

@dindayalredkar763 Жыл бұрын

How old was the sample rock taken frm the beach?? Nobody told us that till the end

@mohitchalia9664 2 жыл бұрын

Can you tell me where is this place?

@JumpJeho Жыл бұрын

How do you know the decay rate of these isotopes if we only have 100 years of experimental data? Extrapolating 100 years of data to 4.5 billion (0.000002% of it's life span) is quite a stretch.

@UnKnown-ku7ro 3 жыл бұрын

At what point do you actually date the rock? What empirical method do you use? Or, like other scientists, did you redefine the empirical method to match your wags?

@thomaseriksson6256 2 жыл бұрын

Hopw can you deside the Pb level in the magma?

@geoffgeoff143 4 жыл бұрын

The short cut method. Open to large errors.

@libertynindependence 11 жыл бұрын

Is there a study that shows this?

@theblue92 10 жыл бұрын

Ah, the relevant wikipedia article seemed to answer the question (Uranium-lead_dating). Feel free to elaborate and/or fact-check, though. :)

@kevinpaquette6339 2 жыл бұрын

What year were they carved

@naithammanku3306 5 жыл бұрын

Sir thank you ,sir I whant some impermation

@ElegantMovement 10 жыл бұрын

Just a quick question: How did scientists determine the half-life of Uranium @4:35 and other elements for that matter? Thanks!

@BerryTheBnnuy 9 жыл бұрын

Uranium decays as a very predictable rate. You only need to measure the number of uranium atoms in a sample, and look at the rate of decay over time to determine the decay rate, then extrapolate the decay rate to figure out how long it'll take for half of the uranium to decay.

@BerryTheBnnuy 7 жыл бұрын

***** Exactly, and as highly radioactive as uranium ore is, the isotope of uranium in the ore has a half life of 4.5 billion years, which nicely illustrates your point.

@shucksful 2 жыл бұрын

@@BerryTheBnnuy ridiculous

@JumpJeho Жыл бұрын

@@BerryTheBnnuy "decays at a very predictable rate" , "look at the rate of decay over time", "extrapolate the decay rate". These are all assumptions. Uranium was only discovered 200 years ago. How can you possibly know how it decays over the eons?

@haggismcbaggis9485 Жыл бұрын

@@JumpJeho Yes, but one can test those assumptions. For example, with a test sample of uranium isotope one could come back ten years later and predict how much decay the uranium would have undergone and then test the sample to see if it corresponds with the predicted rate. Radiometric dating of the ocean floor is also congruent with the observed tectonic movement. Also, other isotope dating methods are in agreement with each other. One formation could date at 50 million years using a variety of dating methods and another lower formation is 60 million years. It would not make sense for different isotopes to have completely random arbitrary decay rates in different formations, but instead they are consistent.

@desertcolt07 9 жыл бұрын

how can we know if there is no existing daughter product in the zircon?

@krickrack 8 жыл бұрын

+desertcolt07 I think Lead is not an element that is incorporated in the process of crystallization of zircon crystals. So there is no Lead when zircon forms.

@wordreet 11 жыл бұрын

DOH! Will you make another video that tells us how old that particular rock on the beach was? :¬)

@user-vs4up4qo1r 3 жыл бұрын

lol

@angelica-vj9yl 3 жыл бұрын

hahahahaha

@shucksful 2 жыл бұрын

Geology is comedy

@wordreet 2 жыл бұрын

@@shucksful My old man was a hobby geologist, and had a great sense of humour, so you're probably right! 😁

@libertynindependence 11 жыл бұрын

What about dating some of the fresh magma after it has cooled, how old does that usually date?

@ronaldsmall8847 3 жыл бұрын

It usually dates to millions of years. Because radiometric dating is bull. It has never worked a single time on a rock of known age. Yet these morons assume it works on rocks of unknown age.

@danielzaharick6652 Жыл бұрын

Explain why at Mount St Helens new cone. Scientist observed new rock forming and dated via this method and came up with an age of over a million years old. Very good video showing the process.

@sandyacombs 6 жыл бұрын

The curve indicates a decrease in the rate of decay, not constant rate. Why does the rate of decay slow down by 50% for the second have life and continue to slow down by the same amount for every half-life there after? What is affecting the rate of decay over time?

@simonthomas1094 6 жыл бұрын

Sandy Combs That's how half life's work. Plot a graph and see for yourself 😉

@sandyacombs 6 жыл бұрын

Indeed, the graph indicate a decrease in the rate of decay over time, a constant rate would be a straight line. Why do some isotope, of let's say C14, take 5730 yrs to decay and others take 23,000 years to decay? Why the variability within the same sample?

@e.l.wagner9766 6 жыл бұрын

The absolute activity rate of decays per second will go down with time, because you have fewer uranium atoms in the crystal once some have decayed. Every time you draw a graph of something you halve, then halve again and again and again, you will get a curve. However, the decay constant does not change. Think of the decay of uranium as something akin to rolling dice or tossing a coin. You can't predict when an individual uranium atom will decay, any more than you can predict what an individual roll of dice will get you, but you can predict what the ratio of rolls will be over time.

@sandyacombs 6 жыл бұрын

Yes the decay rate does decrease with every "half-life" your explanations "because you have fewer uranium atoms in the crystal " is unsupported hypothesizing......maybe or maybe not, all that is known is that the measured rate of decay does decrease with each half-life and you said it's constant and it is not.

@haggismcbaggis9485 Жыл бұрын

I don't think so. Look at the Y axis. It is labelled isotope %, not rate of decay.

@coldxwaterful 4 жыл бұрын

R u gonna tell us how old the rock is?

@pearltears8039 Жыл бұрын

They say you can date the oldest rocks in the world by comparing their levels of rubidium a radioactive element to what it decays into which is strontium a stable element knowing that half of the original rubidium will take 50 billion years to decay you can get a precise date for when the rock first formed HOW DO THEY KNOW IT TAKES 50 BILLION YEARS TO DECAY? ALSO JUST BECAUSE IT TAKES THAT LONG TO DECAY; HOW DOES THAT PROVE HOW OLD IT IS?

@mohitchalia9664 2 жыл бұрын

I want to find very very old rocks

@32goingon17 3 жыл бұрын

How old does freshly cooled magma appear to be using this method?

@haggismcbaggis9485 Жыл бұрын

One million years or more. There is not enough decay for labs to detect. Argon-argon dating can start at 2,000 years.

@AlwelePojas Жыл бұрын

Carbon dating invented in the 1940s . That rock could have appeared in the 1521.....

@laylamorter8163 3 жыл бұрын

2020

@peachyyy7728 6 жыл бұрын

How do they know how long a half life is.

@originaljudah9351 6 жыл бұрын

Paul Mackenzie Hello, my name is Maliek and I study chemistry at a University in Florida with hopes of becoming a nuclear chemist and I think I might be able to help you out. Half life by definition is the time it takes for a radioactive isotope of any element to be reduced in it's abundance from the original sample by half. Now because of the principles laid out in physics regarding the attraction of subatomic particles and possible stable and unstable configurations of these particles within an atom we know that the rate of decay for any particular atom/isotope (which are really just different configurations of the particles or in some cases a change in the number of the particles) is constant by virtue of the fact the particles that make them up have constant and measurable qualities. Because radioactive decay occurs at a constant rate we can observe any radioactive element at any given time and trace back the time of it's initial state of abundance provided that it's known. Pretend I am driving from a starting point let's say Miami to New York at a constant speed the entire time 60 miles an hour, Miami in this case would represent the radioactive sample in it's initial state with New York representing it in it's final state. Since we are driving at a constant speed or velocity V=d/t velocity is known and distance from the starting position is known and velocity remains constant we can mathematically determine the time that has gone by, same basic principal applies when we use half life.

@joshkenedy8828 3 жыл бұрын

They weren't even there a thousand years ago so how would they know how fast it decays and how slow it decays and unless they're smart enough to invent a time machine there's no way they can know

@joshkenedy8828 3 жыл бұрын

Science is learning about new things not guessing the date of the rocks and calling it true

@nibiruresearch 2 жыл бұрын

Geologists only think and talk about periods of millions of years. They have different methods for determining the age of rock layers. However, there is one small problem. Ancient books tell us that a cycle of natural disasters threatens the earth and all living things. The cause of this cycle of disasters is a ninth planet in our solar system orbiting the sun in an eccentric orbit. Features of the natural disaster include a massive tidal wave, higher than the highest mountain, flooding, storms, rain, volcanic eruptions, earthquakes, and a fiery asteroid bombardment. That planet is surrounded by a gigantic twisting cloud of dust and meteorites. That cloud obscures the atmosphere, pollutes the water and covers the whole planet Earth with that dust. At the end of the crossing of this planet 9, the earth is covered with a horizontal layer of wet mud, a mixture of sand, clay, lime, fossils of sea and land animals, shells and the deposit of that dust cloud and asteroids. So in every layer on our planet we will find material of the same antiquity, perhaps many millions of years old: the deposit of extraterrestrial clay and meteorites. Even the youngest, topmost earth layer, which is less than 6,000 years old, also includes the same very old deposit. If you don't know about this cycle, you have no idea how our history has evolved. To learn much more about planet 9, the recurring flood cycle and its timeline, the re-creation of civilizations and ancient high technology, read the e-book: "Planet 9 = Nibiru". It can be read on any computer, tablet or smartphone. Search: invisible nibiru 9