In theory, every atom, and every particle that makes up atoms is traceable to the Big Bang. The entire universe should therefore be the same age, correct? Things may have rearranged and reorganized, but at bottom level, everything comes from the same place, and the same time.
Now focus on Earth. At some point, Earth became a stand alone planet, meaning that no new material was coming in, and no material was going out (I'm ignoring asteroids and meteors). In other words, not only is every element the same age, because they originated at the Big Bang; but now every element, gas and molecule which clustered together to form the earth, could be said to have the same age in respects to the origin of our planet.
So my question is, what does it mean to say the deeper the strata the older it is, if the whole earth is already 4.5 billion years old no matter what depth you're looking at? I don't get what radiometric dating is doing, and how it can determin how old strata is and how old the earth is at the same time.
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That is not correct. Not all particles were created at the big bang.
oh so what was created at the big bang then?
@curiousgeorge: Helium, lithium, and a few other elements.
Why are you disregarding meteorites? The Earth is still a work in progress. Tens of thousands of tons of dust and meteorites rain down every year, though I think we lose a larger amount of hydrogen and helium. I'm not sure about the depth/age thing. The Earth's crust and interior are continually recycling. And when the whole thing was a molten mass, presumably the heavier stuff would have gone deeper, rather than the older stuff. There's also the planetary collision hypothesis, which seeks to explain the origin of the Moon. Hitting a Mars-size object would have reshuffled things pretty thoroughly.
Will this lead to some question about creationism or religion?
no question about religion
but you did bring something up ive also thought about before. why are strata so perfectly straight if the top layer isn't straight, there's hills and valley, rivers and canyon that eat away and rearrange the surface. is any of that seen in previous strata
@Curious George
"no question about religion"
You are aware that this an atheist forum? Non-atheists come here and try to convince us that god created everything. The banana you're holding is a symbol of that attitude. There's an evangelist called Ray Comfort ("Banana Man") who used the banana as an example of god's perfect design of the world.
"We encourage discussion about any and all topics as long as it abides by our forum guidelines. You can ask questions, request input, present a challenging topic for debate or share an idea."
i guess I'm in the wrong forum
@Curious George
"i guess I'm in the wrong forum"
Not necessarily. I'm curious, too, about where these questions are leading.
@Curious George
Absolutely! Geological strata is full of preserved, eroded surfaces. Nor is it always perfectly straight! It's full of bent, tilted, twisted, and broken rock. In some places giant columns of salt have pushed their way up right through the solid rock! That salt originated in ancient, shallow sea deposits made in warm regions where evaporation is key. In the Grand Canyon, when you get down to the old "basement" rock, you are looking at ancient mountains that have been worn down to their roots before burial in sediment! Geology is a fascinating subject. You ought to look into it.
Hi C. George,
"So my question is, what does it mean to say the deeper the strata the older it is, if the whole earth is already 4.5 billion years old no matter what depth you're looking at?"
Yes, to a first approximation, the protons, neutrons and electrons were all formed in the first second after the Big Bang. However, if we were to apply your logic from the rocks to humanity, then you and your parents, and grand parents and great grand parents, etc. all the way back are the same age: 4.5 billion years old.
However, if we take several steps back, look at larger assemblages of atoms, molecules, rock and people, then it becomes obvious that they have different ages at that macro level.
How does radiometric dating work? Different isotopes decay at different rates, therefore by looking at comparative ratios of parent and daughter isotopes, one can estimate the rocks age. See:
https://geomaps.wr.usgs.gov/parks/gtime/radiom.htmlisotopes
By the way, I had a general idea about this, but to be sure, I did a couple of searches and, Voila! Since you are "curious" next time perhaps you can do the searching.
isn't that what science tells us? that we are starstuff and that the elements that make us up were formed all formed in the crucible of starts long ago? we are made of 4.5 billion year old stuff.
by the way I came looking for peoples opinions, hopefully even an expeerts opion. whats the point of ever having a discussion with a person if you can always google the answer? now I don't know if you're smart or if youre just regurgitating some Wikipedia factoid
@Curious George
We are indeed made of star stuff, some of which may be older than 4.5 billion years! We are also made of Big Bang stuff that goes back 13 some billion years. We are also made of younger atoms made at different times, even within a thousand years ago. Some of our atoms come from the fallout of nuclear testing in the 1950s.
In the OP you asked two factual questions, I, more or less, answered both those factual questions. On what aspect did you want an "opinion?" That my protons are old? My hemoglobin bound-iron is younger? That that I am older than the majority of the residual Strontium 90 in my bones and teeth? As they say, age is just a number.
"now I don't know if you're smart or if youre just regurgitating some Wikipedia factoid." I can live with that.
@curious george
Most atoms (outside hydrogen, helium, and some lithium) were created in stars at various times and are being created in stars at this very moment. Elements like carbon, silicon, oxygen build up in the cores of stars that are large enough to carry fusion beyond helium--and are scattered in nova or supernova explosions. Heavier elements, such as uranium, are created by the energies of a supernova. When Earth formed, various geological processes concentrated some of the elements, including some of the radioactive elements. Since then, those radioactive elements have been decaying according to the half-life rule. Earth's geological processes continue to collect or produce various deposits or minerals respectively, and, if radioactive, they constitute "newly set" radiometric clocks. Therefore, the time those rocks were formed (usually this applies to igneous rocks) can be read off from these radiometric clocks. (The individual atoms, themselves, may go back to when the Earth was formed or earlier. The radiometric clocks essentially measure ratios of parent elements and daughter elements.)
With respect to the Earth's age, measurement of the age for the oldest meteorites points to 4.5 billion years. We get ages up to that point but not beyond. Since some meteorites formed at about the same time our solar system formed, essentially the age of the Earth, we would reasonably expect that the oldest meteorites would give the age of the Earth. That figure agrees with a more sophisticated use of radioactive elements to directly measure the Earth's age.