How do we know how old an object is?

[Arnack]

How can we estimate the age of objects? I know radiocarbon dating, but people tell me anything over 50,000 years old is impossible to estimate?

Thanks!

[iNow]

Anybody who tells you that it's impossible to date anything over 50,000 years is wrong. Here is a list of some of the various methods. Click on each to learn more.

 

http://en.wikipedia.org/wiki/Category:dating_methods

 

 

More information here:

http://en.wikipedia.org/wiki/Category:Radiometric_dating

 

 

Potassium-argon is a pretty popular method as I understand it. Regardless, those two links alone flatly debunk the claim of >50K impossiblity.

 

http://en.wikipedia.org/wiki/Radiometric_dating

[Arnack]

Thanks!

[iNow]

You're very welcome.

[NeonBlack]

It is difficult to date once-living (dead?) things which are older than 50000 years using C-14 dating. This is what you probably heard and misunderstood (or heard from someone else who misunderstood.)

[iNow]

It is difficult to date once-living (dead?) things which are older than 50000 years using C-14 dating. This is what you probably heard and misunderstood (or heard from someone else who misunderstood.)

 

Indeed, you're most certainly correct. I was more trying to demonstrate that C-14 is not the only dating method at our disposal, but if we limit the conversation to that approach, your comments are spot on.

 

From the third link in my post above:

 

The carbon-14 dating limit lies around 58,000 to 62,000 years.

[Mokele]

It's also worth noting that we don't date fossils. Instead, we date igenous rock from lava flows that are in the same sediment layers. This is why we can resolve radimetric data to within a few thousand years, but often cannot resolve fossil dates beyond half a million - we just haven't found any igneous deposits closer than that.