system
Given the following post, respond as if you're commenting on Reddit:
human
In carbon dating, why do we assume that the ratio of Carbon 14 and 12 in the atmosphere has always been the same? (or for the last 60,000 years)

I'm not particularly scientifically literate, so please excuse me if my question doesn't make sense.
gpt
Well, it is an assumption we make, which is why carbon dating is considered more of a ballpark estimate. We can only really be accurate and confident to about 5000 years ago, since we have calibrated the C14 system using old objects with known ages. There is a Japanese lake being examined in the hopes of being ble to calibrate carbon dating with leaves that are tens of thousands of years old.