Meteorites are among the oldest objects we know about - formed about 4.5 billion years ago. This article describes the principles and methods used to make that determination.
The other is that the decay products of various atoms are always the same. Just looking at this list, I can see that none of these are actually assumptions used by radioactive dating methods and/or they are known issues and compensated for. Something that this particular website has none of. Basically, just like all creationists, they are making stuff up and then hoping you won’t check them on it. 1) atmosphere has always had the same amount of C-14 This is obviously in reference to carbon-14 dating of formerly living tissue.
This is also actually kind of trivial and easily determined in the lab. Let’s see what the Missing Universe Museum thinks are the assumptions of radioactive dating methods. I guess we have to start at the top and work our way down… During an organisms life, it takes in CO have the common 6 protons and 6 neutrons. However, due to some interesting nuclear chemistry (which I’ll go into if requested), there’s another version of carbon (called an isotope) that has 6 protons and 8 neutrons. Note that if the number of protons change, then the atom is no longer carbon. Amazingly (and unlike what is claimed by the creationists), scientists have known about a variety of methods that create carbon-14 and how those methods have varied over time. Well, we take a carbon sample from a material of a known age and date that. Basically, the calibration curves are off by no more than 16 years over the historical range (6,000 years or so) and no more than 163 years over the last 20,000 years.
(Aside, my dad doesn’t know how old I am, he usually misses by about two years, giving him an error of almost 5%.) Not only, is this not a ‘false assumption’. Oh and here’s a link to the Table of Contents for this set of creationist misconceptions.
There's a small amount of radioactive carbon-14 in all living organisms.
Trees undergo spurts in growth in the spring and summer months while becoming somewhat dormant in the fall and winter months.