Radio carbon dating inaccuracies

When each of these elements, uranium, potassium, radium etc.

So they start with the assumption that dinosaurs lived millions of years ago, then manipulate the results until they agree with their conclusion. So why is it that if the date doesn't fit the theory, they change the facts?Let's say initially every radioactive element was "exploded" into existence from pre-existent elements.None of these early faster half-lives would be the same as they are today.Unbiased science changes the theory to support the facts.They should not change the facts to fit the theory.