I have read else where but this link will suffice. It says that Potasium-argon does not work for recent dates. I wonder, why not?
But you didn't "wonder" so much that you looked it up.
Again, this is typical creationism. Your case is built on things which you personally don't know.
The answer is simple. When rock is molten, as it is when igneous rocks are formed, then the argon, being a gas, boils out of it. But not quite all of it, and the precise quantity will depend on the particular volcano, how hot it was, the original composition of the rocks, and so forth.
This can be verified by measuring the argon content of fresh volcanic rock.
So the question is, why can we know the half life of this method in such a short period of time, and not able to use it on anything under the age of 100kya? If we can know the accuracy of the half life within 200 years, we should be able to use it on anything that is 200 years or older.
Because knowing the half-life is not sufficient: we would also have to know the exact amount of residual argon which did not boil out of the rock.
On pages 171-174 they discuss why all but one potassium/argon date for the Rusinga Island bioites was discarded. Yet they use biotite in an uncritical manor in other areas where the dates they obtained matched their expectations. On Page 174, we can also note: "Unfortunately many of the samples that passed field inspection for suitability and were laboriously collected, later proved unsuitable for dating. . . . Thus, of some 65 samples collected by M. Skinner, only 10 could be used."
Well there is clearly something wrong with this nonsense, 'cos they start off by saying that they "all but one" of the dates were "discarded", and then they say that 10 were used.
They're not even talking about the same samples, are they?
If the creationists can't consistently tell the difference between 1 and 10, is it possible that they've misunderstood the rest of the paper?
No, I believe they knew exactly what they were doing. The point is, their belief in millions of years says that submarine basalts are not suitable because they are not the norm. BUT in a creationists perspective where Noah's flood comes into play, THIS submarine basalts ARE the norm. And therefore these rocks are what give more accurate dates.
Well, you say that, but Bible Science News, November 1994, says:
"Studies have been made of submarine basalt rocks of known recent age near Hawaii. These came from the Kilauea volcano. The results ranged up to 22,000,000 years."
And these are the rocks which you say "give accurate dates"?
Is there any chance you guys could get your story straight?
I don't see a reason why darwinists stick on unchanged values of constants. Change of constants as well as change of physical laws should be something real as change of animals.
Why? The constants of physics don't reproduce with variation.
And yet darwinists - probably much more than physicists - are vey afraid of changes of constants. They are as rigid as fundamentalist. I see no reason - exept reevaluation of radioactive dating of course.
I'm afraid someone has been lying to you.
No-one is "vey afraid of changes of constants".
The reason scientists think that constants are constants is that when they measure them, they're constant. Let me know if there's any part of that you don't understand.