Sylas's reply provided the necessary details, but I thought your post was a perfect illustration of how Creationist misinformation in books and pamphlets and at websites misleads sincere Christians on a range of topics having nothing directly to do with evolution. I assume you didn't just decide on your own that evolutionists first decide on the age they want, then they adjust their equations over and over to get the desired result. I assume you read this someplace from a source you assumed would not mislead you.
Guess what? They misled you.
Why? Did they not know themselves? Did they know what they were writing was wrong?
And why did you believe it? Do you really think that scientists, a fairly large and varied group these days, routinely falsifies their research results? And even if you do accept this ridiculous proposition, don't you understand that since scientific results would be only a matter of opinion and not of evidence that the scientific community would quickly fragment into subgroups divided along subjectively drawn divisions,and that since this hasn't happened your original premise must be wrong? This type of thinking is a suborder of conspiracy theorizing, where the world is the way it is because of the plots of sinister groups working behind the scenes. In this case you could only say what you did about scientists manipulating those equations if you believed there's a huge conspiracy of scientists who agree beforehand on the results they want, then conspire, over and over and over again in paper after paper after paper for year after year after year to keep the conspiracy a secret. Wow!
Accusations of data maniputation is an example of the most egregious type of Creationist misinformation because it is just blantantly wrong. Other examples of the same thing are that the fossils in the geologic column are jumbled up just like you would expect in a flood, that evolution says you can get a cat from a dog, that the likelihood of life forming naturally has only one chance out of 10 raised to the power of 1 followed by a hundred zeroes, that evolutionary and geological ideas derive from a desire to oppose religion, and so forth. These kinds of things are just made up out of whole cloth.
The next level of misinformation is more pernicious because though it is false, it takes its starting point from something true. Examples of this are that the slight depth of moon dust means the moon is young, that the declining magnetic field strength of the earth means the earth is young since extrapolating backwards for more than a few thousand years yields an impossible field strength, that the decreasing diameter of the sun means the solar system is young because if you extrapolate back millions of years the sun would have been larger than the diameter of the earth's orbit which is impossible, that if the earth were really billions of years old the oceans would be far saltier, and so forth.
And so a word to Christians perusing Creationist materials: be careful out there!
I know that all the above is terrible self-serving coming from an evolutionist, implying as it does that the sources of Creationist material are purposefully misleading. All I can say is that you should try to become sure of your information by checking it against other sources, including non-Creationist sources, and to try to understand your argument before you make it. If evolution is really false it will only be demonstrated by evidence that is real, not made up.
--Percy
[Added a title. --Percy]
[This message has been edited by Percy, 02-21-2004]