Imperial_Samurai> There is a BIG difference between a fanatic saying "The sky is blue", which is there for all to see, and the same fanatic claiming that the walls of Jericho fell because some Israelis walked past. In the latter case it's NOt there for all to see.
And again... Who else is there to back up this guys claim? If he's the ONLY one, and it's not accepted among archaeologist... What does that say about his credibility?
En strøm af interstellare atomer suser netop nu gennem solsystemet. Forskere mener, at strømmen er en del af en gigantisk interstellar gassky, som solsystemet befinder sig midt i.
Heldigvis er vores stjernesystem i bedste science fiction-stil udstyret med et skjold. En gigantisk magnetisk bobel kaldet heliosfæren omkranser alle ni planeter, og den har før hjulpet vores klode mod eksploderende stjerner.
Carbon14:
Isotope dating takes advantage of the fact that radioactive materials break down at a rate independent of their environment. Any solid object that formed containing radioactive materials therefore steadily loses them to decay. If it is possible to compare the amount of radioactive material currently present with the amount originally present, one can deduce how long ago the object was formed. The amount originally present cannot, of course, be observed directly, but can be determined by indirect means, such as identifying the decay products.
C-14 dating uses an unstable isotope of carbon that is constantly being produced in the upper atmosphere by cosmic rays. This process is assumed to be in equilibrium with the decay of C-14 throughout the biosphere, so the proportion of carbon that is C-14 as opposed to the stable C-12 and C-13 isotopes is essentially constant in any living organism. When an organism dies, it stops taking up new carbon from its environment, but the C-14 in its body continues to decay. By measuring the amount of C-14 left in organic remains, one can establish how long ago the organism they came from died. Because C-14 has a half-life of only a few thousand years, C-14 dating can only be used for remains less than a few tens of thousands of years old-- after that, the C-14 is entirely gone, to all practical purposes. Other isotopic dating techniques, such as potassium-argon dating, use much longer-lived radionuclides and can reliably measure dates billions of years in the past.
Actually the production rate isn't all that constant, so the amount of C-14 in the biosphere varies somewhat with time. You also need to be sure that the only source of carbon for the organism was atmospheric carbon (via plants). The nominal date from a C-14 reading, based on the present concentration, therefore has to be corrected to get the real date --- but once the correction has been calculated using an independent dating tool like dendrochronology (see below), it can be applied to almost any sample.
There are some known anomalies in C14 dating, such as molluscs that get their carbon from water. Creationists seem to make a habit of taking samples that are known to be useless for C14 dating, presenting them to scientists for examination, representing them as other than they are, and then claiming the anomalous dates they get for them as evidence that C14 dating is all a sham.
While it is true that there may be unknown errors in some dating methods (see the note in section 0 about science "proving" things) this assertion cannot be used to write off isotope dating as evidence of an ancient Earth. This is because:
There are several independent ways of dating objects, including radio-isotopes, dendrochronology, position in rock strata etc. These all give a consistent picture.
Dating methods all point to an old Earth, about half a million times older than the Creationists claim. This requires dating methods which are accurate up to 6,000 years ago and then suddenly start to give completely wrong (but still consistent) answers. Even if our dating methods are out by a factor of 10 or 100, the earth is still thousands of times older than Creationists claim.