the flood.

Originally posted by beerbrewer
I have no doubt that if you poke and prod an ameoba long enough and hard enough, blast it with a little radiation and do all kinds of other "scientific" stuff to it, that it wouldn't change into something... But it still doesn't explain how my turnip changed into a cat.

In an article published in the Zoological Journal of the Linnean Society in 1984 (V ...[text shortened]... rchaeopteryx is not an ancestral bird and transfers it to the dinosaur suborder Theropoda.

Yes, the hypothesis has been advanced that Archaeopteryx is not the precursor of modern birds, however a close relative of Archaeopteryx was. Certainly the fact that Archaeopteryx has bird like features would seem to suggest that conditions existed at the time which favoured bird design. My understanding is that the jury is still very much out on this one.

Originally posted by 7ate9
dating systems i definitely cannot buy, and how much of science is based on this. how far have they advanced on what isn't certain proof?

This may be an exceptionally long post, but I want to spell this out.

All atoms come in various forms called isotopes. Isotopes are atoms with a change in the number of neutrons; it is the number of protons which determines which element an atom is. Protons and neutrons are held together in the nucleus by the strong nuclear force. Protons are positively charged and, as we all know, positive charges repulse each other. Thus the strong nuclear force must indeed be strong to hold the nucleus that is constantly trying to split apart together. However, the strong force only has a limited range, meaning that large atoms are very much more likely to split apart than small ones, which tend to be very stable.

Now I'll deal with the decay of 14C, which is involved in radiocarbon dating. As Googlefudge said 14C is found in the atmosphere, where it is created in the troposphere when a nitrogen atom gets a proton displaced by a neutron (this changing the number of protons from 7 to 6, and thus from nitrogen to carbon). The new 14C atom has 6 protons and 8 neutrons. 14C spontaneously emits a beta particle, changing the "extra" neutron into a proton. Whilst this emittion is spontaneous, it is not instantaneous. The probability of any given atom decaying at a certain time can be given by an exponential decay curve. Likewise, a large population of atoms has a decay following exponential rules. In other words, when there are alot of atoms there, many atoms will decay, when there are less atoms, then less will decay. The decay rate is linearly related to the amount of 14C in the sample.

Plants take C up during photosynthesis, including 14C. Since the 14C concentration in the atmosphere is about constant, we can measure the 14C concentration of any given sample and, if we know the decay constant (the relationship between 14C concentration in the sample and its decay rate) we can interpolate its age.

This, of course, throws up new questions, (1) how do we know that isotopes follow exponential decays and, (2) how do we know the decay constants of different isotopes.

There are a couple of simple ways to measure this. First we can use a short lived isotope and measure the decay in the lab. Something like Sodium 24, with a half life of 15 hours, or Iodine 131 at 8.07 days. This provides direct evidence that radioactive decay follows exponential rules. Okay, but what about something longer lived, like Uranium 238 with a half life of 4.5 billion years? This is simpler than it looks. First, purify some Uranium 238 up to different purities. That is to say different concentrations within the parent material. If exponential decay is correct then these should emit radiation at different rates, which can be predicted. It's not possible to sit there and wait for the amount of Uranium 238 to half in the sample, but we can infer mass differences. This is less dodgy than it sounds. All you have to do is measure the energy output from the sample, and since E=mc^2 you can dervive the mass change, and from that, the decay rate. From multiple samples at different enrichments. This gives an exponential decay.

Now for the heavy isotopes. These follow much the same rules, but radioactive emmission is as a result of the mass convertion to energy when a large, wobbly nucleus splits apart. Unlike 14C which is produced in the atmosphere and is relatively constant, radioactive rocks are produced from radioactove decay within the planets core. This means that they can turn up in rocks at all different concentrations. We need to know the initial parent-daughter isotope ratio before we can work out the amount of mass loss, and therefore the time since that rock became solid. This is easily worked out though. We just take a non-radioactive sample from the same rock strata since this must be the same age. We can then derive the initial amount of the parent isotope in the rock and work out the amount lost over time.

It is elements such as Uranium 238 which allow us to date very old things, like the earth and moon. Both have been dated. In fact, no matter which dating system you use (there are over 40 for differing time scales) you get roughly the same answer for the age of the planet. This age is around 4.53 billion years. The moon is of similar age.

Originally posted by hakaman
so after the flood went down from then until now all races came 2 be,tribes who live in the middle from nowhere with rings in thier noses ,the human race evolved alot if this is true

What? You should hit the "reply and quote" button so we know who, and to what, you are referring.

Originally posted by scottishinnz
Yes, the hypothesis has been advanced that Archaeopteryx is not the precursor of modern birds, however a close relative of Archaeopteryx was. Certainly the fact that Archaeopteryx has bird like features would seem to suggest that conditions existed at the time which favoured bird design. My understanding is that the jury is still very much out on this one.

So why did you cite it as an example, then?

Originally posted by scottishinnz
Nope. But they both had a common ancestor.

Where? What? Or is that your theory (because I can't DISPROVE it) and you're sticking to it?

Originally posted by googlefudge
At no point has any of my lecturers spewed anything on, or at me. one of the most important aspects of a degree is to learn to critically asses arguments and come to a conclusion based on evidence. also those people with 'fancy' degrees are the ones who run, build and designe the modern world, cure your diseases, turn on your lights, cook your food, clea ...[text shortened]... ~100 thousand years puts a flood 4500 yrs ago well within carbon datings range dont you think?

Dude, never once did I claim to know more about anything than anyone else. On the contrary, I believe I stated that I was trying to learn. I thank God for all of those people every night in my prayers. Where would we be without them?

Isn't that what scientists do, quote sources?

Glad to see that your math skills are as finely honed as your wit, but 100,000 years is a far cry from the billions of years you and Scottishitz are trying to tell us it takes something to evolve.

Originally posted by 7ate9
thanks SNZ, i have learnt abit more about dating systems. i believe in what science has in regards to dating systems, but science isn't the problem i see with them.

look at what has happened to the earth through it's existance and you will understand the atmosphere has changed from time to time. i agree with dating systems up to a few thousand years, but af ...[text shortened]... ord!)

over a few thousand years how easy would it be easy to taint a sample being tested?

You can't have a chemical catalyst in a radioactive decay. It's not an equilibrium chemical equation.

Originally posted by beerbrewer
Dude, never once did I claim to know more about anything than anyone else. On the contrary, I believe I stated that I was trying to learn. I thank God for all of those people every night in my prayers. Where would we be without them?

Isn't that what scientists do, quote sources?

Glad to see that your math skills are as finely honed as your wit, but ...[text shortened]... m the billions of years you and Scottishitz are trying to tell us it takes something to evolve.

Radiocarbon dating is only used to date formerly living things and only in recent (ie thousands rather than millions) time periods. If you want further back you measure other isotope decay.

Originally posted by 7ate9
thanks SNZ, i have learnt abit more about dating systems. i believe in what science has in regards to dating systems, but science isn't the problem i see with them.

look at what has happened to the earth through it's existance and you will understand the atmosphere has changed from time to time. i agree with dating systems up to a few thousand years, but af ...[text shortened]... ord!)

over a few thousand years how easy would it be easy to taint a sample being tested?

The atmosphere will have no effect on nuclear interactions. Changes in atmospheric concentrations of gasses can only have chemical effects (i.e. with the electrons orbiting the nucleus), but not nuclear effects. If it did, then different radiodating systems would give different readings for the same samples, because the atoms of each element would be affected differently.

Originally posted by beerbrewer
Glad to see that your math skills are as finely honed as your wit, but 100,000 years is a far cry from the billions of years you and Scottishitz are trying to tell us it takes something to evolve.

Which is why things older than about 60,000 years old, and/or inorganic in composition are subject to other dating methods. As Xanthos correctly points out these are isotopic decay mechanisms.

Originally posted by beerbrewer
Where? What? Or is that your theory (because I can't DISPROVE it) and you're sticking to it?

It's the extrapolation of evolutionary theory. Pretty much all current life must have had a common ancestor. Cells, even from different Kingdoms (plants, animals, fungi, bacteria and archae), share too many common features (by and large, there are some odd archae) to have evolved independantly. The fact that there are fundamental differences between prokaryotic cells (bacteria and archae) and eukaryotic cells (plants, animals and fungi) and between the kingdoms suggests that these splits between the cell line that would eventually become your turnip and the cell line that would eventually become your cat happenned very early on, probably around 1 - 2 billion years ago.