Radiometric Dating

I've been reading up on radiometric dating methods. I've got the general concept of carbon dating at this point, but was wondering if someone can answer a couple questions:

1. I understand that the method has been calibrated using various other dating methods (tree rings, etc.). How far has it been successfully calibrated against other methods that we absolutely trust (i.e. 6000, 15000, 30000 years)? I know that it is supposed to be accurate to 50/60,000 years, but wasn't sure if those later dates were also backed up using other dating methods.
2. A related question is - how do we know that there isn't a need to make other adjustments?
3. What are the comparison methods used for calibration and do we know their reliability?

I don't understand uranium and thorium dating at this point. I only know enough to know that it's a somewhat different approach. So, I'll hold off on those questions for now. Thanks!

MGraser

Here is a very good treatise of the various methods and how they are compared. With over 40 different methods in close agreement we can be fairly certain of their accuracy. Much more info at the website, written by a Christian who is also a scientist.

http://www.asa3.org/ASA/resources/Wiens.html#page%2019

Grumpy

A new technique called Radiocarbon Dating is also being developed for dating objects.It helps in finding the age of the objects by measuring radioactive decay.
Radiocarbon C-14 is a radioactive form of carbon that occurs in traces in the atmosphere.Living organisms absorb radiocarbon from the atmosphere. When they die the radiocarbon decays at a known rate. By measuring the quantity of radiocarbon remains in the organic material, scientists can calculate how long ago the death occurred. This method can date objects upto 70,000 years. Half the radiocarbon in an object decays by releasing particles about every 5700 years( half life is 5700 yrs.) From this information scientists can date the objects.
Scientists also use Uranium-Lead Dating(for rocks older than 20 million yrs.) and Thorium-Lead Dating(for rocks older than 50 million years) to date events beyond the range of radiocarbon.

Hello all,
Here is extract from one website,where the proponent claims that there are indications that humans have 2 information systems,one on material level another one on mirror level:

"DUALISTIC BIOLOGY
This theory is based on the assumption that living organisms make invisible mirror copies of themselves (parallel dimension, mind, dark matter, mirror particles).
Benveniste´s experiment and Kirlian photography of a cut leaf are indications that mirror copies of molecules and atoms are a reality.
Libet`s experiment, blindsight, endospores, seeds, phantom limbs and tardigrades are examples which indicate that organisms have developed a second information system on mirror world level.

Libet´s Sensory Experience Backwards in Time-experiment is a good demonstration that humans have two information systems: 1. The nerve impulse to cerebral cortex + 0.5 sec to consciousness in the material brain. 2. A fraction of a second (faster-than-light) on the unconscious mirror world level to mind brain.
Consciousness appears where mind brain is connected to the materialistic brain. Neurotransmittors act as body-mind transducers.

My interpretation of Benveniste´s experiment: Every molecule has a corresponding mirror copy of the molecule. A copy ("key") can react on a specific receptor molecule ("lock") on body level according to the immunological principle."

http://web.telia.com/~u59500234/ED03.htm


What do you guys think?Is it worth some serious attention or mere speculation?
My major point here is this: ""Libet`s experiment, blindsight, endospores, seeds, phantom limbs and tardigrades are examples which indicate that organisms have developed a second information system on mirror world level."
We got a claim here.Can it be refuted?I think claim on phantom limbs can be refuted,what about the rest?"
Thank you,