Video instructions and help with filling out and completing Can Form 8453 S Calculator

Instructions and Help about Can Form 8453 S Calculator

In the 17th century a theologian called james ussher worked out the age of the universe based on the chronology of the Bible it was created he concluded in a week in October 4004 bc even today millions of people still believe that this 17th century calculation is about right and that the overwhelming evidence of geology cosmology paleontology chemistry astrophysics geophysics stratigraphy and biology is wrong so let's take a look at what that evidence is starting with a principle that even creationists don't dispute the golden rule is that newest sedimentary deposits are always laid on top of older ones so except where rocks have been folded this orange bed would be older than the green one and the green one is older than the blue one geologists can then follow a single bed to make similar deductions in a different locality the dark gray bed may be at the surface or even at a higher point than the others but it's older than all of them and the light gray bed is older still what we end up with is what's called the geological column to get the absolute dates of these rocks scientists use a variety of different methods I'll start with one of the easiest and most recent we all know trees have rings because in summer they grow faster than in winter but seasonal growing conditions vary according to the weather so the band's will vary in size each time period in each geographical location has its own distinctive pattern of tree rings like a fingerprint so if we take word of an urn age we can match the oldest part of it with the youngest part of another piece of wood and so on back through time back ten thousand years in fact and already way beyond the biblical chronology okay I'll spend a bit of time on this one because creationist preachers seem to be obsessed with it our upper atmosphere is constantly being bombarded by radiation from the Sun when a stray Neutron hits a nitrogen atom it changes it into carbon but this is a heavy and unstable form of carbon called carbon 14 or c 14 the normal form of carbon is c12 in the atmosphere c14 combines with oxy to make carbon dioxide which is then absorbed by plants and into the bodies of animals that eat the plants the ratio of these two isotopes in animals and plants is roughly the same as the ratio in the atmosphere around them but when the animal or plant dies see 14 decays over time and reverts back to nitrogen so compared to see 12 which doesn't change the amount of c14 falls at a constant measurable rate by measuring this ratio inside the dead animal or plant scientists can find out when it died before I look at other dating techniques I'll bat a few hoary old myths about carbon 14 out of the ballpark no it's not but sometimes rarely a sample is wrongly dated because it's contaminated bacteria dead skin fungus if care isn't taken it's the carbon in these contaminants that gets dated rather than the sample itself that's why samples from different parts of the same plant or animal have been known to give different results but a similar thing can happen with any kind of sampling contaminated samples don't invalidate the principle of DNA analysis or chromatography or spectroscopy we know they work and we know carbon dating works firstly carbon dating can be checked against artifacts of known age secondly it can be checked by sending the same artifact at different labs for analysis thirdly let's take a sample of organic material from each of these layers if carbon dating was random nonsense you'd expect the chronological order of these samples to be all over the place but that doesn't happen the results show each of these samples in its correct chronological order the ones from the upper beds are younger and the ones from the lower beds are older is its magic or is it because carbon dating works and that's why it's used to quote Kent Hovind samples don't come with labels attached telling the lab their age testing is always blind if it's not blind it's not science and if creationists don't trust the carbon dating method they are perfectly welcome to conduct their own blind test to prove it wrong but carbon dating isn't used on diamonds and co and for very good reason as I explained c14 is formed when neutrons collide with nitrogen atoms the c14 used in carbon dating originated in the atmosphere but you can also get it deep underground in places where decaying uranium is giving off neutrons coal and diamonds are made of carbon so you'd expect to find higher levels of c14 in coal and diamonds close to rocks that contain uranium and much lower levels away from those rocks and that's exactly what we do find carbon dating is only used and only useful for dating organic material in the topmost sedimentary layers now that we've got carbon dating out of the way let's quickly run through a few more absolute dating methods biologists know that human DNA mutates at a fairly regular rate and they can trace these mutations back like following the branches of a tree back to the trunk it's not a greatly accurate method but it does give a rough idea of when humans migrated and a very definite idea of where it doesn't lead back to Mount Ararat 4,000 years ago but to Africa around 50,000 years ago just as other dating methods suggested it should every 250,000 years or so the Earth's magnetic fields flip over and the South Pole becomes the North Pole magnetized minerals within rocks show the polarity of the earth when the rocks were laid down so throughout the geological column rocks show a regular magnetic banding depending on the

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