Results 1 - 24 of Browse bozeman biology resources on Teachers Pay Teachers, Biology Video Guide Bozeman Biology Radiocarbon Dating . which asks students to solve problems quantitatively to investigate movement of molecules. Mr. Andersen explains how carbon dating can be used to date ancient material. The half-life of radioactive carbon into nitrogen is also discussed. Jan 20, Problems of Interpreting Radiocarbon Dates from Dead-Ice Terrain, with an First Meeting American Quaternary Association (AMQUA), Bozeman, p. Proceedings of the North Dakota Academy of Sciences 21, 42–
Hemoglobin (video) | Human biology | Khan Academy
Hebert mentioned a few commonly-used YEC examples of radiometric dates which do not conform to reasonable old-Earth interpretations. One of these was the study done in the s by Steven Austin of the Institute for Creation Research, in which ICR submitted samples from the dacite lava dome eruption of Mt.
Helens to a laboratory for potassium-argon dating. The resultant dates for mineral and whole-rock samples ranged from 0. This experiment by ICR was set up to fail from the beginning. The half-life of potassium is 1. The amount of radiogenic argon produced from potassium in only a few years is miniscule, and so in general, standard K-Ar dating is not recommended for samples believed to be less than 2 million years old, as there is a risk of contamination from residual argon from previous samples.
Additional problems abound, such as the presence of xenocrysts crystals that appear to be derived from the walls of the magma chamber or other sub-volcanic conduits rather than crystallizing from the magma itselfzoned crystals which indicate that mineral grains crystallized in stages in the magma chamberand presence of volcanic glass in the samples which would have trapped much of any argon that was dissolved in the magma.
Radiometric dating ages disagree with ages determined by other methods Dr. There are several obvious problems with this argument: Why would one think that processes with highly variable rates, such as erosion of continents or addition of various salts to seawater, would be more reliable geochronometers than a process with known rates, such as radiometric dating I will address the issue of constant decay rates later?
Hebert used a distorted definition of uniformitarianism in his presentation. I know of no modern geologists who would say that either erosion or sedimentation occurs at a constant rate. This goes for a large number of geological processes. Many have critiqued YEC seawater arguments. There is also no clear evidence that I know of that the oceans are becoming more saline over time. But they have no compelling reason other than their YEC beliefs to plot their magnetic field strength points on an exponential decay curve.
I cannot think of a single geological process that unambiguously points to an Earth that is only years old. I also cannot think of a single geological process that is inconsistent with an Earth that is many millions of years old. Hebert emphasized two examples of discordancy: Flaws in a Young-Earth Argument, Part 1 of 2. To summarize, the YEC team used the present high rate of heat flow in this geothermal field and applied this to the entire thermal history of the area, rather than a thermal history model that takes into account the fact that these rocks have been much cooler for most of their history.
Warm mineral grains lose helium much more rapidly than cool grains do. This is another example of YECs using a distorted version of uniformitarianism by extending the present blindly into the past as the foundation for their young-Earth arguments. All of this biased the results in favor of a younger Earth. Hebert stated that radiocarbon dating assumes the same ratio of carbon radiocarbon in the atmosphere for thousands of years. I was really surprised that he said this; perhaps my notes are wrong.
Hebert stated that there should be no carbon in samples overyears old. He then stated that carbon has been found in coal, dinosaur bones, diamonds, and petroleum, all of which are believed to be millions of years old. It is true that any traces of original carbon in a sample should be gone afteryears.
But there are a number of perfectly reasonable ways for more recently-formed carbon to be present in ancient deposits. One is by groundwater contamination, which brings atmospheric carbon into underground systems. This would be particularly effective at bringing carbon into coal.
AP Biology - Carbon Dating
But the most likely source for carbon in these samples is laboratory contamination. Most of the carbon detected in YEC experiments has been at levels that push the limits of detection. It is impossible to completely clear mass spectrometers and other laboratory equipment of residues from previous analyses, and so chances are, virtually any sample analyzed will register at least some miniscule trace of carbon whether or not there was any actual carbon in the sample.
Radiometric Dating Assumptions Dr. Hebert listed three conditions he called them assumptions that must be true in order for radiometric dating to work: No starting daughter isotope present. Neither parent nor daughter isotope can be added or taken away. Decay rate must be constant. The first of these is true for some radiometric techniques, but not for all.
In many cases, we know that there was some of the daughter isotope present in the sample when it formed. In both of these cases, the mathematics of the technique reveals the amount of daughter element that was present when the sample formed.
If you disagree, then your problem is with math, not with geology. The second condition must be fulfilled in order to determine an accurate radiometric date. Geochronologists will generally avoid samples that have obviously been altered since formation, as these are likely to have experienced gain or loss of either the parent or daughter nuclide.
Instead, they know that it is best to analyze samples that appear fresh, unaltered, and unweathered.The Origin of Life - Scientific Evidence
For isochron techniques, the graphs produced by the analyses will usually reveal whether any parent or daughter elements have been added or removed.
The third condition—constant decay rates—must also be true in order for radiometric dating to work. YECs have spent much effort trying to demonstrate that radioactive decay has greatly accelerated in the past, and have thus far been unsuccessful. We have three oxygens, two hydrogens, one carbon. It's called carbonic acid because it gives away hydrogen protons very easily.
Acids disassociate into their conjugate base and hydrogen protons very easily. So carbonic acid disassociates very easily. It's an acid, although I'll write in some type of an equilibrium right there. If any of this notation really confuses you or you want more detail on it, watch some of the chemistry videos on acid disassociation and equilibrium reactions and all of that, but it essentially can give away one of these hydrogens, but just the proton and it keeps the electron of that hydrogen so you're left with a hydrogen proton plus-- well, you gave away one of the hydrogens so you just have one hydrogen.
This is actually a bicarbonate ion. But it only gave away the proton, kept the electron so you have a minus sign. So all of the charge adds up to neutral and that's neutral over there. So if I'm in a capillary of the leg-- let me see if I can draw this.
So let's say I'm in the capillary of my leg. Let me do a neutral color. So this is a capillary of my leg. I've zoomed in just one part of the capillary. It's always branching off. And over here, I have a bunch of muscle cells right here that are generating a lot of carbon dioxide and they need oxygen. Well, what's going to happen?
Bozeman Creation Conference — Radiometric Dating – GeoChristian
Well, I have my red blood cells flowing along. So essentially they get squeezed as they go through the small capillaries, which a lot of people believe helps them release their contents and maybe some of the oxygen that they have in them. So you have a red blood cell that's coming in here. It's being squeezed through this capillary right here.
It has a bunch of hemoglobin-- and when I say a bunch, you might as well know right now, each red blood cell has million hemoglobin proteins. And if you total up the hemoglobin in the entire body, it's huge because we have 20 to 30 trillion red blood cells. And each of those 20 to 30 trillion red blood cells have million hemoglobin proteins in them. So we have a lot of hemoglobin. We have about trillion or a little bit more, give or take. I've never sat down and counted them.
But anyway, we have million hemoglobin particles or proteins in each red blood cell-- explains why the red blood cells had to shed their nucleuses to make space for all those hemoglobins. So right here we're dealing with-- this is an artery, right? It's coming from the heart. The red blood cell is going in that direction and then it's going to shed its oxygen and then it's going to become a vein.
Now what's going to happen is you have this carbon dioxide. You have a high concentration of carbon dioxide in the muscle cell. It eventually, just by diffusion gradient, ends up-- let me do that same color-- ends up in the blood plasma just like that and some of it can make its way across the membrane into the actual red blood cell. In the red blood cell, you have this carbonic anhydrase which makes the carbon dioxide disassociate into-- or essentially become carbonic acid, which then can release protons.
Well, those protons, we just learned, can allosterically inhibit the uptake of oxygen by hemoglobin. So those protons start bonding to different parts and even the carbon dioxide that hasn't been reacted with-- that can also allosterically inhibit the hemoglobin. So it also bonds to other parts. And that changes the shape of the hemoglobin protein just enough that it can't hold onto its oxygens that well and it starts letting go.
And just as we said we had cooperative binding, the more oxygens you have on, the better it is at accepting more-- the opposite happens.
Bozeman Creation Conference — Radiometric Dating
When you start letting go of oxygen, it becomes harder to retain the other ones. So then all of the oxygens let go. So this, at least in my mind, it's a brilliant, brilliant mechanism because the oxygen gets let go just where it needs to let go.
It doesn't just say, I've left an artery and I'm now in a vein. Maybe I've gone through some capillaries right here and I'm going to go back to a vein. Let me release my oxygen-- because then it would just release the oxygen willy-nilly throughout the body. This system, by being allosterically inhibited by carbon dioxide and an acidic environment, it allows it to release it where it is most needed, where there's the most carbon dioxide, where respiration is occurring most vigorously.
So it's a fascinating, fascinating scheme. And just to get a better understanding of it, right here I have this little chart right here that shows the oxygen uptake by hemoglobin or how saturated it can be.
And you might see this in maybe your biology class so it's a good thing to understand. So right here, we have on the x-axis or the horizontal axis, we have the partial pressure of oxygen. And if you watched the chemistry lectures on partial pressure, you know that partial pressure just means, how frequently are you being bumped into by oxygen?
Pressure is generated by gases or molecules bumping into you. It doesn't have to be gas, but just molecules bumping into you. And then the partial pressure of oxygen is the amount of that that's generated by oxygen molecules bumping into you.
So you can imagine as you go to the right, there's just more and more oxygen around so you're going to get more and more bumped into by oxygen. So this is just essentially saying, how much oxygen is around as you go to the right axis?
And then the vertical axis tells you, how saturated are your hemoglobin molecules? Zero means that none have. So when you have an environment with very little oxygen-- and this actually shows the cooperative binding-- so let's say we're just dealing with an environment with very little oxygen. So once a little bit of oxygen binds, then it makes it even more likely that more and more oxygen will bind. As soon as a little-- that's why the slope is increasing.
I don't want to go into algebra and calculus here, but as you see, we're kind of flattish, and then the slope increases.
So as we bind to some oxygen, it makes it more likely that we'll bind to more. And at some point, it's hard for oxygens to bump just right into the right hemoglobin molecules, but you can see that it kind of accelerates right around here. Now, if we have an acidic environment that has a lot of carbon dioxide so that the hemoglobin is allosterically inhibited, it's not going to be as good at this.
So in an acidic environment, this curve for any level of oxygen partial pressure or any amount of oxygen, we're going to have less bound hemoglobin. Let me do that in a different color.