The physics of flywheels. Things moving in a straight line have momentum (a kind of "power" of motion) and kinetic energy (the energy they have because of their.The Age of the Earth. Other Links: Young- Earth. Arguments: A Second Look. Former creationist Glenn Morton examines several famous. This value is derived from several different. Unfortunately, the age cannot be computed directly from material. Earth. There is evidence that energy from. Earth's accumulation caused the surface to be molten. Further. the processes of erosion and crustal recycling have apparently. The oldest rocks which have been found so far (on the Earth). Some of these rocks are sedimentary, and include. This lower limit is at least concordant with the. Earth's. actual age. The most direct means for calculating the Earth's age is a Pb/Pb. Earth and meteorites. A plot is constructed of. Pb- 2. 06/Pb- 2. 04 versus Pb- 2. Pb- 2. 04. If the solar system formed from a common pool of matter, which. Autoblog Alerts Thanks for subscribing to Autoblog Alerts! As content is published, we'll send it right to you. If you ever need to make changes, you.
Pb isotope ratios, then the. Over time, the amounts of Pb- 2. Pb- 2. 07 will change in some. U- 2. 38 decays to Pb- 2. U- 2. 35 decays to Pb- 2. This causes. the data points to separate from each other. The higher the. uranium- to- lead ratio of a rock, the more the Pb- 2. Pb- 2. 04 and. Pb- 2. Pb- 2. 04 values will change with time. If the source of the solar system was also uniformly distributed. And from the slope of the line we can. See the Isochron Dating FAQ or Faure (1. A young- Earther would object to all of the . However, the test for these assumptions is the plot of the. The actual underlying assumption is that, if those. The resulting plot has data points for each of five meteorites. It looks like this: Most of the other measurements for the age of the Earth rest. Below is a table of radiometric. Type. Number. Dated. Method. Age (billionsof years)Chondrites (CM, CV, H, L, LL, E)1. Sm- Nd. 4. 2. 1 +/- 0. Carbonaceous chondrites. Rb- Sr. 4. 3. 7 +/- 0. Chondrites (undisturbed H, LL, E)3. Rb- Sr. 4. 5. 0 +/- 0. Chondrites (H, L, LL, E)5. Rb- Sr. 4. 4. 3 +/- 0. H Chondrites (undisturbed)1. Rb- Sr. 4. 5. 2 +/- 0. H Chondrites. 15. Rb- Sr. 4. 5. 9 +/- 0. L Chondrites (relatively undisturbed)6. Rb- Sr. 4. 4. 4 +/- 0. L Chondrites. 5Rb- Sr. LL Chondrites (undisturbed)1. Rb- Sr. 4. 4. 9 +/- 0. LL Chondrites. 10. Rb- Sr. 4. 4. 6 +/- 0. E Chondrites (undisturbed)8. Rb- Sr. 4. 5. 1 +/- 0. E Chondrites. 8Rb- Sr. Eucrites (polymict)2. Rb- Sr. 4. 5. 3 +/- 0. Eucrites. 11. Rb- Sr. Eucrites. 13. Lu- Hf. Diogenites. 5Rb- Sr. Iron (plus iron from St. Severin)8. Re- Os. After Dalrymple (1. As shown in the table, there is excellent agreement on about 4. Note that young- Earthers cannot accuse us of. According to Dalrymple (1. For example: Meteorite. Dated. Method. Age (billionsof years)Allendewhole rock. Ar- Ar. 4. 5. 2 +/- 0. Ar- Ar. 4. 5. 3 +/- 0. Ar- Ar. 4. 4. 8 +/- 0. Ar- Ar. 4. 5. 5 +/- 0. Ar- Ar. 4. 5. 5 +/- 0. Ar- Ar. 4. 5. 7 +/- 0. Ar- Ar. 4. 5. 0 +/- 0. Ar- Ar. 4. 5. 6 +/- 0. Guarenawhole rock. Ar- Ar. 4. 4. 4 +/- 0. Rb- Sr. 4. 4. 6 +/- 0. Shawwhole rock. Ar- Ar. Ar- Ar. 4. 4. 0 +/- 0. Ar- Ar. 4. 2. 9 +/- 0. Olivenza. 18 samples. Rb- Sr. 4. 5. 3 +/- 0. Ar- Ar. 4. 4. 9 +/- 0. Saint Severin. 4 samples. Sm- Nd. 4. 5. 5 +/- 0. Rb- Sr. 4. 5. 1 +/- 0. Ar- Ar. 4. 4. 3 +/- 0. Ar- Ar. 4. 3. 8 +/- 0. Ar- Ar. 4. 4. 2 +/- 0. Indarch. 9 samples. Rb- Sr. 4. 4. 6 +/- 0. Rb- Sr. 4. 3. 9 +/- 0. Juvinas. 5 samples. Sm- Nd. 4. 5. 6 +/- 0. Rb- Sr. 4. 5. 0 +/- 0. Moama. 3 samples. Sm- Nd. 4. 4. 6 +/- 0. Sm- Nd. 4. 5. 2 +/- 0. Y- 7. 50. 11. 9 samples. Rb- Sr. 4. 5. 0 +/- 0. Sm- Nd. 4. 5. 2 +/- 0. Rb- Sr. 4. 4. 6 +/- 0. Sm- Nd. 4. 5. 2 +/- 0. Angra dos Reis. 7 samples. Sm- Nd. 4. 5. 5 +/- 0. Sm- Nd. 4. 5. 6 +/- 0. Mundrabrillasilicates. Ar- Ar. 4. 5. 0 +/- 0. Ar- Ar. 4. 5. 7 +/- 0. Ar- Ar. 4. 5. 4 +/- 0. Ar- Ar. 4. 5. 0 +/- 0. Weekeroo Station. Rb- Sr. 4. 3. 9 +/- 0. Ar- Ar. 4. 5. 4 +/- 0. After Dalrymple (1. Also note that the meteorite ages (both when dated mainly by. Rb- Sr dating in groups, and by multiple means individually) are in. Those which. appear the most frequently in talk. Accumulation of helium in the. Decay of the Earth's magnetic. Accumulation of meteoritic dust on the. Moon. Accumulation of metals into the. Note that these aren't necessarily the . However, they are quite popular. Helium is not light. Earth's gravity (unlike hydrogen), and it will. The current level of helium in the. Earth is young. In order. Earthers. handwave away mechanisms by which helium can escape. For example. Henry Morris says. Surely one cannot . Dalrymple. says. Calculations for. He lead to similar results, i. Another possible escape. Sheldon and Kern (1. Dalrymple's references: (1. Banks, P. 6. 31. 7- 6. Sheldon, W. 6. 19. This argument also appears in the following creationist. The young- Earth argument: the dipole component of the magnetic. Assuming the generally accepted . An exponential fit. Earth must be young. The main proponent of. Thomas Barnes. There are several things wrong with this . The primary four are: While there is no complete model to the geodynamo (certain key. If it is possible for energy to be added to the field, then. There is overwhelming evidence that the magnetic field has. Even some young- Earthers admit to that. Humphreys (1. 98. Much of the energy in the field is almost certainly not. This means. that the extrapolation rests on the assumption that fluctuations in. Barnes' extrapolation completely ignores the nondipole. Even if we grant that it is permissible to. Barnes'. extrapolation also ignores portions of the field which are visible. That last part is more important than it may sound. The Earth's. magnetic field is often split in two components when measured. A study in the 1. Strahler (1. 98. 7, pp. While this is. negligible compared to the processes of erosion on the Earth (about. Moon. Young- Earthers claim that the Moon must. Moon is. several billion years old. Morris says, regarding the dust influx rate. He measured the amount. That assumption was wrong and caused his published figures. Pettersson's calculation resulted in the a figure of about 1. In the very same paper, he indicated that he. These measurements give the value (for influx rate. Earth) of about 2. Multiple. measurements (chemical signature of ocean sediments, satellite. Morris. chose to use. Morris chose to pick obsolete data with known problems, and call. With the proper values, the. Moon is less than one. For further information, see Dalrymple (1. Strahler (1. 98. 7, pp. Below it is. the regolith, which is a mixture of rock fragments and. The regolith averages about five. In addition, lunar rocks are broken down by various processes. Quite a bit of the. There is a recent creationist technical paper on this topic. Moon is concordant with. Unfortunately, attempted counter- responses. Thus, until new evidence is forthcoming. The Apollo mission had been preceded. Soviet Luna (six landers). American Ranger (five landers) and Surveyor (seven landers) series. The. physical properties of the lunar surface were well- known years. Further, even prior to the unmanned landings mentioned above. Snelling and Rush document that there was no clear consensus in the. This calculation was. Several creationists have reproduced this table of numbers. I have seen a similar. To. calculate a true upper limit, we must calculate the. We must perform the. If equilibrium is within reach of those. In addition, even if we knew exactly the rates at which. It. would probably require solving a differential equation, and any. These published values are only . Any efflux decreases the rate at which the. Ignoring the three problems. Also, the only two results that agree are 3. Aluminum gives 1. If this is a valid method, then the age. Earth must be less than the lowest . Nobody in the debate would agree on a 1. Earth. These . There is no reason to believe that influx. There is reason to expect. There is no . There is no way. The best methods. The only way a creationist can . Yet, it is quite common. This argument also appears in. Obviously, these are a pretty popular set of . They appear in talk. Earth arguments. They are all built upon. A curious and unbiased observer could quite reasonably refuse to. If I found . These include: Reference to a case where the given method. Claims that the assumptions of a method may. Constancy of radioactive decay rates. Contamination is likely to occur. This is perhaps the most common objection of all. Creationists. point to instances where a given method produced a result that is. Such an argument fails on two counts: First, an instance where a method fails to work does not imply. The question is not whether there are. The fact that one wristwatch has. Yet, when five radiometric. Earth's oldest rock. Dalrymple 1. 98. 6, p. Second, these arguments fail to address the fact that. The claim that the methods produce bad results. These generally include constancy of decay rate and lack. The nucleus. is well- insulated and therefore is relatively immune to. Significant changes to rates of radiometric decay of isotopes. Emery. (1. 97. 2) is a comprehensive survey of experimental results and. Note that the. largest changes reported by Emery are both irrelevant (they do not. FAQ), and. minuscule (decay rate changed by of order 1%) compared to the. Earth into the. young- Earthers' timescale. A short digression on mechanisms for radioactive decay, taken. USEnet article. < CK4. LK. E2. J@ucdavis. Steve Carlip. (subsequently edited in response to Steve's request): For the case of alpha decay, . You will find a simple explanation in any. Ohanion's. Principles of Quantum Mechanics has a nice example of alpha. The fact that the process is probabilistic, and. In principle, this is computable. There are, however. For beta decay, the underlying fundamental theory is different. Glashow, Weinberg and. Salam won their Nobel prize) rather than quantum. As described above, the process of radioactive decay is. In order to. explain old isotopic ages on a young Earth by means of accelerated. Flood period, or accomplished. Flood). Such a huge change in fundamental properties would have plenty. Steve Carlip): So there has been a lot of creative work on how to look. A nice (technical) summary is given by Sisterna and Vucetich. Battle of the Breads: Industrial White or Artisanal Whole- Grain?(Credit: Seregam/Shutterstock)What’s a more healthful option for a sandwich: industrially processed white bread, or artisanal whole- grain bread? To those who seek clear- cut, black- and- white answers to burning questions like this one, we apologize preemptively. The answer is both; it simply depends on who’s eating it. The Better Bread? That conclusion is from researchers at Israel’s Weizmann Institute of Science who recently compared the short- term health effects of switching to a diet heavy in calories from white or whole- grain bread. In a randomized trial, scientists told twenty otherwise healthy people to increase their bread consumption for a week—from 1. Half of the participants supplemented their diet with processed white bread, and half munched on whole- grain sourdough prepared at a local bakery. After the first week, every participant stopped consuming bread for two weeks during what’s called a wash- out period. Then, the experiment was repeated, but this time the white bread group ate whole- grain and vice- versa. Before, during and after each stage of the experiment researchers monitored a host of health indicators: morning glucose levels, markers for inflammation and tissue damage, cholesterol levels, kidney and liver enzymes and levels of vitamins and minerals. Researchers also took stool samples to assess each person’s microbiome—the diverse bacterial community residing in their guts. In short, each person experienced different outcomes. Some people’s metabolic responses were more positive after switching to white bread, while others did better eating whole- grain. When scientists averaged the group data together, it was a wash—there were no clinically significant differences between white and whole- grain. They published their findings Tuesday in the journal Cell Metabolism. Here’s one important caveat: Everyone consumed the same amount of carbohydrates, and whole- grain bread contains fewer carbs. Therefore, participants ate more whole- grain than white bread.“We didn’t take into consideration how much you would eat based on how full you felt. So the story must go on,” says Avraham Levy, a study coauthor. Food Fights. The world is awash in conflicting studies touting the supposed health benefits, or detriments, of various foods. Are eggs a superfood, or are they just as bad as smoking a cigarette? You’ll find dubious evidence for both on a simple web search. Or, look at the various ways countries define a standard alcoholic drink. In Austria, 2. 0 grams of ethanol per drink is the standard, but in the United Kingdom, 8 grams is the accepted definition. Researchers say their study encourages us to tune out the noise and move away from universal dietary guidelines and focus more on individual variations. Indeed, in 2. 01. Weizmann Institute had 8. In other words, what’s healthy for one person may not be healthy for another.“To date, the nutritional values assigned to food have been based on minimal science, and one- size- fits- all diets have failed miserably,” says Eran Elinav, a study coauthor. Elinav and colleagues are a few voices in a chorus of experts casting doubt on the scientific veracity of dietary guidelines. When the federal government rolled out its 2. Dietary Guidelines, nutritionists chided its drafters for sowing public confusion and disregarding scientific evidence. In The Atlantic, journalist James Hamblin highlighted concerns that the meat industry had an outsize role shaping those guidelines. So, it seems, when reading dietary guidelines, it may be prudent to take them with a grain of salt—or not.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. Archives
August 2017
Categories |