Anyway, radioactive decay occurs at an exponential/geometric/non-linear rate. Under this theory, we would nevertheless expect the heat of the earth to decay with time, and decay very rapidly early on.
Two things:
1. The HEAT will only start to decay exponentially when the
fuel is depleted and the earth is just radiating heat.
Just like your example of the open oven. If the heat is still on the oven will
not cool.
2. The fuel is still in the process of being consumed. Indeed radioactive decay is an example of
first order rate kinetic and does decay non-linearly. HOWEVER, the decay is in the presence of the parent isotope. Many of the parent isotopes give rise to radioactive daughters which, themselves, decay along a different first order curve. But indeed the fuel is being consumed. Just as when we turn on the oven and use up electricity we are consuming the coal that makes the electricity. That doesn't mean YOU can measure the amount of "decay of coal" by tracking the temperature in your oven over 15 minutes while it's on. Do you get this point?
Now, we
know for a fact that radioactive decay of elements in the earth is going on and causing heat. There is a
measured geothermal gradient and we know quite a bit about the mineralogy of the mantle and, owing to the presence of p and s-wave shadow zones and travel times measured daily all over the globe, we know approximately what state many of these zones are in, be they liquid or solid or "plastic". Kimberlite pipes and other "windows" into the mantle give us some idea of the pressure and temperature regimes (as evidenced by the mineral assemblages present) down deep.
ALL THAT leads us to the conclusions that the deeper you go into the earth the hotter it is. Indeed it is
still hot down there. Like the open oven that is still on, we have fuel keeping the processes running.
You've been shown ample evidence that the
plates are still moving so where is the mystery? Why make claims that are not supported by the evidence?
If you think the plates were whipping around much faster in the past, then please explain the dating/distance curve from the Hawai'ian island chain or the magnetic anomalies around the spreading centers.
Out of curiosity, do you have a source describing the data underlying the assertion that radioactivity is a energy source for mantle
Do you not believe there are radioactive materials in rocks? Do you not believe in Uranium, Thorium or K-40?
D. Why is the earth hot? Radioactive decay.
1) Radioactive decay of elements in the mantle and crust. Felsic rocks (e.g., continental crust) are particularly enriched in radioactive elements (uranium, potassium, others) compared to mafic and ultramafic rocks (e.g., the mantle), making the crust somewhat hotter than expected (increasing its geothermal gradient). However, the mantle is so massive that even though there is less heat generated per kilogram of rock, much more heat overall is generated in the mantle than in the crust. Most of this heat eventually escapes through mid-ocean ridges.(
SOURCE)
If you would like,
HERE is a discussion of some of the details around heat flux and geothermal gradients.
This theory doesn't sound right to me, since people can walk right up to lava without fear of radioactive poisoning.
Radiation is a fact of life with rocks. It may not be that you will be immediately radioactively poisoned by going up to a piece of granite but it is likely to contain a certain amount of radioactive material. Look at the little pink minerals. Those are a mineral called
orthoclase and it has the chemical formula KAlSi3O8, that K is a give away there. About 1 in 10,000 atoms of potassium is K-40 (approximately), and that's radioactive. In addition Uranium likes to hang out in "felsic" igneous rocks. It's part of the chemistry of this element and these rocks. That's why pegmatites which are even more "felsic", often contain abundant uranium minerals. In addition there are a number of other naturally occuring radioactive elements that are in various igneous rocks and in the magma that makes them, as well as sprinkled throughout the earth in other rocks.
The point being that while an individual chunk of regular rock may not be radioactive enough to melt another rock, the whole of the mantle of the earth plus the "insulative" properties of the huge mass of rock that is the earth, helps to provide enough heat to do the job.
There's no magic there. It's a matter of scale and interacting effects. There isn't a mystery to my knowledge.
I'm not a specialist in radiogenic isotopes, but I do know enough to understand why some cities that are built over large concentrations of certain types of rock have a
radon problem in their homes (
LINKY).
Moreover, heat rises, so I would expect any radioactive magma to be ejected first in any volcanic eruption. I wonder if this is potential new evidence of creationism.
Well, it certainly has all the hallmarks:
1. Oversimplied to the point of cartoonish.
2. Ignorance of any underlying "detail"
3. Presupposition of an outcome
Yup, I bet it
is a new evidence of creationism!
I would not expect plate tectonics to slowly create mountain ranges 29,000 feet high.
Except we do see the plates moving daily and we see Mt. Everest still growing at about 3cm/yr (
SOURCE)
But other than the
facts, why shouldn't you trust your own "gut feelings"?
The amount of friction and resistance would be incredible.
Too bad you don't allow yourself to be awed by nature. That is sad. It's a pretty fascinating and amazing planet we live on. The forces are enormous. Maybe
your world is just a bit too small.
Only a sudden catastrophic evident could create the mountain ranges, and the sharpness of the peaks implies that they are both new and formed after the Flood subsided into the ocean floor.
Well, if you bothered with any of the
details incumbent on any of these proclamations, you might be surprised at what these features say. If you ever fly east to west across the U.S. you'll pass an ancient mountain range called the
Appalachians, which are not mostly gentle mountains. I grew up on the
dust from these mountains in that I grew up in the Midwest. That's the flat boring part you see next as you fly west.
Further west you see younger mountains called the
Rocky Mountains. They are young and still sharp and high. Interestingly they are being eroded away too! In a couple tens of millions of years they'll look like the Appalachians.
It's the cycle of the world. Just as I am younger than my dad and my dad is now decomposing, I am still producing new cells and look somewhat less worn than he does. Or one assumes, it requires a court order to see what my dad looks like now. (actually that's a bit of an untruth, he was cremated)
Convection of the mantle is a poor explanation, since the convection would smooth out the underside of the crust.
Huh?
Picture an raw chicken egg, and swirl the liquid around without breaking the shell. The swirling liquid underneath will not cause the shell itself to deform.
Now try imagining the
actual earth! That would be a nice change! The plates ride around on a layer called
the aesthenosphere and it is much more like "play-doh" in consistency. The bottoms of the lithospheric plates are
known to be rough and uneven. We know this because of
gravity anomalies which indicate "mountain roots" and the like.
As I said in the chemistry section, no one actually expects you to know any of this stuff. This is what one learns after years of study in a field. It is what one gains from years of
disciplined study. No one expects a Creationist to have that discipline or that knowledge. Otherwise they'd attempt to present more than their "gut feelings" and "egg analogies" to the discussion. It would certainly be more fun in general if Creationists would take one or two geology classes before telling geologists how they are mistaken.
This is another instance where 2nd Law dynamics works in favor of creationism, and the Biblical account does a fine job of explaining things as we observe them.
Here we go with the Second Law again. Why don't you take US38's challenge to
do the math and show your homework.
But do also remember the
key caveat of the Second Law that it only applies to a closed system. AND what that means in the larger overall scheme of things is:
IF YOU SEE A LOCAL VIOLATION OF THE SECOND LAW IT IS ONLY POSSIBLE BECAUSE THERE'S A LARGER SCALE COMPLIANCE WITH THE TREND TOWARD ENTROPY INCREASE SOMEWHERE IN THE LARGER SYSTEM.
As has been said about a billion times on this thread alone, the ice forming in your fridge isn't a violation of the Second Law
because the overall entropy of the larger system (the universe) is increasing but locally the water's entropy is decreasing. The back of your fridge is radiating heat for this to occur.
