COMIC ZONE ON NOW- WITH NEAL ADAMS

[Sal]

if i ever get me my own custom title, i think i would like the old adage "Subduction leads to orogeny."

 

remember that the wikipedia is an open-source encyclopedia, and entries may be written by near anyone. they claim to have editors, but lawsamighty i ain't never seen none of them folks around

 

Right. I've had a hellacious time getting my students not to use the durned thing in their research papers.

 

 

no doubt

[Aman619]

At one time most dino guys thought dinosaurs were slow moving, tail dragging grey lizards but now the more accepted view is that they moved more birdlike were brightly colored with more avian then lizard qualities. Science evolves new theories all the time nothing stays the same.

 

Oh.

 

So science may yet evolve to discovering that the universe is growing?

 

yes. Probably. But they'll conclude that everything i sgrowing except Earth just to mess witcha.

[selegue]

 

 

A real good example was the reaction to Neal's simple issue with subduction. Neal asked why, if the granite and basilite rose to the surface of the magma because they're less dense, do they sink back down back into the maga, as subduction purports. Neal expressed an idea in his own words and thoughts but the answer we received was a link to Wikkipedia's Subduction entry.

 

http://en.wikipedia.org/wiki/Subduction

 

Can anybody here answer in their own words why the granite and basalt sink into the magma if they're less dense? I read the entry and tried to put into words what it says about that. Frankly, it's a bit full of double-talk.

 

It basically says that when the less dense material is more dense, it sinks. Well, how did it become more dense? I'd like to understand how the same material is both less dense than the maga and more dense at the same time, just in order to make this theory work.

 

Here's the excerpt which tries to answer this.

 

"Subduction results from the contrast in density between lithosphere (the crust plus the strong portion of the upper mantle) and underlying asthenosphere. Where lithosphere is denser than asthenospheric mantle, it can easily sink back into the mantle at a subduction zone; however, subduction is resisted where lithosphere is less dense than underlying asthenosphere. Whether or not lithosphere is more or less dense than underlying asthenosphere depends on the nature of the associated crust. Crust is always less dense than asthenosphere or lithospheric mantle, but because continental crust is always thicker and less dense than oceanic crust, continental lithosphere is always less dense than oceanic lithosphere. Oceanic lithosphere is generally denser than asthenosphere but continental lithosphere is lighter. Exceptionally, the presence of the large areas of flood basalt that are called large igneous provinces (LIPs), which result in extreme thickening of the oceanic crust, can cause some sections of older oceanic lithosphere to be too buoyant to subduct. Where lithosphere on the downgoing plate is too buoyant to subduct, a collision occurs, hence the adage "Subduction leads to orogeny"."

 

Can anyone here explain this in simple words. Or are we all content in accepting it as an answer to the original question, because it's an entry in Wikkipedia? I thought we were having a discussion with each other, not with an encyclopedia.

 

I'm truly curious if anyone here understands what that paragraph says and can put it into their own words.

 

I think it's pretty clear. Maybe you need this picture.

 

 

*The lithosphere is not uniform.* Some areas are denser than others. In general, the continental lithophere is less dense (because it's got a coating of "light" crust) and the oceanic lithosphere is more dense. When two plates meet, the dense material sinks under the lighter material.

 

 

I'd like to know if anyone truly understands how the less dense matter becomes more dense and sinks into the magma. I'm wondering if anyone here backing the scientific community understand what constitues a "subduction zone"? How do some places on the planet ignore the laws of physics and become a "twilight subduction zone"

 

What is a subduction zone? Does anyone here truly undersand this?

 

I'm no expert, but yes. The wiki explanation was clear. A subduction zone is where two plates come together, more or less by convection currents in the underlying mantle. The mantle is viscous but it can still flow -- remember, this is a very slow process. The denser plate gets forced down into the mantle, under the less dense plate.

 

I'd like to talk to the people I'm talking to. I'm not crazy about having someone else's work referenced in every turn of a discussion. Yes there's a lot of great work out there and much intelligent material, but we're the ones here discussing this, not the authors of these books.

 

Academic culture -- you always reference sources. Statements off the top of your head don't carry much weight, because you could just be making stuff up as you go along!

 

 

 

This would be a great discussion if anyone here can play the encyclopedia's advocate..

 

 

We'll see about that.

 

 

So, how does the less dense matter sink into the more dense one? Anyone? in your words?

 

The less dense matter does not sink. The more dense matter sinks. The less dense matter stays on top. Take another look at the wiki page and what I just wrote.

 

Is this group supposed to discuss comic books? Here you go.

 

 

Just be glad I didn't pick Sgt. Rock.

 

Jack

[shrunkenhead]

 

 

Just be glad I didn't pick Sgt. Rock.

 

Jack

 

[Michael Netzer]

yes. Probably. But they'll conclude that everything i sgrowing except Earth just to mess witcha.

 

I'm a messy guy, so I'll then remind them that the growing earth theory includes the moon and other planets and the sun and the stars in all the other galaxies and all the planets in their solar systems. They picked who to mess with.

[Ze-man]

Is it true there's nothing but gas and plasma inside?

 

Funny thing. Until a couple of weeks ago, scientists and geologists argued vehemently that the earth's core was the most dense of all the planet. Solid iron engulfed by a slightly less dense molten iron mantle. They believed this because of how they read seismic wave measurments.

 

Recently a team of scientists concluded through experriments, that the great pressure and heat in the Earth's core have not been taken into consideration of the seismic wave measuremets. They've concluded that when these factors were taken into consideration, they've discovered that the core is much less dense than previously thought. Much much less dense.

 

For all the scientists and geologists who argued that the growing earth theory doesn't work because the earth's core is too dense to be the cauldron from which the new matter pushes out - I don't hear anyone yet say..."Oh, we were wrong."

 

This is in my own words.

 

Here's the link to the source material.

 

 

Michael, I think he was referring to what was inside Brad's tummy, I think.

 

[topofthetotem]

At one time most dino guys thought dinosaurs were slow moving, tail dragging grey lizards but now the more accepted view is that they moved more birdlike were brightly colored with more avian then lizard qualities. Science evolves new theories all the time nothing stays the same.

 

Oh.

 

So science may yet evolve to discovering that the universe is growing?

 

yes. Probably. But they'll conclude that everything i sgrowing except Earth just to mess witcha.

 

CURSE YOU !!!!! you foiled my plan to have neal adams pm me develope a lifelong freindship and teach how to draw

[selegue]

Is it true there's nothing but gas and plasma inside?

 

Funny thing. Until a couple of weeks ago, scientists and geologists argued vehemently that the earth's core was the most dense of all the planet. Solid iron engulfed by a slightly less dense molten iron mantle. They believed this because of how they read seismic wave measurments.

 

Recently a team of scientists concluded through experriments, that the great pressure and heat in the Earth's core have not been taken into consideration of the seismic wave measuremets. They've concluded that when these factors were taken into consideration, they've discovered that the core is much less dense than previously thought. Much much less dense.

 

For all the scientists and geologists who argued that the growing earth theory doesn't work because the earth's core is too dense to be the cauldron from which the new matter pushes out - I don't hear anyone yet say..."Oh, we were wrong."

 

This is in my own words.

 

Here's the link to the source material.

 

 

Michael, I think he was referring to what was inside Brad's tummy, I think.

 

 

Of course I was. Thet's, ah say, thet's a joke, son.

 

But I've seen that article, and the interpretation is way out of line. Michael, how did you come up your interpretation?

 

They were measuring iron in a diamond anvil cell at about 73 gigapascals and at temperatures up to 1700 kelvin, so they had to extrapolate to core temperatures and pressures.

 

Quote

"Birch pointed out the likely temperature effect on the sound velocities in his original paper in 1961 (2). Our results confirm this idea. It has been shown that the addition of a light element such as Si or S into Fe increases VP and VS under high pressures (32, 33). Considering the temperature effect on VP and VS of hcp-Fe at inner core pressures and 6000 K (20), a few percent of light elements alloyed with Fe are still needed in the inner core to increase VP to match seismic models (Fig. 3). This results in more light elements in Earth's inner core than has been suggested from the linearly extrapolated VP of hcp-Fe at high pressures and room temperature (12)."

 

The correction is tiny! "Much much less dense"? Not true at all! Are you trying to say that this paper supports a gaseous core? Gaseous iron? At high pressure? What??

 

The core is still the densest matter on the planet by far. Very little has changed about the likely temperature and pressure at the core. Yet the scientists indeed wrote, "Oh, we were wrong." (Not in those words. The previous model *may* be *slightly* wrong. This is only a tiny correction.) That's how science works. You make measurments and draw conclusions based on data.

 

I think you didn't "hear anyone yet say..."Oh, we were wrong."" because you never looked at the article at all, just a gross distortion of its content somewhere.

 

Argh. Sorry -- too much technical content for a comic book board. It aggravates me to see that kind of distortion in "support" of a completely opposite conclusion to what's really there. And people will believe it if you say it loudly enough, often enough, make it pretty and simple-looking.

 

I don't know how far off-topic is allowed here. Someone shut me up if I'm out of line.

 

Jack

[Michael Netzer]

I think it's pretty clear. Maybe you need this picture.

 

 

*The lithosphere is not uniform.* Some areas are denser than others. In general, the continental lithophere is less dense (because it's got a coating of "light" crust) and the oceanic lithosphere is more dense. When two plates meet, the dense material sinks under the lighter material.

 

I followed that part. Makes perfect sense. When the approximately 5 mile thick granite and basalt slabs or plates of the ocean floor meet the contintental crust plates, they slide under them. But we're only referencing the relationship between the different densities in the Lithosphere. Not the upper mantle which is rigid and much more dense. How do the ocean lithosphere slabs pierce the denser solid upper mantle?

 

 

I'm no expert, but yes. The wiki explanation was clear. A subduction zone is where two plates come together, more or less by convection currents in the underlying mantle. The mantle is viscous but it can still flow -- remember, this is a very slow process. The denser plate gets forced down into the mantle, under the less dense plate.

 

The upper mantle isn't viscous. It's solid. It would take an incredible force which has not yet been accounted for in order for the oceanic plates to slide under or pierce the upper mantle and reach the lower viscous mantle.

 

This is where the problems begin. The denser plate is only denser than the upper continental crust plate. It's NOT DENSER than the solid upper mantle or the much more dense viscous mantle. So what makes it sink into the denser mantle? Why is the mantle lumped in with the less dense upper continental crust, as if to say that if the ocean plate can slide under the continental crust, it can also pierce the solid upper mantle and then sink into the viscous lower mantle and melt? What force is making this happen? The explanations given so far only explain the relationship with the outer continental crust, not the mantles.

 

Academic culture -- you always reference sources. Statements off the top of your head don't carry much weight, because you could just be making stuff up as you go along!

 

Referencing sources for something you have an understanding of is alright. But has academic culture become such that it's enough to throw sources around and tangle the discussion with source material that may not be conclusive.?

 

 

This would be a great discussion if anyone here can play the encyclopedia's advocate..

 

------------

 

We'll see about that.

 

You can keep score, I trust your fairness implicitly.

 

The less dense matter does not sink. The more dense matter sinks. The less dense matter stays on top. Take another look at the wiki page and what I just wrote.

 

I did look at everything again and I remain with the same question. If the less dense matter stays on top, the less dense ocean floor can't subduct into the more dense mantle. It can subduct under the less dense continental crust, but not into the more dense solid upper mantle - or under that into the viscous lower mantle . Look at the graph again and think about this.

 

Is this group supposed to discuss comic books?

 

Please don't tell the on-topic police. Let's keep this discussion our little secret. A little light of freedom in the vast darkness of netiquette.

 

Just be glad I didn't pick Sgt. Rock.

Jack

 

A nice Kubert cover would be quite refreshing, actually, right about now.

[FlyingDonut]

Okley dokley

 

[Rip]

The upper mantle isn't viscous. It's solid. It would take an incredible force which has not yet been accounted for in order for the oceanic plates to slide under or pierce the upper mantle and reach the lower viscous mantle.

 

This is where the problems begin. The denser plate is only denser than the upper continental crust plate. It's NOT DENSER than the solid upper mantle or the much more dense viscous mantle.

 

Source please.....

 

Are you saying the asthenosphere (upper mantle) DOESN'T behave as a viscous fluid.

It has a relatively low density as far as I've seen on various sources.

[FlyingDonut]

[selegue]

 

I followed that part. Makes perfect sense. When the approximately 5 mile thick granite and basalt slabs or plates of the ocean floor meet the contintental crust plates, they slide under them. But we're only referencing the relationship between the different densities in the Lithosphere. Not the upper mantle which is rigid and much more dense. How do the ocean lithosphere slabs pierce the denser solid upper mantle?

 

 

They don't!

They go UNDER the upper mantle. They don't have to pierce it.

 

 

Sorry, that's a continental-continental (not oceanic) picture but it was the clearest I could find.

 

I'm no expert, but yes. The wiki explanation was clear. A subduction zone is where two plates come together, more or less by convection currents in the underlying mantle. The mantle is viscous but it can still flow -- remember, this is a very slow process. The denser plate gets forced down into the mantle, under the less dense plate.

 

The upper mantle isn't viscous. It's solid. It would take an incredible force which has not yet been accounted for in order for the oceanic plates to slide under or pierce the upper mantle and reach the lower viscous mantle.

 

This is where the problems begin. The denser plate is only denser than the upper continental crust plate. It's NOT DENSER than the solid upper mantle or the much more dense viscous mantle. So what makes it sink into the denser mantle? Why is the mantle lumped in with the less dense upper continental crust, as if to say that if the ocean plate can slide under the continental crust, it can also pierce the solid upper mantle and then sink into the viscous lower mantle and melt? What force is making this happen? The explanations given so far only explain the relationship with the outer continental crust, not the mantles.

 

 

Are you just baiting?

The ocean plate doesn't slide under just the crust, it slides under the whole slab of lithosphere INTO the molten lower mantle. No "piercing of upper mantle" is necessary.

 

Academic culture -- you always reference sources. Statements off the top of your head don't carry much weight, because you could just be making stuff up as you go along!

 

Referencing sources for something you have an understanding of is alright. But has academic culture become such that it's enough to throw sources around and tangle the discussion with source material that may not be conclusive.?

 

I can't imagine why someone would throw around source material that may not be conclusive and then claim that it supports their own argument. Have you seen anyone do that around here lately?

 

Enough (too much) on this topic for me. Back to real work.

 

Jack

[Michael Netzer]

The correction is tiny! "Much much less dense"? Not true at all! Are you trying to say that this paper supports a gaseous core? Gaseous iron? At high pressure? What??

 

How much less dense is a relative issue. I did not say anything about gaseous iron.

 

The more improtant issue in this research is that the factors under which it was assumed the Earth's core is the most dense part of the planet, are now coming into question. The Earth's core may be less dense than previously assumed. How much less dense remains to be seen. What it's made of also remains to be seen. I say this because the basis for the assumption of high density has been shaken, and this, in turn, shakes the assumption that it's made of solid iron:

 

"The composition of Earth’s core has been the subject of scientific debate for years," commented Lin. "The prevailing consensus is that the outer core is a molten cauldron mostly of iron with some light elements and the inner core is made of solid iron with a little bit of light elements. We can’t sample the core directly, so we’ve made these estimates by reading seismic waves as they travel through the interior and through experimentation and theory,"

 

We can't sample the core directly. Our assumptions have been based on pressure and density based on seismic wave measurements which we now see are affected by the high temperatures. Our previous assumptions are very questionable. I undestand that this is simply an assumption, but it highlights that the basis for previous assumptions are now shaky.

 

High pressure and high density are also not the same:

 

"We found that when temperature is added to the experiment, the velocities of the compression waves (the waves that force atoms closer for a moment) and shear waves (when the atoms rub against each other) actually decreased with increasing temperature even though the pressure was moderately high," stated co-author of the study Wolfgang Sturhahn.

 

The pressure remains high but the density is decreased.

 

I think you didn't "hear anyone yet say..."Oh, we were wrong."" because you never looked at the article at all, just a gross distortion of its content somewhere.

 

Really? Is this an academic or scientific assumption? I read the article and understood its implications when it first appeared, Jack. Let's keep this clean.

 

Argh. Sorry -- too much technical content for a comic book board. It aggravates me to see that kind of distortion in "support" of a completely opposite conclusion to what's really there. And people will believe it if you say it loudly enough, often enough, make it pretty and simple-looking.

 

Or really, now. As if Neal's voice or mine or any other comic artist's are a match for the loud proclamations of the scientific community. Are we truly a threat to science, Jack?

 

I like pretty and simple-looking things, actually. Don't you?

 

I don't know how far off-topic is allowed here. Someone shut me up if I'm out of line.

Jack

 

I'm not telling anybody about this. I'll defend your right, with my life, to speak freely in any forum.

 

Are you keeping score?

[Michael Netzer]

Enough (too much) on this topic for me. Back to real work.

Jack

 

I give up, then. YOU WIN.

 

I also have real work. A deadline to finish painting this poster by Monday and it's a lot of work. Have you seen it?

 

A-Z Superhero Poster

 

[october]

Great looking painting! The Flash and Odin are done especially well.

[FFB]

Great looking painting! The Flash and Odin are done especially well.

 

Ditto. Michael, I also like the way you made Spider-Man's costume look like the movie version. Looks better that way.

 

Who is the "U" guy? That's the only one I don't know.

[Michael Netzer]

Thanks, guys.

 

i've been coloring backwards from the bottom and Flash is the latest. It's becoming a painting process but it's all done on a computer, even the linework. back to work.

[Michael Netzer]

The Kubert covers are fabulous, btw. Thanks, FD.

[Rip]