Earth, a Giant Pinball Machine

fooled again by horati0 · 2004-11-20 09:20 · Score: 3, Funny

i hate it when a broad layer change turns out to be a localized density variation!

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The core by oz_ko · 2004-11-20 09:35 · Score: 2, Funny

Nooooooooooooooo..... don't mess with the Earth's core. Don't you know it'll stop spinning and then we'll be all stuffed.

We'll have to watch the movie "The Core" to the end to see how we fix it and that willl cause the extinction of our species.

Pinball? Did someone say pinball? by Anonymous Coward · 2004-11-20 10:01 · Score: 0

Did somebody say pinball?

Does that mean HPFS stands for High-Pressure-Formed-Soil?

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If it's wrong, we'll fix it... by palndrumm · 2004-11-20 10:43 · Score: 5, Insightful

But what if the method is wrong?

If the method is wrong, then our model of the Earth's interior will most likely be wrong. If that's the case, as we continue to gather more data in greater detail, it will become increasingly obvious that the data doesn't fit the model. Once we reach that point, we will either adjust the current model, or create a completely new model, that the data fits the model once again.

In other words, it'll be business as usual for the scientific method...

Re:If it's wrong, we'll fix it... by shaitand · 2004-11-20 13:45 · Score: 2, Informative

But we've been using the current method for a long time. What happens if we adjust the model instead of changing of our method, resulting in a new model which appears to work for a long time. In the meantime this discovery is determined not to be correct.

Eventually it is almost forgotten, but remembered just well enough that anyone who it occurs to, and checks, will see that someone else already thought of that and the theory was found to be incorrect (since it clashed with our new false model).

Sure someday we would probably figure it out, but how long would it take to rediscover the correct solution? How long would mankind of have been robbed of true knowledge by Occums razor?
Re:If it's wrong, we'll fix it... by mopomi · 2004-11-20 19:45 · Score: 2, Interesting

How is this a troll? If our method is wrong, but we just adjust the model (it's not exactly relevant here because the actual problem is not accurately described in the article), we may still get the approximation to reality incorrect.

The problem is simply that the solutions generally found are not necessarily unique, if one assumes a very simple model and doesn't apply additional, independent knowledge to the problem.

However, as another person posted, the reality is that "we've" been doing a pretty good job for a while, and the reason is that "we're" not doing seismology blindly--there is other information that helps to correct misunderstandings or non-uniqueness to JUST the seismological data.

For example, knowing the chemical composition or temperature (e.g., from volcanic eruptions) helps to pin down the more accurate solution to the seismic data.

Also, the experiments were done with a single wave source, and generally we use multiple sources, which will help to clarify the structure of the region of interest.

The structure of the Earth is very similar to what we "see" using the combined data sets that make up "seismological remote sensing".
Re:If it's wrong, we'll fix it... by shaitand · 2004-11-21 11:47 · Score: 2, Interesting

I dare to imply that Occum's razor and the scientific method could need reform, even giving a reasonably likely situation in which this could occur. And having done so makes me a troll?

The scientific method coupled with peer review is wonderful, it has brought us far. Unfortunately it is inherently flawed.

It is flawed because the scientific method relies on the belief that when all evidence is presented the conclusion one logically arrives, which fits all said evidence and symptoms, is the correct one.

The problem with that is that all the cards don't always have only one possible resolution, even if there is only one we can think of at the moment. It's perfectly possible for an incorrect premise to yield correct results. It's perfectly possible for it to do so for 5000 yr, or 10,000, or 10,000,000. The more cards are on the table, the more closely that incorrect premise will be to the FUNCTION of the correct premise but the cards are not always enough to reach the correct premise. The closer the function of false premise is the function of the correct premise, the longer it takes for a decidedly provable evidence of falsehood to appear.

I submit the following premises.

1. The scientific method is flawed due to the assumption that all evidence which can be collected will ultimately yield a correct premise.

2. The closer a false theory is in FUNCTION to a correct theory, the longer it takes to discover a discrepancy in the theory.

3. A false theory which has been adjusted to provide a function which fits new evidence is no closer to being a correct theory, contrary, it is closer to providing the FUNCTION of the correct theory, this in turn triggers assertion 2.

4. Man is inherently flawed, possibly due to our short lifespans and the inevitability of death, and believes that a premise which has not been disproven given a length of time should be attributed credibility.

5. When a premise has attained credibility, other premises that depend on a solution to the evidence it appears to solve will rely on it more and more blindly. This results in more false premises which are close in function to correct premises.

6. Premises arrived at via premise 5 can be correct or incorrect, because they are based on the function of the original premise. This can make the original false premise more difficult to discover.

7. Because of premise 6, a functioning premise having been derived from a premise DOES NOT constitute a reduction in the odds the original premise is false.

8. Because of premise 4, when man encounters a premise as described in premise 2, man will take the most dangerous of false premises and will end up adjusting it, causing premise 3 to take effect. In turn this lengthens the lifespan of the false premise more securely rooting premise 4 and ensuring that this cycle will repeat.

9. Occum's razor is a false premise. Since the CORRECT answer to a problem can be more complex than a false one, and since there is more than one answer which can resolve a given set of evidence, it's perfectly plausible, in fact likely that Occum's razor is regularly used to cut away correct answers. Further premise 4 increases this likelihood.

10. These premises taken together present an unresolvable situation.

Due to human flaws, and flaws in our standard methods, we've unintentionally implemented a hack. That allows us to base further progress on false premises which emulate the function of correct premises. While this certainly results in accelerated tangible progress, ultimately this string of false premises MUST FAIL to be extendable and we will achieve the limits we can progress to using this system.

Although we can't resolve this problem via any solution I am able to think of. What we can is patch the human flaw in the system. We can do this by submitting the same findings to peer review we do now, but doing so again at intervals in the future, assuring as much material is re-reviewed in light of new e
Re:If it's wrong, we'll fix it... by mopomi · 2004-11-23 07:22 · Score: 1

While I don't think you were trolling before, I do think you have some problems with your premises:

1) There is no assumption that we will find the perfectly correct solution to a problem. The assumption is that we will get so close with approximations to the exact solution that for all intents and purposes it'll be "right". There's a difference--one implies that science can get to the "absolute truth", and the other implies that science can provide a working model that is very close to reality.

2) There really is no such thing (see 1)) as a "correct theory", just an approximately correct theory. All theories, by nature (ours) are only approximations to the truth. We know some things, we approximate others, and we ignore others that we either don't understand or we don't know about. Case in point: I research heat flow from lavas to volatiles. There are only so many parameters that I can input into my mathematical model of the heat flow (density, specific heat capacity, time, latent heat, temperature, etc.) before my approximations are "good enough" and any other parameter inputs makes the model cumbersome and unnecessarily complex. I say unnecessarily because the gross behavior is what I'm trying to get at, not the behavior of every single molecule (or atom, or quark). Also, I will NEVER, EVER be able to actually model what a real lava flow will do because I don't have every detail of the "experiment"--what will happen to the lava flow if a cloud passes overhead? what if an observer takes the temperature of a toe lobe? what if . . . None of that really matters when I'm attempting to estimate the gross behavior of something. What does this have to do with 2)? Well, the closer a theory is in function to the truth, the "better" the theory is. If I can approximate the behavior of interacting lava and water well enough to be able to warn people not to come close when the lava enters the ocean in Hawaii, then that's good. If my theory is incorrect, we'll find out soon enough, and either the entire theory (think of the crystal spheres of the heavens before Copernicus) needs to be thrown out or some of the parameters need to be adjusted. This leads us to 3)

3) If my lava flow theory is incorrect, then we WILL find out eventually that it is incorrect. This is the goal of science--to provide enough evidence to overthrow current theories and to "better" approximate nature. If a theory proves to be incorrect, we get rid of it in whole or in part and come up with something that works better. The adding on of special cases does not make a theory work better, it's basically just hanging on to something that doesn't work well because a) we don't have something better or b) someone wants that theory to be correct. b) sucks.

4)There is nothing wrong with agreeing to use a set of approximations because they haven't been shown to be incorrect. You (unknowningly?) use Newton's laws of gravitation every day. You may play basketball, or fly an airplane, or whatever--you use Newton's approximations to Einstein's approximation to reality. It's OK that Newton was "incorrect" because his theory has been so useful, and on "normal, human" scales, it is correct.

5)I'm not sure what you're trying to say here, but basically, yeah, we build up from "first principles" to more and more complex theories. However, we abandon those "first principles" when they turn out to be unuseful because of new evidence. We don't, on the whole, cling to old theories just because they're old and well oiled.

6-10) these are just re-iterating arguments.

Basically, you conclude that we need to "re-review" theories from time-to-time. We do. When we get new evidence that contradicts an established (by that I mean well tested) theory, we first check that the evidence is not flawed. Why do we do this first? Well, because humans are inheriently flawed and there are many, many ways to screw up the taking of data. After we've determined (probably through many independent observations) that the new
Re:If it's wrong, we'll fix it... by shaitand · 2004-11-23 23:10 · Score: 1

"Yes, humans are flawed, but that doesn't mean our method of producing valid approximations to reality haven't been useful. That doesn't mean we don't understand ANYTHING about our universe."

I certainly never said we didn't produce anything, I said the opposite. I said our current method was a cheap hack that has resulted in us producing MORE in a short period of time than we would without it. The problem isn't in what we've produced, the problem is you can only build a house of straw so tall before it collapses under it's own weight... or the wind blows.

Your post was interesting, and I hope you do realize that nothing you said refutes anything in my post. In fact you restated many of my points but tried to paint them as positive things. The only point I must disagree on is this one:

'There really is no such thing (see 1)) as a "correct theory", just an approximately correct theory.'

Correct is defined as truth. There is actually a correct and true answer to every problem in the universe of course. The only requirement for a theory is that it not be proven, it's certainly possible for a theory to be true and correct.

'Basically, you conclude that we need to "re-review" theories from time-to-time. We do. When we get new evidence that contradicts an established (by that I mean well tested) theory, we first check that the evidence is not flawed.'

I'm proposing we not only review the established ones, but the ones that were never accepted to begin with. Further that we need a formal recurring process for making sure this happens instead of simply letting it go it's course.
Re:If it's wrong, we'll fix it... by mopomi · 2004-11-24 03:24 · Score: 1

I don't agree that the current (ideal) scientific method is a cheap hack. There is no reason to think that the current method of reviewing scientific "fact" is going to cause some kind collapse of science. The scientific method has built-in safeguards against the kind of problems that plagued the dark ages. It expectsto have basic, foundation theories revamped or replaced from time-to-time.
However, there are also established facts that are observations, not theories. These observations may be explained by a number of theories. If those theories contradict or are inconsistent with other observations or they are insufficient to explain other observations, they are regarded as incorrect or incomplete. Most theories that "were never accepted to begin with" were not accepted because they didn't adequately explain all available data. Gathering more data will not provide better evidence for incorrect theories.
If I provide a "theory" that objects shaped like a torus will never fall to the surface of the Earth, regardless of their density, and observational evidence shows that the "theory" is wrong (You drop a doughnut and it falls to the floor), no amount of additional evidence will convince anyone (reasonable) that my "theory" was correct. Revisiting it is pointless--let's move on to other theories to show how they do or do not work with the available evidence, or let's gather more evidence to test well-established theories.
Non-theories (like those proposed by creationists) are also a waste of time in the scientific communtiy because they can never be tested. I could propose that there is a tribe of invisible gnomes living in my garden. How would you test that? Well, say we look for their footprints? Oh, I forgot to mention that they don't leave footprints. OK, what about other kinds of evidence: maybe they're visible in the IR? No, they're completely transparent at all wavelengths. I'll just keep adding on addition superpowers to these gnomes until you give up in frustration, but you never were able to provide any evidence to prove my theory wrong, so it must be right and the truth. . .
About there being a correct theory: I didn't really state that well. Yes, you are correct, there can be a correct theory, which is the truth. However we can never know that the theory is 100% correct. We will never have collected all available evidence to test any theory, so all we can do is agree to call a well-tested theory a law. The scientific method has no (meaningful) aspirations toward finding absolute truth (*) because we will not know it when we have it. The scientific method is simply a way for us to make the universe meaningful in ways that are consistent from one observer to another.
* There are statements (let's call them axioms or postulates), like Einstein's Relativity Principal: "Every observer in the Universe must experience the same natural laws", that seem like absolutes, and are, in fact absolutes, but they are not the truth, they are the building blocks of our sciences. If we can't use those, then there is nothing that we can trust about our sciences, as everything is just magical because the laws don't apply to everyone equally. Notice that this axiom says nothing about knowing what those natural laws are, just that everyone follows them.
They're like the field axioms of algebra http://mathworld.wolfram.com/FieldAxioms.html.
Or, maybe Euclidian space is a better example. In 2-D Euclidian space, given any straight line and a point not on it, there "exists one and only one straight line which passes" through that point and never intersects the first line, no matter how far they are extended.
This is intuitively correct, except that it's impossible to prove for all cases. That's because it's an axiom for given, limited set of geometries (Euclidian geometries). There are other, self-consistent geometries which are non-Euclidian

pinball, schimball by BortQ · 2004-11-20 13:03 · Score: 2, Funny

Bah! This is just LiveScience trying to scam us to keep on feeding in the quarters.

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If this is true. by Murphy+Murph · 2004-11-20 13:39 · Score: 3, Informative

If this is true - and their experiment with the slab of aluminum offers decent evidence - why do modern seismological methods work as well as they do?

Money is the prime driver in many forms of research, and nobody has as much money vested in geologic surveys as the oil companies. Why haven't they already discovered this effect?

Question: Do seismic surveys currently employ a Radon transform (like how CAT scans reconstruct a 2D image from 1D projections)? If so, how would this "pinball effect" affect that?

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Re:If this is true. by mopomi · 2004-11-20 19:33 · Score: 2, Informative

Yes, they typically employ a Radon transorm during the inversion. Seismology is very much like a CAT scan w.r.t. methodology. The problem described in the paper (http://acoustics.mines.edu/preprints/vanwijklevsh in04.pdf) is that the multiple scattering caused by small heterogenieties near the surface of an object can cause the same sort of signal (to within error) as a multiply layer object. The radon transfer will have just as much of a problem as any other inverse transform simply because the matrix (data) is "bad". That is, the solution is non-unique and without some other a priori knowledge, we wouldn't be able to distinguish different forward models.

Smallest Pinball machine ... by xmas2003 · 2004-11-20 16:16 · Score: 0, Offtopic

Since the submitter talked about a giant pinball machine, here's the world's smallest pinball machine

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Re:Smallest Pinball machine ... by Anonymous Coward · 2004-11-20 20:42 · Score: 0

I'm sorry for posting this anonomously, but I refuse to get a slashdot account.

At any rate, I can't say that anyone should be surprised by these findings. Of course seismic waves will rebound off of an interface that is of different properties. I wouldn't say that current seismic theories derived off of powerful sources are wrong, per se. You must understand that a certain percentage of a wave's energy will be reflected regardless of the properties of the interface (unless the interface is completely normal to the incident wave).

The longest ST episode title by Scrameustache · 2004-11-20 16:38 · Score: 2, Funny

our model of the Earth's interior

"For the world is hollow and I have touched the sky"

I can't see the words "Earth's interior" without thinking of that title. : )

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You can't take the sky from me...

God help us.. by Anonymous Coward · 2004-11-20 20:38 · Score: 0

..if we get a TILT
who's going to get the ball rolling again??

East L. by Tablizer · 2004-11-21 07:10 · Score: 3, Funny

In a typical survey, geologists generate seismic waves, typically tens to hundreds of yards (meters) long, by igniting sticks of dynamite underground or vibrating the surface with a large, bouncing truck on hydraulic suspension.

And you thought low-riders were all play.

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Re:Pinball? Did someone say pinball? by TorDioMole · 2004-11-22 07:09 · Score: 1

I wanted the poster of this to know I laughed out loud when I saw it. I wonder when my next OS/2 chuckle will be?

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Earth, a Giant Pinball Machine

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