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Comment: Re:Just starting? (Score 2) 175

by n3umh (#38300076) Attached to: Earth's Core Made In Miniature

So, what you're saying is that the popular mechanics article where it specifically says that they were using sodium is false and they were using water?

Unfortunately, that is the case. We find out about weird stuff like this when the piece comes out. The grand total of all the sodium spinning in the three meter experiment so far has been when Santiago Triana and I melted the partially full sphere and spun the inner shaft and sphere by hand a few weeks ago.

I'm not sure why the Popular Mechanics people said we were already running sodium... we certainly didn't tell them that or give them that impression. I was taking data in water for my dissertation. Since I graduated we have mostly been doing logistics and sodium-filling engineering and logistics stuff.

This Nature article is excellent both in the description of the experiments and the projected timeline. Of course things might slip a bit because we always have a lot of work to do, but we DO actually have quite a lot of sodium in there (73% full) and have the rest inbound on a boat from France right now. Won't take too long to top it off. We have a little bit of instrumentation work to do but that's really just wiring some commercially available hall effect sensor into an existing rotating computer. We always have to do some debugging, but we're really quite close.

-Dan Zimmerman

Comment: Re:How can this produce accurate results? (Score 2) 175

by n3umh (#38299976) Attached to: Earth's Core Made In Miniature

How can this produce accurate results that will possibly match that of reality?

One of the things that we're trying to do is generate a dynamo that offers the same challenges to those who wish to simulate Earth's dynamo while keeping a pretty simple geometry and forcing.

We don't use convection because the velocities you can get from convection in the lab are too small, even when you crank up "gravity" which is dominated not as much by Earth's gravity but by centrifugal acceleration. Rotating convection in the lab has been done by heating the OUTSIDE and cooling the inner core. The cold dense fluid at the inner core gets flung outward, the light hot fluid at the outside moves inward.

Centrifugal convection in a sphere is very cool (or in a hemisphere: http://hakusan.s.kanazawa-u.ac.jp/~sumita/%20hemisphere.html) but is not a very likely candidate for dynamo action because convection isn't very vigorous at sane heat fluxes (and by "sane," keep that in context: I'm a dude who thinks spinning 13 tons of sodium isn't really a big deal)

We're forcing our experiment by spinning the two boundaries at different speeds, which isn't really earthlike at all.. but the real point is to help figure out how to make practical computer models of the dynamo process by having a controlled testbed for studying a turbulent dynamo in a geometry that doesn't require the dynamo simulation community to greatly change their codes. They just have to spin the boundaries of their spherical shell simulation instead of using internal heat sources. The geodynamo simulation community has done a lot of optimization for calculating fluid flow and magnetic field generation in rapidly rotating spherical shells.

And from the perspective of relevant physics, the rotation and spherical shell geometry allow some internal waves and vortices that are fairly similar to what might happen in the core.

We can't hope for an exact scale model of the earth that will do earthlike things by itself. Really, we just want to get a laboratory dynamo that has ingredients like rapid rotation and spherical shell geometry. To hit ALL of the parameters correctly to get an exact convective scale model of the Earth's dynamo would probably need something like metallic hydrogen at four million atmospheres pressure (so that it might go into a metallic superfluid state) and a small laboratory black hole at the center.

This is what I like to call an "engineering challenge."

-Dan Zimmerman

Comment: Re:Somebody please hint... (Score 2) 175

by n3umh (#38299772) Attached to: Earth's Core Made In Miniature

Sodium is the best liquid electrical conductor. Order of magnitude better than things like mercury and gallium which are sometimes used in smaller MHD experiments. It's fairly cheap. Gallium is about a thousand dollars a liter and I guess we paid about $7.50/liter for the sodium.

And it's low density (about the same as water). The fluid mass would be about 75 tons if we used gallium and 170 tons if we used mercury.... (honestly I don't even know if you can buy that much of either of them anyway).

Sodium is the only game in town for liquid metal dynamo experiments.

-Dan Zimmerman

Comment: Re:Double blind study (Score 3, Insightful) 298

by n3umh (#32822142) Attached to: Study Hints Ambient Radio Waves May Affect Plant Growth

yea the thing is its kind a waste of time and money for people to repeatedly perform the same badly controlled experiment over and over.

Sure, I agree with that. The next experiment should control for more variables. It's straightforward to improve upon the methods to leave less doubt. You can also do an experiment to show that some OTHER effect was likely responsible. Formulate another hypothesis that would explain Haggerty's data and test those ideas directly.

But if the people with the resources don't care about this particular issue, no one will do the experiment.

You can find out the same thing faster and cheaper if you just design it well to begin with.

I think if Haggerty had managed to get "no difference" among the three cages, no one would be calling for a better experiment, even though it would have been equally uncontrolled. We need to think about this.

Even if we ultimately prove that Haggerty's hypothesis is incorrect, she took a stab at addressing what she perceives as a gap or mistake in knowledge in the RIGHT way. There is no bad experiment as long as you are trying your best within your resources and acting ethically. There are unfortunate consequences of the media and concerned groups trumpeting EVERY paper as "the truth," but if that happens it is not really Haggerty's fault (IMO, after reading the paper.)

Haggerty did the right thing with her concerned skepticism. When was the last time you saw someone concerned about RF do something other than blog endlessly about RF sensitivity or spout mumbo-jumbo about the balances of life force?

Haggerty designed an experiment that controlled for a number of significant variables while changing the RF applied to the plants in a measured way. That's doing it right. Nothing is perfect. You can never control for ALL variables and there is always a need to minimize the impact of that. But you have to start somewhere, and if you have a fringe idea, that will probably be YOU in your own backyard.

Honestly, this takes the wind out of a lot of science **deniers'** sails. It's strong evidence against scientific conspiracy; evidence against "burying" of "weird" ideas. This person with no formal scientific credentials got a paper published that's based around a pretty deeply fringe idea. She deserved that publication on the basis of actually applying decent, if low budget science and getting a result.

I suspect that it won't be very long before there's a flurry of other careful experiments that explain Haggerty's results with a different interpretation of the causes. There will probably be theory papers on the spectral limits of the response of plants (as she cites some papers on outside-of-the-visible-light effects on plants).
It's not going to take that much time or that much money to refute this result, and in the meantime, Haggerty's publication suggests that properly executed scientific inquiry stands on its own, independent of preconcieved notions or weirdness of the result.

Comment: Re:Double blind (Score 1) 298

by n3umh (#32821294) Attached to: Study Hints Ambient Radio Waves May Affect Plant Growth

A double blind study is to prevent placebo effect as well as experimenter bias.

There's yet another reason to do a double blind that has little to do with the results.

If you're a physician administering a placebo to a patient in a drug trial and they die or worsen significantly, it's important that you never know. This is especially true if it turns out that the drug is very effective. The effects of researcher and subject bias when both the experimenter and the subject can communicate nonverbally and instinctively are also an extremely important reason to do double-blind tests in some circumstances.

None of these things apply to subjecting trees to objectively measurable stuff and reporting your methods and results in a reasonably objective way. A certain interest in a question and expectation of the outcome leads one to do experiments in the first place, but that doesn't mean that every test must be carefully tuned to eliminate *any possibility* of researcher bias.

In situations where people are doing controlled, *easily reproducible* experiments and present results based largely on objective measures (in this case, things like biomass, leaf size, fraction of diseased leaf, etc), it's a waste of resources to do blind tests.

Researcher DISHONESTY can still be a problem, but that will ALWAYS be a problem, blind tests or no. People fake data, sabotage results... whatever. That's why independent confirmations are important wherever possible. Working in large groups with blind tests helps reduce this possibility when many independent confirmations are impossible (since it's hard to hold together an actual conspiracy).

But for a single scientist working with reasonably objective methods, it's not worth it. To do a blind test **by yourself** you would have to set up a really convoluted system to hide the methodology from YOURSELF. This is unnecessary if you're doing science right. Some people are prone to confirmation bias. They are bad scientists. They're barely scientists.

Haggerty's paper suggests she's a scientist.

I don't like this result. I don't like it at all. But unless the data were falsified, there's no problem with the method. There are other things that need to be controlled for. It might be something chemically relevant about the aluminum screen. I've found some papers that suggest that the color of a screen can repel certain insects that can pass through the holes anyway... so there could be a difference between fiberglass and aluminum in keeping insects out.

But my concern over the public relations potency of these results and the hypotheses I have about "other factors" are not science. Testing my hypotheses as objectively as I could and presenting the results would be science.

Comment: Re:Right (Score 3, Insightful) 298

by n3umh (#32820250) Attached to: Study Hints Ambient Radio Waves May Affect Plant Growth

Just how unbiased was this person? If they were hoping for a specific result, there are a lot of things they could do in an "experiment" like this, even without thinking that they are doing such things.

Do the experiment yourself and find out. You're skeptical so if anything, you'll have the opposite bias. That's how this works.

No human being is 100% free of subconcious bias. A good scientist will do everything they can to perform objectively identical actions on all members of their various experimental organisms. IN that way, they will minimize the effect of their own biases. And others can reproduce the same objectively identical actions to gather more data.

Haggerty's paper suggests that she attempted to be careful in this regard. She explicitly presents her method. That's one way we know that she was trying to avoid her personal biases.

Comment: Re:Double blind study (Score 4, Interesting) 298

by n3umh (#32820224) Attached to: Study Hints Ambient Radio Waves May Affect Plant Growth

Personally, I think the shielding worked more as a cozy for the plant and gave it a more stable immediate environment upon which to grow.

Read the paper. Haggerty had two cages, one of which was RF-transparent fiberglass which was close to the same air and light blockage as the aluminum faraday cage.

I still think it will come out that something else was the cause.

But as far as personal bias, a good scientist is aware of their own biases and tries to do things that are somewhat antagonistic to their own point of view. This isn't perfect, but that's why you use objective measures and report all your methods. Someone else can try to reproduce the experiment, improve upon it, control for more things, etc.

It is possible that subconcious/unconcious biases in plant care play a role here, but anyone can repeat the experiment, and it's very likely that those repeating it next will be VERY skeptical to the idea that RF is at fault and will be very careful not to baby the RF caged plants.. and if biased they'll be biased the other way. That's a good outcome of such a publication.

Many repeated experiments by people who are skeptical of each other average over personal biases.

Comment: Re:Double blind not needed (Score 1) 298

by n3umh (#32819924) Attached to: Study Hints Ambient Radio Waves May Affect Plant Growth

If there is an opportunity for experimenter bias to creep into any measurement (for example if they are recording something a bit more subjective like bark quality or growth symmetry), then having the person measuring the result be "blind" may be appropriate.

There are a lot of people today that believe that experimenters must PROVE that they are un-biased in a way other than presenting their methods and results.

I think some people in this thread would prefer blind physics experiments :-)

Comment: Re:Maybe it was a response. (Score 2, Insightful) 298

by n3umh (#32819902) Attached to: Study Hints Ambient Radio Waves May Affect Plant Growth

Light was controlled for within 5% of that received by the un-shielded plants. There were three groups, and it was simple... fiberglass screen shaded the "mock shielded" group from the sun the same way the aluminum screen did.

I personally think further experiments will discover some other cause besides RF, but Haggerty controlled for and measured a lot of other things... light, air circulation, etc. That doesn't mean her results will turn out to be correct, but she did present everything anyone would need to do to repeat her experiments to verify or refute them.

Comment: Re:Hints? Might? (Score 5, Insightful) 298

by n3umh (#32819832) Attached to: Study Hints Ambient Radio Waves May Affect Plant Growth

I have a deep concern about over-stating the dangers of RF radiation... honestly, though, I don't see anything wrong with the PAPER and would say that Haggerty
approached the experiment in an appropriate scientific manner.

Come back and talk to me when you have a more definitive study.

This is not a perfect experiment... no experiment is. But the methodology is laid out. The experiment is reproducible, and that's what matters. I think it may spark interest in study... very likely from people who are VERY skeptical that RF could be the cause, and that's perfect.

I think that it's probably the case that something else is the cause, not RF. There are things that aren't controlled for. But you or anyone else can do a better experiment. You're right to be skeptical of a single one, but that doesn't mean Haggerty's work wasn't valuable.

Comment: Re:Flip flop the question: (Score 1) 511

by n3umh (#32767506) Attached to: Do Scientists Understand the Public?

Unfortunately, they are a loud and obnoxious vote, and there's no way for actual science to be communicated against that background.

No doubt, I have a big problem with these people, but it's important to fix the real problem, and make sure that strategy doesn't prove the deniers right. If you suppress them, they become the persecuted "true skeptics" even though they are no such thing... They use pure, evidence-free rhetoric and manipulation of peoples' fears to cast doubt on science.

I think it's kind of useful for scientists to "take back the doubt" in today's current political climate. In a healthy field that's doing real science, there's more than enough skepticism and competition to keep conspiracies from happening.

Unfortunately, as frustrating as it is, I think part of scientists' jobs IS to convince the public that science works. The results are important too, but suppressing the deniers would just give them more power. Making people see that scientific findings have real weight because scientists are constantly trying to prove themselves and each other WRONG is somewhat important.

I think that a lot of the deniers are smart, thinking people without a good understanding of how science works. They get a steady diet of conflicting reports on scientific topics from the media, and they're paying attention, so they see the conflicts. But they don't appreciate how important the conflicts are to the process.

  I notice this on the ham radio websites I hang out on. There are a lot of ham radio operators who think solar physics is a ridiculous pursuit because one group is predicting that the next solar cycle will be incredibly strong and another is predicting, on the basis of a different model, that it will be very weak. These people seem to think that we shouldn't try to predict because our predictions disagree.

They're not dumb. But they are totally missing the point.

The findings are important. But they mean nothing if there's a serious doubt in the process. I think a lot of people couldn't imagine setting themselves up to be publicly wrong like the solar physicists do. Then they try to rationalize the public failures on the basis of more familiar motivations: they're doing it to get attention and funding, to advance their careers. They're bad at their jobs and are wasting taxpayer money. They should just hang it up.

I think a lot of the deniers come out of that kind of thought process.

Comment: Re:Where are the studies? (Score 1) 511

by n3umh (#32766980) Attached to: Do Scientists Understand the Public?

Besides how can you explain things to people without using large words. Those words were created for a purpose, mainly to convey specific meanings of what scientist say. Without large words science would be meaningless.

I dunno. If I run across something I can't re-phrase or re-express on the fly, I feel like I don't really understand it. And I don't feel like I've got a lot of big words that are NEEDED to express what I'm doing. I suppose it depends on the field a bit, but you want to give me an example? What is your latest finding, big words included?

When I describe my experiment and what I've found to a random person, I start in a lightly technical tone .. that way I can scale it back if people don't seem to understand, and I ratchet up the technical language if someone is clearly familiar with it.

Comment: Re:As perhaps a member of the skeptical public.. (Score 2, Insightful) 511

by n3umh (#32766764) Attached to: Do Scientists Understand the Public?

. But I think it's a mistake to take the current theories of the day as "The Truth" (they're so often over turned by later research)

A good scientist is a professional skeptic and will absolutely agree with that. "The Truth" is not the goal of science. It's not even a possible outcome. Science cannot guarantee that we're moving our knowledge closer to "The Truth." It is pretty good at moving our knowledge in a medium-term useful direction. And when we discover something wildly new, like relativity or quantum mechanics, we branch off in a new direction while simultaneously continuing in the old. The most flexible and brilliant scientists send a feeler off toward totally new territory, ***maybe*** making it somewhat more likely that we're approaching "The Truth" in a long term sense... but probably if we're moving toward "Truth," it is purely by accident.

It's still always possible that human science started with some sort of bias (sensory, cognitive) that makes us very, very wrong in a big picture sense. I think it's important to remember that such a possibility exists, but that it's a matter of philosophy until you can present some evidence for that idea.

Science is a way to discard those ideas that are obviously wrong while keeping around a bunch of useful ideas that haven't been shown to be wrong yet. That's what it's for, and it is the best system we've got for that.

I think it's really important that the public understands that scientists are trying to understand the universe but that many of them are deep skeptics who would be willing to completely change everything they think if presented with appropriate EVIDENCE. That's what makes science so useful and strong. It frustrates me that so much of the media discourse about science is focusing on the internal disagreements and the constant overturning of old ideas and pointing to it like it's a BAD thing. It's frustrating. It's kind of like having someone point at you in grade school and call out to all your schoolmates that you're stupid because you're WEARING GLASSES. It should be totally obvious to everyone who's ever seen you that you wear glasses, and yet, in certain social circumstances, people can wield power by pointing out an obvious fact and saying loudly enough that it's a negative thing.

You're absolutely right that you shouldn't look for "Truth" in science. Any good scientist should be on board with you on that. Our most important job is to be professional skeptics and to construct ideas and gather evidence that disproves other ideas and results. That's scientific progress, and having people point at you and make fun of you for doing that shows a certain immaturity, just the same as winning friends by making fun of someone's glasses.

Comment: Re:Or... (Score 1) 511

by n3umh (#32766084) Attached to: Do Scientists Understand the Public?
" it's kind of health to ask for proof, as long as you don't keep denying once you receive it."

To SEEK proof (or, rather, undisproof) regarding things you're skeptical about is great, but the evidence has often been presented already!

There is *always* evidence and methodology presented in scientific presentations, both the source material and in most lay articles (though they could do better on that front, I think). No one should believe or disbelieve the conclusion until they've inspected the evidence and understood why it's evidence for the conclusion. Real skepticism requires a lot of neutrality toward new ideas for at least a few moments.

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