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Comment: Re:OK, fine, do it already. (Score 1) 83

by NF6X (#47743867) Attached to: Sources Say Amazon Will Soon Be Targeting Ads, a la Google AdWords

I bought a couple of 'Hello Kitty' flash drives close to a year ago. It was a joke, people kept stealing my generic looking ones. The Hello Kitty sticks stay in my desk. Since then, every other time I log in, Amazon has to breathlessly show me various Hello Kitty things. An impressive panoply of products, but ones that I'm not especially interested in.

If that bothers you, then definitely avoid clicking any links on The Worst Things for Sale. The recommendation algorithm doesn't automatically discriminate between things you might want to buy vs. things you looked at for shock or humor value. Thanks, Amazon, but I don't need a 55 gallon drum of personal lubricant at the moment.

Comment: It's the interaction, stupid! (Score 4, Insightful) 81

by Okian Warrior (#47678217) Attached to: Is Remote Instruction the Future of College?

People sign up and never finish because the courses are downright awful. And there's no mind nor incentive for them to get better. Instructors think that just recording a lecture and putting it online is good education, but it isn't.

Watch Daphne Koller droning on about graphical models as the video shows her standing at a lectern talking, or showing a powerpoint-style frame while she reads the text on the frame to us.

Watch Anant Agarwal go through a *hugely* dense and boring derivation, only to stop before the end and say "but this derivation is too hard, there's an easier way". Twice. For the same result.

Try to figure out how many degrees of freedom a soccer ball has, then argue with Sebastian Thrun because the answer he thought you should have entered is not the mathematically correct one. (Also, see if you can figure out what this has to do with AI.)

For a breath of fresh air, watch Donald Sadoway take you through a delightful and satisfying explanation of chemistry. (Ignore the 1st lecture which is about class scheduling.) It's wonderful.

I could cite two dozen *major* problems with selected online courses - things that go counter to the fundamental goal of learning that would be obvious to someone familiar with human learning mechanisms or a testing group or even a member of Toastmasters. When I point these out to the chief scientist at edX, he responds with "we can't change the way we do things because of X".

Let me repeat that: the *chief scientist* at edX has no control over teaching techniques or video methods or course quality.

Some people (ie - Dr. Sadoway in the link above) have figured out how to do it right, but the vast majority aren't interested in quality. It's unfortunate that edX got all those millions in seed money, because we'll have to wait until they burn through it before they get hungry enough to worry about quality and effectiveness.

It's insane.

Comment: And another suggestion (Score 1) 123

Third suggestion:

Fungi can be used to remove heavy metal contaminants in flowing water. Place a bunch of fungi mycelium in sandbags in the water stream and the fungi will filter out the contaminants as the water flows through. Come back later, remove the bags and replace with a fresh batch.

Contact Paul Stamets' group over at Fingi Perfecti and see what their experts have to say. They might even have a product you could buy for the purpose.

Here's a paper and some contact info to get you started:

Comment: Here's Two suggestions (Score 3, Informative) 123

First suggestion:

There's been a lot of interest in using Zeolites to absorb heavy metal contamination in water. One specific experiment involved dragging a bag of zeolites through ocean water, the zeolites absorbed enough Thorium to be industrially useful as an ore (if there were a demand for Thorium, which there isn't).

I've found papers that indicate that Zeolites will absorb copper and lead, two of the contaminants listed for the Mount Polley disaster; chances are likely that zeolites would absorb the other contaminants as well.

Here's two papers to get you started:

Second suggestion:

There's been some success in removing non-volatile organic pollutants from soil using steam injection. Essentially, sink a pipe into the soil, inject steam, cover the area with a tarp, and collect the steam/water as it percolates up through the soil. This method can be used to extract non-volatile organic components including tetra-ethyl-lead. (I found that last bit surprising, but this was directly confirmed to me by one of the scientists involved.)

Depending on the chemical nature of the contaminants (ie - solubility, polar/non-polar character &c) this might prove useful in decontaminating some of the mud slurry.

Here's a paper to get you started:

Comment: Actual entropy explanation (Score 5, Informative) 117

by Okian Warrior (#47636439) Attached to: New Process Promises Ammonia From Air, Water, and Sunlight

Before I get slammed by a P-Chem major, here's what's really going on with the entropy.

The reaction is exothermic, and this release of heat increases the entropy of the universe. At the same time, 4 atoms of source become 1 atom of product, so this aspect of the reaction *decreases* the entropy of the universe. (There's more ways that 4 atoms can be arranged in a box than there is to arrange 1 atom.)

At room temperature, the entropy increase from the release of heat is greater than the entropy decrease from the reduction in states, so the reaction is favored.

The entropy from the release of heat is inversely proportional to temperature. Double the [absolute] temperature and you halve the increase in entropy from the release of heat. With higher temperatures, the entropy increase from "release of heat" is smaller than the entropy decrease from "change of states", the total change of entropy is negative, and the reaction is no longer favored.

I wrote a simpler/shorter explanation to avoid losing sight of the main point.

Comment: Some background (Score 5, Informative) 117

by Okian Warrior (#47636245) Attached to: New Process Promises Ammonia From Air, Water, and Sunlight

Here's some background on the Bosch Haber process.

Whether a reaction will occur is based on whether energy is required and whether the reaction increases entropy. In the case of nitrogen+hydrogen => ammonia, the reaction is both exothermic and increases entropy at room temperature and pressure. If one could somehow ignite the process it would be self-sustaining.

The problem is, to ignite the reaction you first need to break N2 molecules into individual N atoms, and this requires a great deal of initial energy which is regained in subsequent steps. Something like 7eV per molecule to break them apart. The molecules in normal air have a bell-curve spread of energies, but very few of them reach energies this high: the reaction happens at room temperature, but very *very* slowly. A handful of molecules per second will react.

To get around this you can raise the temperature, increasing the probability that molecules will have enough energy to break apart. The entropy produced is inversely proportional to temperature, so when you start to have N2 molecules with enough energy to break apart, the reaction is no longer favored because it would result in an entropy decrease.

Since 4 moles of reactants result in 1 mole of product, increasing the pressure of the reactants will tend to favor the products, so you can use this to offset the deficit in entropy.

The Bosch-Haber process tries to find a "sweet spot" by increasing the temperature to get a reasonable number of N2 molecules to break apart, and high pressure to make the process favor the products.

At 200 ATM and 400 degrees, the yield is 15% (!).

Reaction vessels for this pressure and temperature are expensive, and the process requires multiple cycles of compression, decompression, removal of ammonia, and recompression. This takes a *lot* of energy and uses *very* expensive compressors which wear out over time and have to be replaced.

I haven't read the paywalled article yet, but if I'm understanding the abstract, they are breaking apart the nitrogen electrochemically. Just as running a current through molten NaCl will break it into atomic sodium and chlorine, running a current through nitrogen dissolved in KOH and NaOH breaks it apart and the reaction then proceeds at normal conditions. The reaction also supplies its own hydrogen by breaking apart water.

Much of the "green revolution" is due to the use of nitrate fertilizers, and the source material is finite: guano from Peru, for example.

If this process is as efficient as the abstract suggests and can be industrialized, it would be *huge*. It would give us an essentially infinite source of nitrogen-based fertilizer and reduce the worldwide consumption of energy by a couple of percent.

Coupled with a source of renewable energy, it would mean that the world could sustain its food production at current levels indefinitely.

This could be really, *really* big news.

Comment: Re:FUD filled.... (Score 1) 212

It sounds like this transformer had its center tap grounded and was the path to ground on one side of a ground loop as the geomagnetic field moved under pressure from a CME, inducing a common-mode current in the long-distance power line. A gas pipeline in an area of poor ground conductivity in Russia was also destroyed, it is said, resulting in 500 deaths.

One can protect against this phenomenon by use of common-mode breakers and perhaps even overheat breakers. The system will not stay up but nor will it be destroyed. This is a high-current rather than high-voltage phenomenon and thus the various methods used to dissipate lightning currents might not be effective.

Comment: Re:Astronomy, and general poor night-time results. (Score 2) 550

by NF6X (#47526651) Attached to: Laser Eye Surgery, Revisited 10 Years Later
Thank you. I do need correction to see the target at all, particularly at rifle ranges, because I've been nearsighted since at least junior high school. I suppose that once I get bifocals or progressive lenses (probably at my next eye exam), I'll need to learn to find the target first through the long-distance part of the lens, then shift to the near-distance part to focus the sights on the correct blur. I haven't gone shooting since I started to notice the onset of farsightedness, but I can still see well enough at front sight distance without correction. But now I need magnifying glasses to focus on small things like PCB features up close, which is pretty annoying. It's not just that the PCB features are getting smaller I've begun playing around with vintage computers recently, and I even have trouble focusing on the old through-hole stuff now without external optics.

Comment: Re:Astronomy, and general poor night-time results. (Score 2) 550

by NF6X (#47525107) Attached to: Laser Eye Surgery, Revisited 10 Years Later

I'm considering doing that. I'm 45 and my eyes have just begun to change. I'm still generally myopic, but so far the change just requires me to take my glasses off when doing close work.

I'm also 45 and I'm experiencing the same thing. I am overdue for a new set of glasses anyway, but I've noticed my new farsightedness the most when doing work on the test bench. I've had to start using a set of head-mounted magnifying lenses regularly for close-up work. If I was to consider some sort of corrective procedure, I'd need something that's compatible with close-up hands-on work, staring at a computer screen most of the time, and shooting which requires both close-up vision (to see the signs) and long range vision (to see the target). I haven't researched yet whether any of the existing procedures would be a good option for a person of my age with my vision and range of activities.

+ - Letter to Congress: Ending U.S. Dependency on Russia for Access to Space 1

Submitted by Bruce Perens
Bruce Perens (3872) writes "I've sent a letter to my district's senators and member of congress this evening, regarding how we should achieve a swifter end to U.S. dependency on the Russians for access to space. Please read my letter, below. If you like it, please join me and send something similar to your own representatives. Find them here and here. — Bruce

Dear Congressperson Lee,

The U.S. is dependent on the Russians for present and future access to space. Only Soyuz can bring astronauts to and from the Space Station. The space vehicles being built by United Launch Alliance are designed around a Russian engine. NASA's own design for a crewed rocket is in its infancy and will not be useful for a decade, if it ever flies.

Mr. Putin has become much too bold because of other nations dependence. The recent loss of Malaysia Air MH17 and all aboard is one consequence.

Ending our dependency on Russia for access to space, sooner than we previously planned, has become critical. SpaceX has announced the crewed version of their Dragon spaceship. They have had multiple successful flights and returns to Earth of the un-crewed Dragon and their Falcon 9 rocket, which are without unfortunate foreign dependencies. SpaceX is pursuing development using private funds. The U.S. should now support and accelerate that development.

SpaceX has, after only a decade of development, demonstrated many advances over existing and planned paths to space. Recently they have twice successfully brought the first stage of their Falcon 9 rocket back to the ocean surface at a speed that would allow safe landing on ground. They have demonstrated many times the safe takeoff, flight to significant altitude, ground landing and re-flight of two similar test rockets. In October they plan the touchdown of their rocket's first stage on a barge at sea, and its recovery and re-use after a full flight to space. Should their plan for a reusable first-stage, second, and crew vehicle be achieved, it could result in a reduction in the cost of access to space to perhaps 1/100 of the current "astronomical" price. This would open a new frontier to economical access in a way not witnessed by our nation since the transcontinental railroad. The U.S. should now support this effort and reap its tremendous economic rewards.

This plan is not without risk, and like all space research there will be failures, delays, and eventually lost life. However, the many successes of SpaceX argue for our increased support now, and the potential of tremendous benefit to our nation and the world.

Please write back to me.

Many Thanks

Bruce Perens"

I wish you humans would leave me alone.