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Submission Driving Force Behind Alkali Metal Explosions Discovered->

Kunedog writes: Years ago, Dr. Philip E. Mason (aka Thunderf00t on Youtube) found it puzzling that the supposedly "well-understood" explosive reaction of a lump of sodium (an alkali metal) dropped in water could happen at all, given such a limited contact area on which the reaction could take place. And indeed, sometimes an explosion did fail to reliably occur, the lump of metal instead fizzing around the water's surface on a pocket of hydrogen produced by the (slower than explosive) reaction, thus inhibiting any faster reaction of the alkali metal with the water. Mason's best hypothesis was that the (sometimes) explosive reactions must be triggered by a Coulomb explosion, which could result when sodium cations (positive ions) are produced from the reaction and expel each other further into the water.

This theory is now supported by photographic and mathematical evidence, published in the journal Nature Chemistry. In a laboratory at Braunschweig University of Technology in Germany, Mason and other chemists used a high-speed camera to capture the critical moment that makes an explosion inevitable: a liquid drop of sodium-potassium alloy shooting spikes into the water, dramatically increasing the reactive interface. They also developed a computer simulation to model this event, showing it is best explained by a Coulomb explosion.

The Youtube video chronicles the evolution the experimental apparatuses underwent over time, pursuant to keeping the explosions safe, contained, reliable, and visible.

Link to Original Source

Comment Re:Get a Mac, it just works ... (Score 1) 278

I'd be pleased if Apple removed their absolutely painful fullscreen crap. All programs that benefited from fullscreen mode already had it before 10.8 and it worked much better. I keep using old versions of select programs because they use the old style fullscreening instead of the new motion-sickness inducing crap where you can't even float windows over fullscreened apps anymore. I stopped using browsers in fullscreen mode just because using old versions that actually work properly is a security risk!

Comment Re:The real reason the desktop pc is on the declin (Score 1) 219

Disclaimer: I have never seen anybody use a tablet with a keyboard. I don't own one nor do I expect to get one in the foreseeable future.

The (retina) iPad's screen is easily more than 3x as good as that on any netbook I've seen (and in fact better than any PC laptop), even a good phone has better resolution, color and viewing angles. If they sold them as computer monitors I would buy one. If we weren't stuck in the dark ages of fullHD TN panels I'm sure there would be more demand for computing power on desktops, too, but what good will it all do if your photos, websites and games won't look any better? If you can't even have a whole page of a book shown on-screen at once without the text being rendered at such low res as to make it genuinely difficult to read? There are diminishing returns on computing power when your user interface devices are the limiting factor.

I think part of the success of tablets has to do with how advances on traditional PCs have been made too difficult. Windows isn't resolution independent. Netbooks were intentionally marginalized. Outside linux-style package managers you still had to hunt your software down one-by-one from all over the internet until Apple's App Store. The trends for easier and more mobile computers have been apparent for decades. Perhaps "general use" computers aren't all that general use after all if they can't keep up?

Comment Re:Time to burn some points. HEY MBA STUPID PEOPLE (Score 1) 347

They hopefully copied the Nokia 3310, that unassuming phone has reached meme status for its indestructibility. Youtube is full of videos of it getting dropped and hit by a sledgehammer and it survives. The covers absorb almost any shock and fly around everywhere in spectacular fashion, leaving the innards unharmed.

Comment Re:Speaking of Sodom... (Score 1) 1774

I have trouble relating to your position on this. So you can decide you don't want to follow some particular god, fine. What does this have to do with actually believing in him? Have I been misled into thinking that people who "believe in god" actually believe he exists, instead of just playing along with the ceremonies because it's what their culture does?

Comment Re:Distance from the power supply (Score 2) 245

Where do you get music that has frequencies above 22kHz? Is it not more likely that you would get unwanted noise than actual signal in supersonic frequencies because they cannot be deliberately mastered? Even if the high frequency signals came from the recording as intended, AND the speaker could play that high, they would just produce intermodulation distortion on the speaker degrading the quality of the actually audible spectrum.

There is individual variation of course, with claims going as far up as 25kHz. 100kHz however is clearly overkill.

Whoever dies with the most toys wins.