Catch up on stories from the past week (and beyond) at the Slashdot story archive

 



Forgot your password?
typodupeerror
For the out-of-band Slashdot experience (mostly headlines), follow us on Twitter, or Facebook. ×

Comment: Sigh.. (Score 1) 89 89

Another example of overblown novelty... AFM is nothing new, and "olympicene" is also nothing new.. it's been made before... at least as early as 1965.. and possibly earlier still (haven't looked deeply in the scifinder databases).

Here's a literature citation (something the parent article sorely lacks) with proof. You know.. the stuff science is supposedly made of ?

http://pubs.rsc.org/en/Content/ArticleLanding/1965/JR/jr9650005920

Comment: Re:Ah, America! (Score 5, Informative) 562 562

There's two obvious reasons for this: Points on my credit card (i.e. free money/miles/ etc), and convienience. It allows me to watch only my credit card bill and pay it once. Also, there's a little bit of money to made on the float (not much these days w/ the low interest rates).

Comment: Re:Dangerous (Score 1) 350 350

Subreality,

I'm curious, I'm a chemist and I use a UV lamp nearly every day to visualize TLC plates. The lamps, as I understand it emit from ~254-365 nm. The lamp is typically used against a black benchtop background to illuminate a white silica TLC plate, usually impregnated with a fluorescent dye to help visualization (the whole plate typically glows green under UV light, except where your compound is).

I always avoid looking directly at the lamp of course (but occasionally catch sight of it). However, I'm wondering, how dangerous this frequent exposure is. I'm often wearing my regular prescription glasses while doing this (which I believe block UV), but I know some people don't wear anything when looking at their TLCs. Furthermore, I always wear at least reasonably thick gloves when my hands are under the UV, but again, some people do not (this is direct exposure to the UV lamp source, which seems like a really bad idea...). Do you think the reflection is hazardous ? Given the frequency of use by the average bench chemist, it seems like this should be more of a concern than people typically talk about.

A typical lamp used for this purpose is shown here: http://www.uvp.com/compactlamps.html#thumb or here: http://orgchem.colorado.edu/hndbksupport/TLC/TLCprocedure.html#visualize

Also, some people sell enclosures to help visualization, but also to help block the UV light ... the annoyance with these of course is that they're typically quite clunky to use in comparison to the "flashlight" method people often use: http://uvp.com/cabinetsoverview.html.

Comment: Re:Not news (Score 2) 138 138

It's not that it's old... it's that its' NOT new in any tangible way... no new tech , no new application, no real invention here.. which makes it pretty "meh" in perspective.

That this stuff has been sold commercially for decades is pretty damning in terms of this being a "So what? " news item.

Comment: Born-Oppenheimer Approximation (Score 1, Interesting) 127 127

By the way... I think the commentator in the attached perspective (http://www.sciencemag.org/content/331/6016/411.full) gets the born-oppenheimer approximation wrong... he states that :

"The BO approximation makes possible the practical application of quantum mechanics to all of molecular science. As the arrangement of the nuclei changes, the BO approximation postulates that the electrons will remain in a particular quantum state. "

When the BO approximation is the opposite : The atoms DONT move while the electrons DO (relatively speaking) because of their vast difference in mass. That is... the electrons are little bullets whizzing around at top speed, whereas the atoms are massive aircraft carriers in terms of mass (note: this is not meant to be even a remotely accurate analogy, but it's the general idea). You'd think that SCIENCE, of all journals, would get the Born-Oppenheimer approximation right !

Note: That in the second step of a typical quantum mech. calculation (e.g. a geometry optimization), you then use the average field generated in the first part to move the atoms (if they need to move in the particular calculation). Then you iterate to self-consistency.

Comment: Sigh... again ? (Score 1) 299 299

When will the mathematicians give up on Pi as some sort of grand benchmark.... couldn't they do better things to benchmark their systems... like running a folding@home client, or some such thing?

Honestly.. the first thing I thought when I saw this was... wow.. how.. uncreative...

How is this going to help them beat out Google and MS again ?

Not to bash on Yahoo.. they were once a great service/company... but they're quickly becoming a has-been. What they desperately need, and what everyone in this sector needs, is creativity. This sort of horn tooting doesn't really impress me, so much as it depresses me that people are benchmarking their systems on the same old problem again and again.

Murphy's Law, that brash proletarian restatement of Godel's Theorem. -- Thomas Pynchon, "Gravity's Rainbow"

Working...