bunsen_h: (Default)
I'm not sure about the Latin. But I've joined the mass exodus from LJ. I've been get-around-to-it-one-of-these-days-ing about moving to Dreamwidth for quite a while; sometimes I need a kick in the pants.  LJ's new terms of service provided that kick.  I feel that if I want to quote Randy Rainbow in saying that P. and the Ritz "love dic... tatorships", that's valid political satire. Dreamwidth's automated migration tool should be copying all of my old LJ stuff to my new blog, bunsen_h.dreamwidth.org, sometime quite soon.

Meantime, here's a bit of lame chemist humour: (NbO)+[CH3(CH2)10CO2]-.

(Niobyl laurate.)

(Told you it was lame.)

bunsen_h: (Popperi)
The CBC just reported the discovery of a supermassive black hole, of the kind that usually sits at the center of a galaxy, travelling at extremely high speed away from its galaxy.  It's believed to be the result of the merger of two galaxies, with their respective central black holes merging and being flung away.

My intuition explains this as being somewhat like the old children's game "Battling Tops".  In that game, players launch small spinning tops towards each other in a bowl-shaped "arena".  The tops are spinning in the same direction, so at the point of contact, the rims are moving in opposite directions.  The collision transfers some of the rotational momentum of the spins to the tops with respect to each other, slowing the spins and kicking the tops away from each other.  Eventually, the tops slide down the bowl again, and after a few collisions, at least one gets knocked over; the winning player is the one whose top is standing last.

With the black holes, getting flung away from each other after "contact" doesn't work so well.  So a massive pulse of gravitational wave energy gets flung in one direction, and the merged black hole heads in the opposite direction.

Or so my intuition says.  Dammit, I'm a doctor of chemistry, not a doctor of astrophysics.
bunsen_h: (Popperi)

It would not have occurred to me that one might create permanganate at home by dissolving steel wool in bleach.  Nevertheless: I've got that distinctive grape-juice colour that first-year chem students at Queen's used to ask me "is this a purple solution?" about.

I probably won't bother to try to save and purify it; it's likely to be much more fuss than it's worth, I don't need it, it's relatively chemically unstable and would probably decompose before I got to play with it.  My intended product is the rust, ferric oxide.  With which I will make ferric chloride, by dissolving it in hydrochloric acid.  With which I will make jelly.

I have also made some cupric (copper+2) chloride by dissolving fine copper wire in hydrochloric acid with hydrogen peroxide.  Combined with ascorbic acid extracted from vitamin C tablets, I'll be making copper nanoparticle jelly.  The two jellies combined can be used to copper-plate stainless steel so it can be soldered onto.

From there, I hope to be able to build a light-up propeller for my bike helmet.  I'm having some trouble sourcing some of the stainless steel bits, not to mention having to revise my designs as I discover that some items simply aren't available.  I've already gone through a fair bit of hassle getting some T-pins that were supposed to be stainless steel, only to discover (on prior testing, because I'm suspicious) that they were just ordinary nickel-plated regular steel and rusted rapidly when scratched.  (The seller tried to insist that their product was stainless and that I must have switched the pins.  Then that, well, yes, their stuff rusted, but it was still stainless, just really low-quality stainless.  "Of course if you scratch off the protective layer it rusts!")

bunsen_h: (Popperi)
Part of quantum murphydynamics, we have conservation of murphions:

  1. If a thing is fixed, another thing will break.

  2. If a problem is prevented, another failure will become possible.

bunsen_h: (Popperi)
The other day, in a conversation about the meme of "X is natural, so it's good for you!", I jokingly suggested strychnine arsenate.  Strychnine is an alkaloid, so can form a compound with acids, for example arsenic acid (H₃AsO₄, analogous to phosphoric acid).

I am slightly surprised to discover that not only is it a thing, not merely is it a compound with known properties, there are chemical suppliers that will sell it to one.

The only use for it that I've been able to find in a quick on-line search, apart from a cagey "chemical research", is for making homeopathic preparations.  I might have guessed.

It's possible that its real purpose in supply catalogues is to send a warning note to local police agencies that they might want to keep an eye on you.
bunsen_h: (Popperi)
But on drying, gerbil pee leaves a tough white residue, poorly soluble in water and difficult to remove from a plastic surface without damage to the plastic.  However, it is readily soluble in concentrated hydrochloric acid, with evolution of gas.  I suspect it's giving off CO2, but I don't have the resources to try to confirm.  It would probably also dissolve in something like vinegar, but much more slowly.

I miss working in a chemistry lab for many reasons, and one of them is ready access to small amounts of harmless chemicals for personal use.  But some reagents are available from craft and hardware stores, if you know what to look for.  Hydrochloric acid is also known as muriatic acid, and the version sold in hardware stores is pretty close to the concentrated HCl we used in labs.
bunsen_h: (Popperi)
I've heard that when people are put in an environment that's completely devoid of day/night cues, they tend to adopt a wake/sleep cycle of about 26 hours.  (On average; there's considerable individual variation, as with any human characteristic.)  So what happens if people are put in an evironment that matches their wake/sleep period?  Do they tend to be better-rested and able to accomplish more than otherwise?  Unfortunately, most people don't have the resources to flit one or two time zones a day.
bunsen_h: (Popperi)
The Utah DEA is now concerned that marijuana farms will lead to rabbits getting stoned and not showing their normal habits of self-preservation.

First: Rabbits are not exactly an endangered species.

Second: This will create a strong natural selection bias in favour of wildlife that isn't affected by cannabinoids.  In a couple of decades, that may give us some very useful pharmacogenetic data.


Mar. 16th, 2014 09:36 pm
bunsen_h: (Popperi)
I'm having mixed feelings about the new version of the Cosmos TV series.

It's good to have any kind of show teaching reasonably accurate science stuff in an entertaining way.  But... a lot of the graphic stuff isn't accurate.  Our solar system's asteroid belt, and the cloud of debris that coalesced into Earth, have been depicted as being like the typical sci-fi movie dense cloud of rocks.  A blood stream, with "our ship of the imagination" zipping through it, is startlingly devoid of blood cells.  A depiction of a DNA double-helix is bizarrely decorated with lines of light more-or-less-randomly connecting things, making it look like it's covered with cobwebs.

Is it a Brannon Braga thing?

ETA: Some of the spoken science is pretty wrong-in-scale as well.  In this evening's episode, Tyson made some mention of molecules so tiny that a million of them would fit inside a grain of sand.  Seriously?  That's some orders of magnitude off even if we were talking about them fitting across the grain of sand.  Then cube the error.  I recall squawking about some similar error last week.
bunsen_h: (Beaker)
The proper way of doing a pissing contest involves the integral of distance by time.
bunsen_h: (Popperi)
Recent research has shown that the naked mole-rat has a unique variant ribosomal RNA structure.  This appears to significantly reduce errors in DNA replication / transcription compared to other animals, and is believed to be a cause of the animal's remarkably long lifespan and low susceptibility to cancer.  The animal lives for about 30 years, while other animals around the same size would have a lifespan more like 3 years.

In order to apply this to humans, I think we'd have to splice the coding for the variant RNA into our own genes (and, of course, knock out the existing RNA coding).  I'm not sure if it would be feasible except at the egg/sperm stage, i.e. genetic engineering from the start.  Tricky stuff, but not too far beyond current technology, I think.  Given the potential rewards, I wouldn't be surprised if the extremely-wealthy, rules-are-for-other-people types started having extremely long-lived offspring starting in a couple of decades, with the first bad side effects to start showing up only a few years later.  ("Why didn't you test this first?  Why didn't you know this would be a problem?")

Luckily for the population-catastrophists, the 1000-year-lifespan humans will be pre-adapted to living in crowded masses underground.

Food prep

Sep. 29th, 2012 05:24 pm
bunsen_h: (Beaker)
I've noticed that a lot of the ready-to-cook food items now carry warnings about how well-cooked the food has to be to be safe.

But how do I measure the internal temperature of, say, ravioli immersed in boiling water, to make sure that it's at least 74°C?  (Just 73° wouldn't be safe.  Or just waiting until it floats and has a reasonable texture for eating.)  Or the internal temperature of a pizza in the oven?  These would be tricky to measure even with the resources of a well-equipped lab.


Aug. 7th, 2012 09:01 pm
bunsen_h: (Default)
At Farthing Party[livejournal.com profile] elisem mentioned a Cool Thing which I hadn't heard about: electroluminescent wire.  It doesn't use much power and comes in a variety of colours; the potential applications for costuming are diverse.  A child's costume could be spectacular, and driven by a couple of standard batteries.  It doesn't have the same lifetime as electroluminescent night lights (which I've been using and appreciating) but it's plenty long enough for costuming purposes; it is also, alas, not cheap.  Still... hmmm.

(The materials-science geek in me suspects that the limited lifetime may be due to degradation of fluorescent materials used to convert from the usual green-blue / "aqua" / cyan electroluminescent phosphors to other colours, and that if one were willing to settle for the natural emission colour, the wire would last much longer.  There may be other breakdown factors that haven't occurred to me.)
bunsen_h: (Default)
If you'll forgive a brief cane-shaking kids-today-like-crappy-music comment (of the kind I've been making ever since I first heard music not selected by me or by my parents)...

Science, as a discipline — loaded word, that — requires long-term focus, both to learn a subject and to observe experiments.  You need to notice anomalies, exceptions to an expected pattern; if you're very lucky, they can lead to discovery of something novel and important.  If you're attracted by videos full of hard cuts, in which the longest uninterrupted segment is somewhat less than a second long, you're probably not going to do well in research.

(To say nothing of the bizarre and distasteful assumptions embedded in that video, about which much has been said elsewhere.)

Now imagining Magnus Pyke doing a voice-over: "She blinded me!  With science!  It's a Girl Thing!"
bunsen_h: (Default)

All day, Jane had been wandering around in a gloom, ever since Mary Poppins had stopped her from making the cupcake full of solid nitroglycerine.  Not actually crying, but depressed, her mouth set in a bit of a frown.

Suddenly, an idea came to Michael.  He found Jane, who just looked at him — she was upset that he hadn't taken her side.

"D'you think..." he started.  "Do you think, if we put fins on it, it would fly?"

After a moment, she smiled, just a bit.

Sometimes the dreams are weird.  And sometimes they wake me up, because... hmm.

An ice-cream cone cup, classic truncated-cone shape.  Filled with meringue with a conical peak.  Three or four fins at the bottom, made of vanilla wafer, glued on with royal icing.  And a type-D model rocket engine inserted through a hole in the bottom.  It would work.  Probably.

"Cake Canaveral".

Edible rocketry.  This is definitely Muppet Labs material.

(Solid nitroglycerine is not very safe, if it's actually crystalline nitro.  When it's solid because it's adsorbed onto an inert material such as clay, that's dynamite, which is somewhat less unsafe; thank you, Mr. Nobel.  What my dream was calling "solid nitroglycerine" was actually some kind of black-powder substance.  It would burn quickly, but not detonate.)

bunsen_h: (Default)
When a statistic is reported as "plus-or-minus X, 19 times out of 20", it means that 1 time out of 20, the value will not be within plus-or-minus X.  (That is, the people who did the survey rolled a d20, and if it came up 20 — or 1; depends on the local rules — they got to make up some other number.)  If the results being measured follow a "normal" bell-shaped distribution, about 1 time out of 400, the real value will be outside plus-or-minus 1½ X of the reported value.
bunsen_h: (Beaker)
Further thought on my post yesterday...  If you really had a bucket with one hundred pounds of an isotope with a half-life of 3 years or so, it would have to be a very special bucket.  And you and your neighbors would probably not be happy.  If your hypothetical bucket-o-zappy-crap really lost 50 lbs. by conversion to energy in three years... it would be emitting 21.6 gigawatts on average.
bunsen_h: (Beaker)
I've recently been reading The Disappearing Spoon by Sam Kean (Little, Brown and Company, 2010).  It's a sort of anecdotal meander around the periodic table, touching on each element at least once.  (The title refers to an old practical joke, in which a spoon is moulded out of gallium.  When the spoon is put into a cup of hot beverage — or, for that matter, left too long in someone's hand or mouth — it melts.)

The structure seems to be a bit forced.  I get the impression that the material was rearranged several times, from the way that some people and some elements are mentioned several times — not that material is repeated, but the phrasing of the "see also this other chapter" stuff and the way the descriptions are split between the two sections.  In some cases, an element gets less coverage in its "own" chapter than in another chapter where it's compared to some other element.

The book isn't bad, but it could be better.  It's the sort of thing that Asimov did well, and the anecdotal stuff is less engaging than, say, the books by Richard Feynman or Oliver Sacks.

My main complaint about the book is that it's sloppy.  I keep hitting things that make me say "No, that's not right" in my head.  I gather that Asimov had the same problem when he was writing some of his non-science books, such as the ones about Shakespeare or the Bible, but his science writing was usually rigorously correct (at least, as far as then-current information went).  He didn't let the explanations for non-scientists drag his content away from accuracy.  I'm finding The Disappearing Spoon rather irritating.  One paragraph I read yesterday had no fewer than three "gotcha"s.

Detailed grumbling lies beneath... )

I've got the book on loan from the library, with about another week before I have to return it.  At the moment, my brain is mushy enough that I don't want to start either of the new books I just had delivered from Amazon (Seanan McGuire's One Salt Sea and Patricia Wrede's Across the Great Barrier); I want to wait until I can enjoy them properly (which will likely involve reading the earlier books in each series first).  I'm going to continue to read it for now, but if the irritant frequency gets any higher, I'll probably give up.  Perhaps I should just go back to one of my Asimov essay collections.
bunsen_h: (Default)
I was recently pointed towards the "10:23 Campaign", with their YouTube video about "homeopathic vodka".  They explain that a "30C" homeopathic solution, with 30 dilutions by a factor of 100 each, has almost no chance of even a single molecule of solute remaining.  The overall dilution factor is 1:10030, or 1:1060.

This stirred a vague memory of having read that if one took a glass of water, poured it into the ocean and mixed thoroughly, then took back a glass of water, one would end up with some dozens of the original water molecules in the glass.  I decided to try the calculation.

Per the United States Geological Survey, the total amount of water on Earth is about 1.386 * 109 km3.  Most (96.5%) of this is in the oceans; for the sake of simplicity I'll ignore that factor.  In more useful units, this is 1.386 * 1021 L.

Assume a 250mL glass, i.e. about 8 oz., imperial.  Mixing this into the volume of the ocean gives a dilution factor of 1:(1.386 * 1021 L)/0.25 L or 1:5.544 * 1021.

That 250 mL of water has a mass of about 250 g.  Water is about 18 g/mol, and the conversion factor of moles to molecules is Avogadro's number, 6.02 * 1023.  So the number of molecules in the glass of water is (250 g) * (1 mol / 18 g) * (6.02 * 1023 molecules/mol) = 8.36 * 1024 molecules.

Applying the dilution factor, we end up with (8.36 * 1024 molecules) / 5.544 * 1021 = 1510 molecules.  If you took that glass of water, mixed it thoroughly with all the water on Earth, and refilled that glass, you'd have about 1500 of those original molecules back.  (If your starting volume was only a tablespoon, or 14.8 mL, and you did the mix-and-refill thing, you'd still have a statistical average of 5.3 molecules back in your spoon.)

In contrast, if you applied the "30C" homeopathic dilution to your glass, you'd have (statistically) 8.36 * 10-36 molecules.  That is, only 1 chance in 1.2 * 1035 that you'd have even one molecule left.

(And if you want to talk about the water having a "memory" of the original substance, consider all the other places that water has been, and should "remember" just as clearly.)
bunsen_h: (Default)
[livejournal.com profile] beable  asked me to post about one particular reminiscence I had about my early days in a chemistry lab.

Cut for the benefit of the squeamish... )

August 2017

  1 2345
13141516 171819


RSS Atom

Most Popular Tags

Style Credit

Expand Cut Tags

No cut tags
Page generated Sep. 23rd, 2017 12:50 pm
Powered by Dreamwidth Studios