If you've ever spent much time in American farm country, then you've probably noticed that there's a strong tradition there of coating barns and outbuildings with red paint. Why?
Because nuclear fusion.
Okay, the actual answer is simply because red paint has long been a cheap color to buy. But, explains Google engineer Yonatan Zunger, there is some really interesting physics lurking in the background of that price point.
What makes a cheap pigment? Obviously, that it’s plentiful. The red pigment that makes cheap paint is red ochre, which is just iron and oxygen. These are incredibly plentiful: the Earth’s crust is 6% iron and 30% oxygen. Oxygen is plentiful and affects the color of compounds it’s in by shaping them, but the real color is determined by the d-electrons of whatever attaches to it: red from iron, blues and greens from copper, a beautiful deep blue from cobalt, and so on. So if we know that good pigments will all come from elements in that big d-block in the middle, the real question is, why is one of these elements, iron, so much more common than all of the others? Why isn’t our world made mostly of, say, copper, or vanadium?
The answer, again, is nuclear fusion.
You can read the full story on Zunger's Google+ page. In my experience, white is another really common barn color, due to the fact that whitewash — a paint made from calcium hydroxide and chalk (which is also calcium) — is way cheap, as well. Calcium is also one of the most abundant elements in the Earth's crust ... clocking in at number 5, right under iron in the top 10. I'm sure there's some different science that accounts for the high concentrations of calcium on our planet, but the same principal applies. Cheap paint is paint made with abundant (and easily accessible) elements. And abundant elements happen because of physics.
The answer lies in another question. How can PVC — polyvinyl chloride, a commonly used type of plastic — be the stuff that makes tough, rigid sewer pipes and, simultaneously, be the stuff that makes floppy vinyl signs and cheap Goth pants?
"PVC is hard stuff. But if you put in a lot of plasticizer, you can get it to be soft," explains John Pojman, a chemistry professor at Louisiana State University. At a molecular level, PVC is a dense thing. Imagine a slinky in its stiff, compressed state. The plasticizers are chemical compounds derived from coal tar. Mix them with PVC and the small molecules of plasticizer shove their in between the densely packed PVC molecules. Imagine stretching the slinky out so that its coils are now wobbly. Same thing happens here. The more plasticizer you add, the less rigid the PVC.
And it's the plasticizers that produce that smell — the one we associate with the vinyl interior of a new car.
Image: 365:37 - Mar 29 - that new car smell, a Creative Commons Attribution Non-Commercial No-Derivative-Works (2.0) image from waldengirl's photostream
Fertilizer can explode*. We all know that. It was a key ingredient in the bomb that destroyed Oklahoma City’s Alfred P.Read the rest
Tonight, I got to meet Martyn Poliakoff — the fabulously frizzy-haired University of Nottingham chemist who you might recognize from a series of awesome videos about the periodic table that Xeni first blogged about back in 2008.
This is his business card.
It's a microscope image of the world's tiniest periodic table, which Poliakoff's friends inscribed on a strand of his own hair as a birthday gift in 2010. The hair, which Poliakoff keeps in a glass vial, has earned him a spot in The Guinness Book of World Records.
Not all snowflakes are unique in their shape. There's one fact for you.
And here's another: The shape of snowflakes — whether individually distinct or mass-production common — is determined by chemistry. Specifically, the shape is a function of the temperatures and meteorological conditions the snowflakes are exposed to as they form and the way those factors affect the growth of ice crystals.
This short video from Bytesize Science will give you a nice overview of snowflake production and will help you understand why some snowflakes are unique, and why others aren't.
Meet moronic acid. It's special.
Found in mistletoe and the Chinese sumac, this chemical could be one of the reasons those plants have long been associated with herbal medicine. Scientists studying the anti-viral properties of moronic acid have found it to be effective against HIV and herpes. The HIV work is particularly important, because moronic acid seems to target a different receptor on the virus than other drugs — which means it could be effective against HIV strains that have developed a resistance to existing medication. It'll still be a while before this research translates into a commercial product (if it does at all). But moronic acid is, at least, doing well enough to have made it into Phase II clinical trials — which means that smaller studies on humans have shown that it's generally safe. The Phase II trials, usually done with groups of 100 to 300 people, will help scientists understand whether it's as effective in the human body as it seems to be in the lab.
Looking for more molecules with silly names? Chemist Paul May has a whole list of these things — many of them hilariously immature. List includes arsole, cummingtonite, and fucitol.
University of Kentucky chemistry professors John P. Selegue and F. James Holler are collecting comic book references to chemical elements. On their Periodic Table of Comic Books site, you can click through the standard periodic table to see pages from comic books that mention specific elements. The samples seem to be weighted pretty heavily to classic, Golden and Silver Age stuff — there's a lot of 1940s Wonder Woman and miscellaneous anthology series from the 1960s.
They don't have all the elements accounted for yet. In particular, the lanthanides and actinides — aka, those two rows at the bottom where everything ends in "ium" — are lacking comic book shout-outs. Maybe you can help!
Thanks to Jennifer Ouellette!
And, with the help of her colleague Dexter — and their owner/trainer, who is also a chemist — Paige can even teach chemistry.
Here, Paige and Dexter serve as models for a discussion about chemical bonds — the forces that attract one atom to another and form the basis of all the chemicals that make up our world.
Via Matthew Hartings
Yesterday, Cory posted a vintage ad for boys' hats and accessories, which included a small selection of ties made from something called "Aralac". I didn't think much of it, until I noticed J. Brad Hicks' comment pointing out that Aralac was a synthetic wool made from cheese. Which was not a joke.
Seriously. It'll make more sense once you understand how the stuff was actually made.
Think about it this way: Wool (the actual kind, that comes from sheep) is a protein. So is casein, which is found in milk. Making Aralac is basically about getting the protein casein to behave like the protein wool. In 1937, Time magazine described how the process worked:
Having practically the same chemical composition as wool, it is made by mixing acid with skim milk. This extracts the casein, which looks like pot cheese. Evaporated to crystals, it is pulverized and dissolved into a molasses consistency, then forced through spinnerets like macaroni, passed through a hardening chemical bath, cut into fibres of any desired length. From 100 pounds of skim milk come 3.7 pounds of casein which converts to the same weight of lanital. [Aralac was also called Lanital.]
Read the rest
Sometime in the late 1980s or early 1990s, my mom bought me a chemistry set. I was in grade school, but I remember thinking it was pretty cool. I also remember being slightly disappointed (particularly after being told that I could only play with it in the garage) that there was nothing in there that could actually blow up.
Many of us are nostalgic for the lost golden era of certifiably dangerous children's chemistry sets. Even if we weren't alive when that era occurred, we're still, sort of, vicariously nostalgic. At the BBC, Alex Hudson has a story about what was really in those misty colored chemistry sets that have lodged themselves into our cultural memory. Along the way, we learn that their demise was only partly to do with unfounded safety fears—some of the fears were founded, for instance, and in other cases, money and seemingly unrelated legal issues got in the way of fun.
By the 1920s and 30s children had access to substances which would raise eyebrows in today's more safety-conscious times. There were toxic ingredients in pesticides, as well as chemicals now used in bombs or considered likely to increase the risk of cancer. And most parents will not need to be told of the dangers of the sodium cyanide found in the interwar kits or the uranium dust present in the "nuclear" kits of the 1950s.
Most will know cyanide as a deadly poison, but one of its main applications is in gold mining. It can make gold dissolve into water.
...Used often to test the presence of starch, the iodine solution once seen in kits is now regulated as a list I chemical in the US because of its use in the manufacture of methamphetamine. It can also be lethal if more than 2g of pure iodine is consumed.
To celebrate the premiere of Breaking Bad's Fifth Season this week, my fellow trufan Miles O'Brien and I dug into the show's vaults to explore the top 10 chemistry moments in Breaking Bad, from seasons One through Four. Only, there was so much awesome science, we had to choose 11 top chemistry moments, instead.
Also, check out our excellent adventure: air-dropping in to a random Breaking Bad fan's premiere party in the show's hometown of Albuquerque, NM.
MattAttackPro is a chemistry and physics teacher in South Carolina. This is what happened when he dropped a roll of unused camera film into a container of hydrochloric acid.
What you're seeing is the plastic backing separating from the "film" from which film takes its name—a coating of multiple layers of light-sensitive salts suspended in gelatin. Yes, film is like a jello salad. And it makes for a beautiful photograph.
Suxamethonium chloride is a common hospital anesthetic that has, off and on, moonlighted as murder weapon.
Used to paralyze patients so that doctors can more easily put insert a breathing tube, the drug can kill very easily if the person who gets a dose of it doesn't have access to things like respirators, or a medical team. And when somebody is killed by "sux", the death can look conveniently like a simple heart attack. More importantly, writes professional chemist and anonymous science blogger Dr. Rubidium, for many years, there was no way to test for sux in a dead person's bloodstream.
Since the early 1950s, sux has been used in a clinical setting mainly by anesthesiologists. It’s a mystery when it was first used in a homicide, but the first high-profile killings came in the 1966 and 1967. This salacious tale of murder involves anesthesiologist Dr. Carl Coppolino, his mistress, his mistress’ husband dying suddenly in ’66, Coppolino’s wife dying suddenly in ’67, a quick remarriage by Dr. Coppolino (not to that mistress), two trials in different states leading to different verdicts.
Coppolino’s first trial in New Jersey involved a shaky witness (that jilted mistress) and a tricky toxicology problem. ...
Back in the mid-to-late sixties, sux was likely considered a “perfect poison” as no tried-and-true method for detecting it in tissues was developed until the 1980s. Previous analysis had holes – including the analysis presented in both of Coppolino’s trials. It wasn’t sux that was detected, but the metabolites succinic acid and choline.
Her post is part of a bigger series, though. If you dig weird, toxic chemicals, you should check out the "My Favorite Toxic Chemical" blog carnival—a collection of horrifying and wondrous posts about poisons.
A great short video from a CalTech gas-sensing lab explains the science of gas-detection and analysis.