In my last post I heaped praise on “The Wonderful Life of Elements“. Well, how fickle I am. Within three short days I have a new favourite. Now don’t let the title ”Chemical Shifts and Coupling Constants for Silicon-29” (Gupta et al.) nor the drab cover put you off. This book is undoubtably a work of genius.
I’ll let the Amazon reviews speak for themselves. After all I certainly can’t do a better job of demonstrating how undeniably useful this book is. Take Mr. E. Welsby’s glowing testimonial for instance:
At the Boston inst of chemical tech we’ve been looking for ways to expand silicon usage for construction, thanks for the bonding information of this book we’ve successfully managed to merge silicon atoms with that of a small gibbon, who can now phase his physical body between carbon and silicon (sand) at will.
and the equally enthusiastic praise from K.V. Trout:
I don’t know how they came up with the idea to do a book on Chemical Shifts and Coupling Constants for Silicon-29, but I would have never thought it would be worth this much money. These guys are visionaries, because at a time when the rest of us were watching sit-coms and wondering who was going to win American Idol, these guys were gathering together the numerical data and functional relationships of various technical and scientific kadoodleybobs.
I bow to their marketing genius as well as their forward acuity in the sci-market arena. Their...
One of the most frustrating units for me to teach in my sophomore organic chemistry class is the coupling/j-value concept in the NMR chapter. Going through the tree diagrams, we can get to a place where we understand that 3 neighboring protons cause a quartet, but I’m not convinced they really understand why. It gets worse when we get to doublet of doublets. This really goes way over their head. So I delve deeper into the theory so it will become more clear, but the concept only becomes more muddy in their mind. So I go even deeper, really getting into the physics (a class many of them haven’t taken yet), and their eyes start to glaze over and I start to lose the class.
By the end of the unit, we all resign and the students end up ‘memorizing cases’ with little to no understanding of why. I hate ‘memorizing cases.’
So last week I had an epiphany on the drive to work. I was thinking about how to make the concept more clear. Given a proton with a chemical shift, the random up or down spin state of the neighboring proton influences the chemical shift of the observed proton and offsets the chemical shift by an equal value in the positive and negative direction. Total values… a binary up/down spin state… offset by equal amount. Coins!
Given a quarter with a ‘chemical shift’ value of $0.25, a flipped penny will either land heads up or tails (heads down). Say a heads up penny adds $0.01 to the total value, and a heads down penny...
Our reserves of helium are finite and we’re running out. This may come as a mild disappointment to children everywhere but its really bad news for science.
My (and everyone else’s) NMR machines use liquid helium (at 3 Kelvin) as the coolant for their superconducting magnets. The same goes for MRI scanners and those cathedrals of science the particle accelerators like the LHC. And right now there’s a world wide shortage of helium which means that we may have to decommission some of our NMRs. Re-commissioning them will then cost 10s of thousands of dollars, plus it would require huge amounts of liquid helium to cool them down again.
We fill these instruments with liquid helium regularly, replacing the stuff that’s boiled off. The thing is that once that helium has evaporated off and into the atmosphere its gone. There’s no getting is back. So why don’t we bother collecting the boiled off helium? All we’d need to do is stick a balloon on top of the NMR machine, then a simple compressor could be used to turn it back into a liquid.
We don’t bother with this simple bit of recycling because there’s no immediate economic imperative. But hang on, didn’t I just say the reserves are limited, so surely helium is really expensive? Well it aught to be. According to Professor Robert Richardson, who won the Nobel physic prize in 1996 for his research on helium, a helium party balloon should cost $100. Instead they cost about...
When I was an undergrad I found NMR to be one of the trickiest techniques to get my head around. I think it was because the technique involves so many concepts that run counter to everything we’ve learnt before. After all in school we get told about ferromagnets and thats it. Then at uni suddenly someone is trying to tell us that actually there’s these other things called diamagnets and paramagnets, which means that even water is magnetic!
So now that I get to teach NMR I like to demonstrate diamagnetism right from the get go. Of course diamagnetism is really weak so you need a precision built, low friction setup. So I set about building one with ….
A wooden skewer
An old film canister
A neodymium magnet. I get mine from emagnets. The stronger the better I use one with 20 Kg pull.
THIS IS REALLY IMPORTANT
The neodymium magnets are really powerful. So…
Don’t let kids play with them.
Don’t put them near your credit cards, phone, watch or any other electrical equipment.
Don’t put 2 magnets anywhere near each other because they’ll fly towards one another, shatter and send chunks flying.
If you have any medical implants don’t go anywhere near them.
Read the safety instructions that come with the magnets.
1. Push the 2 grapes onto either end of the skewer
2. Push the pin through the cap of the film canister, so that its pointing upward. Put the cap back on the canister.
Skepticism plays a central role in any kind of scientific research. To paraphrase Feynman, you should try never to fool yourself – and you are the easiest person to fool! We chemists all want to believe in the high yield, or the perfect recrystallization that causes us to turn cartwheels…until we realize that we can’t repeat them. Some scientists still take shortcuts to fame – consider the hot water the Sezen saga landed everyone in just a few short years ago. So, how do you keep yourself honest? And how do you sift through wild claims and hyperbole?
Please, don’t hire this magician.
Credit: Arrested Development, 20th Century Fox
Well, magicians are standing by to take our calls.
(Wait…did you just say “magicians?”)
That’s right, magician James Randi offers his services in a recent Wired Opinion post. He references magician Jamy Ian Swiss, who says:
“Any magician worth his salt will tell you that the smarter an audience is, the easier they are to fool. That’s a very counterintuitive idea, but…scientists aren’t trained to study something that’s deceptive.”
Good point. As chemists, we’re always looking out for the next great reaction to come logically shuffling through the door. We don’t often step back and critically question others’ motivations for deceit or trickery. But, of course, that’s how magicians make their careers. Randi invokes Clarke’s third law, which states that “Any sufficiently advanced technology is indistinguishable...