How Air Separates Water And Goes Boom

Fertilizer bombs typically use ammonium nitrate, NH₄NO₃. Bombers use it because the stuff is so ubiquitous and so plentiful.

Wiki draws a pretty picture of ammonium nitrate, which partially reveals its explosive potential:

Don't skip over that structure--it's a work of art: two very different nitrogen atoms separate elements of hydrogen and oxygen. On the left, four hydrogens surround a central nitrogen while on the right, three oxygen atoms surround a central nitrogen. There's an unbalanced symmetry. Those H's and O's would love to get together and quench, making water, leaving the naked nitrogens to couple, making N₂ which is essentially air. The chemical structure of ammonium nitrate is a depiction of air separating water.

We never hear about spontaneous explosions of ammonium nitrate. Why is that? An old word from the Greek called stoichiometry answers why. Try and balance the chemical equation of NH₄NO₃ making N₂ and H₂O:

             NH₄NO₃  =>  N₂  +  H₂O

Look easy? I gave up. The reason is that the hydrogen to oxygen ratio is inherently 4 to 3 on one side and 2 to 1 on the other. No amount of tweaking the coefficients will balance that reaction. The stoichiometry just doesn't work.

This brings up just how fertilizer bombs do work, because they do make air and water from ammonium nitrate. There is always a little admixture of carbon (typically fuel oil) but charcoal would work too. The carbon combines with the "excess" oxygen present in NH₄NO₃, making CO₂. This trick even has a name: cf. detonation vs. deflagration

Here's a question for any munitions experts out there: were ANFO's involved in Boston? I've heard that the differing sounds of detonation versus deflagration are diagnostic.

A second question is technical: is it possible (in theory) to isotopically label the nitrogen in manufactured ammonium nitrate and thus, after isotopic analysis of air samples at the bombing site prior to mixing, identify the source?
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[Added]  Well this breaking news should cause a spike in ammo and food prices. The report says that water sprayed on NH₄NO₃ made it explode. That may actually have been heat from the fire or could have resulted from of what's called heat of hydration when a dry salt suddenly mixes with water. Some salts suddenly mixed with water actually make the water colder.

Ammonium nitrate (AN) is not known to chemically react with water in an explosive way. However, if heated it reacts explosively:

             2NH₄NO₃  =>  2N₂  + O₂  + 4H₂O

Now that reaction really produces a sky-full: nitrogen, oxygen, & cloud.

David Stockman Saw Something Nasty In The Woodshed

Cold Comfort Farm (1995) is such a hilarious movie. I miss talking about it with you.

Fundamental Inequalities

Equality is a cornerstone of the law, but it's not at all a feature of natural law.

Consider Heisenberg's famous Uncertainty Principle (but not in any deeper sense than the nature of the symbols):

 

On the left, Δχ and Δρ (position and momentum) are physical variables; on the right is a fixed value—i.e., half of ħ, the imponderable Planck constant.

Equations are like sentences with the equal sign being like the verb "to be;" they represent either equality or the more subtle notion of equivalency. Inequalities are also familiar from algebra but an inequality also expresses—more or less—an important direction of inequality. In this case, the observables are greater than or equal to the constants.

Bell's Theorem has been called "the most profound [theorem] in science" and it too reduces to an inequality. There's another: the Clausius Inequality, which embodies the Second Law of Thermodynamics, and which expresses changes in entropy against a value of zero. Comparing all three—without even understanding them—it strikes me that they all specifically pit observables against abstract constants. Is this general?

He Let Go Of His Ego...

...and Id emerged:

I know so many people who think they can do it alone

They isolate their heads and stay in their safety zone 

What can you tell them?

What can you say that won't make them defensive? 

Hang on to your ego!

Hang on to your ego!

Hang on to your ego! 

Hang on, but I know that you're gonna lose the fight 

They come on like they're peaceful

But inside they're so uptight

They trip through the day

And waste all their thoughts at night

Now how can I say it?

And how can I come on

When I know I'm guilty? 

Yeah, hang on to your ego!

Hang on to your ego!

Hang on to your ego! 

Hang on, but I know that you're gonna lose the fight 

a doobie doobay-doo

[cool banjo interlude]

Now how can I say it?

And how can I come on

When I know I'm guilty? 

So, hang on to your ego!

Hang on to your ego!

Hang on to your ego! 

Hang on, but I know that you're gonna lose the fight

a doobie doobay...do

[Marylin Wilson to BW's dog]: Banana!

[Brian Wilson]: Hey Chuck is it possible we could bring a horse in here without...if we don't screw anything up?

[Chuck Britz]: I beg your pardon?

[Brian Wilson]: Honest to God, now, the horse is tamed and everything.

Conversations with Henry

Henry:  Did you see that business in the news about negative absolute temperatures?

Me:  You mean this?

Henry:  Yeah, that.  Good thing you know how to manipulate the Internet. I never got the hang of it. You know what that news reminded me of?

Me: No, what Henry?

Henry:  The inverted Marcus region.

Me: Remind me what the inverted Marcus region is.

[Henry moves to the white board, grumbling that people no longer use chalk & blackboards. He sketched three related figures, and then explained them in words]:

Henry: Rudy Marcus laid out three different scenarios for the reaction coordinate of a simple "downhill" reaction using intersecting parabolas to represent reactant and product. Parabolas have a long history in physics (think of pendulums, and they "track" the potential energy in molecules). In the first, notice that the "initial state" reactant parabola is slightly higher in energy than the "final state" product parabola; where they cross represents a moderately uphill barrier given by the distance, ΔG^‡.

In the second (middle) scheme, the initial state (left) parabola is higher in energy while the final state parabola stays the same—follow?  He got there by translating the left hand reactant parabola straight upwards and their intersection slides "down." The barrier to the more downhill reaction is now zero. See that?

Me: Yes!

Henry:  Here is where Marcus was an absolute genius:  if you keep on going as in the third scheme, the initial state parabola gets higher still—this is now a very downhill reaction—but notice that the barrier, ΔG^‡, goes back up because the intersect climbs up the other side!  This is the so-called "Marcus Inverted Region" and is utterly counter intuitive that a more downhill state should require more energy to reach. Boy, he really shook things up with that one!

Me: Fine, but how does that translate to the real world?

Henry: What?  Didn't you read my other stuff?

Me: Here's what I think...I've been saying all along that uphill effort requires more energy than downhill effort, for example here.  But suppose that we have something really severe like the Fiscal Cliff.  Suppose that the fall is so downhill that we will actually face a higher hurdle to get down there than if it weren't so precipitous.

Henry: Hair-brained economics!

Metal Heart

Pure Morpheme Drip

I just rediscovered the word morpheme and realized that that was what I wanted to call purine here.

Purine is a chemical morpheme. Not the word purine, but the two fused rings. There are other chemical morphemes, of course, but that's what I was trying to convey back there.

When I google "chemical morpheme" I get this, which is kinda sorta what I mean.

I Still Don't Get It

Madonna's Woes and Tramping Abroad

Madonna got into a bit of trouble overseas in France. link  I'm mostly bored with the details and won't go into them. The crowd's reaction reminded me of a Patti Smith concert I saw in Florence, Italy, back in 1979.  Smith really riled the crowd and retired from performing afterwards.

My mother salvaged an old diary I kept on that trip and returned it to me last month. Here's what I said about that concert then.

Martedì 10 settembre [1979]
Rome, Villa Borghese 

Wow what a night last night. I went to the Patti Smith concert at the stadium in Florence. The stadium looked like a huge bathtub. I couldn't believe it when I arrived. It was as if Led Zeppelin were playing. There were people all over 5 hours before the concert began. We waited away from the noisy mob collecting near the gates. I caught some sleep. Then there was a shout--the gates were opening. We made for the nearest gate.
After waiting in the hot noisy crowd (like so many grains of sand all trying to get through the neck of an hourglass) we broke through to the inside and picked ourselves some good seats.
Below it was like pigs to a feeding trough, pushing shoving, shouting, etc. I remember laughing as we watched people scaling the fence around the field track. At the top there was 3 wires of barbwire and some people would get their shirts or pants caught.
Well after some length of time the music began. First it was tapes. Lynyrd Skynyrd "Street Survivors" and then Dire Straits--"Down By The Waterfront."
When the equipment was tested, I thought at first it was just the roadies tuning up stuff, but then they played songs, rock like "You Really Got Me" and then quit--the tapes continued. But when the real band began I realized it was the same musicians.
Patti Smith had a hard time with the audience. First of all she barely knew a word of Italian, only "ti capisc" which she pronounced like "ti capeach."  Secondly the audience couldn't understand a word of English.
She had a problem with people climbing up on the stage--the crowd was absolutely unruly.
"Hey man, you wanna climb the stage, get your own stage, man."
The last song they played was "My Generation."  Before this though the guitarist played the first few notes of the Star Spangled Banner (like Hendrix at Woodstock) and a big American flag came up behind them. Then all the Italians gave it the finger. Then the Who song--then a finale and then chaos; people surged up onto the stage like the pressure of being pushed forward reached a breaking point.
Then "Hey man, get the fuck off the stage" but there was nothing that could be done.
Patti tried to talk with them. "Hey you know" she said to one, "you light up my life." She tried to get him to sit down at the piano "fucking sit down, asshole....how do you say sit down in Italian" she said through 80,000 pairs of ears--but to no avail.
The chaos ended when the road crew swept the undesirables off the stage and then, like a giant bathtub, the moment came when the plug was pulled and it started to drain, not without leaving a residue of paper, cans, and bottles though. So went the concert in Italy.

My own recollection of the same concert, written a year and a half ago from memory is here.
It's interesting for me to compare the two accounts--one fresh and the other filtered by 30 years of  experience and memory.

Two from the Foo

Conversations with Henry

Henry: You forgot to mention Allen and Senoff.

Me: Who? 

Henry: Allen and Senoff. They made the first dinitrogen complex from ruthenium, [Ru(NH₃)₅(N₂)]²⁺. That news caused quite a stir back in 1965. Ruthenium rhymes with iron, so you're also speculating about molybdenum. It could be iron doing the fixing in nitrogenase.  Never sell iron short.

Me: *gulps*

Henry: I'm glad to see that you're reading and keeping up with newer stuff. Barry told me you'd be back.

Titanic Centennial: Did Chivalry Go Down With The Titanic?

Just three days after the Titanic tragedy, Dr. Henry van Dyke, professor of English at Princeton University, penned a newspaper editorial which became the introduction to Logan Marshall's "The Sinking of the Titanic and Other Sea Disasters."  I've chosen a selection for discussion. The entire text is here. Whether you agree or not, here it is:

But there is more than this harvest of debts, and lessons, and sorrows, in the tragedy of the sinking of the Titanic. There is a great ideal. It is clearly outlined and set before the mind and heart of the modern world, to approve and follow, or to despise and reject.

It is, 'Women and children first!'

Whatever happened on that dreadful April night among the arctic ice, certainly that was the order given by the brave and steadfast captain; certainly that was the law obeyed by the men on the doomed ship. But why? There is no statute or enactment of any nation to enforce such an order. There is no trace of such to be found in the history of ancient civilizations. There is no authority for it among the heathen races to-day. On a Chinese ship, if we may believe the report of an official representative, the rule would have been 'Men first, children next, and women last.'

There is certainly no argument against this barbaric rule on physical or material grounds. On average, a man is stronger than a woman, he has a longer prospect of life than a woman, he is worth more than a woman. There is no reason in all the range of physical and economic science, no reason in all the philosophy of the Superman, why he should give his place in the life-boat to a woman.

Where, then does this rule which prevailed in the sinking Titanic come from? It comes from God, through the faith of Jesus of Nazareth.

It is the ideal of self-sacrifice. It is the rule that 'the strong ought to bear the infirmities of those who are weak.' It is the devine revelation which is summed up in the words: 'Greater love hath no man than this, that a man lay down his life for his friends.'

It needs a tragic catastrophe like the wreck of the Titanic to bring out the absolute contradiction between this ideal and all the counsels of materialism and selfish expediency.

______________________________

There is no statute or enactment of any nation to enforce such an order. There is no trace of such to be found in the history of ancient civilizations.

There is the story of Damon and Pythias as told by Aristoxenus in which Damon offers to be put to death for the crime of Pythias. This seems to antedate John 15:13.

There is no authority for it among the heathen races to-day. On a Chinese ship, if we may believe the report of an official representative, the rule would have been 'Men first, children next, and women last.'

This could be seen as inflammatory, but the heinous practice of sex-selective abortion (de facto not de jure) supports van Dyke's rhetoric.

There is certainly no argument against this barbaric rule on physical or material grounds. On average, a man is stronger than a woman, he is worth more than a woman, he has a longer prospect of life than a woman, he is worth more than a woman. There is no reason in all the range of physical and economic science, no reason in all the philosophy of the Superman, why he should give his place in the life-boat to a woman.

Van Dyke is clearly referring to Nietzsche with his Superman reference.

Where, then does this rule which prevailed in the sinking Titanic come from? It comes from God, through the faith of Jesus of Nazareth.

The Old Testament has the flood story in which a pair of each species is saved. But notice that the entire range of species was saved--the boat of salvation was not loaded with women and Noah's children--just his family.

The origin of "Women and children first" has its own Wikipedia entry: link The concept is linked to that of male disposability which is an interesting idea. Arguably, in an evolutionary sense at least, a population threatened with extinction can more quickly repopulate with fewer men and a surplus of women.

It is the ideal of self-sacrifice. It is the rule that 'the strong ought to bear the infirmities of those who are weak.'

Could this notion have any bearing on the modern interpretation of healthcare reform?

It is the devine revelation which is summed up in the words: 'Greater love hath no man than this, that a man lay down his life for his friends.'

John 15:13. I am reminded of the Mike Monsoor story, as portrayed in "Act Of Valor."

It needs a tragic catastrophe like the wreck of the Titanic to bring out the absolute contradiction between this ideal and all the counsels of materialism and selfish expediency.

Shenanigans!

Shenanigans was a game we never owned and so I never learned to play it.  Could someone please explain the rules?

The Problem is...

...playing the role of idiot-savant is sustainable--sort of like bookending things. Wouldn't it be nice to be all things between?  Easier said than done. Conservation of something demands that moving to a more well-rounded person must involve sucking inwards from both sides of the bookends. That sucks.

Makes No Sense At All

What It Takes To Win

Stepping back for a moment from the comfort of my cocoon which eschews hackneyed political "greenery," I asked myself:

What objective indicia would gauge the public's position on things green?

The answer should be an unbiased scientific poll. According to new research out of Stanford (link), it's a little known fact that in past elections, candidates who strongly supported green energy initiatives won. If Republicans and Independents can leverage these ideas in 2012, they'll sweep back into power.