Calories are a measure of heat. A small calorie is the amount of heat it takes to raise a gram of water from 3.5 degrees centigrade to 4.5 degrees centigrade. A large Calorie (capital C, also called a kilocalorie) is the amount of heat it takes to raise a kilogram of water (2.2 lbs) from 3.5o C. to 4.5o C. (OK, technically these are 4o calories, so don't write me to complain). The "Calories" we read about in nutrition are large calories. The prototypical male weighs 70 kg. So 70 Calories of heat energy released from food is enough to heat him up one degree centigrade. That's enough to be called a "fever." This seems like a lot of heat, especially as most people eat around 2500 Calories a day. Since there is usually a substantial heat difference between us and the environment and we also lose heat by evaporating water (sensible and insensible water loss), we manage to get rid of the excess we need to keep our bodies at 37o C. (body temperature in centigrade). More on this at the old site here. This post is about the surprisingly large amount of energy in a small amount of sugar. In particular, the energy in one little gummi bear.
&tThe energy in a gummi bear is mainly locked up in table sugar (sucrose). Sucrose is a carbohydrate (a disaccharide, meaning it is made up of two subunits of smaller sugars, glucose and fructose). Each of these is itself a structure made of carbon, hydrogen and oxygen atoms connected in a particular pattern. If you think of the atoms as analogous to bricks and think of a building as made up of these bricks, you will understand two things. One, it takes energy to assemble the bricks into a building. That's the job of the construction trades. The other is that if the building comes tumbling down it releases a lot of energy in the process. Sometimes you have to put in some work to get the building to fall down but when you do it releases more energy than you put into it. That's what's happening with the sucrose in the gummi bear. There is a lot of energy locked up in the structure that gets released when we let it come apart. It comes apart by combining with oxygen and disintegrating.
You can see the remarkable amount of energy in the small amount of sucrose in a single gummi bear by a demonstration. The video below has made the rounds on the internet so you may have seen it before, but there was no explanation for most of the postings. In the demo a gummi bear is dropped into a test tube that has melted potassium chlorate in it. Potassium chlorate is one atom of potassium, one of chlorine and three atoms of oxygen. In other words, it is oxygen rich and is frequently used in highschool chemistry laboratories to generate oxygen gas. One way to do it is just to heat the potassium chlorate, which is a white powder, in a test tube until it melts.
The gummi bear is mainly sucrose (what did you think it was made out of? bear meat?). When it comes in contact with the oxygen in the test tube some of the sucrose disintegrates and this releases heat energy. The released heat causes the potassium chlorate to release more oxygen and a positive feedback loop develops.
Here's the result:
Are US security official coming for my case of Gummi Bears?
This is why we need another Mr. Wizard. Show the kids you can make explosive gummy bears...we'll see a rebirth in the sciences. =)
So, somebody on an airliner with a bag of Gummi Bears and a footpowder can refilled with potassium chlorate can visit the restroom for privacy and the all the water needed to make a handy-dandy firebomb. That's nice to know.
Anyone who took chemistry (and did so seriously) would realize practically everything inside an airliner passenger compartment is fuel. All the terrorist needs to bring aboard is oxidizer -- which explosives detectors will never register.
It's a good thing practically the entire personnel roster of the US government are technically illiterate and ignorant.
OS: Well, you'd have to melt the potassium chlorate, too, not so easy in an airport bathroom.
Reminds me of a time way back in another life, when I boiled a small amount of water in a paper cup using a burning peanut.
I forget where I found this experiment, but I remember it demonstrating several concepts: the amount of energy in a peanut and heat transfer through paper that allowed the water to boil while not allowing the paper cup to get hot enough to ignite. I could take a few attempts to get everything in correct relationship.
Re. Old Scratch: More than the government, the general stupidity and hubris of the terrorists.
I often look at the visible security measures and laugh to myself. They are there mainly to provide a "sense" of security and much like the the lock on your front door, to keep the impulsive amateurs in line.
In reality, most obvious security measures wouldn't stop anyone who gave them a few minutes thought.
The hubris part is that most terrorist want something big and flashy, while smaller events could cause more inconvenience and disruption but not necessarily a front page news event around the world.
As for oxidizer, that's not usually the problem, the problem is energy release rate.
.. practically everything inside an airliner passenger compartment is fuel. All the terrorist needs to bring aboard is oxidizer ..
Give the inexorable "logic" of the DHS turkey farm, I suppose the next thing we should not expect to "carry onboard" is oxygen.
I wish I thought this was just a joke ...
Actually Revere, believe it or not Gummi B's can be used to make one hell of an explosion. As you said, three oxygen atoms. A bag of them in a pure or nearly pure oxygen environment makes them oxidize within about 5 to 10 seconds with a brilliant flame if vented. In an enclosed environment and flooded with oxygen the ensuing ear rupturing explosion and flame is almost as good as an RPG round. Jelly beans work pretty good too.
Randy: That's true with most fuels and sugar is a fuel. We saw what happened with the Air Tran flight in Florida that was carrying oxygen bottles.
Question - what does Andrew Sullivan think all this has to do with climate change?
Here's the explanation...high school style: