Is Science in the purview only of scientists? Has the scientific horizon been pushed out so far that nothing can be reached except through years of rigorous, specialized education and through the performance of hundreds of exacting experiments, trials or observations? Are the millions of science fair projects assembled at the thousands of elementary and secondary schools around the country actually science, or are they science education? Can an ordinary person "do science,"--that is, follow the guidelines of science and expect to arrive at a conclusion that has some significance? Or has everything that is accessible to an ordinary person already been investigated?
The exciting answer is "Yes." We have not yet reached the point where we can state that we understand the world, and that all that is left to do is to painstakingly (and professionally) refine the details. Some will so state, but I believe them to be wrong. True, it is not easy to find examples that show them to be wrong, but I believe that I have finally found such an example.
While helping my daughter search for topics for the annual science fair at her elementary school, I made it a point to read our local paper's weekly basic science experiments column. One week, the experiment seemed unusually interesting, and also simple and inexpensive. It was a variant upon the familiar chemistry experiment of combining vinegar and baking soda. I had performed it many times and seen it performed in many variations. Place baking soda in a balloon, and slip it over a bottle with vinegar in it--the foaming production of carbon dioxide (CO2) will blow up the balloon. Mixed with a little coloring, the foaming mixture has simulated lava flows in countless volcano models in every school in the country.
This version was different, though, and it forced me to reconsider my view of the world. Well, it didn't immediately, but I was intrigued enough by the experiment that I resolved to try it the first chance I had. It required a large bucket whose bottom was covered by vinegar, and into which I poured the baking soda. The newspaper column had pointed out that the CO2 produced would be heavier than normal air (which is mostly nitrogen N2 and oxygen O2), and it would stay in the bucket. Then, the column suggested, you could blow soap bubbles and let them land on the CO2 in the bucket-in a still room, the bubbles float down because they are heavier than air, but they are lighter than the CO2. So, when we tried it, my daughter and I were both completely charmed by the iridescent bubbles bobbing on the surface of the invisible, odorless CO2. So simple.
Since then, I have taken the experiment on the road. I show it at our science fairs, and present it to classrooms. I encourage the students to dump a little CO2 out of the bucket, and then watch afterwards as the bubbles float to a lower level inside the bucket. I warn them to be still, and not breathe too hard, or talk too loud, because they might slosh out too much of the CO2. With the help of a poster, I point out the difference between the oxygen molecule, and the carbon dioxide molecule which is laden with that extra atom of carbon. In front of the more mature students, with appropriate caveats, I lower a lit match into the bucket, and its flame snuffs out right at the place where the bubbles were bouncing. It is a very convincing experiment--the reality of invisible gases and the differences between them are palpable.
I didn't learn anything new, in performing the experiment. I knew that some gases were heavier than others, that's why helium balloons float. I knew that CO2 was heavy, and that fire needed oxygen to burn, and that's why a hand-held CO2 extinguisher is used to put out small fires. So how did it force me to reconsider my view of the world? That is a long story.
When my children were born, my wife and I tried to be conscientious parents. We talked to other parents, our own parents, professionals, and we read books and articles about the latest approaches to caring for a child. We were uncomfortable with some of the advice. The American Society of Pediatrics strongly suggested that infants should sleep on their stomachs. This did not look comfortable to us, but we knew that it was intended to protect our son from the possibility of vomiting and then choking on his own vomit. So, our son and daughters slept on their sides, for the most part, propped against a pillow. We looked around for a better way. One device, which was a brief fad, was a sheepskin slung from the sides of the crib like a small hammock, and it was supposed to improve infant sleep. That looked like it might roll the baby onto its back, and, besides, I was sensitive to wool, so we held off getting one.
Why were we so worried about the sleep of our infant? At that time, the incidence of SIDS (Sudden Infant Death Syndrome) had risen dramatically and public awareness was great. We couldn't imagine a more horrible thing than to walk into the nursery and be confronted with a still and lifeless child. Worse, no one knew what caused it. Did the infants choke on their own vomit? Did they just stop breathing? No one really seemed to know.
As I watched the very first time, with my daughter, the shimmering bubbles bouncing on the "heavy" air inside the bucket, I was stunned. I had just explained to her about oxygen and fire extinguishers-extinguishers suffocate a fire by preventing oxygen from reaching it. She had wondered if the gas were toxic and dangerous, and I had replied that no, it wasn't, and I reminded her that our bodies produce carbon dioxide with every breath. No, I said, it won't hurt you as long as you can get oxygen. At that moment, I suddenly imagined a small child at the bottom of the bucket. Could there be a connection between this experiment and the cause of SIDS? Could SIDS be a matter of suffocation?
The moment soon passed, but I didn't let it stop there. There were a dozen questions about SIDS that had to be answered before I could reasonably think that there might be a connection between SIDS and this vision of carbon dioxide. How did SIDS present itself pathologically? Perhaps there was some component that made it incompatible with suffocation. What were the other factors that have been correlated with SIDS deaths--or were there any? I had very little idea.
The year before, I had helped write a neighborhood newsletter, and we'd included a small article about the recent evidence that babies who slept on their backs had half as much chance of SIDS. That was a dramatic finding, and we felt it important enough to publish immediately. Since then, the American Society of Pediatrics has promoted their "Back to Sleep" campaign to convince parents to let children sleep on their back, and fears of choking on sputum have been shown to be mostly unfounded. Death rates from SIDS have fallen. As I thought about it in the light of our carbon dioxide experiment, it seemed very possible that face-down babies would be at higher risk for SIDS. But the fact that we had published that newsletter article shows how important the issue is to me personally. Perhaps, in considering carbon dioxide, I was just grasping at straws, trying to find any explanation at all for SIDS.
I went to our public library and looked for an overview of SIDS. I did not need a science journal--I probably wouldn't have even understood it. In a newsmagazine, I found the stories about parents who were brought up on murder charges for the deaths of their children. The deaths had been blamed on SIDS. The article stressed how hard it was to differentiate between SIDS and suffocation, that pathologically they were identical. This piece of the puzzle fits my hypothesis, I thought.
I read on. SIDS had many correlations. Children with sleep apnea had a higher incidence of SIDS. Children who had some difficulty breathing had a higher incidence. Children whose parents smoked had a higher incidence. Frail or underweight children had a higher incidence. Children who did not move about much when they slept had a higher incidence. Children who slept in a lot of loose clothing and blankets had a higher incidence. Children who slept in rooms with less ventilation had a higher incidence. All of these things seemed to fit the hypothesis, in that the children might have more difficulty breathing or their access to oxygen might be restricted.
The incidence of SIDS drops dramatically after 6 months of age. In fact, so dramatically that that was what spurred some of the murder investigations-the parents had blamed the deaths of older children upon SIDS. How does this fit into the model of suffocation by carbon dioxide, I wondered? I asked my wife what were the differences between newborns and one-year olds, and she mentioned that the newborn metabolism was significantly higher. Newborns would produce much more carbon dioxide, maybe? At this point, I was convinced that there might be something here, but I also feared that I might be bending facts to fit the theory. In fact, there was one correlation that didn't quite make sense: children in warm rooms had a higher incidence of SIDS. Had I missed or ignored something important just because it didn't fit the theory? There is only one way to find out, and that is by experiment.
I tried breathing into a bucket. I didn't want to suffocate myself, so I did it for a short time, and then blew bubbles into the bucket. They went straight to the bottom. There was no accumulation of carbon dioxide. What happened? How did the carbon dioxide get out of the bucket? For that matter, why isn't all the carbon dioxide puddled up about our chins, at the lowest level of the atmosphere, while the nitrogen and oxygen float above it?
Well, carbon dioxide dissolves in air. As I explained to the fifth-graders at the science fair, if you pour sugar into ice tea, it will fall to the bottom and just lie there. It is heavier than tea. If you stir the tea, the sugar will dissolve into the tea, and from then on, you do not have to worry about the sugar falling to the bottom of the glass. The same with carbon dioxide. It will lie in the bucket, but if it is stirred, by your hands or even a breeze, it will quickly dissolve into the atmosphere. Some of it will stay around--after all, plants need it to survive--but most of it diffuses away. Perhaps it is helped away by the extra heat it picks up inside our bodies, which warms the used air up to body temperature. Maybe, I thought, that would explain the high incidence of SIDS with warm rooms, in that warm rooms won't allow the CO2 to convect away. Or maybe it's just that a warm room is usually a closed room, with less air flow.
At science fair, I relate the story of the tragedy in the African Cameroon. A lake known in local legend as a "killer lake" had quietly accumulated a lower layer of carbonated water from the seepage of acids into the limestone that underlain the lake. The lake suddenly erupted. The carbonated water exploded from the lake like a giant soda can that has been roughly opened. Horribly, the released carbon dioxide hung close to the ground, almost trapped by the lake valley. The huge cloud of carbon dioxide killed animals for miles around the shore of the lake. Before it dissolved, it flowed out of the valley and followed the river's course. It was a huge invisible odorless cloud of death. It floated over small villages and the people in them were left with nothing to breathe. Many died. Eventually, it dissipated, but it left a trail of disaster behind it. As the fifth-graders pour carbon dioxide out of the bucket, I insist that they imagine that cloud of carbon dioxide pouring out of the valley. They have to imagine something, because they can't see a thing!
Well, if it is so dangerous, how have I escaped? Many's the time that I used to burrow into the covers, sometimes sleeping with my feet upon my pillow. A few mornings, I have found my own children in the same quirky position. Does carbon dioxide dissolve so rapidly, or do we produce it in such small quantities that it is not dangerous at all? I turned to the encyclopedia. It was full of facts about metabolic rates, breathing rates, and lung capacities of all age groups. I found the diffusion rates for carbon dioxide and was able to convince myself that my model for SIDS was indeed a possibility. But I still cannot explain how I could have escaped when I pulled my draw string tight on those cold scout camping trips, completely sealing out any of the fresh (but frigid) air.
I read some of the survey articles about SIDS in the professional journals, and the premises seemed to bear out. There was no circumstance that I could not fit into my mental model. I noticed some oblique references to some promising research into rebreathing of air. That sounded a lot like my model! I called the national SIDS hotline and tracked down the research. I talked to the hospital, and they sent me copies of the studies. The research had taken rabbits and fitted them with mockups of infant heads, and let them "sleep" in a child's bed. They used rabbits because a rabbit metabolism, in certain factors, is similar to the metabolism of infants. In some circumstances, the rabbits died, clearly suffocated. It appears that the success of the studies was not enough to completely convince everybody that that was how SIDS worked, but they are still doing research.
Perhaps this article will help spur further research into this important area. Perhaps, the solution to the mystery of SIDS is just around the corner. Perhaps, in my small way, I am helping to find the solution to that problem. Most importantly, the success that I had in thinking about my hypothesis, and finding out that it might be right, convinced me more than ever that science is important to everybody, and that everybody still has a chance to "do science."