Response to "Is a Hypothesis Necessary to do Science?"

Editor,

That's an interesting question (Forrest M. Mims III, Is a Hypothesis Necessary to do Science?The Citizen Scientist, 11 August 2006).

I suppose that I'd say that, in most cases, the hypothesis is implicitly understood to exist, rather than being explicitly stated. For example, with the ozone/eclipse experiment that was conducted, even though there wasn't an explicit hypothesis stated, I have to believe that there was an implicit hypothesis of, "I think there's something going on in the ozone layer during an eclipse." Otherwise, I doubt that the experiment would have been conducted. I think this is likely true with a lot of experiments. The experimenter may not know exactly what they're looking for and thus, may not have an explicit hypothesis, but they almost certainly suspect that something is happening, which forms the basis of their implicit hypothesis.

Of course, it's also quite possible that something unexpected occurs during the running of an experiment. This was apparently the case with Sarah Mims during her experiment concerning microbes arriving with dust from Asia, where her (implicit) hypothesis was that "Microbes can arrive with dust from Asia." (Else why conduct the experiment?). The result of finding microbes from South America was totally unexpected, and wasn't what the experiment was designed to detect, but that doesn't mean that the results aren't worth writing up. I've often heard it said that there are more discoveries based on "That's unusual..." moments than from all of the normal experiments ever conducted.

Note that it's hard to prove the negative. Thus, the lack of any Asian microbes does not mean that microbes can not arrive from Asia; only that they did not during the particular experiment. Of course, a positive result does prove the case.

Fortunately, real scientists (usually) keep an open mind, and are free to pursue the "That's unusual..." moments. This may require them to revise their original (even if implicit) hypothesis, and perform another set of experiments.

Thus, I think I've convinced myself that a hypothesis is necessary, even if it is an implicit hypothesis, and isn't explicitly expressed as a formal, explicit hypothesis.

While experienced scientists can often get away with using implicit hypotheses, beginning students almost certainly benefit from being required to explicitly state their hypotheses. This gives them a clear idea of what they're testing for, rather than running experiments at random, and this organization can result in clearer understanding of the results. However, they should also be taught to keep an open mind, and to be free to revise their hypotheses, possibly running additional experiments to resolve those "That's unusual..." moments, even if this is only expressed as a route of future work.

David W. Glass

Regarding the eclipse study, I simply asked if something happens to the ozone layer during a solar eclipse. A question is quite different from a hypothesis, which assumes or predicts that specific things will happen. Sarah's finding of microbes in smoke was totally unexpected and occurred without a hypothesis. Finally, as noted so well by the scientists quoted in my editorial, most scientific papers do not state a hypothesis. In short, students should not be required to state a hypothesis in their science projects when the project was guided by a question or an unexpected finding. Editor.

In Support of the Hypothesis Editorial

Editor,

The rhetorical questions you raised in your last editorial concerning hypotheses and science fairs hit the nail on the head of something that has always quietly bothered me but I was always embarrassed that it was simply that I just didn't "get it." Why do the experiment if you can already make a hypothesis about the result? And what happens to serendipity if the researcher is locked into a hypothesis?

I know that in my own fooling around with science activities, I become most frustrated when nature is trying to show me the truth when it doesn't agree with my expectations. It's like people who put too much faith into computer simulations.

Do you remember about 15 years ago when there were activists suggesting that it was no longer necessary to do experiments on animals since we now had computer simulations? I have an older friend who is a retired electronics tech from the University of Illinois. He used to get so frustrated with graduate students who would design a circuit with all the SPICE resources and then wonder why their high-frequency circuit didn't work when it was finally built.

Sorry, I appear to have begun to ramble. My main comment is that I am afraid your observation points to the possibility that even a lot of our well-meaning educators do not have much real experience with hands on science and research. But then again, the science fairs are better than nothing.

Thank you again!

Tim Kraemer

Your most signiifcant comment just might be this: "My main comment is that I am afraid your observation points to the possibility that even a lot of our well-meaning educators do not have much real experience with hands on science and research." I am afraid you are right. How many science educators have you met who did science projects in their teenage years? How many do science projects now? Your comment about the circuit simulation software SPICE is certainly relevant, for many would-be circuit designers have learned the hard way that such programs do not necessarily account for such factors as high frequency phenomena and unwanted and capacitive and inductive coupling and so forth. Editor.

Folklore Physics: A Penny for Your Thoughts

Editor,

There is a thought experiment involving a penny thrown at an oncoming train. The question generated is simply one of whether or not the penny came to a complete stop during impact. The folklore aspect of the problem is the response: the people in the train would have fallen down if the penny had come to a complete stop.

The penny can be substituted for one of those hanging mailbags that trains can pick up without stopping, as was once depicted in a cartoon about the Old West. The mailbag will be grasped from a complete stop over ground, whether it was the elasticity of the mailbag or a dedicated shock-absorption implement that accelerated the mailbag to the train’s speed within the tensile limits of all components involved.

The idea is that the train, as a whole, would be slowed inversely proportionally to its relative mass superiority over the object impacted, but the portion of the train in contact with the object during the collision would share the object’s acceleration/deceleration over ground. It is the elasticity of the “attachment zone” between the impacted region and the rest of the train that would allow the train to be affected only minimally, and indeed undetectably, whether the impact is with a mailbag or a penny.

Tim Valentine

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