9, Kinds of Science - Basic&Applied

And welcome back to the wonderful world of the scientific hypothesis. My name is Brad Alger and in this video we're going to begin exploring the concept of different kinds of science or different modes of science or ways of going about science. Now by different kinds I don't mean anything spooky or bizarre. They're all solid empirical methods that are based on observations and experiments in the real world. The different kinds do have somewhat divergent objectives however they're all complementary ways of helping us address an overarching goal of understanding and coping with the world. The focus today is on the fundamental split between basic and applied science. Now you're probably at least vaguely aware of this distinction but maybe haven't given it a lot of thought. In this video you'll see how the different kinds are related to each other and to the scientific hypothesis and you'll see why the distinction between them is so central to complicated contentious issues that confront us as ordinary citizens. Now this topic of different kinds of science is very large and complex and in a later video I'll return to it from an entirely different point of view. So what about these two kinds or modes of science? We'll look at different objectives or goals of basic and applied science and we'll discuss why the distinction matters for our understanding of science as well as how it affects current controversies at a societal level. So what are the goals of basic and applied science? Well basic science strives to discover truth, big T truth, universal, eternal and certain, the ideal that we can never quite reach and is never satisfied. Applied science on the other hand strives for the best available information, workable, efficient, useful knowledge and it is temporarily satisfied by good enough explanations. Now let's start by looking at a dramatic example to illustrate this difference. Suppose we take the statement we've heard many times that no scientific fact is 100% unquestionably certifiably true and the question is do we really believe that and it seems to me that most of us don't. In our heart of hearts we think there are some things that science has discovered that are beyond reasonable doubt, beyond question. For example, doesn't the earth go around the sun in an elliptical orbit? You may first think that this must be true because if you look in the Sunday supplement of any newspaper that illustrates the solar system you'll see the earth going around the sun in an elliptical orbit. However even if we ignore the fact that both the sun and the earth are revolving around the center of mass of the solar system we see that the sun is actually not stationary but it's moving through space and it's not moving along a straight line such as illustrated here but it's moving around the spiral arm of the Milky Way galaxy. The Milky Way is moving with respect to our local cluster of galaxies, the local cluster is moving with respect to the universe and the universe itself is expanding. So we can see that the actual motion of the earth in space is vastly more complicated than a simple ellipse around the sun. And this is the level of investigation that basic science seeks. It wants to know how things really are at their very deepest level. However applied science is different. Applied science seeks to support certain actions and we know that there are all kinds of actions that are very well satisfied by assuming that the earth goes around the sun in a simple elliptical orbit. So we have this kind of odd situation where for basic science the earth does not go around the sun in an elliptical orbit. However for the purposes of applied science it does. There are all kinds of actions that we can take, all sorts of things that we can do such as launch satellites, fly airplanes and predict the onset of seasons based on the assumption of a simple elliptical orbit. In other words for basic science the hypothesis of an elliptical orbit for the earth has been falsified whereas in a certain sense for applied science it hasn't. Now another way of making a similar point is to look at something that's been called the levels of explanation in science or what I'm calling why is Aunt Minnie in the hospital after an anecdote that I stole from Richard Feynman. One day you hear that your dear old Aunt Minnie is in the hospital with a broken hip and you ask why and you're told that she slipped on the ice. Well if you then ask why, why is ice slippery, in other words why did she fall, you might hear the hypothesis that a very thin layer of water formed when the ice melted under the heel of her boot when she stepped on it. Now this hypothesis predicts that ice that is so cold that it can't melt won't be slippery. The way to test this is to measure the slipperiness of ice near absolute zero, a temperature so cold that water can't form. When this experiment has been done it is found that ice at temperatures near absolute zero is still slippery. The conclusion then is to reject this hypothesis. So why is ice slippery? Well it's still a mystery. The answer almost certainly lies at the atomic or subatomic level and the interactions among the water molecules as we go from the surface of the ice deep into the interior. What changes or how it changes however is still quite uncertain. At the moment we simply have to accept that slipperiness seems to be an intrinsic property of ice. Notice however that we don't have to have a theory of slipperiness to know why Aunt Minnie is in the hospital. We do. She slipped on the ice and we don't have to know all of the atomic details of slipperiness to know how to help her out in the future. We'll spread sand or salt on the ice. So we've seen that applied science supports actions that is actually doing things in the world. Technology makes use of applied science when it builds cars and bridges, develops vaccines, and we trust our lives to them. So this must be a very secure kind of knowledge and it illustrates the rational practical goals of applied science. It's worth mentioning in this context however that scientific experiments, even those experiments that are devoted to basic science and finding out the ultimate truth, those actual experiments are also actions that are built on current uncertain information. We have to assume that we know how microscopes work and the principles of chemistry and biology in order to make future discoveries. No scientific fact can be 100% undeniably true. All actions, including those actions devoted to driving basic science forward, are always based on incomplete information. The distinction between basic and applied sciences can have important real-world consequences. For example, tobacco companies, climate change deniers, and others often exploit confusion about what science knows by obscuring the differences between basic and applied science. All the data are not yet in, we often hear as an excuse for not taking a certain action. And of course the folks who say all the data are not in are right. All the data will never be in to achieve the goals of basic science, so we keep investigating. We've seen however that we don't need all of the data to take rational action based on the best available applied science. So to review quickly what we've said, applied and basic sciences and the scientific hypotheses are related in slightly different ways. Explanations provided by the scientific hypothesis may be adequate at one level of investigation and yet be rejected at another. Hypotheses can be tested and evaluated according to the goals appropriate to the level of investigation that is underway. Testing hypotheses depends on prior assumptions that we accept in order to do experiments but that at some level of investigation will fail. In particular, the hypothesis that is sufficient for the goals of applied science will fail to meet the standards of basic science. So these differences between basic and applied science illustrate one sense of what I mean by different kinds of science. We'll come back to this concept of different kinds of science and different goals and we'll explore it from an entirely different point of view. Thanks for watching. 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