Science is normally thought of as a study of the natural world a process whereby people attempt to understand how the constituents of the universe interact to produce the beautiful and varied phenomena that we see around us. On the other hand, science is a method a particular procedure by which a scientist operates. So interwoven are the method and the subject that it is easy to confuse them. By stating that science is a method, one deemphasizes the collection of facts and figures that must accompany a serious study of nature, and one suggests that the method of science can be applied to other areas of study.
The classical presentation of the scientific method suggests that science proceeds by a series of steps. Step 1: A scientist makes some observation of a particular phenomenon. Step 2: He develops a tentative explanation, called a model or a hypothesis. Step 3: The scientist tests the hypothesis by making further observations and checking whether they agree or disagree with his hypothesis. (That's because a good hypothesis not only explains the previous observations but also suggests additional relationships) Step 4: If the new observations do not agree with the hypothesis, the scientist may do one of two things: He may modify the hypothesis, if the disagreements are not major, and then resume testing; that is, he returns to step 3. Or he may scrap the hypothesis entirely and develop a new one, returning to step 2. If the new observations do agree with the hypothesis, and the hypothesis has been tested only a few times, he continues testing; that is, he returns to step 3. Or if the hypothesis has been tested successfully many times, it is raised to the status of a theory. The testing generally continues.
We see that this method depends entirely on observation and represents an orderly way of assimilating and organizing knowledge. A scientist attempts to organize knowledge and compare new information with his previous understanding. Implicit in this process is the concept of repeatability. A single event does not constitute sufficient evidence to build a theory or even a hypothesis. Generally, a hypothesis must be tested and supported by other independent researchers before it can be accepted by the scientific community at large.
There are other requirements that a theory or hypothesis must meet before it can be generally accepted. As previously mentioned, a good hypothesis must predict new observations. An explanation that cannot be tested is not a useful scientific statement, even though it might be true. Thus, while you might assert "God made it that way" in order to explain craters on the moon, this is not a good scientific hypothesis. It may be a very good philosophical statement, but it is not a useful scientific one, because there is no way to verify the truthfulness of it by further observations and the application of other theories.
Another more subjective attribute of an acceptable scientific hypothesis is its simplicity. Usually scientists are striving to find the simplest yet most general explanation that they can. As an example, do the planets really move around the sun? Or does everything move around the earth? It is possible to adopt the latter view and develop the necessary equations to predict and describe the motion of the planets in this geocentric system in detail. However, the heliocentric model explains all the data in a much more simple and less complicated way. Thus it is the one adopted by science.
Taking the requirement of simplicity one step further, science generally does not accept a hypothesis that is as complicated as the phenomenon itself. That is, if one must attach all sorts of qualifiers, conditions, and exceptions, then the hypothesis is not regarded as being valuable. For example, there are several independent ways of determining the length of time Planet Earth has been in existence. With out going into all the details, these predict a range of ages, all of them on the order of millions or billions of years. Now it is possible to formulate a specific explanation or exception for each of these several methods, questioning their accuracy and thus allowing a short time scale for earth's history! However, by the time all the exceptions and possible conditions are attached, the final model becomes so complicated that it is untenable for even the scientist who was hoping to find the earth to be only a few thousand years old based solely on the physical evidence.
The concern for repeatability and independent verification somewhat limits the types of phenomena amenable to a scientific understanding. Science definitely has certain limitations, and scientists must operate by a set of rules. In order for one to understand the theories and results of science fully, it is necessary to realize its limitations. It is also necessary to be aware of the basic assumptions that may be present in the logical processes that culminate in a particular conclusion. It is important to put any statements or results of science into their proper perspective.
The aspect of repeatability is of primary importance. Indeed, modem science was able to develop only because the observation was made that nature seems to behave in an orderly and consistent manner. An experiment done at one particular time will yield the same results if repeated at any later time under identical conditions. If the universe were being run in a way such that the basic rules were constantly being changed, science could not exist. If an experiment would give different results when the time or location is changed, then no general rules or laws could be derived. A possible exception is a change in the rules according to a regular pattern. In such a case, the pattern of change could be determined. An example would be a situation in which all experiments done on Tuesdays would be similar, but would give different results from Friday's experiments; or in which the results change from day to day in a regular manner that can be predicted from previous observations.
Thus single unique events that are not repeatable and cannot be scrutinized by several independent observers at will are outside the realm of science. Phenomena that follow certain rules but repeat so seldom that they cannot be observed in a systematic way must also lie somewhat outside the realm of science. Perhaps at a future date such phenomena will become part of science.
Another constraint is that science is concerned with the how of nature rather than the why. Thus questions of ultimate reasons behind certain phenomena are outside the realm of science. Science is restricted to empirical observations and the process whereby models are developed explaining the relationships observed in these observations.
A scientist has no other alternative but to follow the scientific method and to develop a hypothesis or model that agrees with these observations. Implicit within the model are usually several assumptions. The most desirable model is one that best fits the observations with the least number of assumptions or the most reasonable assumptions. A scientific conclusion then must be understood in light of these basic assumptions and the fundamental limitations of science. Science studies the orderly, repeated events in nature. The general laws, such as Newton's laws, are really statements that matter behaves in the same way at all times and in all places, given the same conditions. In a God-run universe this is a statement that He is an orderly and consistent God. However, science is not especially concerned with the reason why nature is orderly, but rather with the rules by which it is run. Most scientists study nature without a concern of using the results to test an attribute of God; that is, they are generally more interested in explaining the phenomena, and they are less interested in "nonscientific" philosophical discussions.
However, a Christian can use science and nature as a means of studying an aspect of God's character. This perhaps can be considered nonscientific, but it is an important part of a Christian under standing of the universe.
Returning to our previous example of the determination of ages, we quickly discover that science ascribes very old ages to the earth, our sun, the stars, and the universe. These age estimates come from the best scientific models that we have models based upon present understandings of nature's processes within the limited scope of our observations.
The Christian can seek to understand how these ages can be made consistent with his belief in the way God operates. In this sense one can be concerned with how old the stars really are. Science only gives numbers that must be understood within the context of how they are derived and of the limitation that they may not represent ultimate reality. The best scientific models give ages that can be thought of simply as useful parameters, however large they may be. Use of these parameters may lead to further investigation. By working with these age parameters, one only admits that within the scientific framework the uni verse appears to have, or at least is best described by, an age of billions of years.
Furthermore, the current scientific models are by no means complete and final. The large amount- of information that is now known is in reality a small fraction of what could be discovered. Several different models may explain the observations equally well. In this case one must choose between them on the basis of other philosophical or religious criteria. There is no comprehensive hypothesis that explains all the observations without any difficulty.
We cannot say how God must act or why He behaves in a certain way. It is quite possible that He does not run the universe exactly the same way at all times. Other wise, Creation week is not possible, unless such acts are presently being done. He certainly can cause events that are "miracles" in the scientific sense for which there is no explanation in terms of the known general laws, but this does not imply that He acts in an inconsistent manner. The existence of angels suggests that our knowledge is incomplete. Presumably there are certain natural laws for angel material, but because we do not repeatedly observe angels, we do not know their physics. Until we are able to determine the basic laws of angel material, they will be outside the realm of science.
This is not to say God is violating natural law. He is the source of law, and it is established operationally by His method of running the universe. We can observe and perceive only an exceedingly small portion of His activity. Certainly God can do things that violate our small under standing, and we must not insist that God must do things in a particular way. Yet He cannot violate His own established laws.
A God with infinite power has the ability to run the universe in any way He wishes. He could have called the entire universe into existence only a short time ago with all the appearances of having a great age, if He would so choose. Science can only propose that within the frame work of the assumptions and the best available model, our sun is about 4.5 billion years old. It cannot say with absolute certainty that it is really any particular age. The reality of science is no more than what the scientific method can observe and interpret. Reality beyond the scope of science must be accepted on the basis of confidence in the integrity of the personalities through whom this information is revealed.