21: What is Science?
- Page ID
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\(\newcommand{\avec}{\mathbf a}\) \(\newcommand{\bvec}{\mathbf b}\) \(\newcommand{\cvec}{\mathbf c}\) \(\newcommand{\dvec}{\mathbf d}\) \(\newcommand{\dtil}{\widetilde{\mathbf d}}\) \(\newcommand{\evec}{\mathbf e}\) \(\newcommand{\fvec}{\mathbf f}\) \(\newcommand{\nvec}{\mathbf n}\) \(\newcommand{\pvec}{\mathbf p}\) \(\newcommand{\qvec}{\mathbf q}\) \(\newcommand{\svec}{\mathbf s}\) \(\newcommand{\tvec}{\mathbf t}\) \(\newcommand{\uvec}{\mathbf u}\) \(\newcommand{\vvec}{\mathbf v}\) \(\newcommand{\wvec}{\mathbf w}\) \(\newcommand{\xvec}{\mathbf x}\) \(\newcommand{\yvec}{\mathbf y}\) \(\newcommand{\zvec}{\mathbf z}\) \(\newcommand{\rvec}{\mathbf r}\) \(\newcommand{\mvec}{\mathbf m}\) \(\newcommand{\zerovec}{\mathbf 0}\) \(\newcommand{\onevec}{\mathbf 1}\) \(\newcommand{\real}{\mathbb R}\) \(\newcommand{\twovec}[2]{\left[\begin{array}{r}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\ctwovec}[2]{\left[\begin{array}{c}#1 \\ #2 \end{array}\right]}\) \(\newcommand{\threevec}[3]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\cthreevec}[3]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \end{array}\right]}\) \(\newcommand{\fourvec}[4]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\cfourvec}[4]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \end{array}\right]}\) \(\newcommand{\fivevec}[5]{\left[\begin{array}{r}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\cfivevec}[5]{\left[\begin{array}{c}#1 \\ #2 \\ #3 \\ #4 \\ #5 \\ \end{array}\right]}\) \(\newcommand{\mattwo}[4]{\left[\begin{array}{rr}#1 \amp #2 \\ #3 \amp #4 \\ \end{array}\right]}\) \(\newcommand{\laspan}[1]{\text{Span}\{#1\}}\) \(\newcommand{\bcal}{\cal B}\) \(\newcommand{\ccal}{\cal C}\) \(\newcommand{\scal}{\cal S}\) \(\newcommand{\wcal}{\cal W}\) \(\newcommand{\ecal}{\cal E}\) \(\newcommand{\coords}[2]{\left\{#1\right\}_{#2}}\) \(\newcommand{\gray}[1]{\color{gray}{#1}}\) \(\newcommand{\lgray}[1]{\color{lightgray}{#1}}\) \(\newcommand{\rank}{\operatorname{rank}}\) \(\newcommand{\row}{\text{Row}}\) \(\newcommand{\col}{\text{Col}}\) \(\renewcommand{\row}{\text{Row}}\) \(\newcommand{\nul}{\text{Nul}}\) \(\newcommand{\var}{\text{Var}}\) \(\newcommand{\corr}{\text{corr}}\) \(\newcommand{\len}[1]{\left|#1\right|}\) \(\newcommand{\bbar}{\overline{\bvec}}\) \(\newcommand{\bhat}{\widehat{\bvec}}\) \(\newcommand{\bperp}{\bvec^\perp}\) \(\newcommand{\xhat}{\widehat{\xvec}}\) \(\newcommand{\vhat}{\widehat{\vvec}}\) \(\newcommand{\uhat}{\widehat{\uvec}}\) \(\newcommand{\what}{\widehat{\wvec}}\) \(\newcommand{\Sighat}{\widehat{\Sigma}}\) \(\newcommand{\lt}{<}\) \(\newcommand{\gt}{>}\) \(\newcommand{\amp}{&}\) \(\definecolor{fillinmathshade}{gray}{0.9}\)What is Science?
- Please read and watch the following.
- Reading the material to gain understanding and taking notes during the videos will take approximately 45 minutes.
- Bolded terms are located at the end of the unit in the Glossary. There is also a Unit Summary with Review Questions at the end of the Unit.
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- Communicate experimental findings, analyses and interpretations both orally and in writing.
- Evaluate societal issues from a natural science perspective, ask questions about the evidence presented, and make informed judgments about science-related topics and policies.
Did you ever wonder why a moose, like the one in Figure \(\PageIndex{1}\), grows large antlers? The antlers may grow as wide as 1.8 m (6 ft) from tip to tip! The antlers use up a lot of energy to grow and carry around. They can even get caught in brush and trees. In these ways, they would seem to be more of a detriment than a help, so what purpose do the antlers serve? And why do only male moose grow them? If you've ever asked questions such as these about the natural world, then you were thinking like a scientist.
Defining Science
Science is a distinctive way of gaining knowledge about the natural world that begins with a question and then attempts to answer it with evidence and logic. Science is an exciting exploration of all the whys and hows that any curious person might have about the world. You can be part of that exploration. Besides your curiosity, all you need is a basic understanding of how scientists think and how science is done. In this section, you'll learn how to think like a scientist.
Thinking Like a Scientist
Thinking like a scientist rests on certain underlying assumptions. Scientists assume that:
- Nature can be understood through systematic study.
- Scientific ideas are open to revision.
- Sound scientific ideas withstand the test of time.
- Science cannot provide answers to all questions.
Nature is Understandable
Scientists view nature as a unified system governed by natural laws. By discovering natural laws, scientists strive to increase their understanding of the natural world. Laws of nature are expressed as scientific laws. A scientific law is a statement that describes what always happens under certain conditions in nature.
Examples of scientific laws include Mendel's Laws of Inheritance. These laws were discovered by an Austrian Monk, named Gregor Mendel (Figure \(\PageIndex{2}\)), in the mid-1800s. The laws describe how certain traits are inherited from parents by their offspring. Although Mendel discovered his laws of inheritance by experimenting with pea plants, we now know that these laws apply to many other organisms, including humans. The laws describe how we inherit relatively simple genetic traits, such as blood type, from our parents. For example, if you know the blood types of your parents, you can use Mendel's laws to predict your chances of having a particular blood type.
Barbara McClintock (Figure \(\PageIndex{2}\)) added to our understanding of inheritance in the 1950s by discovering how chromosomes exchange information during meiosis. Meiosis is how organisms produce reproductive cells (such as eggs or sperm). McClintock worked with corn and, using the color traits in the kernels, demonstrated how crossing-over is used to exchange information between chromosomes. An understanding of how crossing-over works is essential to our understanding of inheritance because it explains why using Mendelian rules of inheritance does not always produce the correct ratios.
Scientific Ideas are Open to Change
Science is more of a process than a set body of knowledge. Scientists continually test and revise their ideas, and as new observations are made, existing ideas may be challenged. Ideas may be replaced with new ideas that better fit the facts, but more often existing ideas are simply revised. For example, when scientists discovered how genes control genetic traits, they didn't throw out Mendel's laws of inheritance. The new discoveries helped to explain why Mendel's laws applied to certain traits but not others. They showed that Mendel's laws are part of a bigger picture. Through numerous new discoveries over time, scientists have gradually built an increasingly accurate and detailed understanding of the natural world.
Occasionally, scientific ideas change radically. Radical changes in scientific ideas were given the name paradigm shifts by the philosopher Thomas Kuhn in 1962. Kuhn agreed that scientific knowledge typically accumulates gradually, as new details are added to established theories. However, Kuhn also argued that from time to time, a scientific revolution occurs in which current theories are abandoned, and completely new ideas take their place.
Although there is debate among scientists as to what constitutes a paradigm shift, the theory of evolution is widely accepted as a good example in biology. In fact, some scientists argue that it is the only example of a paradigm shift in biology. Prior to Charles Darwin's publication of his theory of evolution in the 1860s, most scientists believed that God had created living species and that the species on Earth had not changed since they were created. Drawing on a wealth of evidence and logical arguments, Darwin demonstrated that species can change and that new species can arise from pre-existing ones. This was such a radical shift in scientific thinking that Darwin was reluctant to publish his ideas, fearing a backlash from other scientists and the public. Indeed, Darwin was initially ridiculed for his evolutionary theory, but over time, it gained widespread acceptance and became a cornerstone of all life sciences.
Scientific Knowledge May Be Long Lasting
Many scientific ideas have withstood the test of time. For example, about 200 years ago, the scientist John Dalton proposed the atomic theory — the theory that all matter is made of tiny particles called atoms. This theory is still valid today. Over the past two centuries, a great deal more has been learned about atoms and the even smaller particles that comprise them. Nonetheless, the idea that all matter consists of atoms remains a valid concept. There are numerous other examples of fundamental scientific ideas that have been repeatedly tested and found to be sound. You will learn about many of them as you study the biology of women.
This video highlights the importance of women in science.
With an increase in diverse perspectives represented in scientific fields, including medicine and public health, it is thought that there will be more research into women's health and wellness.
Questions after watching:
If you are majoring in a health or education-related field, how might you put some of these ideas into practice?
How does this video resonate with you if you are not majoring in a science-related field?
Two Types of Science: Basic Science and Applied Science
The scientific community has been debating for the last few decades about the value of different types of science. Is it valuable to pursue science for the sake of simply gaining knowledge, or does scientific knowledge only have worth if we can apply it to solving a specific problem or to bettering our lives? This question focuses on the differences between two types of science: basic science and applied science.
Basic science or “pure” science seeks to expand knowledge regardless of the short-term application of that knowledge. It is not focused on developing a product or a service of immediate public or commercial value. The immediate goal of basic science is knowledge for knowledge’s sake, though this does not mean that, in the end, it may not result in a practical application.
In contrast, applied science or “technology” aims to use science to solve real-world problems, making it possible, for example, to improve a crop yield, find a cure for a particular disease, or save animals threatened by a natural disaster (Figure \(\PageIndex{1}\)). In applied science, the problem is usually defined for the researcher.
Some individuals may perceive applied science as “useful” and basic science as “useless.” A question these people might pose to a scientist advocating knowledge acquisition would be, “What for?” A careful examination of the history of science, however, reveals that basic knowledge has led to numerous remarkable applications of great value. For example, basic science has led to the MRI machine (from early work in understanding atomic structures), vaccines (from evidence that milkmaids who had been exposed to cowpox did not get smallpox), most technology we use daily (like GPS and WiFi), and breakthrough medications like GLP-1s (e.g., Ozempic) and immunotherapy treatments for cancer.
Many scientists think that a fundamental understanding of science is essential before an application is developed; therefore, applied science relies on the results generated through basic science. Other scientists think it is time to move beyond basic science and instead focus solutions to real-world problems. Both approaches are valid. It is true that there are problems that demand immediate attention; however, few solutions would be found without the help of the wide knowledge foundation generated through basic science.
One example of how basic and applied science can work together to solve practical problems is the discovery of the DNA structure, which led to an understanding of the molecular mechanisms governing DNA replication. Strands of DNA, unique in every human, are found in our cells, where they provide the instructions necessary for life. During DNA replication, DNA makes new copies of itself shortly before a cell divides. Understanding the mechanisms of DNA replication has enabled scientists to develop laboratory techniques that are now used to identify genetic diseases, pinpoint individuals at a crime scene, and determine paternity. Without basic science, it is unlikely that applied science would exist.
Another example of the link between basic and applied research is the Human Genome Project, a study in which each human chromosome was analyzed and mapped to determine the precise sequence of DNA subunits and the exact location of each gene. (The gene is the basic unit of heredity; an individual’s complete collection of genes is his or her genome). Other, less complex organisms have also been studied as part of this project to gain a better understanding of human chromosomes. The Human Genome Project relied on basic research carried out with simple organisms and, later, with the human genome (Figure \(\PageIndex{2}\)). It was a 13-year collaborative effort among researchers working in several different fields of science to sequence the entire human genome and was completed in 2003. An important end goal of the project eventually became using the data for applied research, seeking cures and early diagnoses for genetically related diseases.
While research efforts in both basic and applied sciences are usually carefully planned, it is essential to note that some discoveries are made by serendipity, that is, through a fortunate accident or a lucky surprise. Penicillin was discovered when biologist Alexander Fleming accidentally left a petri dish of Staphylococcus bacteria open. An unwanted mold grew on the dish, killing the bacteria. The mold was identified as Penicillium, and a new antibiotic was subsequently discovered. Even in the highly organized world of science, luck—when combined with an observant, curious mind—can lead to unexpected breakthroughs.
Scientific research is often reported in the popular media, and that is how most people learn about new scientific findings. Informing the public about scientific research is a valuable media service, but the types of scientific investigations that are reported may lead to a distorted public perception of what science is and how reliable its results are. Why? There are actually two types of science, often referred to as consensus science and frontier science. The latter type of science is the type that usually makes the news, but the media generally do not distinguish between the two types. Therefore, many people may infer that what they read about frontier science is typical of all science.
- Consensus science refers to scientific ideas that have been researched for a long period of time and for which a great deal of evidence has accumulated. This type of research typically aligns well with current scientific paradigms. A notable example of consensus science is the issue of global climate change. Data showing the impact of increasing levels of atmospheric carbon dioxide, due to human activities, on global warming have been accumulating for many decades. Today, virtually all climate scientists agree that global warming is occurring and that human actions are largely responsible for it. However, the few scientists — and many politicians — who disagree with the consensus view receive greater media attention because the consensus view is considered "old" news. The findings have been accumulating for years, and new research in the area continues to yield similar results.
- Frontier science, in contrast, refers to scientific ideas that are relatively new and have not yet been supported by years of scientific evidence. Frontier research occurs at the forefront of knowledge in a specific field. A good example of frontier science is research into the presumed link between dietary cholesterol and blood cholesterol levels. The consensus view for many years was that a diet high in cholesterol increases blood levels of cholesterol, which may lead, in turn, to cardiovascular disease. Recent research challenging the accepted view found that genes play a more significant role than diet in determining blood levels of cholesterol and the risk of cardiovascular disease.
The media tend to focus on frontier science because it is exciting, may seem controversial, and could lead to major new scientific breakthroughs. With more research, ideas in frontier science may be supported by more evidence, gain wider acceptance, and become consensus science. In some cases, frontier science that contradicts a current paradigm may even lead to a paradigm shift.
However, the opposite may happen instead. Additional research may undermine the initial findings of frontier research, leading to the rejection of new and exciting ideas. Unfortunately, when frontier science is later shown to be mistaken, people may infer that all science, including consensus science, is unreliable.
Not All Questions Can be Answered by Science Currently
Science rests on evidence and logic, and evidence comes from observations. Therefore, science deals only with things that can be observed. An observation is anything that is detected through human senses or with instruments and measuring devices that extend human senses. Things that cannot be observed or measured by current means or technology — such as supernatural beings or events — are outside the bounds of science. Consider these two questions about life on Earth:
- Did life on Earth evolve over time?
- Was life on Earth created by a supernatural deity?
The first question can be answered by science based on scientific evidence, such as fossils, molecular clocks, geological evidence, and more.
The second question could be a matter of belief, but no evidence can be gathered to support or refute it. Therefore, it is outside the realm of science.
Attributions
- Moose Superior by USDA Forest Service, public domain via Wikimedia Commons
- Gregor Mendel by Hugo Iltis via the Wellcome Library, London, public domain via Wikimedia Commons
- Barbara McClintock by Smithsonian Institution/Science Service; Restored by Adam Cuerden, public domain via Wikimedia Commons